CN105734413A

CN105734413A - Controlling Liquid Metal Embrittlement In Galvanized Press-Hardened Components

Info

Publication number: CN105734413A
Application number: CN201511036174.4A
Authority: CN
Inventors: A·K·萨奇德夫; T·W·布朗
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2014-11-26
Filing date: 2015-11-26
Publication date: 2016-07-06
Also published as: US20160145731A1

Abstract

Methods for press hardening galvanized, pre-treated, optionally non-annealed steel alloys are provided. The press-hardened steel alloy may have an ultimate tensile strength (UTS) of at least about 1,000 MPa and is substantially free of liquid metal embrittlement (LME). The press-hardened steel alloy may be further quenched to below room temperature. The press-hardened steel may have a multi-phase microstructure of ferrite at greater than or equal to about 1% to less than or equal to about 60% by volume and a combined volume percentage of martensite, retained austenite, and other transformation products at greater than or equal to about 40% to less than or equal to about 99%.

Description

Control the liquid metal embrittlement of zinc-plated compacting hardened component

The cross reference of related application

This application claims with the rights and interests of the U.S. Provisional Application No.62/085,081 submitted on November 26th, 2014.The complete disclosure of above-mentioned application is herein incorporated by reference the application.

Technical field

The application relates to a kind of by zinc-plated for steel alloy compacting hardening, pretreatment, the optional method not being annealed forming high intensity compacting hardened component, and these parts there is no liquid metal embrittlement.

Background technology

This part provides the background information relevant to the disclosure, and it is also not necessarily prior art.

Compacting hardening steel (PHS), also referred to as " drop stamping steel ", is the one of the strongest steel applied for automotive body structure, and it has the tensile strength properties of about 1500 MPas (MPa).This steel has desired performance, including forming the steel part with the intensity-mass values significantly improved.PHS parts are more and more general in various industry and application, and described various industry and application include general manufacturing, Architectural Equipment, automobile or other transportation industry, family or industrial structure etc..Such as, when manufacturing vehicle, particularly during automobile, it may be desirable to continue to improve fuel efficiency and performance, PHS parts are therefore more and more used.PHS parts are frequently used for forming load-supporting part, for instance Men Liang, it typically requires high-strength material.Therefore, the finished product state of these steel is designed as and has high intensity and enough ductility to resist external force, for instance, the intrusion of passenger compartment is not broken to provide the protection to passenger by opposing.Additionally, zinc-plated PHS parts can provide cathodic protection.

Conventional PHS technique includes carrying out austenitizing in the stove of steel billet plate, is suppressed in a mold by plate immediately after and quenches.There are two kinds of major type of PHS techniques: indirectly and directly.Austenitizing generally carries out in the scope of about 900 DEG C.In direct method, PHS parts shape in the mould making steel quench simultaneously and suppress.In indirect method, the cold forming before austenitizing of PHS parts is middle local shape, then carries out suppressing and quenching Step.The quenching of PHS parts by making microstructure be changed into martensite from austenite so that part cure.In the degree that PHS parts are not coated, from stove to mould, during transfer, oxide-film is formed.Therefore, after quenching, it is necessary to remove oxide from PHS parts and mould.Oxide is generally removed by shot-peening.

PHS parts can be coated before pre-cold forming applicatory (if using indirect processes) or austenitizing.Coating PHS parts provide protective layer (such as, zinc-plated protection) to following steel part.Described coating generally includes alusil alloy and/or zinc.Spelter coating provides cathodic protection；Coating is as sacrifice layer, and substitutes steel part and corrode, when being exposed even at steel.

During shaping, when metal system exposes to liquid metal (such as zinc), liquid metal embrittlement (LME) it may happen that, cause potential breaking and reducing the breaking elongation of material or the ductility weakened.LME may also lead to the reduction of ultimate tensile strength.In order to avoid the LME of zinc coating PHS parts, generally adopt indirect method (namely carrying out cold forming before austenitizing).The method includes being annealed before steel carries out galvanizing by dipping in zinc-plated bath.Additionally, before for the heating of austenitizing, preliminary forming step is used, to reduce the embrittlement effect of Zn.Yet with needing other step, the indirect method of compacting hardening is equally effective not as direct method.Accordingly, there exist the lasting demand to PHS technique, so that providing the ability of the zinc-plated PHS parts that there is no LME to rationalize by direct pressing method for curing.

Summary of the invention

This part provides the general introduction of the disclosure rather than the comprehensive disclosure to its four corner or its all features.

In some respects, present disclosure contemplates a kind of method suppressing hardening steel alloy.The method includes forming base from the steel alloy of zinc-plated pretreatment.Base is heated to the temperature less than or equal to about 782 DEG C so that galvanized steel alloy component austenitizing.Base suppresses hardening subsequently to form compacting hardened component.Compacting hardened component has the intensity (such as ultimate tensile strength, UTS) more than or equal to about 1000MPa, and substantially without liquid metal embrittlement.In some aspects, compacting hardened component can have for more than or equal to about 1000MPa to the intensity (UTS) less than or equal to about 2000MPa.In some variations, compacting hardened component is quenched into lower than room temperature after compacting hardening.In some other modification, pretreatment galvanized steel alloy is unannealed cold-rolled steel alloy before formation base.In some aspects, galvanized steel can pass through galvanizing by dipping.Therefore, the method can farther include pretreatment steel alloy is carried out galvanizing by dipping in zinc-plated bath.In other respects, the method can farther include the steel alloy of galvanizing by dipping pretreatment is carried out zinc-plated annealing.In other, the method can farther include pretreatment steel alloy is carried out electrogalvanizing.Steel alloy can include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%.Steel alloy can include more than 0wt% to the manganese less than or equal to about 6wt%, and in some variations, including more than or equal to about 1wt% to the manganese less than or equal to about 2wt%.Steel alloy can further include greater than 0wt% to the silicon less than or equal to about 1wt%.In some variations, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.Compacting hardened component can have more than or equal to about 1000MPa to the intensity less than or equal to about 2000MPa.Can heat at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.Compacting hardened component can include poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

In other respects, it is provided that a kind of method suppressing hardening galvanized steel alloy, it includes forming base from cold rolling without annealing galvanized steel alloy.Base is heated to the temperature less than or equal to about 782 DEG C, so that galvanized steel alloy component austenitizing.Then compacting hardens this base to form compacting hardening steel components, and wherein compacting hardened component has the intensity (such as ultimate tensile strength, UTS) more than or equal to about 1000MPa, and substantially without liquid metal embrittlement.In some aspects, steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%, or in some variations, steel alloy includes alternatively more than or equal to about 1wt% to the manganese less than or equal to about 2wt% and/or includes more than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%.Steel alloy can further include greater than 0wt% to the silicon less than or equal to about 1wt%.In other modification, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.Compacting hardened component is substantially without liquid metal embrittlement.Compacting hardened component also can be quenched into lower than room temperature after compacting hardening.In some variations, cold rolling, nothing is annealed, galvanized steel can pass through galvanizing by dipping.In other respects, the method can farther include cold-rolled steel alloy is carried out zinc-plated annealing.In other respects, the method can include pretreatment steel alloy is carried out electrogalvanizing.Compacting hardened component can have more than or equal to about 1000MPa to the intensity less than or equal to about 2000MPa.Heating can occur at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.Compacting hardened component can include poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

In other respects, it is provided that a kind of method suppressing hardening galvanized steel alloy, it includes forming base from cold rolling without annealing galvanized steel alloy.Base is heated to the temperature less than or equal to about 782 DEG C, so that galvanized steel alloy component austenitizing.Then compacting hardens this base to form compacting hardened component, this compacting hardened component includes poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.Compacting hardened component is substantially without liquid metal embrittlement.In some variations, compacting hardened component is also quenched into lower than room temperature after compacting hardening.In some variations, cold rolling nothing annealing galvanized steel can pass through galvanizing by dipping.In other respects, the method can farther include cold-rolled steel alloy is carried out zinc-plated annealing.In other respects, the method can include pretreatment steel alloy is carried out electrogalvanizing.Steel alloy can include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and include more than 0wt% to the manganese less than or equal to about 6wt%, or in some variations, steel alloy can include alternatively more than or equal to about 1wt% to the manganese less than or equal to about 2wt% and/or include more than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%.Steel alloy can include more than 0wt% to the silicon less than or equal to about 1wt%.In other modification, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.Compacting hardened component can have more than or equal to about 1000MPa to the intensity less than or equal to about 2000MPa.Heating can occur at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.

In some change, the method is further substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, and it is cold rolling without annealing galvanizing by dipping steel alloy to be formed that this cold rolling alloy without annealed steel carries out galvanizing by dipping, wind this cold rolling without annealing galvanizing by dipping steel alloy, then before heating uncoiling this is cold rolling without annealing galvanizing by dipping steel alloy make base from it.

On the other hand, the method can substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, and it is cold rolling without annealing galvanizing by dipping steel alloy to be formed that this cold rolling alloy without annealed steel carries out galvanizing by dipping in zinc-plated bath, wind this cold rolling without annealing galvanizing by dipping steel alloy, then uncoiling this cold rolling without annealing galvanizing by dipping steel alloy and from its formed base, be then heated step.

In other modification, the method is further substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, and it is cold rolling without annealing galvanizing by dipping steel alloy to be formed that this cold rolling alloy without annealed steel carries out galvanizing by dipping in zinc-plated bath, wind this cold rolling without annealing galvanizing by dipping steel alloy, then before heating steps uncoiling this cold rolling without annealing galvanizing by dipping steel alloy and from its formed base.After the method further includes at compacting cure step, hardened component is suppressed in quenching.

Additionally the suitability in region becomes apparent upon from description provided herein.Description and concrete example in this general introduction are merely intended to illustrate, and are not intended to limit the scope of the present disclosure.

The present invention farther includes following scheme.

Scheme 1: a kind of method suppressing hardening galvanized steel alloy, including:

Base is formed by the galvanized steel alloy of pretreatment；

Heating base to less than or equal to about 782 DEG C so that galvanized steel alloy component austenitizing；And

The base of compacting hardening galvanized steel alloy is to form compacting hardened component, and this compacting hardened component has more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa, and it there is no liquid metal embrittlement.

Scheme 2: such as the method for scheme 1, wherein steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than 0wt% to the manganese less than or equal to about 6wt%.

Scheme 3: such as the method for scheme 1, wherein steel alloy includes:

More than or equal to about 1wt% to the manganese less than or equal to about 2wt%；

More than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%；Or

More than or equal to about 1wt% to the manganese less than or equal to about 2wt% with more than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%.

Scheme 4: such as the method for scheme 1, wherein steel alloy includes more than 0wt% to the silicon less than or equal to about 1wt%.

Scheme 5: such as the method for scheme 1, wherein heats and is occurring at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.

Scheme 6: such as the method for scheme 1, is quenched into below room temperature by compacting hardened component after further including at compacting hardening.

Scheme 7: such as the method for scheme 1, wherein this compacting hardened component has poly-phase microcosmos structure, including the ferrite by volume arrived more than or equal to about 1% less than or equal to about 60%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

Scheme 8: a kind of method suppressing hardening galvanized steel alloy, including:

Base is formed from the galvanized steel alloy of pretreatment；

Heating base is to the temperature less than or equal to about 782 DEG C so that galvanized steel alloy component austenitizing；And

The base of compacting hardening galvanized steel alloy is to form compacting hardened component, this compacting hardened component has microstructure, it includes the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

Scheme 9: such as the method for scheme 8, wherein steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than 0wt% to the manganese less than or equal to about 6wt%.

Scheme 10: such as the method for scheme 8, wherein steel alloy includes:

Scheme 11: such as the method for scheme 8, wherein steel alloy includes more than 0wt% to the silicon less than or equal to about 1wt%.

Scheme 12: such as the method for scheme 8, wherein compacting hardened component has more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa.

Scheme 13: such as the method for scheme 8, wherein heats and is occurring at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.

Scheme 14: such as the method for scheme 8, is quenched into below room temperature by compacting hardened component after further including at compacting hardening.

Scheme 15: a kind of method suppressing hardening galvanized steel alloy, including:

Base is formed without annealing galvanizing by dipping steel alloy from cold rolling；

Heating base to less than or equal to about 782 DEG C so that galvanized steel alloy component austenitizing；

Scheme 16: such as the method for scheme 15, wherein steel alloy includes:

More than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%；

More than 0wt% to the silicon less than or equal to about 1wt%；Or

More than or equal to about 1wt% to the manganese less than or equal to about 2wt%, more than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%, and more than 0wt% to the silicon less than or equal to about 1wt%.

Scheme 17: such as the method for scheme 15, wherein compacting hardened component has more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa.

Scheme 18: such as the method for scheme 15, wherein heats and is occurring at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.

Scheme 19: such as the method for scheme 15, is quenched into below room temperature by compacting hardened component after further including at compacting hardening.

Scheme 20: such as the method for scheme 15, substantially by consisting of: the cold rolling without annealing volume uncoiling of steel alloy will be included, and it is cold rolling without annealing galvanizing by dipping steel alloy to be formed that this cold rolling alloy without annealed steel carries out galvanizing by dipping, wind this cold rolling without annealing galvanizing by dipping steel alloy, then before heating uncoiling this cold rolling without annealing galvanizing by dipping steel alloy and from its formed base.

Scheme 21: such as the method for scheme 15, substantially by consisting of: the cold rolling without annealing volume uncoiling of steel alloy will be included, and it is cold rolling without annealing galvanizing by dipping steel alloy to be formed that this cold rolling alloy without annealed steel carries out galvanizing by dipping in zinc-plated bath, wind this cold rolling without annealing galvanizing by dipping steel alloy, before heating uncoiling this cold rolling without annealing galvanizing by dipping steel alloy and from its formed base, and compacting cure step after quenching compacting hardened component.

Accompanying drawing explanation

Accompanying drawing as herein described be only place for the illustrative purpose to selected embodiment, but not all of possible embodiment, and be not intended to limit the scope of the present disclosure.

Fig. 1 illustrates the representational automobile A column manufactured according to an aspect of the present invention；

Fig. 2 illustrates the representational automobile B-column manufactured according to an aspect of the present invention；

Fig. 3 illustrates the common process for forming galvanizing by dipping compacting hardening steel (PHS) parts；

Fig. 4 illustrates that some aspect according to the disclosure provides the illustrative processes of the cold rolling alloy without annealed steel of galvanizing by dipping；

Fig. 5 illustrates that some other aspect according to the disclosure provides the illustrative processes of galvanizing by dipping austenitizing steel alloy；And

Fig. 6 is the schematic diagram that can be depending on the ultimate tensile strength that the austenitizing temperature according to known steel alloy obtains.

Running through several view, corresponding accompanying drawing labelling represents corresponding parts.

Detailed Description Of The Invention

Description is more fully described specific embodiment.

To those skilled in the art, the exemplary embodiment provided thoroughly and fully describes the design of the present invention.In order to provide the thorough understanding of embodiment of this disclosure, it is proposed that many concrete details, for instance the example of concrete composition, parts, equipment and method.It will be apparent to those skilled in the art that and be required for detail, exemplary embodiment can be implemented in different forms, and it should not constitute the restriction to the application scope yet.In some exemplary embodiments, it does not have known technique, known device structure and known technology are described in detail.

Term used herein is only used to describe certain exemplary embodiments and be not intended as restrictive.Unless explicitly pointed out herein, " one (a) ", " one (an) " and " being somebody's turn to do (the) " of singulative as used in this article is also intended to include plural form.Vocabulary " includes (comprises) ", " including (comprising) ", " including (including) ", " having " are all inclusives, therefore specifically illustrate the existence of described feature, entirety, step, operation, element and/or parts, and be not excluded for existence or the interpolation of one or more other features, entirety, step, operation, element, parts and/or their group.Unless specifically determined execution sequence, method step described herein, technique and operation should be construed to must with discussed or illustrate carry out their execution of requirement.Will also be appreciated that unless the contrary indication, it is possible to use step additionally or alternatively.

When mention parts, element or layer be in another element or layer " on " with another element or layer " joint ", " connection " or " connection " time, can exist these parts, element or layer be directly in another parts, element or layer " on " with another element or layer directly " joint ", " connection " or " connection ", or can also there is intermediary element or layer.Otherwise, when mention another element of element " being directly in " or layer " on " with another element or layer " directly engaging ", " being directly connected to " or " directly coupling " time, then be absent from intermediary element or layer.For describing other words of relation between element and also should explain in a similar manner (as " between " and " between directly ", " adjacent " and " direct neighbor " etc.).As used herein, vocabulary "and/or" includes any and all combination in one or more relevant article enumerated.

Although word first, second, third, etc. used herein describe various step, element, parts, region, layer and/or part, but these steps, element, parts, region, layer and/or part should not be subject to the restriction of these words, unless otherwise noted.These words are used only for distinguishing a step, element, parts, region, layer or part with other steps, element, parts, region, layer or part.Unless clearly indicated by literary composition, the word of such as " first ", " second " and other numerical value words used herein does not indicate that order or order.Therefore, first step, element, parts, region, layer or the part being discussed below can also be referred to as second step, element, parts, region, layer or part without the instruction deviateing these exemplary embodiments.

Can use herein and represent the word about room and time, such as " before ", " afterwards ", " inside ", " outside ", " ... under ", " ... below ", " lower section ", " ... on ", " top " etc., in order to the relation as illustrated in the drawing between an element or feature and another element or feature is described.Word about room and time can be intended to include removing orientation external equipment or system different azimuth in use or operation shown in figure.

It is understandable that, statement for a kind of method of " including " some step, key element or feature, composition, equipment or system, in the modification of certain replacement, it is believed that this kind of method, composition, equipment or system " substantially " are by the step enumerated, key element or feature " composition ", so any other can the basic and novel step of feature of the substantial change present invention, key element or feature be left out.

In the disclosure, measured value that numeric representation is about or be limited to the scope of the little deviation containing set-point and embodiment, described set-point and embodiment have about above-mentioned value and just above-mentioned value.Except being described in detail in last processing example, numerical value including parameter all of in this specification of appended claims (such as quantity or condition), all examples are all revised by term " about ", no matter whether actually " about " occurs before this numerical value." about " represents that described numerical value allows some slight inaccuracy (close to exact numerical；About or rational close to numerical value；Almost similar).If the inaccuracy that " about " brings cannot be understood with its ordinary meaning of this area, then the modification representing that the such parameter at least measured by conventional method and use is brought used herein to " about ".If owing to certain reason, the inaccuracy that " about " brings cannot be understood with its ordinary meaning of this area, then used herein to " about " represent relative to represent value exist at most 5% be likely to change, or relative to general measuring method exist 5% difference.

As it is used in the present context, term " composition " represents the material at least including preferred metallic element or compound widely, but it optionally also includes other material or compound, including additive and impurity.Term " material " also refers to the material including preferred compound or composition widely.

It addition, scope of disclosure includes all values and the division scope of disclosed gamut, including end points and the subrange of this scope.

The present invention provides a kind of and suppresses the method that the zinc-plated pretreatment steel alloy that hardens forms compacting hardened component, and this compacting hardened component has high intensity and without liquid metal embrittlement.With reference first to Fig. 1 and 2, structural partsof automobiles, for instance shown A post 10 and B post 20 can be made up of the compacting hardening steel components including galvanizing coating, and this compacting hardening steel components is formed by zinc-plated pretreatment steel alloy base.In some variations, compacting hardening steel components includes galvanizing coating, and it includes zinc, and it is formed by galvanizing by dipping, steel alloy base (such as this base was not annealed before forming base or do not carrying out any annealing process) cold rolling, without annealing.In some variations, described cold rolling, without annealing, galvanized steel pass through galvanizing by dipping.In other respects, the method can farther include this cold-rolled steel alloy is carried out zinc-plated annealing.In other respects, the method includes this pretreatment steel is carried out electrogalvanizing.To those skilled in the art it should be appreciated that the method for the present invention can be used to manufacture multiple miscellaneous part, and these other parts all regard as within the scope of the invention.Therefore, although with description example components shown in entire disclosure, but it is to be understood that the inventive concept of the disclosure may be used in any structure member that can be formed by zinc-plated pretreatment steel alloy, including in vehicle, such as automobile application, include but not limited to, post (such as hinge pillar), plate (includes structural slab, door-plate and door assembly), indoor floor, floor (floorpan), roof, outer surface, underbody guard shield, wheel, storage area (includes glove box, control chamber, luggage case, baggage compartment floor, compartment, lamp bag and miscellaneous part), impact tower cap, control arm and other suspensions, chassis and power train part etc..Especially, the disclosure is particularly well-suited to be subject to load, impact (such as load-bearing) or need any metal device of cathodic protection.

As it has been described above, the such galvanizing coating being used on compacting hardening steel has multiple advantage relative to without Coated Steels.This galvanizing coating (such as includes zinc) provides cathodic protection for following steel.Except providing the corrosion-resistant measure of such as barrier coatings, it is not necessary to then after compacting hardening subsequently cleaning operation with from removing oxide layer on die surface and parts.

In in every respect, a kind of steel specially suitable, unrestriced is commercially available American Iron and Steel Institute (AISI) 1530, when by when modifying of some aspect of the disclosure, it can be used for efficient streamlined compacting hardening process and forms high intensity PHS parts.AISI1530 includes the carbon of 0.3wt% weight and the manganese of 1.5wt%.Alternatively, AISI1530 alloy may also include the silicon less equal than about 0.05wt%, less equal than the aluminum of about 0.03wt%, less equal than the phosphorus of about 0.04wt%, less equal than the sulfur of about 0.05wt%.In some aspects, the disclosure considers that revising this conventional steel alloy composition makes it can have galvanizing coating, and has high intensity and the parts of insignificant liquid metal (such as zinc) embrittlement (LME) by suppressing hardening (PHS) processing to be formed.

Spelter coating can cause LME in the temperature higher than 782 DEG C.But, at the PHS parts that the conventional steel alloy processed through being heated to the heating steps lower than 782 DEG C in stove is formed, its ultimate tensile strength is only heated to 2/3rds more than or equal to about 900 DEG C of ultimate tensile strengths to the PHS parts less than or equal to about 950 DEG C in stove.Therefore, temperature is fallen below 782 DEG C to avoid LME time, compacting hardening steel lacks enough intensity.Although other steps are used alleviate the impact of LME and increase intensity, as below will be discussed further, but these steps can cause other process time and cost.

According to various aspects of the disclosure, the method forming the compacting hardening steel with galvanizing coating is heated to less than or equal to about 782 DEG C, and shows the intensity of excellence and minimum LME simultaneously.

Different aspect according to the present invention, compacting hardening steel (PHS) parts there is no liquid metal embrittlement (LME).The terms " there is no " to refer to and means LME microstructure and defect and reduce to a certain extent so that exist along with it and the less desirable physical property that produces and restricted elimination (such as break, ductility loss and/or loss of strength).In certain embodiments, " there is no " that the PHS parts of LME defect include the LME kind less than about 5wt% or defect, more preferably less than about 4wt%, optional less than about 3wt%, optional less than about 2wt%, optional less than about 1wt%, optionally less than about 0.5wt%, and include LME kind or the defect of 0wt% in certain embodiments.

Suitable composition of steel can include the carbon more than or equal to 0.1wt%, or is optionally greater than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, or is optionally greater than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%.In some aspects, steel can have more than 0wt% to the manganese less than or equal to about 6wt%, it is optionally greater than or equal to about 1wt% to the manganese less than or equal to about 2wt%, and in some aspects, manganese is optionally greater than or equal to about 1wt% to less than or equal to about 1.5wt%.Silicon optionally exists less than or equal to about 0.5wt%.Aluminum optionally exists less than or equal to about 0.01wt%.One or more impurities accumulation in steel alloy are less than or equal to about 0.5wt%.The surplus of this composition of steel is ferrum.

In other, the disclosure considers that being applicable to when being heated to the temperature lower than 782 DEG C provides high intensity and show the composition of steel alloy of minimum LME, has the about 0.1wt% included more than or equal to alloy alternatively to the composition of the carbon less than or equal to about 0.6wt%.Manganese there can optionally be alloy more than or equal to about 1wt% to less than or equal to about 6wt%.Silicon optionally exists less than or equal to about 1wt%.Aluminum optionally exists more than or equal to about 0.02wt% to less than or equal to about 0.2wt%.Niobium optionally exists less than or equal to about 0.2wt%.One or more impurities accumulation in steel alloy be alloy less than or equal to about 0.5wt%, surplus is ferrum.

With reference to Fig. 3, it is shown that illustrate the flow chart of the step of conventional compacting hardening process 100.The cold rolling coil 110 of steel alloy is annealed the temperature of about 680 DEG C in annealing chamber 120.Steel alloy after annealing carries out galvanizing by dipping in zinc-plated bath 130, and cold rolling, annealing, galvanizing by dipping steel alloy are wound providing cold rolling, annealing, galvanizing by dipping steel alloy volume 140 subsequently.Steel alloy volume 140 uncoiling subsequently, and shear to form base 150.Base 150 carried out cold forming 160 before austenitizing.Then preformed base is heated approximately to the temperature of 950 DEG C in stove 170 and reaches predetermined a period of time (such as, about 300 seconds).Preformed base suppresses hardening subsequently to form PHS parts 195 and simultaneously to its quenching in mould 180 and 190.Then PHS parts 195 are cleaned, for instance by shot-peening 200, thus removing oxide layer when needed.

Some aspect according to the disclosure, the method for the compacting hardening steel components considered uses galvanizing by dipping steel alloy, but provides the ability saving one or more steps subsequently: the annealing steps of PHS parts, preliminary forming step and/or surface cleaning step.Additionally, PHS parts have high intensity.Therefore, the whole techniques according to the disclosure preferably reduce process time, energy demand and cost.It addition, the use according to the galvanizing by dipping steel alloy of the disclosure eliminates if not all of the probability that LME occurs also being big portion.

As in this article, term " pretreatment " represent by cold rolling or by austenite one or both from high temperature cooling to obtain predetermined microstructure, described microstructure includes martensite, bainite, pearlite, austenite, ferrite etc., including their combination.Generally, when pretreatment includes cold rolling, cold rolling completed by conventional method known in the art, to be increased the intensity of steel alloy by strain hardening.Generally, when pretreatment includes austenitizing, this pretreatment include heating steel alloy to more than or equal to about 900 DEG C to less than or equal to about 950 DEG C to promote austenitic formation.Alternatively, the method (such as hot rolling) including high temperature that this technique can pass through other prior aries known utilizes austenite.Quench subsequently including austenitic steel alloy, quickly cool down, or Slow cooling, so that steel alloy experience microstructure is changed at least one in martensite, bainite, pearlite, austenite, ferrite etc., including their combination.In some preferred aspect, austenitizing steel alloy quenches to allow martensite transfor mation.Then this pretreatment alloy can form the base for the processing according to some aspect of the disclosure.

With reference to Fig. 4, it is shown that the technique 210 according to an aspect of this disclosure.The first cold rolling rolling 220 of steel alloy.Cold-rolled steel alloy increases steel alloy intensity by strain hardening.Then steel alloy is rolled up 220 uncoilings, and carries out galvanizing by dipping in zinc-plated bath 230.In some change, although it is not shown, galvanization annealing furnace (such as induction furnace) can be used after zinc-plated bath 230 to carry out the zinc-plated annealing of galvanizing coating.Significantly, this technique need not be annealed (such as the annealing furnace 120 shown in Fig. 3) before carrying out galvanizing by dipping in zinc-plated bath 230.Therefore, can be conducted directly in zinc-plated bath 230 without annealing cold-rolled steel alloy.

Continuous hot-dipping galvanizing is used for coated steel alloy.Be coated in by uncoiling steel alloy by higher than about 420 DEG C and more preferably in more than or equal to about 420 DEG C until about 480 DEG C temperature keep zinc-plated baths 230 and apply, subsequently cooling zinc is solidified in face coat.Continuous hot-dipping galvanizing provides a kind of relatively pure spelter coating with high resistance to cathodic corrosion.Alternatively, aluminum can add in zinc-plated bath 230, promotes to avoid the formation of the layer of the extensive diffusive between zinc and ferrum.In some aspects, after galvanizing by dipping, by galvanizing by dipping steel alloy is heated to more than or equal to about 500 DEG C to less than or equal to about 565 DEG C and keep the several seconds to make the zinc-plated annealing of steel alloy.Steel alloy then can again wrap around rolling 240 so that rodability.Significantly, step 220 and 240 is optional.

If through winding, steel alloy is uncoiling subsequently, and then base 250 is formed by the cutting out section of steel alloy.Base 250 may utilize shearing die (trimdie), alligator shears machine, bench shears, guillotine (guillotine), Electric shearing machine, shears without larynx formula shearing machine (throatlessshear) etc..The steel alloy according to the disclosure is used to be made without preliminary forming step (such as the step 160 shown in Fig. 3).

Base 250 is placed in stove 260 (such as austenitizing stove).Base 250 is heated to less than or equal to about 782 DEG C so that as those skilled in the art recognize, the temperature in stove 260 can potentially more than 782 DEG C.Significantly, lead into the base 250 in stove 260 and be made without preform to realize required intensity, and there is no LME.By way of example, base 250 is put in stove at least 5 minutes so that base reaches about 780 DEG C.The base 265 of heating is immediately transferred to mould 270 and 280, and compacting hardens into PHS parts 290.Due to temperature lower than about 782 DEG C of the temperature of base 250, thus limiting LME, if it there will be.

Alternatively, PHS parts 290 are by quickly cooling technique quenching, and PHS parts 290 can quench in mould 270 and 280, for instance, quench so that austenite is changed into martensite with the speed more than 27 DEG C/s.

Spelter coating protection PHS parts 290 avoid oxidation, and otherwise oxidation can occur between austenitizing and compacting cure step.Therefore, the surface of PHS parts 290 need not substantially be cleaned after compacting hardening.

With reference to Fig. 5, it is shown that the technique 310 according to another aspect of the disclosure.First steel alloy is carrying out austenitizing more than or equal to about 900 DEG C at less than or equal to about 950 DEG C in austenitizing stove 220.The steel alloy of austenitizing carries out quenching, quickly cooling down or Slow cooling subsequently, and to obtain microstructure, this microstructure includes martensite, bainite, pearlite, austenite, ferrite etc., including their combination.Preferably, the steel alloy of austenitizing carries out quenching to allow martensite transfor mation.The steel alloy of austenitizing carries out galvanizing by dipping subsequently in zinc-plated bath 330, and this zinc-plated bath includes galvanization annealing furnace alternatively.

Use continuous hot-dipping galvanizing coated steel alloy.By by steel alloy by higher than about 420 DEG C of zinc-plated baths 330 kept, more preferably in more than or equal to about 420 DEG C until the temperature of about 480 DEG C is coated with application layer, carry out cooling subsequently and make zinc be condensed into face coat.Continuous hot-dipping galvanizing provides a kind of relatively pure spelter coating with high resistance to cathodic corrosion.Alternatively, aluminum can add in zinc-plated bath 330, promotes to form the layer avoiding the extensive diffusive between zinc and ferrum.In some aspects, after zinc-plated, by galvanizing by dipping steel alloy is heated to more than or equal to about 500 DEG C to less than or equal to about 565 DEG C and keep the several seconds to make the zinc-plated annealing of steel alloy.Then steel alloy can be again wrapped around rolling 340 so that transporting.Significantly, step 340 is optional.

If through winding, steel alloy is uncoiling subsequently, and then base 350 is formed by the cutting out section of steel alloy.Base 350 may utilize shearing die, alligator shears machine, bench shears, guillotine, Electric shearing machine, shears without larynx formula shearing machine etc..The steel alloy according to the disclosure is used to be made without preliminary forming step (such as the step 160 shown in Fig. 3).

Base 350 is placed in stove 360 (such as austenitizing stove).Base 350 is heated to less than or equal to about 782 DEG C, and as known to those skilled in the art, the temperature in stove 360 can potentially more than 782 DEG C.Significantly, introduce the base 350 entered in stove 360 and be made without preform to realize required intensity, and there is no LME.In an illustrative manner, base 350 is put in stove at least 5 minutes so that base reaches about 780 DEG C.The base 365 of heating is typically immediately transferred to mould 370 and 380, and compacting hardens into PHS parts 390.Due to temperature lower than about 782 DEG C of the temperature of base 350, thus limiting LME, if there will be.

Alternatively, PHS parts 390 are by quickly cooling technique quenching, and PHS parts 390 can quench in mould 370 and 380, for instance, quench with the speed more than 27 DEG C/s and make austenite be changed into martensite.

Spelter coating protection PHS parts 390 avoid oxidation, and otherwise oxidation can occur between austenitizing and compacting cure step.Therefore, the surface of PHS parts 390 need not substantially be cleaned after compacting hardening.

Zinc-plated, pretreatment compacting hardening steel alloy according to the disclosure provides excellent intensity.When pretreatment includes cold rolling, compacting hardening steel is not annealed alternatively.More specifically, the zinc-plated pretreatment compacting hardening steel alloy according to the disclosure has more than or equal to about 1000MPa to the ultimate tensile strength (UTS) less than or equal to about 2000MPa.Fig. 6 illustrates some existing conventional steel alloy (such as 22MnB5, by weight percentage, including 0.22%C, 0.44%Mn, 0.19%Si, 0.001%B, surplus is Fe) (it is appointed as " 620 " being heated to various austenitizing, by DEG C in units of) time the ultimate tensile strength (being appointed as " 610 ", in units of MPa) that reaches.More specifically, surrender standing the ultimate tensile strength place only in about 900MPa of the conventional steel alloy according to the austenitizing at the temperature less than or equal to about 782 DEG C of the disclosure.This conventional ingredient does not reduce austenitizing temperature fully to 782 DEG C or lower, so that the amount of the martensite formed during PHS technique maximizes.Therefore, this steel alloy needs the chemical composition of amendment alloy, for instance add other manganese and/or carbon, to increase martensite transfor mation at all, and improves intensity to acceptable level under hardening state (such as in PHS parts).If it is desire to PHS parts have better toughness, it is necessary to reduce carbon, increase manganese simultaneously, select the alloy with the austenitizing temperature at or below 782 DEG C simultaneously.

Zinc-plated pretreatment steel alloy according to the disclosure provides the PHS parts with the poly-phase microcosmos structure including martensite.When cooling, if rate of cooling is more than 27 DEG C/s, then at the temperature of about 400 DEG C, PHS parts experience is without diffusion martensite transfor mation.Martensite transfor mation is in about 280 DEG C of end.In some aspects, martensite transfor mation is that PHS parts provide high intensity.Carbon amount in zinc-plated pretreatment steel alloy and austenitizing temperature determine and are changed into austenite and and then are changed into the ferritic amount of martensite.In some aspects, PHS parts can have poly-phase microcosmos structure, including pressing the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

In an exemplary method, this technique includes being formed base by zinc-plated pretreatment steel alloy.Then this base heats in stove so that base is less than or is equal to the temperature of about 782 DEG C, so that this galvanized steel alloy component austenitizing.Then the base heated is typically immediately transferred in mould and suppresses and hardens into PHS parts.PHS parts have the ultimate tensile strength more than or equal to about 1000MPa, and are substantially free of liquid metal embrittlement.In some other modification, pretreatment galvanizing by dipping steel alloy was not annealed before forming base.PHS parts are quenched into lower than room temperature after can further including at compacting hardening by this technique.This technique farther includes cold rolling alloy without annealed steel is carried out galvanizing by dipping in zinc-plated bath.In other respects, this technique farther includes the zinc-plated annealing of pretreatment steel alloy.In other, this technique can include pretreatment steel electrogalvanizing.In some aspects, steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%, or in some variations, steel alloy optionally includes more than or equal to about 1wt% to the manganese less than or equal to about 2wt% and/or more than or equal to about 0.3wt% to the carbon less than or equal to about 0.5wt%.Steel alloy can further include greater than 0wt% to the silicon less than or equal to about 1wt%.In other modification, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.PHS parts can have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa.Can in the heating issuing green compact more than or equal to about 725 DEG C to the temperature less than or equal to about 782 DEG C.PHS parts can include poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

In another example, this technique is substantially made up of below step.This cold rolling alloy without annealed steel by uncoiling, can be carried out galvanizing by dipping cold rolling without annealing galvanizing by dipping steel alloy to be formed by volume including cold rolling alloy without annealed steel subsequently in zinc-plated bath.Then, this cold rolling nothing annealing galvanizing by dipping steel alloy is wound, and is cut into base by volume, and in stove, heating is less than or is equal to the temperature of about 782 DEG C subsequently.Then, the base of heating is typically immediately transferred to mould and compacting hardens into PHS parts so that these PHS parts have the ultimate tensile strength more than or equal to about 1000MPa, and there is no liquid metal embrittlement.In some variations, this technique limits as follows further: (1) this technique substantially forms lower than room temperature by being quenched into by PHS parts after compacting hardening further；(2) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%；(3) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(4) steel alloy is made to include more than 0wt% to the silicon less than or equal to about 1wt%；(5) steel alloy includes the carbon of about 0.3wt% and the manganese of about 1.5wt%；(6) PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(7) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；(8) this technique can substantially formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further；And the PHS parts that (9) this technique is made, it has poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.Significantly, this technique can form high intensity PHS parts and avoid liquid metal embrittlement simultaneously, discharges one or more following steps simultaneously: annealing, preform or the cleaning step that conventional PHS technique needs, thus result in the benefit of saving time, energy and cost.Further, austenitizing temperature is lower than known PHS technique.

In another exemplary method, this technique can be substantially made up of following steps.Including steel alloy cold rolling without annealing volume can uncoiling, then carry out in zinc-plated bath galvanizing by dipping with formed cold rolling without annealing galvanizing by dipping steel alloy.This cold rolling nothing annealing galvanizing by dipping steel alloy can wind, and is cut into base from volume, and in stove, heating is less than or is equal to the temperature of about 782 DEG C subsequently.Then, the base of heating is typically immediately transferred to mould, and compacting hardening and quenching form PHS parts, and wherein these PHS parts have the ultimate tensile strength more than or equal to about 1000MPa, and there is no liquid metal embrittlement.In some change, this technique limits as follows further: (1) makes steel alloy include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%；(2) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(3) steel alloy is made to include more than 0wt% to the silicon less than or equal to about 1wt%；(4) steel alloy is made to include the carbon of about 0.3wt% and the manganese of about 1.5wt%；(5) wherein PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(6) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；(7) wherein this technique is substantially being formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further；And (8) wherein PHS parts have poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.Significantly, this technique eliminates the conventional annealing, preform and the cleaning step that had previously needed in conventional PHS technique, which results in and consumes less energy to form PHS parts thus having saved the benefit of cost owing to needing.Additionally, austenitizing temperature is lower than known PHS technique.

In another exemplary method, this technique includes forming base from zinc-plated cold rolling alloy without annealed steel.Then this base is heated to the temperature less than or equal to about 782 DEG C in stove so that this galvanized steel alloy component austenitizing.Then the base heated is typically immediately transferred in mould and suppresses and hardens into PHS parts.These PHS parts have the intensity (such as ultimate tensile strength, UTS) more than or equal to about 1000MPa, and are substantially free of liquid metal embrittlement.In some aspects, steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%, or in some change, steel alloy includes alternatively more than or equal to about 1wt% to the manganese less than or equal to about 2wt% and/or more than or equal to 0.3wt% to the carbon less than or equal to 0.5wt%.Steel alloy further includes greater than 0wt% to the silicon less than or equal to about 1wt%.In other changes, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.PHS parts can have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa.Heating can occur at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.PHS parts can include poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.This technique can further include in zinc-plated bath and cold rolling alloy without annealed steel is carried out galvanizing by dipping.This technique carries out zinc-plated annealing after can further including at galvanizing by dipping.In other respects, this technique can include pretreatment steel is carried out electrogalvanizing.PHS parts are quenched into lower than room temperature after can further including at compacting hardening by this technique.

In another example, this technique can substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, then cold rolling alloy without annealed steel is carried out galvanizing by dipping cold rolling without annealing galvanizing by dipping steel alloy to be formed in zinc-plated bath, wind this cold rolling without annealing galvanizing by dipping steel alloy rolling, and be cut into base from volume.Base can heat the temperature it being less than or equal to about 782 DEG C in stove.The base of heating is typically immediately transferred to mould and compacting hardens into PHS parts.Steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%.In some change, this technique limits as follows further: (1) substantially forms lower than room temperature by being quenched into by PHS parts after hardening in compacting further；(2) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(3) steel alloy is made to include more than 0wt% to the silicon less than or equal to 1wt%；(4) steel alloy is made to include the carbon of about 0.3wt% and the manganese of about 1.5wt%；(5) wherein PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(6) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；(7) substantially formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further；And (8) wherein PHS parts have poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.Significantly, this technique eliminates annealing, preform and cleaning step, which results in and consumes less energy to form PHS parts thus having saved the benefit of cost owing to needing.Further, austenitizing temperature is lower than the temperature of known PHS technique.

In another exemplary method, this technique is substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, cold rolling alloy without annealed steel is carried out by zinc-plated bath galvanizing by dipping cold rolling without annealing galvanizing by dipping steel alloy to be formed, wind this cold rolling without annealing galvanizing by dipping steel alloy, and be cut into base from volume.Base heats the temperature it being less than or equal to about 782 DEG C in stove.Then, the base of heating is typically immediately transferred to mould, the compacting of hot base to be hardened and to quench to form PHS parts.PHS parts have the intensity (such as ultimate tensile strength, UTS) more than or equal to about 1000MPa, and are substantially free of liquid metal embrittlement.Steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%.At some in other changes, this technique can limit as follows further: (1) makes steel alloy include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(2) steel alloy is made to include more than 0wt% to the silicon less than or equal to 1wt%；(3) steel alloy is made to include the carbon of about 0.3wt% and the manganese of about 1.5wt%；(4) wherein PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(5) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；(6) substantially formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further；And (7) wherein PHS parts have poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.Significantly, this technique gets rid of the conventional annealing, preform and the cleaning step that had previously needed in conventional PHS technique, which results in and consumes less energy to form PHS parts thus having saved the benefit of cost owing to needing.Additionally, austenitizing temperature is lower than known PHS technique.

In another exemplary method, this technique includes forming base from zinc-plated cold rolling alloy without annealed steel.This base is then heated to the temperature less than or equal to about 782 DEG C in stove so that this galvanized steel alloy component austenitizing.The base of heating is then typically immediately transferred to mould and compacting hardens into PHS parts.PHS parts include poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.PHS parts are quenched into lower than room temperature after can further including at compacting hardening by this technique.This technique can further include in zinc-plated bath and cold rolling alloy without annealed steel is carried out galvanizing by dipping.This technique can farther include without annealed steel alloy, galvanizing by dipping pretreatment is carried out zinc-plated annealing.In other respects, this technique can include pretreatment steel electrogalvanizing.Steel alloy can include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%, and in some other modification, including more than or equal to about 1wt% to the manganese less than or equal to about 2wt%.Steel alloy can further include greater than 0wt% to the silicon less than or equal to about 1wt%.In other modification, steel alloy can include the carbon of about 0.3wt% and the manganese of about 1.5wt%.PHS parts can have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa.Heating may alternatively appear in more than or equal to about 725 DEG C of temperature arrived less than or equal to about 782 DEG C.

In another method, technique can substantially by consisting of: will include the cold rolling without annealing volume uncoiling of steel alloy, cold rolling alloy without annealed steel is carried out by zinc-plated bath galvanizing by dipping cold rolling without annealing galvanizing by dipping steel alloy to be formed, wind this cold rolling without annealing galvanizing by dipping steel alloy, it is cut into base from volume, stove is heated to the temperature less than or equal to about 782 DEG C, the base of heating is typically immediately transferred to mould and the compacting of hot base is hardened into PHS parts, PHS parts are made to have poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the martensite less than or equal to about 99%, the combined volume percentage ratio of retained austenite and other transmutation products.In some other modification, this technique can limit as follows further: (1) substantially forms lower than room temperature by being quenched into by PHS parts after compacting hardening further；(2) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than 0wt% to the manganese less than or equal to about 6wt%；(3) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt% with more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(4) steel alloy is made to include more than 0wt% to the silicon less than or equal to about 1wt%；(5) steel alloy is made to include the carbon of about 0.3wt% and the manganese of about 1.5wt%；(6) wherein PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(7) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；And (8) are substantially being formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further.Significantly, this technique eliminates the conventional annealing, preform and the cleaning step that had previously needed in conventional PHS technique, which results in and consumes less energy to form PHS parts thus having saved the benefit of cost owing to needing.Additionally, austenitizing temperature is lower than known PHS technique.

In another illustrative processes, method substantially can by consisting of: include the cold rolling without annealing volume uncoiling of steel alloy by one, then cold rolling alloy without annealed steel carries out galvanizing by dipping in zinc-plated bath obtain forming cold rolling nothing annealing galvanizing by dipping steel alloy, wind this cold rolling without annealing galvanizing by dipping steel alloy, and be cut into base by from volume.Base can heat the temperature being less than or equal to about 782 DEG C in stove,.Then, the base of heating is typically immediately transferred to mould and the compacting of hot base is hardened and be quenched to PHS parts, these PHS parts are made to have poly-phase microcosmos structure, it has the ferrite by volume arrived less than or equal to about 60% more than or equal to about 1%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.In some other modification, this technique can limit as follows further: (1) makes steel alloy include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than 0wt% to the manganese less than or equal to about 6wt%；(2) steel alloy is made to include more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than or equal to about 1wt% to the manganese less than or equal to about 2wt%；(3) steel alloy is made to include more than 0wt% to the silicon less than or equal to about 1wt%；(4) steel alloy is made to include the carbon of about 0.3wt% and the manganese of about 1.5wt%；(5) wherein PHS parts have more than or equal to about 1000MPa to the ultimate tensile strength less than or equal to about 2000MPa；(6) cold rolling galvanizing by dipping steel alloy is carried out zinc-plated annealing；And (7) this technique is substantially being formed to the heating temperatures less than or equal to about 782 DEG C more than or equal to about 725 DEG C by stove further.Significantly, this technique eliminates the conventional annealing, preform and the cleaning step that had previously needed in conventional PHS technique, which results in and consumes less energy to form PHS parts thus having saved the benefit of cost owing to needing.Additionally, austenitizing temperature is lower than known PHS technique.

For the purpose of illustration and description, the description of embodiment provided above.But it is not intended to the detailed or restriction disclosure.The single element of specific embodiment or feature are generally not limited to this specific embodiment, but, in suitable part, they can exchange and can be used in selected embodiment, even without specifically illustrating or describing.It can also be changed by various ways.These changes do not regard as the deviation disclosure, and all these changes are intended to be included within the scope of the present disclosure.

Claims

1. the method suppressing hardening galvanized steel alloy, including:

Base is formed by the galvanized steel alloy of pretreatment；

2. the method for claim 1, wherein steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than 0wt% to the manganese less than or equal to about 6wt%.

3. the method for claim 1, wherein steel alloy includes:

4. the method for claim 1, wherein steel alloy includes more than 0wt% to the silicon less than or equal to about 1wt%.

5. the method for claim 1, wherein heats and is occurring at the temperature less than or equal to about 782 DEG C more than or equal to about 725 DEG C.

6. the method for claim 1, is quenched into below room temperature by compacting hardened component after further including at compacting hardening.

7. the method for claim 1, wherein this compacting hardened component has poly-phase microcosmos structure, including the ferrite by volume arrived more than or equal to about 1% less than or equal to about 60%, and more than or equal to about 40% to the combined volume percentage ratio of the martensite less than or equal to about 99%, retained austenite and other transmutation products.

8. the method suppressing hardening galvanized steel alloy, including:

Base is formed from the galvanized steel alloy of pretreatment；

9. method as claimed in claim 8, wherein steel alloy includes more than or equal to about 0.1wt% to the carbon less than or equal to about 0.6wt%, and more than 0wt% to the manganese less than or equal to about 6wt%.

10. the method suppressing hardening galvanized steel alloy, including: