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CN118441205B - Hot forming steel and preparation method and application thereof, preparation method of parts for automobile and train lower doors and the like - Google Patents

Hot forming steel and preparation method and application thereof, preparation method of parts for automobile and train lower doors and the like Download PDF

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Publication number
CN118441205B
CN118441205B CN202410539717.7A CN202410539717A CN118441205B CN 118441205 B CN118441205 B CN 118441205B CN 202410539717 A CN202410539717 A CN 202410539717A CN 118441205 B CN118441205 B CN 118441205B
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hot
formed steel
temperature
rolling
preparation
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CN118441205A (en
Inventor
赵岩
邓向星
隆聪
汪健
李金龙
桂林涛
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Chongqing Shuyuandao Technology Co ltd
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Chongqing Shuyuandao Technology Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60J—WINDOWS, WINDSCREENS, NON-FIXED ROOFS, DOORS, OR SIMILAR DEVICES FOR VEHICLES; REMOVABLE EXTERNAL PROTECTIVE COVERINGS SPECIALLY ADAPTED FOR VEHICLES
    • B60J5/00—Doors
    • B60J5/04—Doors arranged at the vehicle sides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60J—WINDOWS, WINDSCREENS, NON-FIXED ROOFS, DOORS, OR SIMILAR DEVICES FOR VEHICLES; REMOVABLE EXTERNAL PROTECTIVE COVERINGS SPECIALLY ADAPTED FOR VEHICLES
    • B60J5/00—Doors
    • B60J5/04—Doors arranged at the vehicle sides
    • B60J5/048—Doors arranged at the vehicle sides characterised by the material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61D—BODY DETAILS OR KINDS OF RAILWAY VEHICLES
    • B61D19/00—Door arrangements specially adapted for rail vehicles
    • B61D19/02—Door arrangements specially adapted for rail vehicles for carriages
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Abstract

本发明涉及金属材料加工技术领域，公开了一种热成形钢及其制备方法与应用、汽车与火车下车门等用零件的制备方法。热成形钢由内到外依次包括基体和致密复合氧化层；其中，致密复合氧化层中，三氧化二铁的含量为2wt％以下。通过控制致密复合氧化层的微观结构以及三氧化二铁的含量，使热成形钢具有优异的抗高温氧化性能，基体的组织为铁素体和珠光体，使热成形钢具有合适的屈服强度、抗拉强度和延伸率；通过对热处理温度、热轧温度和卷取温度的调控，卷取处理后可免去酸洗、抛丸和退火处理；卷取后热成形钢可直接用于制备汽车用零件，具有优异的屈服强度、抗拉强度、延伸率、表面硬度、抗氧化性能和漆膜附着力，可以实现无涂层、免抛丸效果。

The present invention relates to the technical field of metal material processing, and discloses a hot-formed steel and its preparation method and application, and a preparation method for parts for automobile and train lower doors, etc. The hot-formed steel includes a matrix and a dense composite oxide layer from the inside to the outside; wherein, in the dense composite oxide layer, the content of ferric oxide is less than 2wt%. By controlling the microstructure of the dense composite oxide layer and the content of ferric oxide, the hot-formed steel has excellent high-temperature oxidation resistance, and the structure of the matrix is ferrite and pearlite, so that the hot-formed steel has suitable yield strength, tensile strength and elongation; by regulating the heat treatment temperature, hot rolling temperature and coiling temperature, pickling, shot blasting and annealing can be avoided after coiling; after coiling, the hot-formed steel can be directly used to prepare automotive parts, and has excellent yield strength, tensile strength, elongation, surface hardness, oxidation resistance and paint film adhesion, and can achieve a coating-free and shot-free effect.

Description

Hot forming steel and preparation method and application thereof, preparation method of parts for automobile and train lower doors and the like
Technical Field
The invention relates to the technical field of metal material processing, in particular to hot forming steel, a preparation method and application thereof, a preparation method of parts for automobile and train lower doors and the like.
Background
The weight reduction of commercial vehicle compartments is an important trend in the current automotive industry. With the improvement of environmental awareness, the reduction of the overall weight of the vehicle is an effective way for reducing fuel consumption and exhaust emission, and accords with the global carbon emission reduction trend. The fuel economy of the commercial vehicle can be improved by light weight, and the pressure on the environment is reduced. The commercial vehicle is light in weight, so that carrying capacity and freight efficiency are improved, and transportation cost is reduced. By reducing the weight of the vehicle itself, the payload can be increased to achieve higher cargo transport efficiency. The service life of the commercial vehicle can be prolonged due to light weight, and the maintenance cost is reduced. The weight of the vehicle can be reduced, the abrasion and fatigue of parts can be reduced, the reliability and durability of the vehicle can be improved, and the maintenance frequency and cost can be reduced. Therefore, the demand for the weight reduction of the commercial vehicle is not only caused by the attention of environmental protection and energy efficiency, but also represents the omnibearing pursuit of transportation efficiency, economy and safety.
The steel of the carriage of the commercial vehicle is changed from low-strength Q235 and Q345 to high-strength T700 and NM450, and with the continuous improvement of the strength, the requirements on the high-strength steel on the die in the cold forming process are more strict, so that the damage is more serious. Not only is the rebound problem after forming more obvious, but also the part itself is easy to crack in the forming process, thereby leading to the reduction of the yield. Currently, commercial vehicles are still cold formed by adopting steel plates of ferrite-pearlite 590MPa series and bainite 780MPa series. Cold forming of a hot rolled steel plate with the strength of 780MPa and the thickness of 2-6mm is close to the limit of a die, and micro cracks and larger internal stress are generated after forming, so that fatigue performance is deteriorated, and potential safety hazards are brought to the service process.
The hot forming technology is a technology of heating a metal material to above an austenitizing temperature and then carrying out press forming under the state, so that the problems of severe press cracking, serious rebound, poor dimensional accuracy and the like of complex parts are solved.
At present, commercial hot forming steel is mainly divided into Al-Si plated steel and bare plate (non-plated steel), wherein the primary function of the Al-Si plated layer is to prevent decarburization and oxidation of the surface of the steel plate in the austenitizing process, and the plated layer can isolate the steel plate substrate from the external environment, so that the steel plate has a certain corrosion prevention function. Although the al—si plating layer can prevent oxidation and decarburization during hot forming of the steel sheet, it is liable to cause sticking of rolls, and the production process of the al—si plating layer is monopolized by foreign enterprises, resulting in high price thereof. The loose oxide layer is easy to form on the surface of the bare board in the hot stamping process, the oxide layer is easy to fall off in the hot forming engineering, the oxide scale in the die is required to be temporarily produced and cleaned, the hard oxide scale is easy to cause the scratch of the die, the service life of the die is seriously reduced, and the other part of the bare board with the hairsurface after hot forming is required to be subjected to shot blasting treatment, so that the environment is polluted, and the process and the working time are increased. Meanwhile, due to the problem of hardenability, the hot forming steel for the commercial vehicle can only manufacture parts with the diameter less than or equal to 6.0mm, so that martensite can be obtained at the core of the parts, and the application of the hot forming technology on large-scale thick plate parts is limited.
CN113832407a discloses a method for preparing thick hot-formed steel, a hot-rolled steel plate and hot-formed steel, which can realize the effects of no coating and no shot blasting. However, the yield strength after hot rolling is too high (more than 900 MPa) to exceed the performance requirement of a plate shearing machine in the actual production process, and blanking processing cannot be performed.
Therefore, the preparation process of the alloy components of the hot-formed steel needs to be further optimized, so that the strength after hot rolling can be reduced, no coating and shot blasting can be realized, and the hot-formed steel can be simultaneously applied to the fields of direct hot forming and indirect hot forming.
Disclosure of Invention
The invention aims to solve the problems that the hot forming steel in the prior art needs to be treated by an Al-Si coating, the material cost is high, the working procedure is complex, hydrogen embrittlement, sticking roller and coating cracking can occur, the bare plate of the existing hot forming steel without the coating has insufficient high-temperature oxidation resistance in the hot forming process, shot blasting is required, and the hot forming steel needs to be subjected to processes such as acid washing, annealing and the like to prepare automobile parts, and provides the hot forming steel, a preparation method and application thereof, and a preparation method of automobile and train lower door parts and the like.
In order to achieve the above object, a first aspect of the present invention provides a hot-formed steel, wherein the hot-formed steel comprises a matrix and a dense composite oxide layer in this order from the inside to the outside;
wherein, the content of ferric oxide in the compact composite oxide layer is below 2 wt%.
The second aspect of the invention provides a method for preparing a hot-formed steel, wherein the method comprises the steps of sequentially carrying out heat treatment, hot rolling and coiling on a continuous casting blank to obtain the hot-formed steel;
wherein the conditions of the heat treatment, hot rolling and coiling are such that the content of ferric oxide in the layer formed on the surface of the hot-formed steel is 2wt% or less;
the heat treatment temperature is 1260-1340 ℃, the hot rolling start temperature is 1160-1200 ℃ and the hot rolling finish temperature is 850-890 ℃, and the coiling temperature is 610-680 ℃.
In a third aspect, the present invention provides a hot-formed steel produced by the above-described production method.
A fourth aspect of the present invention provides the use of the above-described hot-formed steel for the preparation of parts for automobile and train doors and the like.
The fifth aspect of the invention provides a method for manufacturing parts for automobile and train doors and the like, comprising the step of carrying out hot forming treatment on the hot formed steel.
Through the technical scheme, the technical scheme provided by the invention has the following beneficial effects:
(1) The hot forming steel provided by the invention has excellent oxidation resistance due to the fact that the content of ferric oxide in a compact composite oxide layer is below 2wt% through a high-temperature coiling process, and on the other hand, the structure of a matrix after high-temperature coiling is ferrite and pearlite, the volume content of the ferrite is 55-75%, and the volume content of the pearlite is 25-45%, so that the hot forming steel has proper yield strength, tensile strength and elongation, and is convenient to cut and blank;
(2) According to the preparation method of the hot forming steel, the component design (Si-Cr-RE) is matched with the regulation and control of the technological parameters such as the heat treatment temperature, the hot rolling temperature and the coiling temperature, so that the content of ferric oxide formed on the surface of the hot forming steel is below 2wt%, and acid washing, shot blasting and annealing treatment can be omitted after the coiling treatment. The oxidation resistance of the steel can be improved by controlling the contents of Cr, si and RE, and dense oxides Cr 2O3 and SiO 2 are formed before Fe and oxygen. In the oxide layer, si and Cr are helpful to form a composite compact oxide layer Fe 2(SixCryREz)O4, while RE element has good stability to the oxide layer, and can improve the bonding force between the compact composite layer and the matrix. The compact Fe 2(SixCryREz)O4 layer is beneficial to preventing oxygen from diffusing to the matrix and Fe from diffusing to the outside, improving the high-temperature oxidation resistance of the matrix and promoting the compact Fe 3O4 to generate;
(3) The hot forming steel provided by the invention is applied to preparing parts for automobiles, train doors and the like, and the matrix of the prepared automobile part contains martensite with the volume ratio of more than 95%, contains or does not contain a small amount of ferrite, bainite or residual austenite, has excellent mechanical properties, has the yield strength of 1030-1180MPa, the tensile strength of 1580-1610MPa, the elongation of 10.2-10.5% and the surface hardness of more than 480HV, and can realize the effects of no coating and no shot blasting;
(4) According to the preparation method of the parts for the automobile, the train lower door and the like, the compact composite oxide layer can deform together with the matrix in the thermoforming treatment process, no oxide layer falls off on the surface after thermoforming, and the effects of no coating and no shot blasting are achieved.
Drawings
FIG. 1 is an SEM image of a dense composite oxide layer of a hot formed steel prepared in example 1 of the present invention;
FIG. 2 is a matrix structure diagram of the hot-formed steel prepared in example 1 of the present invention;
FIG. 3 is a diagram showing the matrix structure of a hot-formed steel part in example 1 of the present invention;
FIG. 4 is an SEM image of a dense composite oxide layer of an automotive part prepared in example 1 of the present invention;
FIG. 5 is an XRD pattern of the dense composite oxide layer for automobiles prepared in example 1 of the present invention;
FIG. 6 is an SEM image of a composite oxide layer of a hot formed steel prepared in comparative example 7 of the present invention;
FIG. 7 is an XRD pattern of a composite oxide layer of an automobile part prepared in comparative example 7 of the present invention;
FIG. 8 is an SEM image of a dense composite oxide layer of an automotive part prepared in comparative example 7 of the present invention;
FIG. 9 is a matrix structure of an automobile part prepared in comparative example 7 of the present invention.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
The invention provides a hot forming steel, wherein the hot forming steel sequentially comprises a matrix and a compact composite oxide layer from inside to outside;
wherein, the content of ferric oxide in the compact composite oxide layer is below 2 wt%.
In the invention, when the content of ferric oxide in the compact composite oxide layer does not meet the range, the antioxidation effect of the hot-formed steel is weakened, the oxide layer on the surface can fall off after hot forming, and the effect of shot-free direct coating cannot be realized.
In the invention, the term "from inside to outside" means that the hot-formed steel has a structure of a matrix and a dense composite oxide layer.
According to the invention, the compact composite oxide layer comprises a Fe 2(SixCryREz)O4 layer and a Fe 3O4 layer from inside to outside.
According to the present invention, the structure and phase composition of the dense composite oxide layer can be determined by a scanning electron microscope and a method of X-ray diffraction analyte phase analysis. The Fe 2(SixCryREz)O4 layer contains 28-32wt% Fe, 16-20wt% Si, 34-38wt% Cr, and 0.01-0.02wt% RE, based on the total weight of the Fe 2(SixCryREz)O4 layer.
In the invention, in the Fe 2(SixCryREz)O4 layer, x+y+z is more than or equal to 0.95 and less than or equal to 1.05, specifically, the values of x, y and z are not particularly required, and only the value of x+y+z meets the limit of the invention.
According to the invention, 72-73wt% of Fe, based on the total weight of the Fe 3O4 layer.
According to the invention, the porosity of the dense composite oxide layer is 0.2-2%, preferably 0.2-1%.
In the invention, when the porosity content of the compact composite oxide layer does not meet the range, the porosity is more than 2%, the binding force between the matrix of the hot-formed steel and the composite oxide layer is weakened, the oxide layer on the surface can fall off after hot forming, and the effect of no shot blasting direct coating cannot be realized.
According to the present invention, the thickness of the dense composite oxide layer is 10 μm or less, preferably 8 μm or less.
In the invention, when the thickness of the compact composite oxide layer does not meet the range, the welding performance of the hot-formed steel is weakened, and the requirements of a host factory on the welding performance cannot be met.
According to the invention, the thickness of the Fe 2(SixCryREz)O4 layer is 0.05-0.2. Mu.m, preferably 0.1-0.15. Mu.m.
In the present invention, when the thickness of the Fe 2(SixCryREz)O4 layer does not satisfy the above range, oxidation resistance of the hot-formed steel and adhesion of the composite oxide layer are weakened.
According to the present invention, the thickness of the Fe 3O4 layer is 9.8 μm or less, preferably 8 μm or less.
In the present invention, when the thickness of the Fe 3O4 layer does not satisfy the above range, the weldability of the hot-formed steel is weakened.
In the present invention, the dense composite oxide layer contains iron sesquioxide in an amount of 2wt% or less as a whole.
According to the invention, the matrix is composed of ferrite and pearlite.
According to the invention, the volume content of ferrite in the matrix is 55-75% and the volume content of pearlite is 25-45% based on the total volume of the matrix.
According to the invention, the hot-formed steel has a yield strength of 500-600MPa, a tensile strength of 700-800MPa and an elongation of 18-24%.
According to the invention, the hot-formed steel contains 0.12-0.4 wt.% C, 1-2 wt.% Si, 0.01-0.5 wt.% Al, 0.5-1.6 wt.% Cr, 0.003-0.008 wt.% RE, less than 0.008 wt.% S+P, not more than 2 wt.% Mn, not more than 0.004 wt.% B, not more than 0.1 wt.% Ti, 93.381-96.698 wt.% Fe+impurities, based on the total weight of the hot-formed steel.
Further, the hot-formed steel contains 0.2 to 0.3wt% of C, 1.5 to 1.9wt% of Si, 0.2 to 0.4wt% of Al, 1.0 to 1.5wt% of Cr, 0.004 to 0.008wt% of RE, less than 0.005wt% of S+P, not more than 1.5wt% of Mn, not more than 0.002wt% of B, not more than 0.03wt% of Ti, and 94.455 to 96.0842wt% of Fe+impurities, based on the total weight of the hot-formed steel.
According to the invention, RE is selected from Ce and/or Y, and RE adopted in the following embodiments is Ce.
The second aspect of the invention provides a method for preparing a hot-formed steel, wherein the method comprises the steps of sequentially carrying out heat treatment, hot rolling and coiling on a continuous casting blank to obtain the hot-formed steel;
wherein the conditions of the heat treatment, hot rolling and coiling are such that the content of ferric oxide in the layer formed on the surface of the hot-formed steel is 2wt% or less;
the heat treatment temperature is 1260-1340 ℃, the hot rolling start temperature is 1160-1200 ℃ and the hot rolling finish temperature is 850-890 ℃, and the coiling temperature is 610-680 ℃.
In the invention, the heat treatment temperature, the hot rolling temperature and the coiling temperature are regulated, so that the content of ferric oxide in a layer formed on the surface of the hot forming steel is below 2wt%, and acid washing, shot blasting and annealing treatment can be omitted after the coiling treatment.
According to the invention, the continuous casting ingot is preceded by a steelmaking process.
According to the invention, the conditions of the heat treatment include a temperature of 1270-1320 ℃, preferably 1280-1300 ℃, and a time of 1.3-2.2 hours, preferably 1.6-2 hours.
In the invention, when the heat treatment condition does not meet the above range, the temperature is higher than 1320 ℃, the Fe 2(SixCryREz)O4 layer is completely changed into liquid, and diffuses to the oxide layer along the grain boundary to form a diffusion channel of oxygen atoms and iron atoms, thereby promoting the oxidation of the matrix, reducing the high-temperature oxidation resistance of the matrix, reducing the subsequent descaling effect, enabling the unremoved oxide skin to be pressed into the matrix in the rolling engineering, and reducing the oxidation resistance and the surface quality of the matrix, wherein the temperature is lower than 1260 ℃.
According to the invention, the heat treatment process comprises the steps of carrying out first full-high-pressure water descaling after heat treatment, wherein the descaling water pressure is more than or equal to 20MPa.
According to the invention, the hot rolling process comprises rough rolling and finish rolling.
According to the invention, the rough rolling process comprises the steps of rolling at a starting temperature of 1160-1200 ℃, preferably 1170-1190 ℃, a finishing temperature of 990-1080 ℃, preferably 1030-1050 ℃, 3-7 rough rolling, preferably 4-6 rough rolling, wherein the deformation of each rough rolling is more than or equal to 20%, and then performing second high-pressure water descaling.
In the invention, when the temperatures of the initial rolling and the final rolling of the rough rolling do not meet the above range, the initial rolling temperature is higher than 1200 ℃, so that crystal grains are coarsened to influence the final strength of the material, the initial rolling temperature is lower than 1160 ℃, so that the structure is uneven, the crystal grains grow slowly, the plasticity and the toughness of the material are influenced, the deformation of the material becomes more difficult, the final rolling temperature is higher than 1080 ℃, so that the crystal grains are coarsened to influence the final strength of the material, and the final rolling temperature is lower than 990 ℃, so that the hardness and the strength of the material are higher due to the incompletely recrystallized structure, but the toughness is relatively poor.
According to the invention, the finishing conditions include a start rolling temperature of 900-980 ℃, preferably 850-890 ℃, a finish rolling temperature of 850-890 ℃, preferably 860-880 ℃, and a finish rolling to a target thickness of 2-6mm by 4-7 passes.
In the invention, when the temperatures of the initial rolling and the final rolling of the finish rolling do not meet the above range, the initial rolling temperature is higher than 980 ℃, so that crystal grains are coarsened to influence the final strength of the material, the initial rolling temperature is lower than 900 ℃, the low initial rolling temperature causes uneven structure, slow growth of crystal grains to influence the plasticity and toughness of the material, the final rolling temperature is higher than 890 ℃, coarse austenite crystal grains and mixed crystal structure are easy to generate to influence the final strength of the material, and the final rolling temperature is lower than 850 ℃, so that the structure is uneven and the residual stress is increased.
According to the invention, the temperature of the reeling is 630-650 ℃.
In the invention, when the coiling temperature does not meet the range, the temperature is higher than 680 ℃, the thickness of the surface composite oxide layer is increased, which is unfavorable for the subsequent hot forming process and weakening the welding performance, the temperature is lower than 610 ℃, the content of Fe 2O3 in the composite oxide layer is increased, the oxidation resistance is reduced, and on the other hand, the curling temperature is reduced, so that the substrate generates bainite or martensite, the yield strength is increased, and the subsequent blanking and blanking processes are unfavorable.
In a third aspect, the present invention provides a hot-formed steel produced by the above-described production method.
A fourth aspect of the present invention provides the use of the above-described hot-formed steel for the preparation of parts for automobile and train doors and the like.
The fifth aspect of the invention provides a method for manufacturing parts for automobile and train doors and the like, comprising the step of carrying out hot forming treatment on the hot formed steel.
The direct hot forming comprises the steps of preserving heat of hot forming steel for 4-8min at 900-960 ℃ in air or nitrogen protective atmosphere, and then rapidly transferring the hot forming steel into a mould for hot forming to obtain an automobile part;
The indirect hot forming comprises the steps of carrying out cold stamping preforming on hot forming steel by 10-20%, preserving heat for 4-6min at 850-930 ℃, then rapidly transferring into a die, carrying out pressure maintaining quenching, and completing 80-90% deformation to obtain a part for a train door, wherein the temperature before entering the die is 810-890 ℃, the pressure maintaining pressure is 100-600MPa, and the pressure maintaining time is 10-40s. The prepared parts for the train have good molding quality, no warpage, deformation and cracking, the yield strength is more than 1000MPa, and the tensile strength is more than 1500MPa.
The present invention will be described in detail by examples. In the following examples of the present invention,
The content of each element is measured according to GB/T1467-2008 general rule of metallurgical product chemical analysis method standard;
Porosity was measured from a microstructure photograph of the oxide layer using ImageJ software;
the mechanical properties are measured according to the first part of the tensile test of GB/T228.1-2010 metal material: room temperature test method;
the reliability of the metallographic structure is detected according to GB/T13298-1991 metal microstructure inspection method;
paint film adhesion was measured according to the standard procedure for qualitative adhesion test of ASTM B571 Metal coating;
The raw materials used in the examples and comparative examples are all commercially available.
Example 1
Sequentially carrying out heat treatment, hot rolling and coiling on the continuous casting blank to obtain hot forming steel;
wherein the continuous casting billet comprises 0.25wt% of C, 1.7wt% of Si, 0.3wt% of Al, 1.2wt% of Cr, 0.006wt% of RE, 0.003wt% of S+P, 1.2wt% of Mn, 0.001wt% of B, 0.02wt% of Ti, the balance Fe and other unavoidable impurities, the heat treatment conditions comprise a temperature of 1290 ℃ for 1.8 hours, the first full-high-pressure water descaling, the rough rolling process comprises a rolling start temperature of 1180 ℃ and a rolling finish temperature of 1040 ℃, the intermediate billet is rolled to 18mm after 5 passes of rough rolling, the second full-high-pressure water descaling is carried out, the finish rolling condition comprises a rolling start temperature of 940 ℃, a rolling finish temperature of 870 ℃, the rolling finish rolling to a target thickness of 4mm and a coiling temperature of 640 ℃ to obtain the hot formed steel A1.
Fig. 1 is an SEM image of a dense composite oxide layer of the hot-formed steel prepared in example 1 of the present invention, and it can be seen from the figure that 1 is a Fe 2(SixCryREz)O4 layer and 2 is a Fe 3O4 layer.
Fig. 2 is a matrix structure diagram of the hot-formed steel prepared in example 1 of the present invention, from which it can be seen that 1 (dark gray area) is pearlite and 2 (white area) is ferrite.
FIG. 3 is a drawing showing the microstructure of a hot-formed steel part in example 1 of the present invention, from which it can be seen that the matrix is almost entirely lath-like martensite.
Fig. 4 is an SEM image of the dense composite oxide layer of the automobile part prepared in example 1 of the present invention, and it can be seen from the figure that the structure of the dense composite oxide layer on the surface of the part is not significantly changed and the thickness is only slightly increased after the part is thermoformed.
Fig. 5 is an XRD pattern of the dense composite oxide layer for automobile prepared in example 1 of the present invention, and it can be seen from the figure that the dense composite oxide layer is composed of two phases of Fe 3O4 and Fe 2(SixCryREz)O4.
Examples 2 to 5
A hot-formed steel was produced in the same manner as in example 1 except that the kinds and amounts of the respective elements in the continuously cast slab were different from those in example 1, as shown in Table 1, and the conditions for heat treatment, the course of rough rolling, the conditions for finish rolling and the temperature of coiling were different from those in example 1, as shown in Table 1. Hot-formed steels A2 to A5 were produced, respectively.
Comparative examples 1 to 7
A hot-formed steel was produced in the same manner as in example 1 except that the kinds and amounts of the respective elements in the continuously cast slab were different from those in example 1, as shown in Table 1, and the conditions for heat treatment, the course of rough rolling, the conditions for finish rolling and the temperature of coiling were different from those in example 1, as shown in Table 1. Hot-formed steels D1 to D7 were produced, respectively.
Fig. 6 is an SEM image of the composite oxide layer of the hot-formed steel prepared in comparative example 7 of the present invention, and it can be seen from the image that the surface oxide layer not only has loose Fe 2O3 but also does not form continuous dense Fe 2(SixCryREz)O4, reducing the oxidation resistance of the hot-formed steel.
Fig. 7 is an XRD pattern of the composite oxide layer of the automobile part prepared in comparative example 7 of the present invention, and it can be seen from the figure that 1 (light gray area) is pearlite, 2 (white area) ferrite, and 3 (dark gray area) is carbide.
Fig. 8 is an SEM image of a dense composite oxide layer of an automotive part prepared in comparative example 7 of the present invention, from which it can be seen that three phases of Fe 2O3、Fe3O4 and Fe 2(SixCryREz)O4 exist in the composite oxide layer of the hot-formed steel.
Fig. 9 is a diagram showing a matrix structure of an automobile part prepared in comparative example 7 according to the present invention, and it can be seen from the diagram that the matrix is composed of martensite, ferrite and bainite, and the completion of quenching is not achieved, thereby degrading the mechanical properties of the part.
TABLE 1 variety and amount of elements per weight% in continuous casting billets of examples and comparative examples
Table 1 (follow) preparation process parameters of each example and comparative example
Test example 1
The hot-formed steels produced in examples and comparative examples were tested and the results are shown in Table 2.
TABLE 2
Table 2 (subsequent)
Numbering device Yield strength/MPa Tensile strength/MPa Elongation/%
A1 550 760 22
A2 540 750 20
A3 520 800 18
A4 560 730 21
A5 600 780 24
D1 550 789 13
D2 562 852 12
D3 668 875 11
D4 1056 1354 10
D5 1120 1450 9.8
D6 895 1350 9.9
D7 520 781 15.2
As can be seen from Table 2, the hot-formed steel prepared according to the present invention has a structure in which the content of ferric oxide in the layer formed on the surface of the hot-formed steel is 2wt% or less, the structure of the matrix is ferrite and pearlite, the volume content of ferrite is 56-68%, the volume content of pearlite is 32-44%, and the porosity of the dense composite oxide layer is 0.2-0.8%, so that the hot-formed steel has a suitable yield strength, tensile strength and elongation, and is convenient for cutting and blanking, and the pickling, shot blasting and annealing treatments can be omitted after the coiling treatment in the preparation method. The hot-formed steels produced in comparative examples 1 to 7 had a surface-formed iron sesquioxide content of 2wt% or more, a ferrite content of 42 to 82% by volume, a pearlite content of 15 to 51% by volume, and a matrix structure, other than ferrite and pearlite, also produced other structures such as martensite and bainite structures shown in fig. 93, and a dense composite oxide layer had a porosity of 2.4 to 6.7%, resulting in excessively high yield strength and tensile strength, excessively low elongation, and unfavorable for shearing and blanking.
Test example 2
The hot-formed steels produced in examples and comparative examples were used to prepare automobile parts.
The specific method for preparing the automobile part is as follows:
and (3) under the protection of nitrogen, preserving the temperature of the hot forming steel at 930 ℃ for 6min, and then rapidly transferring the hot forming steel into a die for hot forming to obtain the automobile part.
The results are shown in Table 3.
TABLE 3 Table 3
As is clear from Table 3, the automotive parts prepared by the present application, after heat treatment, contain martensite in an amount of 95% or more by volume and contain or do not contain a small amount of ferrite, bainite or retained austenite in the matrix of the automotive parts, so that they have excellent mechanical properties, yield strength, tensile strength, elongation, surface hardness, oxidation resistance (no oxide layer drop) and paint film adhesion.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims (25)

1.一种热成形钢，其特征在于，所述热成形钢由内到外依次包括基体和致密复合氧化层；1. A hot-formed steel, characterized in that the hot-formed steel comprises a matrix and a dense composite oxide layer from inside to outside; 其中，所述致密复合氧化层中，三氧化二铁的含量为2wt%以下；Wherein, the content of ferric oxide in the dense composite oxide layer is less than 2wt%; 所述致密复合氧化层的孔隙率为0.2-2%；The porosity of the dense composite oxide layer is 0.2-2%; 所述致密复合氧化层由内到外依次包括Fe2(SixCryREz)O4层和Fe3O4层；The dense composite oxide layer includes Fe 2 (Si x Cr y RE z )O 4 layers and Fe 3 O 4 layers from the inside to the outside; 基于所述Fe2(SixCryREz)O4层的总重量，所述Fe2(SixCryREz)O4层含有28-32wt%的Fe、16-20wt%的Si、34-38wt%的Cr和0.01-0.02wt%的RE，其中，0.95≤x+y+z≤1.05，所述RE选自Ce和/或Y；Based on the total weight of the Fe2(SixCryREz)O4 layer, the Fe2(SixCryREz ) O4 layer contains 28-32wt % of Fe , 16-20wt% of Si, 34-38wt% of Cr and 0.01-0.02wt% of RE, wherein 0.95≤x+y+z≤1.05, and the RE is selected from Ce and/or Y; 基于所述Fe3O4层的总重量，所述Fe3O4层含有72-73wt%的Fe；The Fe 3 O 4 layer contains 72-73 wt % of Fe based on the total weight of the Fe 3 O 4 layer; 所述热成形钢的制备方法包括：将连铸坯料依次进行热处理、热轧和卷取，得到热成形钢；The method for preparing hot-formed steel comprises: sequentially subjecting a continuous casting billet to heat treatment, hot rolling and coiling to obtain hot-formed steel; 其中，所述热处理、热轧和卷取的条件使得，所述热成形钢的表面形成的层中，三氧化二铁的含量为2wt%以下；The conditions of heat treatment, hot rolling and coiling are such that the content of ferric oxide in the layer formed on the surface of the hot-formed steel is less than 2 wt %; 所述热处理的温度为1260-1340℃；所述热轧的开轧温度为1160-1200℃和终轧温度为850-890℃；所述卷取的温度为610-680℃。The temperature of the heat treatment is 1260-1340°C; the starting temperature of the hot rolling is 1160-1200°C and the final rolling temperature is 850-890°C; the coiling temperature is 610-680°C. 2.根据权利要求1所述的热成形钢，其中，所述致密复合氧化层的孔隙率为0.2-1%。2. The hot-formed steel according to claim 1, wherein the porosity of the dense composite oxide layer is 0.2-1%. 3.根据权利要求1或2所述的热成形钢，其中，所述致密复合氧化层的厚度为10μm以下。3 . The hot-formed steel according to claim 1 , wherein the thickness of the dense composite oxide layer is 10 μm or less. 4.根据权利要求3所述的热成形钢，其中，所述致密复合氧化层的厚度为8μm以下。The hot-formed steel according to claim 3 , wherein the thickness of the dense composite oxide layer is 8 μm or less. 5.根据权利要求3所述的热成形钢，其中，所述Fe2(SixCryREz)O4层的厚度为0.05-0.2μm。The hot-formed steel according to claim 3, wherein the Fe2 ( SixCryREz ) O4 layer has a thickness of 0.05-0.2 μm . 6.根据权利要求5所述的热成形钢，其中，所述Fe2(SixCryREz)O4层的厚度为0.1-0.15μm。The hot-formed steel according to claim 5, wherein the Fe2 ( SixCryREz ) O4 layer has a thickness of 0.1-0.15 μm . 7.根据权利要求3所述的热成形钢，其中，所述Fe3O4层的厚度为9.8μm以下。7 . The hot-formed steel according to claim 3 , wherein the Fe 3 O 4 layer has a thickness of 9.8 μm or less. 8.根据权利要求7所述的热成形钢，其中，所述Fe3O4层的厚度为8μm以下。8 . The hot-formed steel according to claim 7 , wherein the Fe 3 O 4 layer has a thickness of 8 μm or less. 9.根据权利要求4-8中任意一项所述的热成形钢，其中，所述基体的组织为铁素体和珠光体。9. The hot-formed steel according to any one of claims 4 to 8, wherein the microstructure of the matrix is ferrite and pearlite. 10.根据权利要求9所述的热成形钢，其中，基于所述基体的总体积，所述基体中所述铁素体的体积含量为55-75%，所述珠光体的体积含量为25-45%。10. The hot-formed steel according to claim 9, wherein, based on the total volume of the matrix, the volume content of the ferrite in the matrix is 55-75%, and the volume content of the pearlite is 25-45%. 11.根据权利要求4-8中任意一项的所述的热成形钢，其中，所述热成形钢的屈服强度为500-600MPa、抗拉强度为700-800MPa和延伸率为18-24%。11. The hot-formed steel according to any one of claims 4 to 8, wherein the yield strength of the hot-formed steel is 500-600 MPa, the tensile strength is 700-800 MPa and the elongation is 18-24%. 12.根据权利要求1或2所述的热成形钢，其中，基于所述热成形钢的总重量，所述热成形钢含有0.12-0.4wt%的C、1-2wt%的Si、0.01-0.5wt%的Al、0.5-1.6wt%的Cr、0.003-0.008wt%的所述RE、小于0.008wt%的S+P、不大于2wt%的Mn、不大于0.004wt%的B、不大于0.1wt%的Ti、93.381-96.698wt%的Fe+杂质。12. The hot-formed steel according to claim 1 or 2, wherein the hot-formed steel contains 0.12-0.4wt% of C, 1-2wt% of Si, 0.01-0.5wt% of Al, 0.5-1.6wt% of Cr, 0.003-0.008wt% of RE, less than 0.008wt% of S+P, not more than 2wt% of Mn, not more than 0.004wt% of B, not more than 0.1wt% of Ti, and 93.381-96.698wt% of Fe+impurities, based on the total weight of the hot-formed steel. 13.根据权利要求12所述的热成形钢，其中，基于所述热成形钢的总重量，所述热成形钢含有0.2-0.3wt%的C、1.5-1.9wt%的Si、0.2-0.4wt%的Al、1-1.5wt%的Cr、0.004-0.008wt%的所述RE、小于0.005wt%的S+P、不大于1.4wt%的Mn、不大于0.002wt%的B、不大于0.03wt%的Ti、94.455-96.0842wt%的Fe+杂质。13. The hot-formed steel according to claim 12, wherein the hot-formed steel contains 0.2-0.3wt% of C, 1.5-1.9wt% of Si, 0.2-0.4wt% of Al, 1-1.5wt% of Cr, 0.004-0.008wt% of the RE, less than 0.005wt% of S+P, not more than 1.4wt% of Mn, not more than 0.002wt% of B, not more than 0.03wt% of Ti, and 94.455-96.0842wt% of Fe+impurities, based on the total weight of the hot-formed steel. 14.一种权利要求1-13中任意一项所述的热成形钢的制备方法，其特征在于，所述制备方法包括：将连铸坯料依次进行热处理、热轧和卷取，得到热成形钢；14. A method for preparing hot-formed steel according to any one of claims 1 to 13, characterized in that the method comprises: subjecting the continuous casting billet to heat treatment, hot rolling and coiling in sequence to obtain the hot-formed steel; 其中，所述热处理、热轧和卷取的条件使得，所述热成形钢的表面形成的层中，三氧化二铁的含量为2wt%以下；The conditions of heat treatment, hot rolling and coiling are such that the content of ferric oxide in the layer formed on the surface of the hot-formed steel is less than 2 wt %; 所述热处理的温度为1260-1340℃；所述热轧的开轧温度为1160-1200℃和终轧温度为850-890℃；所述卷取的温度为610-680℃。The temperature of the heat treatment is 1260-1340°C; the starting temperature of the hot rolling is 1160-1200°C and the final rolling temperature is 850-890°C; the coiling temperature is 610-680°C. 15.根据权利要求14所述的制备方法，其中，所述热处理的条件包括：温度为1270-1320℃，时间为1.3-2.2h。15. The preparation method according to claim 14, wherein the heat treatment conditions include: temperature of 1270-1320°C and time of 1.3-2.2h. 16.根据权利要求15所述的制备方法，其中，所述热处理的条件包括：温度为1280-1300℃，时间为1.6-2h。16. The preparation method according to claim 15, wherein the heat treatment conditions include: temperature of 1280-1300°C and time of 1.6-2h. 17.根据权利要求14-16中任意一项所述的制备方法，其中，所述热处理的过程包括：热处理后进行第一次全高压水除鳞。17. The preparation method according to any one of claims 14 to 16, wherein the heat treatment process comprises: performing a first full high-pressure water descaling after the heat treatment. 18.根据权利要求17所述的制备方法，其中，所述热轧的过程包括：粗轧和精轧。18. The preparation method according to claim 17, wherein the hot rolling process comprises: rough rolling and finish rolling. 19.根据权利要求18所述的制备方法，其中，所述粗轧的过程包括：开轧温度为1160-1200℃；终轧温度为990-1080℃；经过3-7道次粗轧；而后进行第二次全高压水除鳞。19. The preparation method according to claim 18, wherein the rough rolling process comprises: a starting rolling temperature of 1160-1200°C; a final rolling temperature of 990-1080°C; 3-7 rough rolling passes; and then a second full high-pressure water descaling. 20.根据权利要求19所述的制备方法，其中，所述粗轧的过程包括：开轧温度为1170-1190℃；终轧温度为1030-1050℃，经过4-6道次粗轧，而后进行第二次全高压水除鳞。20. The preparation method according to claim 19, wherein the rough rolling process comprises: a starting rolling temperature of 1170-1190°C; a final rolling temperature of 1030-1050°C, 4-6 passes of rough rolling, and then a second full high-pressure water descaling. 21.根据权利要求18-20中任意一项所述的制备方法，其中，所述精轧的条件包括：开轧温度为900-980℃；终轧温度为850-890℃；经过4-7道次精轧。21. The preparation method according to any one of claims 18 to 20, wherein the conditions for the finish rolling include: a starting rolling temperature of 900-980°C; a final rolling temperature of 850-890°C; and 4-7 passes of finish rolling. 22.根据权利要求21所述的制备方法，其中，所述精轧的条件包括：开轧温度为930-950℃；终轧温度为860-880℃。22. The preparation method according to claim 21, wherein the conditions of the finish rolling include: a starting rolling temperature of 930-950°C; and a final rolling temperature of 860-880°C. 23.根据权利要求21所述的制备方法，其中，所述卷取的温度为630-650℃。23. The preparation method according to claim 21, wherein the coiling temperature is 630-650°C. 24.一种权利要求1-13中任意一项所述的热成形钢在制备汽车和火车下车门用零件中的应用。24. Use of the hot-formed steel according to any one of claims 1 to 13 in the manufacture of parts for lower doors of automobiles and trains. 25.一种汽车与火车下车门等用零件的制备方法，该方法包括：将权利要求1-13中任意一项所述的热成形钢进行热成形处理。25. A method for preparing parts for automobile and train lower doors, etc., the method comprising: subjecting the hot-formed steel according to any one of claims 1 to 13 to hot-forming treatment.
CN202410539717.7A 2024-04-30 2024-04-30 Hot forming steel and preparation method and application thereof, preparation method of parts for automobile and train lower doors and the like Active CN118441205B (en)

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CN1978688A (en) * 2005-12-06 2007-06-13 鞍钢股份有限公司 Hot-rolled black skin surface steel plate with firmly adhered oxide layer and manufacturing method thereof
CN116837296A (en) * 2023-08-22 2023-10-03 北京理工大学重庆创新中心 Preparation method and application of anti-oxidation hot forming steel suitable for thick specification

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CN113832388A (en) * 2020-06-23 2021-12-24 上海梅山钢铁股份有限公司 Pickling-free hot-rolled steel plate with yield strength of 220MPa and manufacturing method thereof
CN116949360A (en) * 2023-07-31 2023-10-27 北京科技大学 Thin slab continuous casting and rolling 2000MPa grade high-strength plastic oxidation-resistant hot forming steel and production method thereof

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1978688A (en) * 2005-12-06 2007-06-13 鞍钢股份有限公司 Hot-rolled black skin surface steel plate with firmly adhered oxide layer and manufacturing method thereof
CN116837296A (en) * 2023-08-22 2023-10-03 北京理工大学重庆创新中心 Preparation method and application of anti-oxidation hot forming steel suitable for thick specification

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