CN113637905B - Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof - Google Patents
Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof Download PDFInfo
- Publication number
- CN113637905B CN113637905B CN202110857186.2A CN202110857186A CN113637905B CN 113637905 B CN113637905 B CN 113637905B CN 202110857186 A CN202110857186 A CN 202110857186A CN 113637905 B CN113637905 B CN 113637905B
- Authority
- CN
- China
- Prior art keywords
- steel
- temperature
- rolled
- cold
- thickness
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910000870 Weathering steel Inorganic materials 0.000 title claims abstract description 30
- 238000002360 preparation method Methods 0.000 title abstract description 10
- 238000005096 rolling process Methods 0.000 claims abstract description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 19
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 11
- 238000005098 hot rolling Methods 0.000 claims abstract description 10
- 239000000126 substance Substances 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims abstract description 7
- 229910052742 iron Inorganic materials 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 6
- 238000003466 welding Methods 0.000 claims description 19
- 238000000137 annealing Methods 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 6
- 238000005097 cold rolling Methods 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 4
- 238000005266 casting Methods 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 238000010583 slow cooling Methods 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 abstract description 70
- 239000010959 steel Substances 0.000 abstract description 70
- 230000007797 corrosion Effects 0.000 abstract description 34
- 238000005260 corrosion Methods 0.000 abstract description 34
- 238000000034 method Methods 0.000 abstract description 16
- 238000004519 manufacturing process Methods 0.000 abstract description 11
- 238000012545 processing Methods 0.000 abstract description 3
- 239000010949 copper Substances 0.000 description 23
- 239000011572 manganese Substances 0.000 description 12
- 230000008569 process Effects 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 229910052698 phosphorus Inorganic materials 0.000 description 8
- 238000005728 strengthening Methods 0.000 description 8
- 229910052802 copper Inorganic materials 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 239000010703 silicon Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 229910000859 α-Fe Inorganic materials 0.000 description 6
- 229910052804 chromium Inorganic materials 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 229910001562 pearlite Inorganic materials 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 239000010960 cold rolled steel Substances 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 238000005204 segregation Methods 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000009931 harmful effect Effects 0.000 description 2
- 201000009240 nasopharyngitis Diseases 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000004886 process control Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 229910052841 tephroite Inorganic materials 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 206010057040 Temperature intolerance Diseases 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000008543 heat sensitivity Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical compound [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Images
Classifications
-
- 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
-
- 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
- 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
- C21D8/0236—Cold rolling
-
- 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
- C21D8/0242—Flattening; Dressing; Flexing
-
- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0273—Final recrystallisation annealing
-
- 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
- C22C38/04—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
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- 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
- C21D2211/009—Pearlite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention relates to the field of steel smelting, relates to production and manufacturing of cold-rolled weathering steel for automobiles, and particularly relates to low-cost weathering steel for 310 MPa-grade cold-rolled automobiles and a preparation method thereof. The weathering steel comprises the following chemical components in percentage by weight: c: 0 to 0.09, 0.10 to 0.40 Si, Mn: 0.20-0.50, P is 0.05-0.12, S: 0 to 0.015, Al: 0.010-0.030, Cu: 0.2 to 0.4, and the balance of Fe and inevitable impurities. The method mainly adopts measures of controlling the hot rolling in-furnace time, dephosphorizing high-pressure water pressure, rough rolling temperature and the like, and reduces the occurrence probability and degree of Cu brittleness and iron scale. The steel has the characteristics of low cost, excellent surface quality, excellent processing forming and atmospheric corrosion resistance and the like, and can be applied to industries requiring corrosion resistance, such as automobiles, household appliances and the like.
Description
Technical Field
The invention relates to the field of steel smelting, relates to production and manufacturing of cold-rolled weathering steel for automobiles, and particularly relates to low-cost weathering steel for 310 MPa-grade cold-rolled automobiles and a preparation method thereof.
Background
Atmospheric corrosion is the interaction of a material with its surrounding atmospheric environment, and ordinary ferrous materials are easily corroded (rusted) in the atmosphere. According to statistics, 1/6 in the world annual steel yield is lost due to corrosion, and the direct economic loss of China annually caused by steel corrosion exceeds 100 billion yuan.
The weathering steel, i.e. the atmospheric corrosion resistant steel, is made by adding a small amount of alloy elements into steel, so that a layer of compact amorphous spinel oxide film with the thickness of about 50-100 μm and good adhesion with the base metal is formed between the rust layer and the base, and because of the existence of the compact oxide film, oxygen and water in the atmosphere are prevented from permeating into the steel base, the deep development of rust to the steel material is slowed down, and the atmospheric corrosion resistance of the steel material is greatly improved. The weather-resistant steel has the atmospheric corrosion resistance 2-8 times that of common steel, and the longer the service life is, the more prominent the corrosion resistance is.
With the vigorous development of the automobile industry, the requirement of the automobile industry on the corrosion resistance of the automobile steel material is higher and higher, and meanwhile, a plurality of automobile parts cannot be coated due to the influence of the automobile structure and the like, so that the requirement of the parts on the corrosion resistance of the material is higher. The weathering steel prevents the matrix from being further corroded by the external environment by a compact rust layer generated by the weathering steel, thereby achieving the purpose of coating-free.
In the prior art, the components and the production process of hot-rolled weathering steel have been studied more, but the production and preparation methods of cold-rolled weathering steel, in particular cold-rolled weathering steel used in the automobile industry, are relatively few.
The patent with the application number of 201910703774.3 discloses cold-rolled weathering steel and a preparation method thereof, wherein the cold-rolled weathering steel comprises the following chemical components in percentage by weight: c: 0.05 to 0.08%, Si: 0.25 to 0.40%, Mn: 0.25-0.40%, P: 0.060 to 0.100%, S: less than or equal to 0.020%, Als: 0.008-0.030%, Ni: 0.12 to 0.20%, Cu: 0.25 to 0.40%, Cr: 0.30-0.50%, N: the steel is less than or equal to 0.0080 percent, the balance of Fe and inevitable impurities, and through reasonable chemical composition design, noble metal alloys such as Ti, Nb, B and the like are not added, and through the control of hot rolling, cold rolling, continuous annealing and leveling processes, cold-rolled weather-resistant steel with good surface quality is obtained, the yield strength is more than or equal to 350MPa, the tensile strength is more than or equal to 500MPa, the elongation of A50 is more than or equal to 30 percent, and the steel has good atmospheric corrosion resistance and welding performance. However, the patent adds more noble metals such as Cr, Ni and the like, and the alloy cost is high.
A patent with application number of 202010769262.X discloses 400MPa high-silicon weathering steel and a preparation method and application thereof, wherein the preparation method comprises the following steps: c is less than or equal to 0.12%, Si: 1.20-2.00%, Mn is less than or equal to 1.50%, P: 0.005-0.030%, S is less than or equal to 0.015%, Cr: 0.20 to 0.80%, Ni: 0.10 to 0.40%, Cu: 0.20-0.60%, Als is more than or equal to 0.010%, and the balance is Fe and inevitable impurities, the atmospheric corrosion resistance index I of the high-silicon weathering steel reaches 8.05-9.16, which is obviously higher than 6.0, so that the high-silicon weathering steel has excellent atmospheric corrosion resistance, can be used in dry areas for bare or light coating, can be widely used in the fields of buildings, bridge construction or vehicle manufacturing, and has good application value. However, the patent adds more noble metals such as Cr, Ni, etc., the alloy cost is higher, and the high silicon composition design is not favorable for controlling the surface quality of the product, and in the product preparation process, in order to reduce the influence of the surface quality caused by the high silicon content, a more strict process control is required, thereby further increasing the preparation cost of the product.
The document with the application number of 202010950167.X discloses a production method of cold-rolled weather-resistant steel with the yield strength of more than 310MPa, and the method obtains a cold-rolled weather-resistant steel strip product with the thickness of 0.5-2.5 mm by reasonable chemical composition design, steelmaking smelting, hot rolling process, acid rolling process and continuous annealing process control, wherein the internal tissues of the cold-rolled weather-resistant steel product are ferrite, pearlite and cementite; the mechanical property result of the finished cold-rolled weather-resistant steel product is that the yield strength is more than or equal to 310MPa, the tensile strength is more than or equal to 450MPa, the elongation after fracture is more than or equal to 28 percent, the mechanical property is stable, the forming and atmospheric corrosion resistance of the steel strip product are excellent, and the steel strip product can be applied to the relevant fields of air preheaters, plate heat exchangers and the like. However, the addition of 0.10% to 0.25% of Ni element and 0.3% to 0.45% of Cr element results in higher alloy cost, and no data on the atmospheric corrosion resistance of the steel sheet is shown in the method.
Disclosure of Invention
Technical problem to be solved
The invention aims to provide low-cost weathering steel for 310MPa cold-rolled automobiles and a manufacturing method thereof, and aims to solve the problems of more alloy addition and high cost of the existing weathering steel. The steel has the characteristics of low cost, excellent surface quality, excellent processing forming and atmospheric corrosion resistance and the like, is particularly suitable for structural members which cannot be coated in automobiles, and can also be used in industries which have requirements on corrosion resistance, such as household appliances and the like.
(II) technical scheme
The invention aims to overcome the defects in the prior art and provides a low-cost weathering steel for a 310MPa cold-rolled automobile and a manufacturing method thereof, wherein the thickness of the weathering steel is 0.7-2.0 mm.
The 310 MPa-grade cold-rolled low-cost weathering steel for the automobile has the advantages that the yield strength is 310-380 MPa, the tensile strength is 400-480 MPa, the elongation A is more than 36% (a tensile test sample adopts a P4 sample of GB-T228.1), the metallographic structure is ferrite and a small amount of pearlite, the grain size reaches more than 10 grade, and the atmospheric corrosion resistance is less than or equal to 60% relative to the Q235 corrosion rate.
The measures for realizing the aim are as follows:
a low-cost weathering steel for 310MPa cold-rolled automobiles comprises the following chemical components in percentage by weight: c: not more than 0.09, Si 0.10-0.40, Mn: 0.20-0.50, 0.05-0.12 of P, less than or equal to 0.015 of S, Als: 0.010-0.030, Cu: 0.2 to 0.4, and the balance of Fe and inevitable impurities.
Preferably: the weight percentage content of C is 0.03-0.07.
Preferably: the weight percentage content of Si is 0.15-0.35.
Preferably: the Mn content is 0.30-0.45 wt%.
Preferably: the weight percentage content of P is 0.07-0.11.
Preferably: the Cu content is 0.25-0.35 wt%.
The invention relates to low-cost weathering steel for 310MPa cold-rolled automobiles, which is prepared by the following steps:
(1) adopting desulfurized molten iron, smelting and casting the product into a plate blank according to preset components;
(2) heating the plate blank, and then carrying out hot continuous rolling, wherein the hot rolling heating temperature is 1230-1270 ℃, and the temperature is kept for 130-160 min; carrying out dephosphorization, wherein the high-pressure water pressure is over 180 MPa; carrying out rough rolling on the heat-insulated plate blank, wherein the rough rolling temperature is 1040-1060 ℃; carrying out finish rolling at the finishing temperature of 850-880 ℃; coiling, wherein the coiling temperature is set according to the thickness of a hot-rolled finished product: when the thickness of the finished product is less than 3mm, the coiling temperature is 676-684 ℃; when the thickness of the finished product is less than or equal to 5mm and is less than or equal to 3mm, the coiling temperature is 656-664 ℃; when the thickness of the finished product is more than 5mm, the coiling temperature is 636-644 ℃.
(3) And (3) rolling the hot rolled plate after acid washing by an acid washing continuous rolling unit, wherein the cold rolling reduction rate is 50-70%, and a laser welding machine is adopted for unit welding.
(4) And annealing in a continuous annealing unit, wherein the continuous annealing temperature is 795-805 ℃, the slow cooling temperature is 645-655 ℃, the fast cooling temperature is 445-455 ℃, the overaging temperature is 420-360 ℃, the final cooling temperature is 170-180 ℃, and the annealing speed of the heating furnace is kept in the range of 160-250 m/min.
(5) Leveling, setting the leveling elongation according to the thickness of a cold-rolled finished product: the thickness of the finished product is less than or equal to 1.2mm, and the leveling elongation is 1.0-1.4%; the thickness of the finished product is more than 1.2mm, and the flat elongation is 1.4-1.8%.
The main elements and the process of the invention have the following functions and mechanisms:
c: carbon is a basic element in steel, and is also the most economical and effective strengthening element, and the strength of the steel sheet is obviously increased with the increase of the content of C, but the plasticity and the formability of the steel sheet are reduced, the welding performance is deteriorated, and the corrosion resistance of the steel sheet is influenced. Therefore, the C content is controlled to be less than 0.09%, and preferably, the C content is 0.03-0.07%.
Si: silicon is a solid solution strengthening element, is an economical strengthening element and has strong solid solution strengthening effect. The Si element can be used as a reducing agent and a deoxidizing agent to be added into steel in the smelting process, the hardenability and tempering resistance of the steel can be improved, the increase of the Si element can reduce the overall corrosion resistance rate of a steel plate, the Si element can be matched with Cu, P and other elements in the steel to improve the corrosion resistance of the steel, but the low-temperature toughness and the welding performance of the steel can be reduced if the Si element is too high, and meanwhile, the Si element can easily form a compact oxide layer Mn2SiO4 on the surface of the steel plate, so that the surface quality of the material is seriously influenced. Therefore, the Si content is controlled to be 0.10 to 0.40%, preferably 0.15 to 0.35%.
Mn: manganese is a relatively economic strengthening element and mainly plays a role in solid solution strengthening and grain refinement. While the strength of the steel can be improved by adding a proper amount of Mn, excessive Mn causes coarsening of crystal grains, thereby causing temper brittleness, increasing the heat sensitivity of the steel, and deteriorating the center segregation of the steel sheet. Therefore, the Mn content is controlled to be 0.20 to 0.50%, preferably 0.30 to 0.45%.
P: phosphorus is a solid solution strengthening element, is a relatively economic strengthening element, can greatly improve the strength and hardness of steel, and is easy to segregate due to excessively high P element, so that the plasticity, low-temperature toughness and welding performance of the steel are obviously reduced. The element P is one of the most effective alloy elements for improving the weather resistance of steel, and has a special effect in promoting the rust layer to have amorphous properties. When P and Cu are added into the steel in combination, excellent synergistic weather resisting effect is shown, and under the condition of atmospheric corrosion, P in the steel is an anode depolarizer and can accelerate uniform dissolution of the steel and Fe2+The oxidation rate of (A) is favorable for forming a uniform FeO0H rust layer on the surface of steel and promoting the generation of FeO rich in amorphous light-base iron oxidex(OH)3-2XThe protective film is compact, thereby being a protective barrier for preventing corrosive media from entering a steel matrix and preventing the interior of the steel from being corroded by atmosphere. Therefore, considering the contribution of P element to the strength, the content of P is controlled to be 0.05-0.12%, preferably 0.07-0.11%.
S: sulfur is a harmful element. The S element in the steel is easy to form MnS inclusion with the Mn element, a pitting corrosion source is formed in the steel, the weather resistance of the steel plate is deteriorated, and meanwhile, the plasticity and the toughness of the steel are reduced. Therefore, the S content is controlled to 0.015% or less.
Al: in the refining step, the steel is deoxidized to remove oxygen dissolved in the molten steel, and Al suppresses solid solution of nitrogen in ferrite to form AlN to suppress coarsening of crystal grains. If the Al content is too high, inclusions in the steel increase, and the toughness of the steel decreases. Therefore, the Al content is controlled to be 0.01-0.03%.
Cu: copper is the most prominent element for improving the weather resistance of the steel plate, a barrier layer mainly comprising Cu and P can be formed between the substrate and the rust layer, the barrier layer is firmly combined with the substrate to have good protection on the steel plate, and in addition, Cu can offset the harmful effect of impurity element S in the steel plate and has important effect on the corrosion resistance of the steel plate. However, excessive Cu addition causes a problem of "Cu brittleness". Therefore, the Cu content is controlled to 0.2 to 0.4%, preferably 0.25 to 0.35%.
The invention controls the furnace time of the hot rolled plate blank to be kept at the temperature of 130-150 min, the dephosphorization high-pressure water pressure to be more than 180MPa and the rough rolling temperature to be 1040-1060 ℃, and mainly aims to reduce the occurrence of Cu brittleness. When the heating temperature of the plate blank is higher than the melting point (1083 ℃) of the Cu element, the precipitated copper-rich phase is in a molten state and reaches a certain degree, and a Cu brittle defect of a crack-shaped crack is formed on the surface in the deformation process. Therefore, the in-furnace time of the plate blank is reduced, the in-furnace time is controlled to be 130-150 min, and the diffusion of Cu elements in the grain boundary is reduced. And secondly, controlling the rough rolling temperature to be 1040-1060 ℃, avoiding the melting point temperature of the Cu element, and reducing the melting of the Cu element. Finally, Cu element is easy to enrich at the interface of the iron sheet and the matrix in the hot rolling and heating process, and Si element is easy to form a compact oxide layer Mn2SiO4 on the surface to influence the surface quality of the steel plate, so the descaling effect is ensured and the pressing-in of the iron sheet is eliminated by enhancing the descaling pressure of a rough rolling area. When producing common steel grades, the dephosphorization high-pressure water pressure is below 130MPa, so the hot rolling dephosphorization high-pressure water pressure is controlled to be above 180 MPa.
The coiling temperature adopted by the invention is set according to the thickness of the hot-rolled finished product, and is used for ensuring the uniformity and stability of the mechanical properties of cold-rolled steel sheets with different thickness specifications. The coiling temperature is controlled to be 636-.
According to the invention, a laser welding machine is adopted for welding continuous production, mainly because the content of P in the weathering steel is 0.05-0.12% of that of a common cold-rolled steel plate, the content of P in the weathering steel is 6-10 times of that of a common cold-rolled steel plate, grain boundary segregation in the welding process P is easy to cause grain boundary cold-brittle cracking, and the risk of cracking at a welding seam during rolling is high, so that a laser welding process is preferred, and the welding seam is subjected to heat treatment after welding, the welding seam structure is improved, the ingredient segregation is reduced, and the welding seam cracking in the rolling process is avoided, so that the belt breakage is further caused.
The continuous annealing is adopted, the continuous annealing temperature is 795-805 ℃, the annealing temperature is improved mainly due to the fact that the surface quality of the continuous annealing is better controlled, and meanwhile, the mechanical property target of a product is combined, the fully recrystallized structure is promoted and obtained, and the stamping performance of the steel plate is improved.
The invention sets the leveling elongation rate according to the thickness of the cold-rolled product, and aims to ensure the uniformity and stability of the mechanical properties of cold-rolled steel sheets with different thickness specifications and endow the steel sheets with good surface quality and roughness.
(III) advantageous effects
The invention has the following beneficial effects:
according to the invention, only cheap alloy elements such as Mn, Si, P and the like are added, and precious metals such as Cr, Ni, Ti and the like are not added, so that the manufacturing cost is greatly reduced; measures such as controlling the hot rolling in-furnace time, removing phosphorus high pressure water pressure, rough rolling temperature and the like are adopted, so that the occurrence probability and degree of Cu brittleness and iron scale are reduced, and the surface quality of the steel plate is improved; the key point is to design the hot rolling coiling temperature and the cold rolling leveling elongation rate process according to the thickness of the finished product, thereby ensuring the uniformity and stability of the mechanical properties of the steel plates with different thicknesses of the finished product. The steel has the characteristics of low cost, excellent surface quality, excellent processing forming and atmospheric corrosion resistance and the like, is particularly suitable for structural members which cannot be coated in automobiles, and can also be used in industries which have requirements on corrosion resistance, such as household appliances and the like.
Drawings
FIG. 1 is a metallographic phase magnified 200 times observation of the steel plate of the present invention, and the metallographic structure is ferrite plus a small amount of pearlite.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiments of the invention are produced according to the following steps:
(1) adopting desulfurized molten iron, smelting and casting the product into a plate blank according to preset components;
(2) heating the plate blank, and then carrying out hot continuous rolling, wherein the hot rolling heating temperature is 1230-1270 ℃, and the temperature is kept for 130-160 min; carrying out dephosphorization, wherein the high-pressure water pressure is over 180 MPa; roughly rolling the plate blank after heat preservation, wherein the rough rolling temperature is 1040-1060 ℃; carrying out finish rolling at the finishing temperature of 850-880 ℃; coiling, setting the coiling temperature according to the thickness of the hot rolled finished product: when the thickness of the finished product is less than 3mm, the coiling temperature is 676-684 ℃; when the thickness of the finished product is less than or equal to 5mm and is less than or equal to 3mm, the coiling temperature is 656-664 ℃; when the thickness of the finished product is more than 5mm, the coiling temperature is 636-644 ℃.
(3) And (3) rolling the hot rolled plate after the hot rolled plate is acid-washed by an acid-washing continuous rolling mill, wherein the cold rolling reduction rate is 50-70%, and a laser welding machine is adopted for welding the mill.
(4) Annealing treatment is carried out in a continuous annealing unit, the continuous annealing temperature is 795-805 ℃, the slow cooling temperature is 645-655 ℃, the fast cooling temperature is 445-455 ℃, the overaging temperature is 420-360 ℃, the final cooling temperature is 170-180 ℃, and the annealing speed of a heating furnace is kept in the range of 160-250 m/min.
(5) Leveling, setting the leveling elongation according to the thickness of a cold-rolled finished product: the thickness of the finished product is less than or equal to 1.2mm, and the leveling elongation is 1.0-1.4%; the thickness of the finished product is more than 1.2mm, and the flat elongation is 1.4-1.8%.
To further illustrate the technical effect of the present invention, the composition parameters of the examples are shown in the following table.
TABLE 1 list of chemical compositions (wt%) of inventive and comparative examples
TABLE 2 List of the main process parameters of the examples of the invention and the comparative examples
TABLE 3 Main Process parameter List for inventive and comparative examples
The products of the above examples and comparative examples were tested separately and the results were as follows:
TABLE 3 Table of the results of mechanical Properties measurements of the examples of the invention and the comparative examples
The corrosion resistance tests of the above examples and comparative examples are carried out, Q235 is used as a comparative sample, the chemical components of the test are shown in Table 4, the corrosion resistance tests are carried out according to TB/T2375, the test time is 72h, and the test results of the corrosion resistance are shown in Table 5.
TABLE 4Q235 chemical composition
TABLE 5 Corrosion resistance test results
The tensile test samples of the mechanical property are P4 samples of GB-T228.1. As can be seen from the examples 1-10 in Table 3, the economic weather-resistant steel plate produced by the invention has the advantages of yield strength of 310-380 MPa, tensile strength of 400-480 MPa, elongation A of more than 36%, a metallographic structure of ferrite and a small amount of pearlite, grain size of more than 10 grade, atmospheric corrosion resistance of less than or equal to 60 percent relative to Q235 corrosion rate, and good atmospheric corrosion resistance. Meanwhile, the performance of the steel plates with different finished product thicknesses is kept stable. As can be seen from the comparative example, in the comparative example 1, the edge Cu of the steel plate is seriously brittle due to the higher rough rolling temperature, so that the surface quality is influenced; comparative example 2, the performance was higher due to the addition of excessive Mn element. The above examples are merely preferred examples and are not intended to limit the embodiments of the present invention. As shown in fig. 1, the metallographic phase of the steel plate manufactured in example 1 of the present invention is observed by magnifying the metallographic phase by 200 times, and the metallographic structure is ferrite + a small amount of pearlite, and the microstructure is compact and consistent with macroscopic data, which shows that the technical effect of the present invention is significant.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (2)
1. The low-cost weathering steel for the 310MPa cold-rolled automobile is characterized by comprising the following chemical components in percentage by weight: c: 0 to 0.09, 0.10 to 0.40 Si, Mn: 0.20-0.50, P is 0.05-0.12, S: 0-0.015, Al: 0.010-0.030, Cu: 0.2 to 0.4, and the balance of Fe and inevitable impurities;
the low-cost weathering steel for the 310MPa cold-rolled automobile is prepared by the following steps:
(1) adding the product into a molten desulfurized iron according to predetermined components, smelting and casting to form a plate blank;
(2) heating the plate blank, and then carrying out hot continuous rolling, wherein the hot rolling heating temperature is 1230-1270 ℃, and the temperature is kept for 130-160 min; carrying out dephosphorization, wherein the high-pressure water pressure is over 180 MPa; carrying out rough rolling on the heat-insulated plate blank, wherein the rough rolling temperature is 1040-1060 ℃; carrying out finish rolling at the finishing temperature of 850-880 ℃; coiling, setting the coiling temperature according to the thickness of the hot rolled finished product: when the thickness of the finished product is less than 3mm, the coiling temperature is 676-684 ℃; when the thickness of the finished product is less than or equal to 5mm and less than or equal to 3mm, the coiling temperature is 656-664 ℃; when the thickness of the finished product is more than 5mm, the coiling temperature is 636-644 ℃;
(3) the hot rolled plate is rolled after being acid-washed by an acid-washing continuous rolling mill, the cold rolling reduction rate is 50-70%, and a laser welding machine is adopted for welding;
(4) annealing treatment is carried out in a continuous annealing unit, the continuous annealing temperature is 795-805 ℃, the slow cooling temperature is 645-655 ℃, the fast cooling temperature is 445-455 ℃, the overaging temperature is 420-360 ℃, the final cooling temperature is 170-180 ℃, and the annealing speed of a heating furnace is kept in the range of 160-250 m/min;
(5) leveling, setting the leveling elongation according to the thickness of a cold-rolled finished product: the thickness of the finished product is less than or equal to 1.2mm, and the leveling elongation is 0.8-1.2%; the thickness of the finished product is larger than 1.2mm, and the flat elongation is 1.2-1.6%.
2. The low-cost weathering steel for cold-rolled automobiles with grade 310MPa according to claim 1, wherein the content of C is 0.03 to 0.07 weight percent; the weight percentage content of Si is 0.15-0.35; the weight percentage content of Mn is 0.30-0.45; the weight percentage content of P is 0.07-0.11; the Cu content is 0.25-0.35 wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110857186.2A CN113637905B (en) | 2021-07-28 | 2021-07-28 | Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110857186.2A CN113637905B (en) | 2021-07-28 | 2021-07-28 | Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113637905A CN113637905A (en) | 2021-11-12 |
| CN113637905B true CN113637905B (en) | 2022-06-17 |
Family
ID=78418660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110857186.2A Active CN113637905B (en) | 2021-07-28 | 2021-07-28 | Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113637905B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115418566B (en) * | 2022-08-30 | 2023-09-08 | 日照钢铁控股集团有限公司 | Manufacturing method of low-cost high-P weather-resistant steel |
| CN115679212B (en) * | 2022-10-28 | 2023-09-22 | 武汉钢铁有限公司 | Novel high-strength corrosion-resistant steel for railway open car and preparation method thereof |
| CN116219306A (en) * | 2022-12-20 | 2023-06-06 | 攀钢集团攀枝花钢铁研究院有限公司 | Antimony-containing weather-resistant steel for low-cost 800 MPa-level photovoltaic bracket and preparation method thereof |
| CN117181810B (en) * | 2023-09-26 | 2024-04-19 | 江苏甬金金属科技有限公司 | Preparation method of ultrathin cold-rolled weather-resistant steel strip |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4105962B2 (en) * | 2003-02-28 | 2008-06-25 | 新日本製鐵株式会社 | Sulfuric acid dew-point corrosion steel cold-rolled steel sheet for air preheater heat transfer element and manufacturing method thereof |
| CN100334248C (en) * | 2005-12-30 | 2007-08-29 | 武汉钢铁(集团)公司 | Colding rolling weather resistant depth impacting plate for vehicle and mfg. method thereof |
| JP4954922B2 (en) * | 2008-03-05 | 2012-06-20 | 新日本製鐵株式会社 | High-strength hot-rolled steel sheet with excellent fatigue characteristics and method for producing the same |
| KR101087420B1 (en) * | 2008-12-24 | 2011-11-25 | 현대제철 주식회사 | High strength hot rolled steel sheet and manufacturing method |
| CN101709426A (en) * | 2009-12-15 | 2010-05-19 | 武汉钢铁(集团)公司 | Economical weathering steel for transmission tower and preparation method thereof |
| JP6048385B2 (en) * | 2013-12-12 | 2016-12-21 | Ｊｆｅスチール株式会社 | Steel for crude oil tanks and crude oil tanks with excellent corrosion resistance |
| RU2578618C1 (en) * | 2014-11-18 | 2016-03-27 | Публичное акционерное общество "Северсталь" (ПАО "Северсталь") | Manufacturing method of strips of low-alloyed weld steel |
| KR101657833B1 (en) * | 2014-12-24 | 2016-09-20 | 주식회사 포스코 | Aluminum clad steel sheet having excellent high temperature brazing-resistance and strength and manufacturing method thereof |
| CN110229948A (en) * | 2019-06-04 | 2019-09-13 | 甘肃酒钢集团宏兴钢铁股份有限公司 | A kind of Cu, P, Cr, Ni class cold rolling atmospheric corrosion resistance steel band and its production method |
| CN112126855A (en) * | 2020-09-11 | 2020-12-25 | 山东钢铁集团日照有限公司 | Production method of cold-rolled weather-resistant steel with yield strength of more than 310MPa |
-
2021
- 2021-07-28 CN CN202110857186.2A patent/CN113637905B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113637905A (en) | 2021-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113637905B (en) | Low-cost weathering steel for 310MPa cold-rolled automobile and preparation method thereof | |
| US11519046B2 (en) | Cold-rolled high-strength steel plate having excellent phosphating performance and formability and manufacturing method therefor | |
| EP4527965A1 (en) | High-strength and high-plasticity hot-rolled strip steel with high weather resistance and manufacturing method therefor | |
| JP7280364B2 (en) | Plated steel sheet for hot forming with excellent impact properties after hot forming, hot formed member, and manufacturing method thereof | |
| CN110343964B (en) | Enamel cold-rolled steel plate with yield strength of more than 500MPa and production method thereof | |
| EP4159886A1 (en) | Ultrahigh-strength dual-phase steel and manufacturing method therefor | |
| JP2019524993A (en) | Hot formed member excellent in crack propagation resistance and ductility, and manufacturing method thereof | |
| CN113846269B (en) | Cold-rolled high-weather-resistance steel plate with high strength and plasticity and preparation method thereof | |
| CN113637903A (en) | Cold-rolled automobile weathering steel containing rare earth and having yield strength of 310MPa and production method thereof | |
| JP4457681B2 (en) | High workability ultra-high strength cold-rolled steel sheet and manufacturing method thereof | |
| EP3428302A1 (en) | Hot-dip galvanized steel sheet with superior bake hardenability and aging resistance, and manufacturing method thereof | |
| CN113637901A (en) | Cold-rolled automobile economic weathering steel with yield strength of 280MPa and production method thereof | |
| CN110117759B (en) | Manufacturing process of austenitic stainless steel for roll forming high-strength steel structural member | |
| CN110714165A (en) | Cold-rolled sheet for 320 MPa-level household appliance panel and production method thereof | |
| CN115151673B (en) | Steel sheet, member, and method for producing same | |
| CN116018416A (en) | Steel plate and manufacturing method thereof | |
| EP4159887A1 (en) | Electro-galvanized super-strength dual-phase steel resistant to delayed cracking, and manufacturing method therefor | |
| CN113637902A (en) | Cold-rolled automobile weathering steel containing rare earth and having yield strength of 280MPa and production method thereof | |
| CN113637904B (en) | 340 MPa-grade cold-rolled low-cost weathering steel for automobiles and manufacturing method thereof | |
| CN115537664A (en) | Hot-rolled acid-pickling steel for enameling with yield strength of more than or equal to 300MPa after enameling and production method thereof | |
| JP4848722B2 (en) | Method for producing ultra-high-strength cold-rolled steel sheet with excellent workability | |
| JP2003003216A (en) | Method for producing high strength galvanized steel sheet having excellent deep drawability and secondary working brittleness resistance | |
| JP2802513B2 (en) | Method for producing steel sheet having excellent press formability, remarkable hardenability by heat treatment after molding and high corrosion resistance, and method for producing steel structural member using the steel sheet | |
| CN116875892B (en) | 1300 MPa-grade hot rolled steel plate for automobile upper assembly and production method thereof | |
| CN116875890B (en) | Hot rolled steel plate for 850 MPa-level automobile upper assembly and production method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |