CN105937011A - High strength cold-rolled steel plate with low yield strength and preparation method thereof - Google Patents
High strength cold-rolled steel plate with low yield strength and preparation method thereof Download PDFInfo
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- CN105937011A CN105937011A CN201610543876.XA CN201610543876A CN105937011A CN 105937011 A CN105937011 A CN 105937011A CN 201610543876 A CN201610543876 A CN 201610543876A CN 105937011 A CN105937011 A CN 105937011A
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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
-
- 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
- C21D8/0247—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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- 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
Abstract
The invention relates to a high strength cold-rolled steel plate with a low yield strength and a preparation method thereof, and belongs to the technical field of high strength cold-rolled steel for automobiles. The provided steel plate is mainly composed of ferrite and bainite, the yield strength is 230 to 260 MPa, the tensile strength is 400 to 440 MPa, and the elongation rate is 40.0 to 43.0%. The steel plate is prepared by the following steps: smelting a steel plate slab, subjecting the casted slab to heating, scale removing, coarse rolling, finishing rolling and laminar cooling to obtain a hot-rolled roll, subjecting the hot-rolled roll to acid washing, carrying out cold rolling to obtain a cold-rolled thin steel belt, and subjecting the cold-rolled thin steel belt to continuous annealing to obtain a high strength cold-rolled steel plate. The cold-rolled steel plate has good comprehensive properties, has the advantages of excellent moulding property, low yield strength, low yield ratio, and long elongation rate, and contains little C, Si, and Mn, the welding performance is excellent, moreover, the preparation method is simple, the production cost is low, and the popularization is easy.
Description
Technical field
The present invention relates to low yield strength cold rolling high strength steel plate and preparation method thereof, belong to automobile cold-rolled high-strength steel technical field.
Background technology
Along with the development of automotive light weight technology technology, automobile steel develops towards high-strength steel direction and becomes inexorable trend.Dual phase steel etc.
High-strength steel has the features such as low yield strength, high-tensile and excellent plasticity, becomes the first-selected high-strength steel of automobile, and its consumption is pre-
Counting will be more than 70% in the advanced high-strength steel of automobile.Along with the continuous release of internal vapor sweep production capacity, the competition in high-strength steel market
The most more and more fierce, the high-strength steel of low-cost and high-performance has become as the target that each enterprise is pursued, of great interest.
Patent CN 104195434A discloses tensile strength 390MPa level car inner structural member hot-dip galvanized high-strength steel and life thereof
Product method, its chemical composition mass percent is: C:0.0027～0.0035%, Si:0.071～0.095%, Mn:0.78～0.95%,
P:0.060～0.075%, S≤0.003%, Als:0.015～0.030%, Nb:0.040～0.045%, Ti:0.039～0.045%,
B:0.0008～0.0014%, N≤0.003%, surplus is Fe and inevitable impurity；By 935～955 DEG C of finish to gauges, 680～700 DEG C
Batch, 790～810 DEG C of annealing have obtained the tensile strength hot-dip galvanized high-strength steel more than 390MPa.Although by its chemical composition and
Cold-rolled high-strength prepared by production method has excellent mechanical property and forming property, but this high-strength steel is ultra-low-carbon steel, needs
Carrying out the operations such as RH application of vacuum, its production difficulty and manufacturing cost are higher.
Patent CN 103882292A discloses a kind of carbon structural steels production method, and its chemical composition percentage ratio is: C:
0.06～0.10%, Si≤0.60%, Mn:1.20～1.50%, Al:0.02～0.06%, P≤0.030%, S≤0.010%, N:
0.0020～0.0050%, surplus is Fe and inevitable impurity；By 860～900 DEG C of finish to gauges, 600～640 DEG C batch, 760～800 DEG C
Annealing, 650～680 DEG C of slow cooling, 360～400 DEG C of Wetted constructures have obtained the tensile strength cold rolling carbon structure more than 400MPa
Steel.The cold rolling carbon structural steels produced by the method meets mechanical property requirements, but C, Mn content is higher affects its weldability
Can, make STEELMAKING PRODUCTION difficulty and cost increase simultaneously need to accurately control N content.
Summary of the invention
First technical problem to be solved by this invention is to provide a kind of welding performance more preferable low yield strength cold rolling high strength steel
Plate.
The chemical composition of this low yield strength cold rolling high strength steel plate is by mass percentage: C:0.03～0.05%,
Si≤0.10%, Mn:1.0～1.30%, Als:0.02～0.06%, P≤0.020%, S≤0.015%, N≤0.006%, surplus
For Fe and inevitable impurity.
Further, described low yield strength cold rolling high strength steel plate, chemical composition mass percent is preferred: C:0.03～0.05%,
Si≤0.05%, Mn:1.00～1.15%, Als:0.03～0.05%, P≤0.015%, S≤0.010%, N≤0.005%, surplus
For Fe and inevitable impurity.
Carbon: C, as one of most important component of high intensity, determines the intensity of steel plate, plasticity and forming property.C is iron and steel
The most obvious element of solid solution strengthening effect in material, in steel, solid solution C content increases by 0.1%, and its intensity can improve about 450MPa.
When C content is too low, the stability of austenite and martensite hardenability decline, and cause low strength, are typically not less than in high intensity
0.02%；When C content is too high, the plasticity of high intensity and welding performance decline, and are generally not more than 0.20% in high intensity.The present invention
C content is 0.03～0.06%, preferably 0.03～0.05%, can meet the steel plate requirement to intensity, plasticity and forming property.
Silicon: Si can be solid-solution in the intensity improving steel in ferrite and austenite, and its effect is only second to C, P, relatively Mn, Cr, Ti
Strong with elements such as Ni；Si can also suppress the precipitation of carbide in ferrite, makes solid solution C atom fully be enriched with in austenite,
Thus improve its stability.But, during Si too high levels, the scale on surface that Si is formed in heating furnace is very difficult to remove, and increases
Add de-scaling difficulty.Si content≤0.10% of the present invention, is preferably≤0.05%, and yield strength can meet requirement.
Manganese: Mn is good deoxidizer and desulfurizing agent, is also solution strengthening element conventional in steel, is typically not less than in high intensity
1.20%.Mn both can be combined the multiple carbide of formation and play the effect of precipitation strength with C, it is possible to be dissolved in matrix enhancing solid solution strong
Change effect.Mn is easily combined formation high melting compound MnS with S, thus eliminates or weaken the hot-short phenomenon caused due to FeS,
Improve the hot-working character of steel.Mn can improve stabilization of austenite, makes C curve move to right, thus significantly reduces martensite
Critical cooling rate.Mn content of the present invention is 0.90～1.30%, and preferably 1.00～1.20% can obtain certain volume mark
Bainite structure.
Aluminum: Al is deoxidizer common in steel, can form AlN pinning crystal boundary simultaneously, thus play the effect of crystal grain thinning；
It addition, Al to Si effect is similar, Carbide Precipitation can be suppressed, so that the fully rich carbon of austenite.Al content of the present invention is
0.02～0.06%, preferably 0.03～0.05%, meet the steel demand to deoxidizer.
Further, described low yield strength cold rolling high strength steel plate, mainly it is made up of ferrite and bainite, its yield strength
Being 230～260MPa, tensile strength is 400～440MPa, and percentage elongation is 40.0～43.0%.
Further, described low yield strength cold rolling high strength steel plate, adopt and prepare with the following method:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～8 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature；
Wherein slow cooling speed CR1 preferably 5～8 DEG C/s, rapid cooling speed CR2 preferably 25～35 DEG C/s.
Further, described coiling temperature is 645～670.
Further, described cold rolling reduction ratio is 61～69%.
The Second Problem that the invention solves the problems that is to provide manufacture above-mentioned welding performance more preferable low yield strength cold rolling high strength steel plate
Method, the method comprises the steps:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～5 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature.
Further, in the preparation method of low yield strength cold rolling high strength steel plate, coiling temperature is 645～670.
Further, in the preparation method of low yield strength cold rolling high strength steel plate, cold rolling reduction ratio is 61～69%.
For the present invention compares traditional cold rolling high-strength steel, reduce C content and add Mn content to improve its combination property simultaneously,
Have the advantages that
(1) excellent formability energy, yield strength and yield tensile ratio are relatively low, and percentage elongation is higher；
(2) constituent content such as C, Si, Mn is less, has superior weldability energy；
(3) its preparation method is simple, and production cost is low, easily promotes.
Accompanying drawing explanation
Fig. 1 is the continuous annealing process schematic diagram of low yield strength cold rolling high strength steel plate of the present invention；
Fig. 2 is the microstructure morphology figure of low yield strength cold rolling high strength steel plate of the present invention.
Reference: CR1-slow cooling speed, CR2-rapid cooling speed, I-heating, the insulation of II-two-phase section, III-slow cooling, IV-
Rapid cooling, V-overaging, VI-eventually the coldest.
Detailed description of the invention
The invention provides a kind of welding performance more preferable low yield strength cold rolling high strength steel plate, this low yield strength is cold rolling high-strength
The chemical composition of degree steel plate is by mass percentage: C:0.03～0.05%, Si≤0.10%, Mn:1.0～1.30%, Als:
0.02～0.06%, P≤0.020%, S≤0.015%, N≤0.006%, surplus is Fe and inevitable impurity.
Further, described low yield strength cold rolling high strength steel plate, chemical composition mass percent is preferred: C:0.03～0.05%,
Si≤0.05%, Mn:1.00～1.15%, Als:0.03～0.05%, P≤0.015%, S≤0.010%, N≤0.005%, surplus
For Fe and inevitable impurity.
Carbon: C, as one of most important component of high intensity, determines the intensity of steel plate, plasticity and forming property.C is iron and steel
The most obvious element of solid solution strengthening effect in material, in steel, solid solution C content increases by 0.1%, and its intensity can improve about 450MPa.
When C content is too low, the stability of austenite and martensite hardenability decline, and cause low strength, are typically not less than in high intensity
0.02%；When C content is too high, the plasticity of high intensity and welding performance decline, and are generally not more than 0.20% in high intensity.The present invention
C content is 0.03～0.06%, preferably 0.03～0.05%, can meet the steel plate requirement to intensity, plasticity and forming property.
Silicon: Si can be solid-solution in the intensity improving steel in ferrite and austenite, and its effect is only second to C, P, relatively Mn, Cr, Ti
Strong with elements such as Ni；Si can also suppress the precipitation of carbide in ferrite, makes solid solution C atom fully be enriched with in austenite,
Thus improve its stability.But, during Si too high levels, the scale on surface that Si is formed in heating furnace is very difficult to remove, and increases
Add de-scaling difficulty.Si content≤0.10% of the present invention, is preferably≤0.05%, and yield strength can meet requirement.
Manganese: Mn is good deoxidizer and desulfurizing agent, is also solution strengthening element conventional in steel, is typically not less than in high intensity
1.20%.Mn both can be combined the multiple carbide of formation and play the effect of precipitation strength with C, it is possible to be dissolved in matrix enhancing solid solution strong
Change effect.Mn is easily combined formation high melting compound MnS with S, thus eliminates or weaken the hot-short phenomenon caused due to FeS,
Improve the hot-working character of steel.Mn can improve stabilization of austenite, makes C curve move to right, thus significantly reduces martensite
Critical cooling rate.Mn content of the present invention is 0.90～1.30%, and preferably 1.00～1.20% can obtain certain volume mark
Bainite structure.
Aluminum: Al is deoxidizer common in steel, can form AlN pinning crystal boundary simultaneously, thus play the effect of crystal grain thinning；
It addition, Al to Si effect is similar, Carbide Precipitation can be suppressed, so that the fully rich carbon of austenite.Al content of the present invention is
0.02～0.06%, preferably 0.03～0.05%, meet the steel demand to deoxidizer.
Further, described low yield strength cold rolling high strength steel plate, mainly it is made up of ferrite and bainite, its yield strength
Being 230～260MPa, tensile strength is 400～440MPa, and percentage elongation is 40.0～43.0%.
Further, described low yield strength cold rolling high strength steel plate, adopt and prepare with the following method:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～8 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature；
Wherein slow cooling speed CR1 preferably 5～8 DEG C/s, rapid cooling speed CR2 preferably 25～35 DEG C/s.
Further, described coiling temperature is 645～670.
Further, described cold rolling reduction ratio is 61～69%.
The present invention also provides for the method manufacturing above-mentioned welding performance more preferable low yield strength cold rolling high strength steel plate, and the method includes
Following steps:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～5 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature.
Further, in the preparation method of low yield strength cold rolling high strength steel plate, coiling temperature is 645～670.
Further, in the preparation method of low yield strength cold rolling high strength steel plate, cold rolling reduction ratio is 61～69%.
Below in conjunction with embodiment, the detailed description of the invention of the present invention is further described, the most therefore limits the present invention to institute
Among the scope of embodiments stated.
Embodiment 1～4
The low yield strength cold rolling high strength steel plate that the present invention provides, its preparation method is as follows:
(1) through smelting process, it is prepared for the cold rolling high strength steel plate slab of chemical composition as shown in table 1 below:
Table 1 cold rolling high strength steel plate chemical composition (wt.%)
| Embodiment | C | Si | Mn | P | S | Als | N |
| 1 | 0.04 | 0.02 | 1.20 | 0.015 | 0.007 | 0.040 | 0.004 |
| 2 | 0.05 | 0.01 | 1.15 | 0.013 | 0.005 | 0.035 | 0.005 |
| 3 | 0.03 | 0.05 | 1.00 | 0.020 | 0.010 | 0.050 | 0.006 |
| 4 | 0.05 | 0.10 | 1.30 | 0.015 | 0.015 | 0.060 | 0.005 |
(2) strand is obtained after heating, dephosphorization, hot rolling and section cooling hot rolled coil, wherein heating-up temperature 1220～1260 DEG C,
Finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 640～700 DEG C；Concrete Hot-roller
Skill parameter is as shown in table 2 below:
Table 2 high-strength steel hot rolling main technologic parameters
| Embodiment | Heating-up temperature/DEG C | Final rolling temperature/DEG C | Finishing temperature/DEG C | Coiling temperature/DEG C | Hot rolled thickness/mm |
| 1 | 1240 | 1050 | 880～910 | 645～670 | 4.5 |
| 2 | 1240 | 1080 | 910～940 | 685～700 | 3.2 |
| 3 | 1240 | 1100 | 880～910 | 645～670 | 2.8 |
| 4 | 1240 | 1000 | 910～940 | 670～700 | 4.8 |
(3) by after hot rolled coil pickling, it is cold rolled to Thin Strip Steel, wherein embodiment 1, embodiment 2, embodiment 3 and embodiment 4
Cold rolling reduction ratio be respectively 66.7%, 68.8%, 74.0%, 61.3%.
(4) after continuous annealing process processes, cold-rolled thin steel strip being made required product, wherein annealing temperature is 780～820 DEG C,
Slowly cooling to rapid cooling from annealing temperature and start temperature 630～680 DEG C, its slow cooling speed CR1 is 1～5 DEG C/s, the most quickly cools down
To overaging temperature 250～350 DEG C, its rapid cooling speed CR2 is 10～50 DEG C/s, is finally cooled to room temperature.Concrete continuous annealing work
Skill parameter is as shown in table 3:
Table 3 continuous annealing main technologic parameters
Its microstructure of cold rolling high-strength steel prepared through above-mentioned technique is as in figure 2 it is shown, its mechanical property is as shown in table 4 below:
Table 4 present invention cold rolling high-strength steel mechanical property
| Embodiment | Yield strength/MPa | Tensile strength/MPa | Percentage elongation/% | Yield tensile ratio |
| 1 | 239 | 413 | 41.5 | 0.58 |
| 2 | 254 | 428 | 40.0 | 0.59 |
| 3 | 236 | 436 | 40.6 | 0.54 |
| 4 | 243 | 405 | 42.3 | 0.60 |
Result shows, cold rolling high-strength steel microstructure prepared by the present invention is made up of ferrite and bainite, has excellent mechanics
Performance and forming property, its yield strength (230～260MPa) and yield tensile ratio (≤0.60) are relatively low, tensile strength (400-440MPa)
Higher with percentage elongation (40.0-43.0%).
Claims (9)
1. low yield strength cold rolling high strength steel plate, it is characterised in that the chemical composition of described low yield strength cold rolling high strength steel plate
It is by mass percentage: C:0.03～0.05%, Si≤0.10%, Mn:1.0～1.30%, Als:0.02～0.06%, P≤0.020%,
S≤0.015%, N≤0.006%, surplus is Fe and inevitable impurity.
Low yield strength cold rolling high strength steel plate the most according to claim 1, it is characterised in that chemical composition mass percent:
C:0.03～0.05%, Si≤0.05%, Mn:1.00～1.15%, Als:0.03～0.05%, P≤0.015%, S≤0.010%,
N≤0.0050%, surplus is Fe and inevitable impurity.
Low yield strength cold rolling high strength steel plate the most according to claim 1 and 2, it is characterised in that mainly by ferrite and
Bainite forms, and its yield strength is 230～260MPa, and tensile strength is 400～440MPa, and percentage elongation is 40.0～43.0%,
Yield tensile ratio≤0.60.
4. according to the low yield strength cold rolling high strength steel plate described in any one of claim 13, it is characterised in that use as follows
Method prepares:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～8 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature；
Wherein slow cooling speed CR1 preferably 5～8 DEG C/s, rapid cooling speed CR2 preferably 25～35 DEG C/s.
5. want the low yield strength cold rolling high strength steel plate described in 4 according to right, it is characterised in that described coiling temperature is
645～670.
6. want the low yield strength cold rolling high strength steel plate described in 4 according to right, it is characterised in that described cold rolling reduction ratio be 61～
69%.
7. according to the preparation method of the low yield strength cold rolling high strength steel plate described in claim 16, it is characterised in that include
Following steps:
(1) smelting procedure: a, according to chemical composition mass percent smelting steel；B, by a step smelt steel be cast as slab；
(2) hot-rolled process: fluid origin slab is obtained after heating, de-scaling, roughing, finish rolling and section cooling hot rolled coil,
Wherein finish rolling start rolling temperature is 1000～1100 DEG C, and finishing temperature is 880～940 DEG C, and coiling temperature is 645～700 DEG C；
(3) operation is rolled in acid: by above-mentioned hot rolled coil pickling, be then cold rolled to cold-rolled thin steel strip, the most cold rolling reduction ratio be 60～
74%；
(4) continuous annealing operation: by above-mentioned cold-rolled thin steel strip continuous annealing, prepares cold rolling high strength steel plate；
Wherein annealing temperature is 780～820 DEG C, slowly cools to rapid cooling from annealing temperature and starts temperature 630～680 DEG C, its slow cooling
Speed be CR1 be 1～5 DEG C/s, be quickly cooled to overaging temperature 250～350 DEG C immediately, its rapid cooling speed CR2 be 10～
50 DEG C/s, it is finally cooled to room temperature.
The preparation method of low yield strength cold rolling high strength steel plate the most according to claim 7, it is characterised in that described in batch
Temperature is 645～670.
The preparation method of low yield strength cold rolling high strength steel plate the most according to claim 7, it is characterised in that cold in described
Rolling reduction ratio is 61～69%.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106987772A (en) * | 2017-04-28 | 2017-07-28 | 武汉钢铁有限公司 | High-strength fireproof weathering steel and its production method |
| CN108639162A (en) * | 2018-06-22 | 2018-10-12 | 江苏卡威汽车工业集团股份有限公司 | A kind of automotive light weight technology car body |
| CN108754307A (en) * | 2018-05-24 | 2018-11-06 | 山东钢铁集团日照有限公司 | A method of producing the economical cold rolling DP780 steel of different yield strength ranks |
| CN108950405B (en) * | 2018-08-14 | 2020-02-18 | 武汉钢铁有限公司 | 800 MPa-grade multi-phase steel with good flanging performance and production method thereof |
| CN113714288A (en) * | 2021-08-19 | 2021-11-30 | 安钢集团冷轧有限责任公司 | Production method of hot-rolled strip steel for low-cost low-yield-strength DC01 cold-rolled sheet |
| CN115418564A (en) * | 2022-08-18 | 2022-12-02 | 包头钢铁（集团）有限责任公司 | Rare earth treated low-yield-ratio automobile structural steel and production method thereof |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5848636A (en) * | 1981-09-18 | 1983-03-22 | Nippon Steel Corp | Production of high strength cold rolled steel plate for deep drawing having non-aging characteristic and excellent hardenability by baking of painting by continuous annealing |
| KR20110100868A (en) * | 2010-03-05 | 2011-09-15 | 한국기계연구원 | High cold-rolled steel with excellent strength and elongation, and method preparing the same |
| CN103882292A (en) * | 2014-03-05 | 2014-06-25 | 首钢总公司 | Method for producing cold-rolled carbon construction steel |
-
2016
- 2016-07-11 CN CN201610543876.XA patent/CN105937011B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5848636A (en) * | 1981-09-18 | 1983-03-22 | Nippon Steel Corp | Production of high strength cold rolled steel plate for deep drawing having non-aging characteristic and excellent hardenability by baking of painting by continuous annealing |
| KR20110100868A (en) * | 2010-03-05 | 2011-09-15 | 한국기계연구원 | High cold-rolled steel with excellent strength and elongation, and method preparing the same |
| CN103882292A (en) * | 2014-03-05 | 2014-06-25 | 首钢总公司 | Method for producing cold-rolled carbon construction steel |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106987772A (en) * | 2017-04-28 | 2017-07-28 | 武汉钢铁有限公司 | High-strength fireproof weathering steel and its production method |
| CN108754307A (en) * | 2018-05-24 | 2018-11-06 | 山东钢铁集团日照有限公司 | A method of producing the economical cold rolling DP780 steel of different yield strength ranks |
| CN108754307B (en) * | 2018-05-24 | 2020-06-09 | 山东钢铁集团日照有限公司 | Method for producing economical cold-rolled DP780 steel with different yield strength grades |
| CN108639162A (en) * | 2018-06-22 | 2018-10-12 | 江苏卡威汽车工业集团股份有限公司 | A kind of automotive light weight technology car body |
| CN108950405B (en) * | 2018-08-14 | 2020-02-18 | 武汉钢铁有限公司 | 800 MPa-grade multi-phase steel with good flanging performance and production method thereof |
| CN113714288A (en) * | 2021-08-19 | 2021-11-30 | 安钢集团冷轧有限责任公司 | Production method of hot-rolled strip steel for low-cost low-yield-strength DC01 cold-rolled sheet |
| CN115418564A (en) * | 2022-08-18 | 2022-12-02 | 包头钢铁（集团）有限责任公司 | Rare earth treated low-yield-ratio automobile structural steel and production method thereof |
| CN116043095A (en) * | 2022-11-17 | 2023-05-02 | 包头钢铁（集团）有限责任公司 | Production method for mass production of full-thickness galvanized structural steel |
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