CN109536837A - A kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its production technology - Google Patents

A kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its production technology Download PDF

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CN109536837A
CN109536837A CN201811504256.0A CN201811504256A CN109536837A CN 109536837 A CN109536837 A CN 109536837A CN 201811504256 A CN201811504256 A CN 201811504256A CN 109536837 A CN109536837 A CN 109536837A
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cold
fine grained
rolled biphase
steel
content
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CN109536837B (en
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陈雪慧
柴锋
罗小兵
王瑞珍
师仲然
杨丽
杨才福
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ADVANCED STEEL TECHNOLOGY Co Ltd
Central Iron and Steel Research Institute
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ADVANCED STEEL TECHNOLOGY Co Ltd
Central Iron and Steel Research Institute
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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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • 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
    • 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
    • C22C38/002—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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • 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

Abstract

The invention discloses a kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its production technologies, belong to automobile steel technical field, solve the problems, such as that existing cold-rolled biphase steel can not meet superhigh intensity, high-ductility, low yield strength ratio, low cost simultaneously.The ingredient of steel of the present invention is by percentage to the quality are as follows: C:0.14%~0.17%, Si:0.20%~0.30%, Mn:1.5%~2.0%, P≤0.015%, S≤0.010%, V:0.10%~0.15%, Cr:0.03%~0.04%, Als:0.02~0.03%, N:0.012%~0.018%, wherein C/N≤12, N/V≤0.15, surplus are Fe and inevitable impurity.The high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained of the present invention are suitable for automobile steel.

Description

A kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its production technology
Technical field
The invention belongs to automobile steel technical field, in particular to a kind of 1200MPa grades of cold rolling two-phases of high N content Ultra-fine Grained Steel and its production technology.
Background technique
Advanced high-strength steel is the fastest-rising material of current automobile industry, and lightweight and high security are automobile industries Important development direction, this requires automobile steels to have high-intensitive, high-ductility and high strength and ductility (tensile strength and elongation of having no progeny The product of rate) mechanical property.In this field, dual phase steel is most widely used material.According to Goldman Sachs Japan The year two thousand twenty is arrived in prediction, and Global Auto yield is up to 1.07 hundred million, and annual consumption of the dual phase steel in Global Auto can reach 14000000 tons.But with the continuous improvement of intensity, the plasticity of material can worse and worse, and especially 1180MPa's or more is high-strength Steel is spent, anti-damage performance is general, this is to limit one of the principal element that it further develops.
The microscopic structure of dual phase steel is mainly martensite and ferrite, and wherein martensite is that hard phase is considered to have by force Degree, and ferrite is that soft phase is considered to have ductility.How while improving intensity, has higher plasticity, be current Dual phase steel urgent problem.
Patent (CN108193139A) discloses 1180MPa grades of automobile cold-rolled high-strength dual phase steels and its production method, Chemical component percentage are as follows: C:0.10~0.13%, Si:0.45~0.68%, Mn:2.25~2.55%, P≤0.02%, S≤ 0.008%, Ti:0.10~0.14%, Cr:0.40~0.65%, Mo:0.17~0.21%, N≤0.0050%, Als:0.025 ~0.060%, surplus is Fe and inevitable impurity.Pass through the addition of the alloying elements such as Ti, Cr, Mo and the control of continuous annealing process System, producing yield strength is 800~900MPa, and tensile strength is greater than the dual phase steel of 1200MPa, yield tensile ratio is higher, extend compared with Low, forming property is poor, and the addition of excessive alloying element improves cost.The prior art can not meet simultaneously it is low at Sheet, superhigh intensity (tensile strength >=1200MPa), low yield strength ratio (yield tensile ratio≤0.5) and high-elongation (A50>=15%) Requirement.
Summary of the invention
In view of the above analysis, the present invention is intended to provide a kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its life Production. art, by optimized alloy ingredient and adjustment continuous annealing process parameter, fundamentally solving existing cold-rolled biphase steel can not Meet the problem of superhigh intensity, high-ductility, low yield strength ratio, low cost simultaneously.
The purpose of the present invention is mainly achieved through the following technical solutions:
A kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained, ingredient is by percentage to the quality are as follows: and C:0.14%~ 0.17%, Si:0.20%~0.30%, Mn:1.5%~2.0%, P≤0.015%, S≤0.010%, V:0.10%~ 0.15%, Cr:0.03%~0.04%, Als:0.02~0.03%, N:0.012%~0.018%, wherein C/N≤12, N/V ≤ 0.15, surplus is Fe and inevitable impurity.
Further, ingredient is by percentage to the quality are as follows: C:0.15%~0.16%, Si:0.25%~0.28%, Mn: 1.76~1.89%, P≤0.005%, S≤0.004%, V:0.11%~0.136%, Cr:0.034%~0.038%, Als: 0.022~0.024%, N:0.013%~0.017%, wherein C/N≤12, N/V≤0.15, surplus are Fe and inevitably Impurity.
Further, the ferritic volume fraction of steel is 50~65%, and the volume fraction of martensite is 35~50%.
Further, ferritic crystallite dimension≤1.6 μm of steel.
A kind of production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained, which is characterized in that including following step It is rapid:
S1. heating steel billet carries out homogeneous heat treatment；
S2. after high pressure water dephosphorization, hot rolling is carried out, is taken after rolling and rolls rear leading portion cooling technique, with 12~13 DEG C/s Cooling rate be cooled to 450~550 DEG C, batched；
S3. hot rolled plate carries out cold rolling after pickling；
S4. continuous annealing.
Further, in step S1, soaking section temperature is 1220~1250 DEG C, soaking time 120min.
Further, in step S2, hot rolling start rolling temperature is 1150~1200 DEG C, and finishing temperature is higher than 900 DEG C.
Further, in step S3, cold roling reduction control is 60~70%.
Further, step S4, continuous annealing are that control soaking temperature is 740~770 DEG C, and slow cooling temperature is 670~700 DEG C, Overaging temperature is 280~330 DEG C.
Further, the cold-rolled biphase steel of production, with a thickness of 1.0~2.0mm, the yield strength of material is >=600MPa, Tensile strength >=1200MPa, elongation percentage A50>=15%, yield tensile ratio≤0.5.
Compared with prior art, the present invention has the beneficial effect that:
1) present invention uses V-n Microalloying Technology, and when hot rolling, V is precipitated in austenite, can refine austenite crystal Grain；The significant fining ferrite grains in hot rolling cooling procedure；During continuous annealing, V disperse educt in ferrite plays selection Property reinforced ferrite effect, reduce influence of the martensite content to two-phase hardness of steel and ductility.N can be combined with the V in steel It forms second phase particles to be precipitated, and nitrogen pick-up can control precipitation of the V in austenite in steel, changed refined crystalline strengthening effect and sinks The distribution of the V of shallow lake invigoration effect can play the process route of the refined crystalline strengthening effect of V, replace partly precipitated with refined crystalline strengthening Invigoration effect improves the plasticity of matrix in the case where intensity is constant.Yield strength is not less than 600MPa, and tensile strength is not less than 1200MPa, elongation percentage A50Not less than 15%, yield tensile ratio is less than or equal to 0.5, at the same meet superhigh intensity, high-ductility, it is low bend it is strong Than, low cost requirement.
2) steel of the present invention uses V-n Microalloying Technology, by vanadium selective reinforcement ferrite, so that tensile strength It is reduced with the relevance of martensite content, reduces alloy to the sensibility of critical annealing temperature, and obtained 1.6 μm or less and surpass Fine grained texture obtains superhigh intensity, high-ductility cold-rolled biphase steel.
3) cold-rolled biphase steel of the present invention is small to mill load in 900 DEG C or more finish to gauges, and milling train can be effectively ensured Service life.
4) increase of nitrogen promotes the precipitation of V, and the dosage of vanadium can be effectively reduced, saved vanadium resource and reduced costs.
Other features and advantages of the present invention will illustrate in the following description, also, part can become from specification It obtains it is clear that understand through the implementation of the invention.The objectives and other advantages of the invention can be by written explanation Specifically noted structure is achieved and obtained in book and claims.
Specific embodiment
Below in conjunction with specific embodiment to a kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained and its production technology It is described in further detail, these embodiments are served only for the purpose for comparing and explaining, the present invention is not limited to these embodiments In.
A kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained, which is characterized in that chemical component is with mass percent It is calculated as: C:0.14%~0.17%, Si:0.20%~0.30%, Mn:1.5%~2.0%, P≤0.015%, S≤ 0.010%, V:0.10%~0.15%, Cr:0.03%~0.04%, Als:0.02~0.03%, N:0.012%~ 0.018%, wherein C/N≤12, N/V≤0.15, surplus are Fe and inevitable impurity.
By the way of v n micro alloying, the dosage of vanadium can be effectively reduced, saved vanadium resource and reduced and be produced into This, reduces alloy and obtains 1.6 μm or less ultrafine-grained (UFG) microstructures to the sensibility of critical annealing temperature, and pass through vanadium selectivity Ferrite is enhanced, so that tensile strength and the relevance of martensite content reduce, obtains superhigh intensity, high-ductility cold rolling pair Xiang Gang.
Specifically, in above-mentioned 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained, the effect of each element and proportion according to According to as follows:
C is most important solution strengthening element in dual phase steel, is that material obtains high-intensitive guarantee, when carbon content is too low, In identical critical zone (ferrite and austenite) heating, austenite content is low, is unfavorable for obtaining high intensity, but carbon contains Amount is too high, is unfavorable for the welding performance of material, therefore C content need to be controlled in an OK range.Present invention reduces carbon content, But for the precipitation for promoting V, its range is defined as 0.14%~0.17%.
Si is also important solution strengthening element, and the strength of materials on the one hand can be improved, and on the other hand, Si can effectively promote It is enriched with into C element to austenite, improves austenite harden ability, meanwhile, ferritic phase is purified, elongation percentage, but Si element mistake are improved Can mostly adverse effect be brought to welding performance and surface quality.Therefore, intensity, weldability and surface quality in order to balance, by it Range is defined as 0.20%~0.30%.
Mn is the alloying element to play a major role in micro alloyed steel phase transformation strengthening and solution strengthening mechanism, and Austria also can be improved Family name's body stability, moves to right C curve, to significantly reduce the critical cooling rate of martensite.But Mn too high levels can make steel Weldability reduces, therefore its range is defined as 1.5%~2.0%.
P is the impurity element in steel, and P content is fewer, and the performance of dual phase steel is better in the present invention, therefore, limitation P≤ 0.015%.
S is inevitable existing harmful element in steel, will form MnS field trash, reduces the toughness and weldability of steel, because This, content will be reduced as far as, and control its content below 0.010%.
Als is the deoxidier in steel, when Als content is less than 0.02%, cannot play its effect, but Al content also cannot Excessively high, it can form AlN, according to test of many times as a result, its range is defined as 0.02%~0.03% in conjunction with N content.
Cr can be such that pearlite and bainite transformation significantly lags, and austenite harden ability be improved, to obtain the horse of sufficient amount Family name's body proof strength, produces dual phase steel advantageous, but Cr element excessively adds can make cost increase, by repetition test, by it Range is defined as 0.03%~0.04%.
V is the key that micro alloying element in cold-rolled biphase steel of the present invention.When hot rolling, V is precipitated in austenite, Ke Yixi Change austenite grain；These particles can be small with ferritic interface simultaneously, and significant fining ferrite is brilliant in hot rolling cooling procedure Grain.During continuous annealing, V disperse educt in ferrite, it is ferritic to play the role of selective reinforcement, reduces martensite content pair The influence of two-phase hardness of steel and ductility.When content of vanadium is lower than 0.10%, it is unable to satisfy the minimum intensity that the present invention needs and wants It asks.Simultaneously for cost consideration, the upper limit should be controlled 0.15%.
N is the key that micro alloying element in cold-rolled biphase steel of the present invention.N can be combined with the V in steel and be formed the second phase grain Son is precipitated, and nitrogen pick-up can control precipitation of the V in austenite in steel, has changed refined crystalline strengthening effect and precipitation enhancement V distribution, can play V refined crystalline strengthening effect process route, with refined crystalline strengthening replace partly precipitated invigoration effect, Improve the plasticity of matrix in the case that intensity is constant, and the increase of nitrogen promotes the precipitation of V, to reduce the dosage of V, rises To the effect for reducing cost.But N content is excessively high, will increase the aged brittleness of steel.Therefore the content of V is combined, N content should control 0.012%~0.018%.
In addition, N and V content need to meet N/V≤0.15, N and C content need to meet C/N≤12, are important in the present invention Governing factor, when less this is mainly due to N content, remaining V can be precipitated in conjunction with C, reduce the intensity of steel, N content instead It is excessively high, V can not complete fixed nitrogen, increase the aged brittleness of steel.
It, can be to upper in order to further increase the comprehensive performance of above-mentioned high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained It states steel constituent and does further adjustment.Illustratively, composition by weight percentage can be with are as follows: and C:0.15%~ 0.16%, Si:0.25%~0.28%, Mn:1.76~1.89%, P≤0.005%, S≤0.004%, V:0.11%~ 0.136%, Cr:0.034%~0.038%, Als:0.022~0.024%, N:0.013%~0.017%, wherein C/N≤ 12, N/V≤0.15, surplus is Fe and inevitable impurity.
Ferritic volume fraction in above-mentioned steel is 50~65%, and the volume fraction of martensite is 35~50%, iron element The crystallite dimension of body is at 1.6 μm or less.
The microscopic structure of dual phase steel is mainly ferrite and martensite in the present invention, and martensite is hard phase, and ferrite For soft phase.Routinely ingredient produces, and martensite content even 60% or more can be only achieved wanting for 1200MPa 50% or more It asks, but after using v n micro alloying, V is precipitated in austenite using increasing N in hot rolling, fining austenite grains, together When these particles and ferritic interface can small, the significant fining ferrite grains in hot rolling cooling procedure.During continuous annealing, V A large amount of disperse educts in ferrite, it is ferritic to play the role of selective reinforcement, and it is strong to dual phase steel can to reduce martensite content The influence of degree, and by reducing martensite content, increase ferrite content reaches improves plasticity on the basis of not reducing intensity Purpose.
A kind of production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained, mainly comprises the steps that
S1. heating steel billet: by heating steel billet, it is 1220~1250 DEG C that soaking section temperature, which is arranged, soaking time 120min；
S2. hot rolling: after high pressure water dephosphorization, hot rolling is carried out, control start rolling temperature is 1150~1200 DEG C, and finishing temperature is higher than It 900 DEG C, is taken after rolling and rolls rear leading portion cooling technique, be cooled to 450~550 DEG C with the cooling rate of 12~13 DEG C/s, carry out It batches；
S3. cold rolling: hot rolled plate carries out cold rolling after pickling, and cold roling reduction control is 60~70%；
S4. continuous annealing: control soaking temperature is 740~770 DEG C, keeps 120s, and slow cooling temperature is 670~700 DEG C, overaging Temperature is 280~330 DEG C, keeps 600s.
In the present invention the advantages of hot rolling of superhigh intensity cold rolling dual phase steel, continuous annealing process are as follows:
Hot rolling: billet heating temperature is 1220~1250 DEG C, and roughing start rolling temperature is 1150~1200 DEG C, finish rolling finish to gauge temperature Degree is higher than 900 DEG C；Lower to mill milling force request in the controlled rolling of austenite recrystallization area, load is small, is conducive to protect milling train.
Continuous annealing: soaking temperature is 740~770 DEG C, and slow cooling temperature is 670~700 DEG C, and overaging temperature is 280~330 ℃；Soaking temperature is wider, after this mainly uses v n micro alloying to handle, reduces alloy to the sensitivity of critical annealing temperature Property, by vanadium selective reinforcement ferrite, so that tensile strength and the relevance of martensite content reduce, to guarantee in intensity Under the premise of not reducing, the plasticity of cold-rolled biphase steel is improved.
Cold-rolled biphase steel of the present invention, thickness specification be 1.0~2.0mm, yield strength >=600MPa of Steel material of the present invention, Tensile strength >=1200MPa, elongation percentage A50>=15%, yield tensile ratio≤0.5, while meet superhigh intensity, high-ductility, it is low bend it is strong Than, low cost requirement.
The various cold-rolled biphase steels of Examples 1 to 5 and comparative example 1~4 are formed by industrial production, each embodiment and comparison The chemical conversion ingredient of cold-rolled biphase steel is as shown in table 1 in example.The thickness of Examples 1 to 5 be respectively 1.8mm, 1.6mm, 1.4mm, 1.2mm, 1.0mm, the thickness of comparative example 1~4 are 1.2mm, and production technology is as shown in table 2.
The chemical component (wt%) of 1 embodiment of table and comparative example cold-rolled biphase steel
Type C Si Mn P S Cr Als V N C/N N/V
Embodiment 1 0.17 0.29 1.89 0.005 0.004 0.038 0.022 0.149 0.017 10.00 0.114
Embodiment 2 0.16 0.21 1.56 0.005 0.004 0.032 0.022 0.105 0.014 11.43 0.133
Embodiment 3 0.15 0.25 1.76 0.003 0.003 0.034 0.023 0.136 0.014 10.71 0.103
Embodiment 4 0.14 0.28 1.92 0.004 0.003 0.039 0.024 0.147 0.018 7.78 0.122
Embodiment 5 0.14 0.22 1.52 0.005 0.003 0.031 0.023 0.110 0.013 10.77 0.118
Comparative example 1 0.11 0.27 1.81 0.005 0.003 0.027 0.012 0.12 0.013 8.46 0.108
Comparative example 2 0.18 0.26 1.64 0.005 0.003 0.026 0.016 0.11 0.005 36 0.045
Comparative example 3 0.17 0.23 1.63 0.004 0.003 0.027 0.016 0.08 0.012 14.17 0.150
Comparative example 4 0.18 0.27 1.55 0.005 0.003 0.029 0.011 0.11 0.025 7.2 0.227
As can be seen from Table 1, according to 5 kinds of tests steel produced by the invention, chemical component meets requirement of the present invention Range, wherein C/N, N/V be also all satisfied the present invention claims；C content does not meet requirement of the invention in comparative example 1, in comparative example 2 C content, N content and C/N ratio be unsatisfactory for requirement of the invention, the V content and C/N ratio in comparative example 3 are unsatisfactory for of the invention It is required that C content and N/V ratio are unsatisfactory for requirement of the invention in comparative example 4.
The technological parameter of table 2 embodiment and comparative example cold-rolled biphase steel
The heating temperature of continuous annealing is respectively 740 DEG C, 750 DEG C, 760 DEG C, 770 DEG C in embodiment 3-1~embodiment 3-4, is delayed Cold temperature is respectively 670 DEG C, 680 DEG C, 690 DEG C, 700 DEG C, remaining technological parameter is identical, as shown in Table 3 with the reduction of temperature Martensite content is reduced to 39.7% by 47.7%, produces biggish variation, but tensile strength reduced by only 25MPa.This be by Vanadium nitrogen microalloy technology is used in steel of the present invention, a large amount of precipitations of the V in ferrite, selective enhances ferrite, makes up The problem of decline of intensity caused by martensite content reduces, so that tensile strength and the relevance of martensite content reduce；And Yield strength and ferrite grain size fluctuation are all smaller, it is known that steel of the present invention uses vanadium nitrogen microalloy technology, reduces alloy To the sensibility of critical annealing temperature, 1.6 μm or less ultrafine-grained (UFG) microstructures are obtained.
Mechanical property, tissue content and the crystallite dimension of 3 embodiment of table and comparative example cold-rolled biphase steel
As shown in table 3, cold-rolled biphase steel tensile strength of the present invention be 1220~1285MPa, yield strength be 605~ 630MPa, elongation percentage A50It is 15.8~18.4%, yield tensile ratio is 0.484~0.496, and martensite content is 37.3~48.9, iron Ferritic crystallite dimension is 1.40~1.58 μm.The cold-rolled biphase steel yield strength that comparative example 1, comparative example 2 and comparative example 3 produce is low In 600MPa, tensile strength is lower than 1200MPa, cannot meet the requirements, the elongation percentage of comparative example 4 cannot be met the requirements.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto, In the technical scope disclosed by the present invention, any changes or substitutions that can be easily thought of by anyone skilled in the art, It should be covered by the protection scope of the present invention.

Claims (10)

1. a kind of 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained, which is characterized in that ingredient is by percentage to the quality are as follows: C: 0.14%~0.17%, Si:0.20%~0.30%, Mn:1.5%~2.0%, P≤0.015%, S≤0.010%, V: 0.10%~0.15%, Cr:0.03%~0.04%, Als:0.02~0.03%, N:0.012%~0.018%, wherein C/N ≤ 12, N/V≤0.15, surplus are Fe and inevitable impurity.
2. 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained according to claim 1, which is characterized in that ingredient is with matter Measure percentages are as follows: C:0.15%~0.16%, Si:0.25%~0.28%, Mn:1.76~1.89%, P≤0.005%, S ≤ 0.004%, V:0.11%~0.136%, Cr:0.034%~0.038%, Als:0.022~0.024%, N:0.013% ~0.017%, wherein C/N≤12, N/V≤0.15, surplus are Fe and inevitable impurity.
3. 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained according to claim 1, which is characterized in that the steel Ferritic volume fraction is 50~65%, and the volume fraction of martensite is 35~50%.
4. 1200MPa grades of cold-rolled biphase steels of high N content Ultra-fine Grained according to claim 1-3, which is characterized in that Ferritic crystallite dimension≤1.6 μm of the steel.
5. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained according to claim 1-4, Characterized by comprising the following steps:
S1. heating steel billet carries out homogeneous heat treatment；
S2. after high pressure water dephosphorization, hot rolling is carried out, is taken after rolling and rolls rear leading portion cooling technique, with the cold of 12~13 DEG C/s Speed is cooled to 450~550 DEG C, is batched；
S3. hot rolled plate carries out cold rolling after pickling；
S4. continuous annealing.
6. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained according to claim 5, feature exist In in the step S1, soaking section temperature is 1220~1250 DEG C, soaking time 120min.
7. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained according to claim 5, feature exist In in the step S2, hot rolling start rolling temperature is 1150~1200 DEG C, and finishing temperature is higher than 900 DEG C.
8. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained according to claim 5, feature exist In in the step S3, cold roling reduction control is 60~70%.
9. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained according to claim 5, feature exist In the step S4, continuous annealing is that control soaking temperature is 740~770 DEG C, and slow cooling temperature is 670~700 DEG C, overaging temperature It is 280~330 DEG C.
10. the production technology of high 1200MPa grades of cold-rolled biphase steels of N content Ultra-fine Grained, feature according to claim 5-9 It is, the cold-rolled biphase steel of production, with a thickness of 1.0~2.0mm, the yield strength of material is >=600MPa, tensile strength >= 1200MPa, elongation percentage A50>=15%, yield tensile ratio≤0.5.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110592347A (en) * 2019-09-02 2019-12-20 河钢股份有限公司承德分公司 Production method of 1200 MPa-grade complex phase steel coil plate by hot rolling on-line heat treatment
CN112095046A (en) * 2020-09-07 2020-12-18 鞍钢股份有限公司 Ultrahigh-strength cold-rolled DH1180 steel and preparation method thereof

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008291304A (en) * 2007-05-24 2008-12-04 Jfe Steel Kk High-strength cold-rolled steel sheet and high strength hot-dip galvanized steel sheet both excellent in deep-drawability and strength-ductility balance, and producing method of the both
JP2009024227A (en) * 2007-07-20 2009-02-05 Nippon Steel Corp Dual-phase steel sheet superior in formability, and manufacturing method therefor
CN101768695A (en) * 2010-01-21 2010-07-07 北京科技大学 Ti microalloyed ultra-fine grained cold rolling dual-phase steel of 1,000MPa level and preparation method thereof
JP2011052293A (en) * 2009-09-03 2011-03-17 Nippon Steel Corp Steel sheet with composite structure having excellent formability and fatigue property and method for producing the same
CN103556048A (en) * 2013-10-24 2014-02-05 钢铁研究总院 Two-phase automobile steel plate with low yield-strength ratio and high strength and production method of two-phase automobile steel plate
CN105803321A (en) * 2016-03-23 2016-07-27 攀钢集团攀枝花钢铁研究院有限公司 980 MPa-level vanadium-contained ultrafine grain cold rolled dual-phase steel and preparing method thereof
CN105925912A (en) * 2016-07-11 2016-09-07 攀钢集团攀枝花钢铁研究院有限公司 Tensile strength-780 MPa-stage vanadium-contained cold-rolled dual-phase steel and preparation method thereof
CN107058869A (en) * 2017-05-22 2017-08-18 钢铁研究总院 Ultralow yield tensile ratio 980MPa grades of cold-rolled biphase steels and its manufacture method
CN108486494A (en) * 2018-06-05 2018-09-04 西北工业大学 The production method of vanadium micro-alloying 1300MPa grade high-strengths hot rolled steel plate and cold-rolled biphase steel plate

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008291304A (en) * 2007-05-24 2008-12-04 Jfe Steel Kk High-strength cold-rolled steel sheet and high strength hot-dip galvanized steel sheet both excellent in deep-drawability and strength-ductility balance, and producing method of the both
JP2009024227A (en) * 2007-07-20 2009-02-05 Nippon Steel Corp Dual-phase steel sheet superior in formability, and manufacturing method therefor
JP2011052293A (en) * 2009-09-03 2011-03-17 Nippon Steel Corp Steel sheet with composite structure having excellent formability and fatigue property and method for producing the same
CN101768695A (en) * 2010-01-21 2010-07-07 北京科技大学 Ti microalloyed ultra-fine grained cold rolling dual-phase steel of 1,000MPa level and preparation method thereof
CN103556048A (en) * 2013-10-24 2014-02-05 钢铁研究总院 Two-phase automobile steel plate with low yield-strength ratio and high strength and production method of two-phase automobile steel plate
CN105803321A (en) * 2016-03-23 2016-07-27 攀钢集团攀枝花钢铁研究院有限公司 980 MPa-level vanadium-contained ultrafine grain cold rolled dual-phase steel and preparing method thereof
CN105925912A (en) * 2016-07-11 2016-09-07 攀钢集团攀枝花钢铁研究院有限公司 Tensile strength-780 MPa-stage vanadium-contained cold-rolled dual-phase steel and preparation method thereof
CN107058869A (en) * 2017-05-22 2017-08-18 钢铁研究总院 Ultralow yield tensile ratio 980MPa grades of cold-rolled biphase steels and its manufacture method
CN108486494A (en) * 2018-06-05 2018-09-04 西北工业大学 The production method of vanadium micro-alloying 1300MPa grade high-strengths hot rolled steel plate and cold-rolled biphase steel plate

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
康卓等: "钒氮微合金化技术在高强度钢中的应用", 《天津冶金》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110592347A (en) * 2019-09-02 2019-12-20 河钢股份有限公司承德分公司 Production method of 1200 MPa-grade complex phase steel coil plate by hot rolling on-line heat treatment
CN110592347B (en) * 2019-09-02 2021-09-10 河钢股份有限公司承德分公司 Production method of 1200 MPa-grade complex phase steel coil plate by hot rolling on-line heat treatment
CN112095046A (en) * 2020-09-07 2020-12-18 鞍钢股份有限公司 Ultrahigh-strength cold-rolled DH1180 steel and preparation method thereof
CN112095046B (en) * 2020-09-07 2021-12-24 鞍钢股份有限公司 Ultrahigh-strength cold-rolled DH1180 steel and preparation method thereof

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