CN101603144A - 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate and manufacture method thereof - Google Patents
700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate and manufacture method thereof Download PDFInfo
- Publication number
- CN101603144A CN101603144A CNA2009100633376A CN200910063337A CN101603144A CN 101603144 A CN101603144 A CN 101603144A CN A2009100633376 A CNA2009100633376 A CN A2009100633376A CN 200910063337 A CN200910063337 A CN 200910063337A CN 101603144 A CN101603144 A CN 101603144A
- Authority
- CN
- China
- Prior art keywords
- temperature
- controlled
- cooling
- steel plate
- cold rolling
- 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.)
- Granted
Links
Abstract
The invention discloses a kind of 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate and manufacture method thereof, the weight percent of this each component of steel plate is: C:0.18～0.23%; Al:1.20～1.50%; Mn:1.50～1.80%, Si≤0.50%; P≤0.040%, S≤0.005%; Surplus is Fe and unavoidable impurities.Manufacture method of the present invention may further comprise the steps: desulfurizing iron, converter smelting, RH vacuum-treat, continuous casting, slab inspection and cleaning, slab heating, hot rolling, laminar flow cool off, batch, pickling, cold rolling, continuous annealing, smooth, finishing, oiling, packing etc.Through evidence, the tensile strength of carbon-aluminum-manganese steel plate of the present invention is good above 700MPa level and welding property, and production method of the present invention has the advantage that production cost is low, industrial production adaptability is good.
Description
Technical field
The invention belongs to the high-strength steel production technical field, be specifically related to a kind of 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate and manufacture method thereof.
Background technology
700MPa level high-strength steel is meant the steel of tensile strength greater than 700MPa, and it can be used for important safety parts such as stamped automobile front and back collision bumper, the crashproof column of car body, frame member and stiffener, improves vehicle safety.Simultaneously, adopt high-strength plate to make automobile structure, can reduce steel plate thickness more than 20%, reduce automobile assembly weight, both reduced materials consumption, and reduced fuel consumption and exhaust gas emission again, greatly developing high-strength steel is the important method that reduces automobile making cost, use cost and energy-saving and emission-reduction.
In the design of tradition high-strength steel, mostly add micro alloying element V, Ti, Nb, these elements are solid-solubilized in the base steel under steel plate heating high temperature, subsequently hot rolling and cold rolled annealed in separate out with VCN, TiCN, NbCN grade in an imperial examination two-phase particle form, these nano level fine particle can effectively stop grain growth or alligatoring, thereby obtain the tiny weave construction of grain-size, reach the refined crystalline strengthening effect that improves intensity, keeps good unit elongation.In addition, improve the intensity and the plasticity of material by interpolation malleablization element such as Cr, Mo.But the interpolation of V, Ti, Nb has increased material cost on the one hand; The cost of cost height, the especially Mo of Cr, Mo element is higher.
Again because the high-strength steel of 700MPa level needs high-intensity roll, high required steel band and integrated conditions such as the welding technique between the steel band, template control techniques and quick cooling power of mill load ability, continuous production when cold rolling production, these capacities of equipment and state of the art are not that the milling train and the laboratory facilities of laboratory routine can compare or realize, especially production gordian technique and difficult point control require level higher.So the interpolation of V, Ti, Nb has also brought great difficulty to controlling of production process, increased the technology cost.
In addition, 700MPa level high-strength steel alloying element total amount is higher, commissure intensity takes place obviously to reduce easily when welding, the loss of strength of 100～200MPa can appear, corresponding grain-size also shows remarkable alligatoring, and may follow weld metal crack or cracking, and have a strong impact on the normal use of material, lose the use value of material.
Therefore, three big bottlenecks such as the cold rolling high-strength plate of traditional 700MPa level exists that the chemical ingredients cost is higher, the higher achievement industrialization of manufacturing process cost difficulty, weldability can differ from are not seen the bibliographical information that can solve above-mentioned Three Difficult Issues simultaneously in the related data both at home and abroad at present as yet yet.
Summary of the invention
Purpose of the present invention will provide a kind of 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate and manufacture method thereof exactly.Its tensile strength surpasses the 700MPa level, and has good welding property; Its manufacture method has the advantages that production cost is low, industrial production adaptability is good.
For achieving the above object, the 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate that the present invention is designed is that wherein the weight percent of each component is: C:0.18～0.23% based on the steel alloy of C, Al, the conventional element of Mn; Al:1.40～1.70%; Mn:1.50～1.80%; Si≤0.50%; P≤0.040%; S≤0.015%; Surplus is Fe and unavoidable impurities.
The manufacture method of above-mentioned 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate, may further comprise the steps: desulfurizing iron, converter smelting, RH vacuum-treat, continuous casting, slab inspection and cleaning, slab heating, hot rolling, laminar flow cool off, batch, pickling, cold rolling, continuous annealing, smooth, finishing and oiling, it is characterized in that:
The vacuum treated time of described RH is controlled at 18～23min; Described continuous casting adopts the above large vol ladle of 200t to smelt and the cast of refinement granular protecting cinder, and the molten steel tapping temperature is at 1650～1660 ℃, and the tapping end temp is at 1600～1615 ℃, and casting temperature is at 1560～1570 ℃; Described slab heating temperature is controlled at 1180～1220 ℃; Described hot rolled roughing temperature is controlled at 1060～1100 ℃, and finishing temperature is controlled at 830～870 ℃; Described laminar flow speed of cooling is controlled at 20～40 ℃/s, cooling time 6～12s; Described coiling temperature is controlled at 580～620 ℃; Described cold rolling draft is controlled at 60～80%;
The technology pattern of described continuous annealing comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature insulation, the cooling of low-temperature zone middling speed, and wherein the rapid heating speed control is at 5～10 ℃/s, heat-up time 75～160s; The temperature of of short duration soak is controlled at 750～800 ℃, soaking time 180～240s; The quick speed of cooling of high temperature section is controlled at 20～40 ℃/s, cooling time 8～20s; The temperature of of short duration low temperature insulation is controlled at 390～410 ℃, soaking time 120～180s; Low-temperature zone middling speed speed of cooling is controlled at 20～30 ℃/s, cooling time 10～15s.
The chemical ingredients mechanism of action of the present invention, production technique and beneficial effect are as follows:
One. the chemical ingredients mechanism of action of steel plate of the present invention:
Carbon is ideal gap strengthening element, and it is cheap, and strengthening effect is fairly obvious, and carbon content is high more good more to strengthening effect.But carbon content is too high, and is unfavorable to welding property, so material of the present invention design carbon content higher limit is 0.23%, and lower value is 0.18%.Except gaining in strength, carbon also plays crucial effects to the improvement of plasticity in the present invention.Carbon can be solid-solubilized in the austenite that does not change under the high temperature, improves austenitic stability, by controlled chilling, at room temperature obtains the residual austenite that has good stability.Residual austenite absorbs crackle front end stress under external force, slows down crackle unstability process, thereby improves material plasticity; Simultaneously, residual austenite is changed martensite into, can improve the strength of materials.So, be the residual austenite of one of main stable element with carbon, can improve the intensity and the plasticity of material simultaneously.
Aluminium also is cheap highly malleablized element, have effect of intensive crystal grain thinning and stable residual austenite, aluminium forms tiny and uniform AlN with nitrogen in steel, in hot rolling and cold rolled continuous annealing process, stop grain growth, to obtain the metallographic structure of ferrite grain size below 3 μ m.Simultaneously, aluminium belongs to non-carbide forming element, urgees in carbon atom is diffused in the austenite from ferrite, thereby increases quantity and the stability of residual austenite.In addition, conventional high-strength steel is mostly assisted the quantity and stability that improves residual austenite by adding element silicon, but element silicon forms fine and close SiO at surface of steel plate easily
2And influence the surface quality of material, so the present invention adopts aluminium element to replace element silicon.But aluminium element increases molten steel viscosity, stops up the mouth of a river in industrial production continuous casting process easily.So, solve high aluminum steel continous casting sprue and stop up a difficult problem, also be one of key problem in technology of patent industrialization production of the present invention.The upper limit content of aluminium element in steel is controlled at below 1.50%, and lower limit is controlled at more than 1.20%.
Manganese element is conventional highly malleablized element, as austenite former, enlarging the austenitic area, reduces finishing temperature, postpones austenitic transformation, can play crystal grain thinning and the austenitic effect of stable residual simultaneously.But manganese element content is too high, increases cost on the one hand, increases the hardening capacity of steel on the other hand, makes weld structure hardened layer occur and causes crackle weld seam and heat-affected zone crack susceptibility to increase.Therefore, the manganese upper content limit due to below 1.80%, is defined in more than 1.50% down.
Si content forms compact oxide greater than 0.5% o'clock easily at surface of steel plate, is unfavorable for cold rolling preceding surface acid-washing, and is unfavorable to zinc-plated or japanning adhesion property subsequently, and therefore, silicone content requires to be controlled at below 0.50%.
P, S are detrimental impurity, and its content is low more good more, and the P content requirement is less than 0.040%, and the S content requirement is less than 0.015%.
Two. the critical process step and the technical parameter of steel plate of the present invention are as follows:
(1) desulfurizing iron
Sulphur is harmful element, and element sulphur often exists with the manganese sulfide form in the steel, and this sulfide inclusion is very unfavorable to the low-temperature impact toughness of steel, and causes anisotropy of material.Therefore, sulphur content is low more good more.In addition, sulphur content is higher, can consume too much manganese element, influences the highly malleablized effect of material, or increases the cost of material.For this reason, molten iron is handled by desulfurization, and its sulphur content is controlled at below 0.015%.
(2) external refining is the RH vacuum-treat
Harmful element in the steel can be further eliminated in external refining, comprise the oxygen element that produces in the smelting process, reduce harmful inclusion in the steel, simultaneously, external refining is the content of control C, Al, Mn three big elements accurately, improves the control accuracy and the maintenance level of material structure and performance.The vacuum processing time of material is at 18～23min.
(3) continuous casting
The molten steel viscosity that aluminium content is high is higher, causes nozzle clogging in the continuous casting process easily, brings difficulty to production.In order to solve the metallurgical difficult problem of this steel, the present invention has adopted the measures such as covering slag casting of large vol smelting and process thinning processing, has obtained positive effect.Large vol smelt be ladleful more than every stove 200t, slow to guarantee molten steel temperature drop; Simultaneously, adopt covering slag granularity during cast steel, make the covering slag densification of liquid steel level tight, be not easy heat radiation through thinning processing.Facts have proved that molten steel tapping temperature of the present invention is more than 1650 ℃, the tapping end temp adopts protection casting measure more than 1600 ℃, and the cast steel end temp still remains on more than 1580 ℃, has guaranteed molten steel casting smoothly continuously.The present invention does not have to adopt the simple way that improves the cast steel temperature, to avoid the increase of production technique cost; But take the above large vol converter smelting of 200t; not only can enhance productivity; and can protect the pure and Composition Control of steel quality, because the molten steel capacity is big, under the certain condition of foreing impuritys quantity; the ratio that is mingled with of molten steel also just reduces; simultaneously, the molten steel amount is big more, and the composition fluctuation of molten steel is more little; composition is also just even more, and this also is the advantage that large vol is smelted.
(4) slab heating
The alloying element content of high-strength steel is higher, needs usually to adopt higher Heating temperature, especially contains microalloy elements such as vanadium, niobium, titanium, needs slab heating temperature to remain on about 1250 ℃, makes the abundant solid solution of micro alloying element.Not only energy consumption is big for heat, the process furnace damage is big, and the steel plate oxidation is serious, brings pressure and difficulty for the steel rolling dephosphorization.Do not add micro alloying element in the steel of the present invention, slab heating temperature designs at 1180～1220 ℃, is starkly lower than traditional high-strength steel.
(5) hot rolling
The roughing temperature is controlled at 1060～1100 ℃, the finishing temperature design is promptly guaranteeing that steel plate austenite one phase district is rolling with when obtaining uniform grain-size at 830～870 ℃, and controlled temperature is in lower range as far as possible, because finishing temperature is low more, steel plate organizes grain fineness number tiny more.
(6) laminar flow cooling
Speed of cooling is controlled at 20～40 ℃/s, and the time is 6～12s.Steel plate cooling back coiling temperature is controlled at 580～620 ℃, is controlled at lower range as far as possible.
(7) cold rolling
The cold-rolling of steel plate raw thickness generally is controlled at 3.0～5.0mm, finished product thickness is generally at 0.8～2.0mm, the cold rolling draft of steel plate is controlled at 60～80%, bigger draft can accumulate higher storage energy in cold rolling fibrous tissue, to improve the motivating force and the quantity of crystal grain forming core, reach the effect of grain refining.
(8) continuous annealing
Continuous annealing is the critical process that the present invention obtains the weave construction of tiny ferrite, bainite or martensite and an amount of residual austenite, this technology pattern has adopted rapid heating, high temperature and two sections insulations of low temperature, quick and two sections coolings of middling speed, and concrete technology is: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating is for fear of steel plate grain growth alligatoring in heat-processed; Adopting of short duration soak is for fear of the long grain growth that causes of soaking time, and tiny and uniform ferrite formed in this stage, guaranteed that crystal grain is tiny uniform distribution, and quantitative proportion is about 40%; High temperature section cooling fast is to form for fear of perlite, because the following speed of cooling of 20 ℃/s forms perlite easily, and the cementite in the perlite has consumed more effective carbon atom, influences quantity and the stability of residual austenite; The insulation of of short duration low temperature be for strengthen carbon atom from ferrite to austenitic diffusion, form granular bainite, its quantitative proportion is about 50%; Form martensite and residual austenite in the low-temperature zone middling speed process of cooling, both mostly exist with martensite, residual austenite island structure, and its ratio is about 10%, and wherein, the residual austenite ratio is about 7%.
Steel of the present invention do not add any micro alloying element, through optimization of Chemical Composition design and special smelting of the present invention, hot rolling, the control of series of processes such as cold rolling and continuous annealing, the product weave construction that obtains is: ferrite, bainite and martensite-residual austenite, wherein, ferrite quantity ratio is about 40%, its grain-size is below 10 μ m, the bainite ratio is about 50%, its form is a particulate state, and size and is evenly distributed about 2～3 μ m, martensite-residual austenite is a combined state, be difficult to differentiate under metaloscope, its position should be at bainite and ferrite at the interface, and quantitative proportion is about 10%.
Compare with traditional high-strength steel, adopt formability, weldability and the weld seam roll-forming of material of the present invention to have the following advantages:
(1) contain residual austenite about 7% in the invention material, in bending forming process, residual austenite is converted into martensite because of absorbing external energy, and the release of this flexural deformation stress also is that distortion back accessory size keeps stable major cause.Because it is limited to bend to deflection, so residual austenite is not finished transformation.
(2) same, the invention material contains stable residual austenite, and in welding process, residual austenite can absorb crack tip stress, alleviate crackle formation and expansion, and this also is that crackle and rimose major cause do not take place in the part welding process.
(3) in addition, because the residual austenite in the material, in the roll-forming process after welding, residual austenite absorbs moulding stress, slows down and stops tiny crack in the material to form and expand, and embody good rolling formation performance.
Embodiment
Below in conjunction with several specific embodiments high-strength cold rolling carbon-aluminum-manganese steel plate of the present invention and manufacture method thereof are elaborated.
Embodiment 1:
Each Chemical Composition weight percent of steel plate is: C:0.21; Al:1.51; Mn:1.64; Si:0.14; P:0.019, S:0.002; Surplus is Fe and unavoidable impurities.
Manufacture method is: molten steel is controlled at 18～19min, continuous casting employing 250t ladle smelting and the cast of refinement granular protecting cinder through desulfurizing iron, converter smelting, RH vacuum-treat treatment time, the molten steel tapping temperature is at 1650～1660 ℃, the tapping end temp is at 1600～1610 ℃, casting temperature is cleared up on inspection at 1560～1570 ℃, slab, slab heating temperature is controlled at 1180～1200 ℃, the roughing temperature is controlled at 1060～1080 ℃ during hot rolling, finishing temperature is controlled at 830～850 ℃, laminar flow speed of cooling and is controlled at 20～25 ℃/s, cooling time 6～8s; , coiling temperature is controlled at 600～620 ℃; Pickling, cold rolling draft are controlled at 60～65%; Continuous annealing, annealing ignition technique pattern comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating speed control wherein is at 5～8 ℃/s, heat-up time 75～80s; The temperature of of short duration soak is controlled at 750～770 ℃, soaking time 180～190s; The quick speed of cooling of high temperature section is controlled at 20～25 ℃/s, cooling time 18～20s; The temperature of of short duration low temperature insulation is controlled at 400～410 ℃, soaking time 120～125s; Low-temperature zone middling speed speed of cooling is at 20～25 ℃/s, and cooling time is at 13～15s; Then through smooth, finishing, oiling, packing and finished product.
Embodiment 2:
Each Chemical Composition weight percent of steel plate is: C:0.22; Al:1.46; Mn:1.65; Si:0.12; P:0.016, S:0.002; Surplus is Fe and unavoidable impurities.
Manufacture method is: molten steel is controlled at 22～23min, continuous casting employing 250t ladle smelting and the cast of refinement granular protecting cinder through desulfurizing iron, converter smelting, RH vacuum-treat treatment time, the molten steel tapping temperature is at 1655～1660 ℃, the tapping end temp is at 1610～1615 ℃, casting temperature is cleared up on inspection at 1560～1570 ℃, slab, slab heating temperature is controlled at 1190～1200 ℃, the roughing temperature is controlled at 1080～1100 ℃ during hot rolling, finishing temperature is controlled at 850～870 ℃, laminar flow speed of cooling and is controlled at 35～40 ℃/s, cooling time 10～12s; Coiling temperature is controlled at 580～600 ℃; Pickling, cold rolling draft are controlled at 75～80%; Continuous annealing, the annealing process pattern comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating speed control wherein is at 8～10 ℃/s, heat-up time 150～160s; The temperature of of short duration soak is controlled at 790～800 ℃, soaking time 230～240s; The quick speed of cooling of high temperature section is controlled at 35～40 ℃/s, cooling time 8～15s; The temperature of of short duration low temperature insulation is controlled at 400～410 ℃, soaking time 160～180s; Low-temperature zone middling speed speed of cooling is at 25～30 ℃/s, and cooling time is at 10～12s; Then through smooth, finishing, oiling, packing and finished product.
Embodiment 3:
Each Chemical Composition weight percent of steel plate is: C:0.22; Al:1.19; Mn:1.62; Si:0.13; P:0.016, S:0.003; Surplus is Fe and unavoidable impurities.
Manufacture method is: molten steel is controlled at 19～20min, continuous casting employing 230t ladle smelting and the cast of refinement granular protecting cinder through desulfurizing iron, converter smelting, RH vacuum-treat treatment time, the molten steel tapping temperature is at 1650～1660 ℃, the tapping end temp is at 1600～1615 ℃, casting temperature is cleared up on inspection at 1565～1570 ℃, slab, slab heating temperature is controlled at 1200～1210 ℃, the roughing temperature is controlled at 1090～1100 ℃ during hot rolling, finishing temperature is controlled at 840～860 ℃, laminar flow speed of cooling and is controlled at 20～30 ℃/s, cooling time 8～10s; Coiling temperature is controlled at 590～600 ℃; Pickling, cold rolling draft are controlled at 70～75%; Continuous annealing, the annealing process pattern comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating speed control wherein is at 6～10 ℃/s, heat-up time 150～160s; The temperature of of short duration soak is controlled at 760～770 ℃, soaking time 210～220s; The quick speed of cooling of high temperature section is controlled at 20～30 ℃/s, cooling time 10～12s; The temperature of of short duration low temperature insulation is controlled at 400～410 ℃, soaking time 130～140s; Low-temperature zone middling speed speed of cooling is at 20～26 ℃/s, and cooling time is at 10～12s; Then through smooth, finishing, oiling, packing and finished product.
Embodiment 4:
Each Chemical Composition weight percent of steel plate is: C:0.22; Al:1.43; Mn:1.62; Si:0.14; P:0.013, S:0.001; Surplus is Fe and unavoidable impurities.
Manufacture method is: molten steel is controlled at 20～22min, continuous casting employing 250t ladle smelting and the cast of refinement granular protecting cinder through desulfurizing iron, converter smelting, RH vacuum-treat treatment time, the molten steel tapping temperature is at 1650～1660 ℃, the tapping end temp is at 1605～1615 ℃, casting temperature is cleared up on inspection at 1560～1570 ℃, slab, slab heating temperature is controlled at 1090～1220 ℃, the roughing temperature is controlled at 1080～1090 ℃ during hot rolling, finishing temperature is controlled at 850～870 ℃, laminar flow speed of cooling and is controlled at 30～35 ℃/s, cooling time 6～8s; Coiling temperature is controlled at 600～620 ℃; Pickling, cold rolling draft are controlled at 65～70%; Continuous annealing, annealing ignition technique pattern comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating speed control wherein is at 7～10 ℃/s, heat-up time 75～80s; The temperature of of short duration soak is controlled at 770～790 ℃, soaking time 220～230s; The quick speed of cooling of high temperature section is controlled at 20～20 ℃/s, cooling time 16～18s; The temperature of of short duration low temperature insulation is controlled at 390～400 ℃, soaking time 130～150s; Low-temperature zone middling speed speed of cooling is at 25～30 ℃/s, and cooling time is at 11～13s; Then through smooth, finishing, oiling, packing and finished product.
Embodiment 5:
Each Chemical Composition weight percent of steel plate is: C:0.23; Al:1.59; Mn:1.69; Si:0.15; P:0.015, S:0.001; Surplus is Fe and unavoidable impurities.
Manufacture method is: molten steel is controlled at 18～22min, continuous casting employing 250t ladle smelting and the cast of refinement granular protecting cinder through desulfurizing iron, converter smelting, RH vacuum-treat treatment time, the molten steel tapping temperature is at 1655～1660 ℃, the tapping end temp is at 1605～1615 ℃, casting temperature is cleared up on inspection at 1560～1570 ℃, slab, slab heating temperature is controlled at 1190～1200 ℃, the roughing temperature is controlled at 1080～1100 ℃ during hot rolling, finishing temperature is controlled at 850～870 ℃, laminar flow speed of cooling and is controlled at 30～40 ℃/s, cooling time 6～8s; Coiling temperature is controlled at 600～610 ℃; Pickling, cold rolling draft are controlled at 70～75%; Continuous annealing, annealing ignition technique pattern comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature is incubated, the cooling of low-temperature zone middling speed.Rapid heating speed control wherein is at 5～10 ℃/s, heat-up time 120～140s; The temperature of of short duration soak is controlled at 780～800 ℃, soaking time 200～210s; The quick speed of cooling of high temperature section is controlled at 30～35 ℃/s, cooling time 12～16s; The temperature of of short duration low temperature insulation is controlled at 400～410 ℃, soaking time 150～160s; Low-temperature zone middling speed speed of cooling is at 25～30 ℃/s, and cooling time is at 10～12s; Then through smooth, finishing, oiling, packing and finished product.
Respectively mechanical properties such as the yield strength of above five embodiment products, tensile strength, unit elongation, yield tensile ratio, strain hardening index are detected, its detected result correspondence is as shown in table 1:
Table 1: the mechanical property of five embodiment of product of the present invention:
| Embodiment | Thickness of slab mm | Yield strength MPa | Tensile strength MPa | Yield tensile ratio | Unit elongation % | The strain hardening index |
| 1 | 1.40 | 460 | 715 | 0.64 | 28 | 0.19 |
| 2 | 1.40 | 460 | 710 | 0.65 | 28 | 0.19 |
| 3 | 1.40 | 465 | 725 | 0.64 | 29 | 0.19 |
| 4 | 1.40 | 465 | 735 | 0.63 | 28 | 0.19 |
| 5 | 1.40 | 470 | 725 | 0.64 | 28 | 0.19 |
Data as can be known from table 1, the yield strength of embodiments of the invention product and tensile strength are all above the yield strength (conventional steel is below the 400MPa) and the tensile strength (conventional steel is below 700MPa) of conventional high-strength steel, wherein, yield strength and tensile strength ratio are 0.63, are starkly lower than the lower value 0.70 of conventional high-strength steel.Yield tensile ratio is low, mean that the forming ability of material is good, and anti-fracture energy is strong, this index, and the high-strength steel of using for impact briquetting is even more important.Because if the yield strength height, then corresponding forming mould requirement of strength is higher, brings pressure for the cost of mould, simultaneously, yield strength is too high, and resilience promptly takes place the shape easy deformation of part after the punching press, can not satisfy the dimension precision requirement of part.The unit elongation of embodiments of the invention product steel is all above 24% of conventional steel requirement simultaneously, work hardening exponent is all above 0.18 of conventional steel requirement, thereby steel of the present invention demonstrates good bending forming performance and accessory size stability, good welding conformability, good weld seam roll-forming performance, can satisfy the moulding of cylinder part, welding and making, and can promote the use of like product, compare with traditional vanadium niobium titanium high strength, not only production cost is low, and formability, weldability and weld seam roll-forming are stable, have embodied to have better market prospect and remarkable social benefit and economic benefit.
Claims (2)
1. 700MPa level high-strength cold rolling carbon-aluminum-manganese steel plate, it is characterized in that: the weight percent of each component is in this steel plate: C:0.18～0.23%; Al:1.20～1.50%; Mn:1.50～1.80%; Si≤0.50%; P≤0.040%, S≤0.005%; Surplus is Fe and unavoidable impurities.
2. the manufacture method of the described 700MPa level of claim 1 high-strength cold rolling carbon-aluminum-manganese steel plate, may further comprise the steps: desulfurizing iron, converter smelting, RH vacuum-treat, continuous casting, slab inspection and cleaning, slab heating, hot rolling, laminar flow cool off, batch, pickling, cold rolling, continuous annealing, smooth, finishing and oiling, it is characterized in that:
The vacuum treated time of described RH is controlled at 18～23min; Described continuous casting adopts the above large vol ladle of 200t to smelt and the cast of refinement granular protecting cinder, and the molten steel tapping temperature is at 1650～1660 ℃, and the tapping end temp is at 1600～1615 ℃, and casting temperature is at 1560～1570 ℃; Described slab heating temperature is controlled at 1180～1220 ℃; Described hot rolled roughing temperature is controlled at 1060～1100 ℃, and finishing temperature is controlled at 830～870 ℃; Described laminar flow speed of cooling is controlled at 20～40 ℃/s, cooling time 6～12s; Described coiling temperature is controlled at 580～620 ℃; Described cold rolling draft is controlled at 60～80%;
The technology pattern of described continuous annealing comprises: rapid heating, of short duration soak, high temperature section are cooled off fast, of short duration low temperature insulation, the cooling of low-temperature zone middling speed, and wherein the rapid heating speed control is at 5～10 ℃/s, heat-up time 75～160s; The temperature of of short duration soak is controlled at 750～800 ℃, soaking time 180～240s; The quick speed of cooling of high temperature section is controlled at 20～40 ℃/s, cooling time 8～20s; The temperature of of short duration low temperature insulation is controlled at 390～410 ℃, soaking time 120～180s; Low-temperature zone middling speed speed of cooling is controlled at 20～30 ℃/s, cooling time 10～15s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100633376A CN101603144B (en) | 2009-07-28 | 2009-07-28 | Manufacturing method of 700 MPa level high-strength cold rolling carbon-aluminum-manganese steel plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100633376A CN101603144B (en) | 2009-07-28 | 2009-07-28 | Manufacturing method of 700 MPa level high-strength cold rolling carbon-aluminum-manganese steel plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101603144A true CN101603144A (en) | 2009-12-16 |
| CN101603144B CN101603144B (en) | 2011-04-27 |
Family
ID=41469043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100633376A Expired - Fee Related CN101603144B (en) | 2009-07-28 | 2009-07-28 | Manufacturing method of 700 MPa level high-strength cold rolling carbon-aluminum-manganese steel plate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101603144B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102011060A (en) * | 2010-09-30 | 2011-04-13 | 广州珠江钢铁有限责任公司 | 700MPa-grade cold rolled steel plate with high weather resistance and preparation method thereof |
| CN106862379A (en) * | 2017-01-18 | 2017-06-20 | 滁州市新康达金属制品有限公司 | A kind of refrigerator bottom plate stamping part processing and treating method |
| CN107475630A (en) * | 2017-09-01 | 2017-12-15 | 新冶高科技集团有限公司 | A kind of galvanizing nano reinforcement high strength low-carbon Nb bearing steel and preparation method thereof |
| CN107916359A (en) * | 2017-10-31 | 2018-04-17 | 华晨汽车集团控股有限公司 | A kind of preparation method of the medium managese steel with favorable forming property |
-
2009
- 2009-07-28 CN CN2009100633376A patent/CN101603144B/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102011060A (en) * | 2010-09-30 | 2011-04-13 | 广州珠江钢铁有限责任公司 | 700MPa-grade cold rolled steel plate with high weather resistance and preparation method thereof |
| CN106862379A (en) * | 2017-01-18 | 2017-06-20 | 滁州市新康达金属制品有限公司 | A kind of refrigerator bottom plate stamping part processing and treating method |
| CN107475630A (en) * | 2017-09-01 | 2017-12-15 | 新冶高科技集团有限公司 | A kind of galvanizing nano reinforcement high strength low-carbon Nb bearing steel and preparation method thereof |
| CN107475630B (en) * | 2017-09-01 | 2019-09-27 | 新冶高科技集团有限公司 | A kind of hot galvanizing nano reinforcement high strength low-carbon Nb bearing steel and preparation method thereof |
| CN107916359A (en) * | 2017-10-31 | 2018-04-17 | 华晨汽车集团控股有限公司 | A kind of preparation method of the medium managese steel with favorable forming property |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101603144B (en) | 2011-04-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101701316B (en) | Automobile beam steel with tensile strength of 590MPa and manufacturing method thereof | |
| CN101928885B (en) | Hydrothion corrosion resistant pipe steel and production method thereof | |
| CN101812635B (en) | Class Q345F steel sheet with thickness of 80mm and manufacturing method thereof | |
| CN103614640B (en) | A kind of non-coating hot press-formed steel of resistance to high temperature oxidation | |
| CN101864536B (en) | Q 390E class super-thick steel plate with thickness of 100mm and manufacturing method thereof | |
| CN101153371B (en) | High-strength cold-formed hot continuous rolled steel plate and method of preparing the same | |
| CN107964624A (en) | A kind of yield strength 500MPa level structure steel and preparation method thereof | |
| CN106811700B (en) | A kind of think gauge acid-resisting X60MS hot-rolled coils and its manufacture method | |
| CN104264038A (en) | 440 MPa-grade continuous-annealed and cold-rolled structural steel plate and production process thereof | |
| EP3828293A1 (en) | Corrosion-resistant mirror die steel and manufacturing method therefor | |
| CN102089099A (en) | Continuously cast slab and process for production of same | |
| CN103849812A (en) | Low-brittleness 700MPa-level automobile beam steel and manufacturing method thereof | |
| CN109609845A (en) | A kind of 500MPa grades of weathering steel and its production method | |
| CN102409233A (en) | Low-temperature steel for engineering machinery and production method thereof | |
| CN104131238B (en) | High molding high durable Ultra-thin hot rolled steel plate and CSP production technology thereof | |
| CN111471937A (en) | Low-cost chromium-containing Q460MC steel plate and production method thereof | |
| CN111118387A (en) | Method for improving surface quality of boron-containing steel continuous casting slab | |
| CN101603144B (en) | Manufacturing method of 700 MPa level high-strength cold rolling carbon-aluminum-manganese steel plate | |
| CN103361552A (en) | V-N microalloying 460MPa-level thick plate and manufacturing method thereof | |
| CN105734414A (en) | Medium-carbon non-quenched and tempered steel and production method thereof | |
| CN107641762B (en) | 340 MPa-grade hot-rolled automobile structural steel plate with excellent cold formability and manufacturing method thereof | |
| CN107723607B (en) | 420 MPa-grade hot-rolled automobile structural steel plate with excellent cold formability and manufacturing method thereof | |
| CN113957359A (en) | High-strength steel for automobile wheels and preparation method thereof | |
| CN107641760A (en) | 460MPa levels have the Hot Rolling Automobile structural steel and iron and manufacture method of good fatigue behaviour | |
| CN107641761A (en) | 500MPa levels have the Hot Rolling Automobile structural steel and iron and manufacture method of good welds performance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170714 Address after: 430083, Hubei Wuhan Qingshan District Factory No. 2 Gate joint stock company organs Patentee after: Wuhan iron and Steel Company Limited Address before: 430083 Qingshan District, Hubei, Wuhan factory before the door No. 2 Patentee before: Wuhan Iron & Steel (Group) Corp. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110427 Termination date: 20190728 |