CN113430457A - 1300 MPa-grade high-elongation low-delay-cracking-sensitivity hot forming steel and production method thereof - Google Patents
1300 MPa-grade high-elongation low-delay-cracking-sensitivity hot forming steel and production method thereof Download PDFInfo
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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
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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- 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
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- 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
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
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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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- 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
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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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
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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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
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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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
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- 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 1300MPa grade high-elongation low-delay cracking sensitive hot forming steel and a production method thereof, wherein the steel comprises the following components in percentage by weight: 0.14 to 0.18%, Si: 1.50-2.0%, Mn: 1.0-1.5%, P is less than or equal to O.Ol, S is less than or equal to 0.005%, A1S: 0.025-0.070%, Cr: 1.0-1.4%, Ni: 0.20 to 0.50%, Ti: 0.020 to 0.050%, Nb 0.020 to 0.050%, Cu: 0.20-0.40%; b: 0.002-0.005%, and the balance of Fe and inevitable impurities. The hot forming steel has tensile strength of more than 1300MPa, has higher extensibility and lower sensitivity of delayed cracking caused by hydrogen by adding alloys such as Ni, Cu, Nb, titanium and the like and increasing the austenite content in the steel in the quenching process through the distribution process, is applied to manufacturing structural members and safety members on an upper automobile body and a lower automobile body of an automobile, can reduce the weight of the automobile body, and can effectively protect the safety of drivers and passengers.
Description
Technical Field
The invention belongs to the field of high-strength steel production in metallurgical industry, is particularly suitable for producing hot-forming high-strength steel, and particularly belongs to hot-forming steel.
Background
With the rapid development of the automobile industry, light weight and safety become the main direction of the development of the automobile industry. The use of the hot formed steel is the most effective measure for improving the automobile collision safety at present and is also an important way for light weight. At present, the steel plate is most applied to low-carbon Mn-B series steel plates, the structure of the steel plate is changed into uniform martensite after quenching, the strength reaches 1300MPa, and the steel plate is applied to the positions of A columns, B columns, front and rear bumpers, hinge reinforcing plates, door anti-collision beams, middle channels and the like.
However, as the strength is increased, the delayed cracking problem of steel also occurs, which becomes a significant problem restricting the application and development of ultra-high strength steel. The delayed cracking is a phenomenon that the material is subjected to brittle failure after a certain time under the action of static stress, is a result of interaction between the material and the environment and stress, is caused by hydrogen in the service environment of the material, is a form of material degradation caused by the hydrogen, and has more remarkable cracking sensitivity when the strength level exceeds 1000 MPa. Delayed cracking often occurs suddenly when the level of applied stress to which the material is subjected is significantly lower than its yield strength, and as brittle fracture occurs, the energy absorption effect of the steel is greatly reduced, often resulting in more severe damage and consequences.
At present, the specific measures adopted at home and abroad are as follows. (1) And refining grains, namely adding Al, Ti, Nb, V and other elements to generate dispersed and precipitated carbonitride to refine the prior austenite grains, so that the toughness can be improved while the strength is improved. (2) Reducing grain boundary segregation, reducing the content of impurity elements such as phosphorus, sulfur and the like, improving the grain boundary binding force, delaying the initiation of delayed fracture cracks, and further improving the delayed fracture resistance of the high-strength steel. (3) Reduce the amount of hydrogen invading the steel surface or add the hydrogen-repellent element to make the hydrogen not to be enriched at the grain boundary. (4) The intruding hydrogen is made harmless, and a proper amount of micro alloy elements such as V, Ti, Nb and the like are added to form fine carbonitride which can be used as a hydrogen trap to inhibit the diffusion of hydrogen, so that the hydrogen in the steel is uniformly distributed.
Disclosure of Invention
Based on the defects of the prior art, the technical problem to be solved by the invention is to provide the production method for effectively producing the low-hydrogen delayed cracking sensitive hot formed steel, and the production method for the 1300MPa grade high-elongation low-delayed cracking sensitive hot formed steel can effectively solve the problems that the existing 1300MPa hot formed steel has high hydrogen delayed cracking sensitivity and has cracking risk in use.
In order to solve the technical problems, the invention provides 1300 MPa-grade high-elongation low-delay crack sensitive hot forming steel which comprises the following components in percentage by weight: 0.14 to 0.18%, Si: 1.50-2.0%, Mn: 1.0-1.5%, P is less than or equal to 0.0 l%, S is less than or equal to 0.005%, A1S: 0.025-0.070%, Cr: 1.0-1.4%, Ni: 0.20 to 0.50%, Ti: 0.020 to 0.050%, Nb 0.020 to 0.050%, Cu: 0.20-0.40%; b: 0.002-0.005%, and the balance of Fe and inevitable impurities.
Preferably, the 1300MPa grade high elongation low delayed crack sensitivity hot forming steel provided by the invention further comprises part or all of the following technical characteristics:
as an improvement of the technical scheme, the 1300MPa grade high-elongation low-delay crack sensitive hot forming steel has yield strength Rp0.2850-1000 MPa, tensile strength Rm not less than 1300MPa, and elongation A50mmNot less than 12 percent, hydrogen embrittlement sensitivity Iε≤50％。
A method of producing a 1300MPa grade high elongation low delayed crack sensitivity hot formed steel as described in any of the above, comprising the steps of:
desulfurizing molten iron, smelting in a converter, and controlling the smelting end point C: 0.05-0.06 percent of steel, less than or equal to 0.008 percent of P, less than or equal to 0.002 percent of S, less than or equal to 0.004 percent of N, and the tapping temperature is 1700-1780 ℃;
smelting in a converter and continuously casting into a blank; slowly cooling the casting blank, exhausting gas in steel, heating the casting blank to 1200-1250 ℃ in the hot rolling process, carrying out rough rolling and fine rolling, and controlling the final rolling temperature to 840-880 ℃;
after laminar cooling, controlling the coiling temperature to be 600-630 ℃; in the cold rolling process, firstly, carrying out conventional pickling and cold rolling, and then carrying out continuous annealing, wherein the annealing temperature is controlled to be 750-810 ℃;
performing conventional finishing and shearing, and blanking the sheared material on a cold stamping die;
heating the sample wafer in a nitrogen protective atmosphere, keeping the heating temperature at 880-930 ℃, preserving heat for 180-300 s for austenitizing, then quickly placing the sample wafer in a die with a temperature control device for stamping and forming, controlling the quenching temperature of a steel plate to be 340-360 ℃, quickly heating to 420-460 ℃, preserving heat for 2-5 minutes, and then quenching to room temperature to obtain a lath martensite structure and a residual austenite structure, and measuring the content of the residual austenite by using an XRD diffractometer to be about 3-4%, thereby obtaining better elongation and delayed cracking resistance.
The action and mechanism of each element and main process in the invention
C: carbon is a strong solid solution strengthening element and plays a determining role in obtaining ultrahigh strength, the carbon content has great influence on the structure form and the performance of a final product, but the content is too high, a large amount of pearlite, bainite and martensite are easily formed in the cooling process after finish rolling, the content is higher, the strength is higher, the plasticity is reduced, and blanking before forming is difficult. Therefore, the carbon content is not easy to be too high on the premise of ensuring the heat treatment strengthening. Therefore, the content is limited to 0.14 to 0.18%.
Si: the silicon has strong solid solution strengthening effect, can improve the strength of the steel, simultaneously can improve the hardenability of the steel, has the function of reducing the volume change when the austenite is transformed into martensite, thereby effectively controlling the generation of quenching cracks, can block the diffusion of carbon during low-temperature tempering, can improve the activity of C in the austenite by Si, can increase the stability of the austenite during the hot forming process, obtains more residual austenite, improves the extensibility, and can influence the surface quality of the steel when the silicon content is too high. Therefore, the content is limited to 1.50 to 2.0%.
Mn: manganese plays a role in solid solution strengthening and obviously improves the quality of steel. And MnS with high melting point can be generated with sulfide, and has enough plasticity during hot processing, so that the steel does not generate hot brittleness, the harmful effect of sulfur is reduced, and the hot processing performance of the steel is improved. Manganese can reduce the phase transformation driving force, make the C curve shift to the right, improve the hardenability of steel, enlarge the austenite phase region, reduce the Ms point of steel, thus can ensure to obtain martensite at proper cooling speed and can increase the stability of retained austenite. Therefore, the content is limited to 1.0 to 1.5%.
P is a harmful element in steel, and is easy to cause central segregation of a casting blank. The steel is easy to be deviated to a grain boundary in the subsequent hot continuous rolling heating process, so that the brittleness of the steel is obviously increased. Meanwhile, the content is controlled to be below 0.01 percent based on the consideration of cost and without influencing the performance of steel.
S sulfur is a very harmful element. Sulfur in steel often exists in the form of sulfide of manganese, and this sulfide inclusion deteriorates toughness of steel and causes anisotropy of properties, so that the lower the sulfur content in steel, the better. The sulfur content in steel is controlled to 0.005% or less in consideration of the manufacturing cost.
Cr: chromium increases the hardenability of steel and has a secondary hardening effect, the hardness and wear resistance of carbon steel can be improved without making the steel brittle, Cr can improve the strength and hardness of the steel in a rolled state, the elongation and the reduction of area are reduced, Cr can improve the hardenability, the steel has better comprehensive mechanical properties after quenching and tempering, in addition, chromium can improve the tempering stability of the steel, and carbide of Cr has a hydrogen adsorption effect and can inhibit the diffusion of hydrogen, so that the Cr content is required to be in the range of 1.0-1.40%.
B, boron is an element for strongly improving the hardenability, and the hardenability of the steel can be obviously improved by adding trace boron into the steel. However, the content thereof is less than 0.002% or more than 0.005%, and the effect of improving hardenability is not significant. Therefore, the content is limited to 0.002 to 0.005% in consideration of practical production and hardenability effect.
Al: the alloy has a deoxidation effect in steel, a certain amount of acid-soluble aluminum in the steel is ensured, otherwise the effect cannot be exerted, meanwhile, a proper amount of aluminum is added into the steel, the adverse effect of nitrogen and oxygen atoms in the steel on the performance can be eliminated, and the diffusion coefficient of hydrogen in the steel can be reduced by adding Al. Therefore, the content of Als is limited to the range of O.025 to 0.070%.
Ti, Ti is a strong C, N compound forming element, and is added into steel for two main purposes, one is to protect B in the steel and improve the hardenability of the steel, and the other is to precipitate and strengthen the strength and the toughness of the steel. Ti added into the steel can be combined with C to generate stable TiC, and TiC particles have the function of preventing crystal grains from growing, can refine the crystal grains and improve the strength and the toughness. The carbon and the nitride of the titanium are good hydrogen traps, can effectively inhibit the diffusion of hydrogen in the steel, and are favorable for improving the delayed cracking resistance of the steel. The content of the steel is limited to 0.020-0.050%.
Nb: niobium is also a strong C, N compound forming element and can play a role in refining austenite grains, and a small amount of niobium is added into steel to form a certain amount of niobium carbon and nitride, so that the austenite grains are prevented from growing, therefore, the quenched martensite lath has a small size, and the strength of the steel is greatly improved; in addition, niobium carbon and nitride are good hydrogen traps, hydrogen diffusion in steel can be effectively inhibited, and delayed cracking resistance of the steel is improved, however, the content of Nb is expensive alloy, and the generation cost is increased. Therefore, the content is controlled to be 0.020-0.050%.
Ni: the nickel can improve the hardenability of the steel and the toughness of the steel, in addition, the nickel can improve the corrosion resistance of the steel, can resist acid and corrosion of alkali and atmosphere so as to reduce the risk of environmental fracture, and simultaneously the nickel can effectively pin hydrogen atoms so as to reduce the diffusion rate of the hydrogen in the steel and prevent hydrogen from gathering, and the content of the Ni in the steel is controlled to be 0.20-0.50 percent.
Cu: the outstanding effect of copper in steel is to improve the corrosion performance of low alloy steel, thereby inhibiting the steel from absorbing hydrogen from the environment in the service process, and simultaneously Cu has the function of repelling hydrogen, and copper element can repel hydrogen when in a grain boundary, so that hydrogen is difficult to enrich at the grain boundary, but the copper content is too high to generate hot brittleness, so the copper content in the steel is controlled to be 0.20-0.40%.
Compared with the prior art, the invention has the advantages that the tensile strength is more than 1300MPa, the austenite content in steel is increased through adding alloys such as Ni, Cu, Nb, titanium and the like and through the distribution process in the quenching process, so that the ductility is higher and the hydrogen-induced delayed cracking sensitivity is lower.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects: the technology optimizes the components and the process to manufacture the hot forming steel, has 1300MPa of tensile strength, greatly improves the extensibility of the material, has higher product of strength and elongation, and has better performance of resisting delayed cracking.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the contents of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following detailed description is given in conjunction with the preferred embodiments.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.
FIG. 1 is a metallographic result chart showing a 1300MPa grade high elongation low delayed crack sensitivity hot-forming steel of example 1 of the present invention.
Detailed Description
Other aspects, features and advantages of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention.
The chemical composition of the steel sheets was as shown in table 1 below,
TABLE 1 tabulated (wt%) chemical composition values for each example of the invention and comparative example
TABLE 2 Main Process for examples of the invention and comparative examples
The conventional mechanical properties of the test steel and the comparative steel are compared, and the results are shown in Table 3; meanwhile, the delayed cracking performance of the test steel and the comparative steel are compared, an SSRT slow tensile test is carried out in 0.1mol/L HCl, and the tensile strain rate is 1.0 multiplied by 10-5Per s by calculating the loss of elongation (hydrogen embrittlement index I)
To evaluate the delayed cracking resistance, IεSmaller values represent better resistance to delayed cracking. The comparative steel and the hydrogen embrittlement resistant hot forming steel produced by the method are compared in resistance to delayed cracking as shown in Table 3.
TABLE 3 results of testing the properties of the inventive and comparative examples
Compared with the prior art, the invention has the advantages that the tensile strength is more than 1300MPa, the austenite content in steel is increased through adding alloys such as Ni, Cu, Nb, titanium and the like and through the distribution process in the quenching process, so that the ductility is higher and the hydrogen-induced delayed cracking sensitivity is lower.
The raw materials listed in the invention, the upper and lower limits and interval values of the raw materials of the invention, and the upper and lower limits and interval values of the process parameters (such as temperature, time and the like) can all realize the invention, and the examples are not listed.
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims (4)
1. A1300 MPa grade high elongation low delayed cracking sensitive hot forming steel is characterized in that: the components and weight percentage content are as follows: 0.14 to 0.18%, Si: 1.50-2.0%, Mn: 1.0-1.5%, P is less than or equal to O.Ol, S is less than or equal to 0.005%, A1S: 0.025-0.070%, Cr: 1.0-1.4%, Ni: 0.20 to 0.50%, Ti: 0.020 to 0.050%, Nb 0.020 to 0.050%, Cu: 0.20-0.40%; b: 0.002-0.005%, and the balance of Fe and inevitable impurities.
2. A 1300MPa grade high elongation low delayed crack susceptible hot formed steel according to claim 1 wherein: the 1300MPa grade high-elongation low-delay crack sensitive hot forming steel has yield strength RpO.2850-1000 MPa, tensile strength Rm not less than 1300MPa, and elongation A50mmNot less than 12 percent, hydrogen embrittlement sensitivity Iε≤50％。
3. A method of producing a 1300MPa grade high elongation low delayed crack sensitivity hot formed steel according to claim 1 or 2, comprising the steps of:
desulfurizing molten iron, smelting in a converter, and controlling the smelting end point C: 0.05-O.06 percent, less than or equal to 0.008 percent of P, less than or equal to 0.002 percent of S, less than or equal to 0.004 percent of N, and the tapping temperature is 1700-1780 ℃;
smelting in a converter and continuously casting into a blank; slowly cooling the casting blank, exhausting gas in steel, heating the casting blank to 1200-1250 ℃ in the hot rolling process, carrying out rough rolling and fine rolling, and controlling the final rolling temperature to 840-880 ℃;
after laminar cooling, controlling the coiling temperature to be 600-630 ℃; in the cold rolling process, firstly, carrying out conventional pickling and cold rolling, and then carrying out continuous annealing, wherein the annealing temperature is controlled to be 750-810 ℃;
performing conventional finishing and shearing, and blanking the sheared material on a cold stamping die;
heating the sample wafer in a nitrogen protective atmosphere at 880-930 ℃, preserving heat for 180-300 s for austenitizing, then quickly placing the sample wafer in a die with a temperature control device for stamping and forming, controlling the quenching temperature of a steel plate to be 340-360 ℃, quickly heating to 420-460 ℃, preserving heat for 2-5 minutes, and then quenching to room temperature.
4. A method of producing a 1300MPa grade high elongation low delayed crack sensitivity hot formed steel according to claim 3, characterized in that: the 1300MPa grade high-elongation low-delay cracking sensitive hot forming steel prepared has the residual austenite content of about 3-4%.
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|---|---|---|---|---|
| CN101275200A (en) * | 2008-05-21 | 2008-10-01 | 钢铁研究总院 | Hotforming martensitic steel |
| CN101638749A (en) * | 2009-08-12 | 2010-02-03 | 钢铁研究总院 | Automobile steel with low cost and high strength ductility balance and preparation method thereof |
| CN111748736A (en) * | 2020-06-24 | 2020-10-09 | 武汉钢铁有限公司 | 1800 MPa-grade low-hydrogen delayed cracking sensitive hot forming steel and production method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101275200A (en) * | 2008-05-21 | 2008-10-01 | 钢铁研究总院 | Hotforming martensitic steel |
| CN101638749A (en) * | 2009-08-12 | 2010-02-03 | 钢铁研究总院 | Automobile steel with low cost and high strength ductility balance and preparation method thereof |
| CN111748736A (en) * | 2020-06-24 | 2020-10-09 | 武汉钢铁有限公司 | 1800 MPa-grade low-hydrogen delayed cracking sensitive hot forming steel and production method thereof |
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