CN114908302B - Hydrogen embrittlement resistant high-strength spring steel and heat treatment method thereof - Google Patents
Hydrogen embrittlement resistant high-strength spring steel and heat treatment method thereof Download PDFInfo
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Abstract
A hydrogen embrittlement resistant high strength spring steel and a heat treatment method thereof belong to the technical field of metal structural materials. The mass content of the chemical components is as follows: 0.35 to 0.50 percent of C, less than or equal to 0.15 percent of Si, 1.30 to 1.70 percent of Mn, 1.20 to 2.00 percent of Cr, 0.30 to 0.55 percent of Mo, 2.8 to 3.5 percent of Ni, 1.3 to 2.0 percent of Cu, 0.9 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe. The steel has the advantages that the strength meets the 1500-1900 level requirement, the hydrogen embrittlement resistance can be improved by 30-50%, and the steel is suitable for being used as high-end spring steel.
Description
Technical Field
The invention belongs to the technical field of spring steel, and particularly provides hydrogen embrittlement resistant high-strength spring steel and a heat treatment method thereof. The method is suitable for manufacturing spring structural parts in the fields of automobiles, engineering machinery, such as suspension springs, leaf springs and the like.
Background
With the rapid development of the industries of automobiles and engineering machinery, attention is paid to the high-reinforcement application and development of steel materials for reducing cost, weight and energy conservation. However, as the strength increases, the sensitivity to delayed fracture increases, and hydrogen-induced delayed fracture has become a key factor in impeding the wide use of high strength steels. In order to realize the light weight and collision safety of automobiles and improve the strength of steel for automobiles, the automobile industry in China is one of the main ways, the autonomous research and development and application of high-strength steel are urgently needed, the strength of parts for manufacturing bumpers, door anti-collision beams, springs, bolts and the like at present reaches 1500MPa or higher, the application of ultra-high-strength materials in China gradually becomes trend, and the problem of hydrogen-induced delay fracture sensitivity is more remarkable. The suspension spring is a typical part which is easy to generate delayed fracture, the strength of the suspension spring belongs to a higher level in the field of automobile steel, and the suspension spring is widely applied to the fields of high-speed trains, heavy-duty trucks, engineering machinery, high-end equipment manufacturing and the like. The alloy spring steel is used in the automobile industry and accounts for more than 65% of the total consumption, the automobile suspension spring steel has the high-strength tempered martensite structure, and the suspension spring is also subjected to a load equivalent to the weight of a vehicle body in an automobile static state, so that the risk of delayed fracture is increased. The suspension spring is coated with a resin film to prevent the stress corrosion surface, but during long-time service, the resin film coated part is often damaged along with the sliding of the end part of the spring caused by the flying stone collision and repeated deformation during running, and the damage part has the risk of causing hydrogen embrittlement fracture due to the entry of environmental hydrogen, so that safety accidents occur. In particular, in order to reduce the weight of a suspension spring, when the spring steel is made stronger, it is necessary to design the spring steel to be resistant to hydrogen embrittlement.
The prior spring steel has no obvious hydrogen embrittlement resistance, the traditional method for improving the hydrogen embrittlement resistance by adopting carbide as a hydrogen trap requires a complex heat treatment process, and the heat treatment tempering temperature for obtaining carbide precipitation is higher, so that the effect of the hydrogen trap cannot be exerted under the heat treatment process commonly adopted in the prior spring manufacturing, and therefore, the spring steel with high strength for resisting the hydrogen embrittlement and the corresponding heat treatment system are required to be provided, and the problem of insufficient hydrogen embrittlement resistance of the prior spring steel is solved.
Disclosure of Invention
The invention aims to provide hydrogen embrittlement resistant high-strength spring steel and a heat treatment method thereof, which solve the problem that the high-strength spring steel cannot be realized and has the hydrogen embrittlement resistance in the prior art.
The aim of the invention is mainly realized by the following technical scheme: the invention provides hydrogen embrittlement resistant high-strength spring steel, which comprises the following components in percentage by mass: 0.35 to 0.50 percent of C, less than or equal to 0.15 percent of Si, 1.30 to 1.70 percent of Mn, 1.20 to 2.00 percent of Cr, 0.30 to 0.55 percent of Mo, 2.8 to 3.5 percent of Ni, 1.3 to 2.0 percent of Cu, 0.9 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
Furthermore, the elements in the hydrogen embrittlement resistant high-strength spring steel are Ni, cu and Al are less than or equal to 3 and less than or equal to 1.
Furthermore, the hydrogen embrittlement resistant high-strength spring steel contains nano-scale NiAl and Cu precipitated phases, and the size is in the range of 2-10nm.
Further, the precipitated phase and the matrix in the hydrogen embrittlement resistant high-strength spring steel keep a coherent relation, and the precipitation strengthening increment reaches 300-400MPa.
The hydrogen embrittlement resistant high-strength spring steel structure is a lath martensite tempering structure plus NiAl and Cu precipitated phase.
The size of the precipitated phases of the Ni Al and the Cu in the BCC structures in the B2 structure is 2-10nm, and the precipitated phases and the matrix are kept in a coherent relation.
Further, the hydrogen embrittlement resistant high-strength spring steel comprises the following components in percentage by mass: 0.37 to 0.47 percent of C, less than or equal to 0.15 percent of Si, 1.40 to 1.60 percent of Mn, 1.50 to 1.80 percent of Cr, 0.35 to 0.45 percent of Mo, 2.9 to 3.3 percent of Ni, 1.5 to 1.8 percent of Cu, 1.00 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
Further, the hydrogen embrittlement resistant high-strength spring steel comprises the following components in percentage by mass: 0.39 to 0.43 percent of C, less than or equal to 0.15 percent of Si, 1.45 to 1.55 percent of Mn, 1.55 to 1.65 percent of Cr, 0.38 to 0.43 percent of Mo, 3.0 to 3.2 percent of Ni, 1.65 to 1.75 percent of Cu, 1.20 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
The strength of the hydrogen embrittlement resistant high-strength spring steel provided by the invention can meet the high-strength spring grade requirement, and the strength increment is 300-400MPa, the strength of the spring steel is 1500-1900MPa, and the delayed fracture resistance is improved by 30-50% compared with that of the traditional spring steel.
The effect of adding chemical elements into the hydrogen embrittlement resistant high-strength spring steel provided by the invention is as follows:
c: the strength and hardenability of the steel are improved by using the element C, and the strength and plasticity of the steel are well matched by controlling the content of the element C. As the common precipitation strengthening of NiAl and Cu is adopted, the content of C element in the steel can be reduced by 20-40% compared with that of the traditional spring steel.
Si: by controlling the content of Si element, the influence of Si on cold forming performance of the steel is avoided, so that the steel can be used for preparing parts such as cold coil springs and the like.
Mn: mn is utilized to improve the hardenability and the cold work hardening rate of the steel, and through dosage control, segregation of Mn element in the steel solidification process is avoided, and adverse effect on cold plastic deformation of the steel is reduced. Mn in the steel of the present invention can promote nucleation of a precipitated phase of NiAl and promote precipitation thereof.
Cr: cr is utilized to improve the hardenability, wear resistance, corrosion resistance and high-temperature strength of the steel; by controlling the content, the influence on the cold working performance of the steel is avoided; in addition, cr can reduce decarburization tendency, and can meet the requirement of the spring steel on surface decarburization after heat treatment.
Mo: the quenchability of the steel is adjusted by using Mo element, the sensitivity of the steel to the tempering brittleness is reduced, the tempering brittleness of the steel after high-temperature tempering is prevented, and the tensile strength of the steel under the high-temperature tempering condition is greatly influenced.
Ni: the hardenability, low-temperature toughness and weather resistance of the steel are improved by utilizing Ni element, a NiAl precipitated phase with a B2 type structure can be formed, and the strength of the steel can be improved and used as a hydrogen trap.
Cu: the Cu element is utilized to form nanocluster precipitation in the heat treatment process, so that the precipitation strengthening effect is improved, and the Cu element can be used as a hydrogen trap to improve the hydrogen embrittlement resistance.
Al: the NiAl precipitated phase with Ni to form a B2 type structure can improve the strength of steel and act as a hydrogen trap.
P: the content of the P element is controlled in the range, so that micro segregation of the P element during solidification of molten steel can be avoided, and the delayed fracture sensitivity of the steel is reduced.
S: the S element content is controlled in the range, so that MnS inclusion formed by the S element and Mn can be avoided, and the influence of the inclusion on the hot workability of the steel is reduced.
N: the content of N element is controlled in the range, so that the N content is reduced to avoid forming TiN inclusion in the steel and damaging the toughness of the steel.
The invention also provides a heat treatment method of the hydrogen embrittlement-resistant high-strength spring steel, which is used for obtaining the service performance of the hydrogen embrittlement-resistant high-strength steel, and comprises the following steps of:
(1) Carrying out quenching heat treatment on the spring round steel to obtain a uniform quenched martensitic structure; wherein the quenching temperature is 860-900 ℃, the quenching heat preservation time is 1-2 min/mm, and the cooling mode is water cooling or oil cooling;
(2) Tempering heat treatment is carried out on the spring steel to obtain nano-scale NiAl and Cu precipitated phases, and thus the hydrogen embrittlement resistant high-strength spring steel is obtained; the tempering temperature is 430-470 ℃, and the heat preservation time is 2-3 min/mm. The cooling mode is as follows: air-cooled or water-cooled.
Further: tempering is carried out twice in the step (2), wherein the spring steel is subjected to tempering heat treatment once, so that nano-grade NiAl and Cu precipitated phases are obtained, and the hydrogen embrittlement resistant high-strength spring steel is obtained; the tempering temperature is 390-410 ℃, and the heat preservation time is 1-2 min/mm. The cooling mode is as follows: air cooling or water cooling;
carrying out secondary tempering heat treatment on the spring steel to obtain nano-grade NiAl and Cu precipitated phases, and obtaining the hydrogen embrittlement resistant high-strength spring steel; the tempering temperature is 430-470 ℃, and the heat preservation time is 2-3 min/mm. The cooling mode is as follows: air-cooled or water-cooled.
Compared with the prior art, the invention has at least one of the following beneficial effects:
a) According to the hydrogen embrittlement resistance high-strength spring steel provided by the invention, the nano-grade NiAl and Cu precipitated phases with the size of 2-10nm are obtained by controlling the proportion of NiAl and Cu, and form a coherent relation with a matrix, and the precipitated phases have a hydrogen trap function, can adsorb diffusible hydrogen, improve the hydrogen embrittlement resistance of the high-strength steel, improve the hydrogen embrittlement resistance of the spring steel with the pressure of more than 1500MPa by 30-50%, and solve the contradiction problem between high reinforcement and hydrogen embrittlement of the spring steel. The technical scheme of the invention is different from the method of taking the traditional carbide as the strengthening and hydrogen trapping, the strength of more than 1500MPa can be obtained while the carbon is reduced, larger strength increment can be obtained by adopting fewer alloying elements, the hydrogen embrittlement resistance effect of taking NiAl and Cu as the hydrogen trapping is superior to that of the traditional carbide, and the high strengthening and hydrogen embrittlement resistance are realized, so that the high-performance spring can be used for high-performance springs applied to automobiles, rail transit, high-speed rail and other direct contact complex environments.
b) The hydrogen embrittlement resistance high-strength spring steel provided by the invention can meet the high-strength spring grade requirement, the strength increment of 300-400MPa is realized by means of precipitation strengthening of the common lattice of NiAl and Cu, the strength of the spring steel after heat treatment reaches 1500-1900MPa, and the delayed fracture resistance is improved by 30-50% compared with the traditional spring steel.
c) According to the heat treatment process of the hydrogen embrittlement resistant high-strength spring steel, through carrying out tempering heat treatment in the precipitation ranges of NiAl and Cu, nano-size precipitated phases which are coherent with a matrix can be obtained, and the sizes of the precipitated phases in the steel are regulated so as to obtain spring steel with different strength levels.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like reference numerals being used to refer to like parts throughout the several views.
Fig. 1 is a microstructure TEM morphology of the hydrogen embrittlement resistant high strength spring steel of example 1 of the present invention.
Fig. 2 is a TEM morphology and a diffraction pattern of a crystal structure of the NiAl and Cu precipitated phases of the hydrogen embrittlement resistant high strength spring steel of example 1 of the present invention after heat treatment.
FIG. 3 shows the elemental composition of the NiAl and Cu precipitated phases of the hydrogen embrittlement resistant high strength spring steel of example 1 of the present invention after heat treatment.
Fig. 4 shows the tensile curves of examples 1 to 3 according to the present invention after different heat treatment processes.
Fig. 5 is a graph showing the hydrogen embrittlement resistance (tensile strength lowering rate after hydrogen charging) of examples 2, 3 and 1 of the present invention.
Detailed Description
Preferred embodiments of the present invention are described in detail below with reference to the attached drawing figures, which form a part of the present invention and are used in conjunction with the embodiments of the present invention to illustrate the principles of the present invention.
The invention provides hydrogen embrittlement resistant high-strength spring steel, which comprises the following components in percentage by mass: 0.35 to 0.50 percent of C, less than or equal to 0.15 percent of Si, 1.30 to 1.70 percent of Mn, 1.20 to 2.00 percent of Cr, 0.30 to 0.55 percent of Mo, 2.8 to 3.5 percent of Ni, 1.3 to 2.0 percent of Cu, 0.9 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
Compared with the prior art, the hydrogen embrittlement resistance high-strength spring steel provided by the invention has the advantages that through controlling the proportion of NiAl to Cu, the precipitated phases of NiAl and Cu with the size of 2-10nm are obtained, the precipitated phases keep the nano size and form a coherent relation with a matrix, the precipitated phases have a hydrogen trap function, can adsorb diffusible hydrogen, improve the hydrogen embrittlement resistance of the high-strength steel, improve the hydrogen embrittlement resistance of the spring steel with the pressure of more than 1500MPa by 30-50%, and solve the contradiction problem between high reinforcement and hydrogen embrittlement of the spring steel. The technical scheme of the invention is different from the method of taking the traditional carbide as the strengthening and hydrogen trapping, the strength of more than 1500MPa can be obtained while the carbon is reduced, larger strength increment can be obtained by adopting fewer alloying elements, the hydrogen embrittlement resistance effect of taking NiAl and Cu as the hydrogen trapping is superior to that of the traditional carbide, and the high strengthening and hydrogen embrittlement resistance are realized, so that the high-performance spring can be used for high-performance springs applied to automobiles, rail transit, high-speed rail and other direct contact complex environments.
Through the regulation and control of components and a preparation method, for the hydrogen embrittlement resistant high-strength spring steel, a microstructure of a matrix is a medium-high temperature tempered structure of martensite, separated NiAl and Cu separated phases are distributed on the matrix, and the size is 2-10nm. .
In order to further adjust the comprehensive properties, such as strength and hydrogen embrittlement resistance, of the hydrogen embrittlement resistant high-strength spring steel, the hydrogen embrittlement resistant high-strength spring steel comprises the following components in percentage by mass: 0.37 to 0.47 percent of C, less than or equal to 0.15 percent of Si, 1.40 to 1.60 percent of Mn, 1.50 to 1.80 percent of Cr, 0.35 to 0.45 percent of Mo, 2.9 to 3.3 percent of Ni, 1.5 to 1.8 percent of Cu, 1.00 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
In order to further adjust the comprehensive properties, such as strength and hydrogen embrittlement resistance, of the hydrogen embrittlement resistant high strength spring steel, the hydrogen embrittlement resistant high strength spring steel comprises the following components in percentage by mass: 0.39 to 0.43 percent of C, less than or equal to 0.15 percent of Si, 1.45 to 1.55 percent of Mn, 1.55 to 1.65 percent of Cr, 0.38 to 0.43 percent of Mo, 3.0 to 3.2 percent of Ni, 1.65 to 1.75 percent of Cu, 1.20 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe.
It is worth noting that in practical application, the heat treatment process of the hydrogen embrittlement resistant high-strength spring steel can affect the delayed fracture resistance, so that the quenching and tempering process of the hydrogen embrittlement resistant high-strength spring steel should ensure that the NiAl and Cu are precipitated in nanometer size and keep a coherent relation with the matrix.
The invention provides a heat treatment method of hydrogen embrittlement resistant high-strength spring steel, which is used for preparing the spring steel and comprises the following steps:
step 1: and carrying out quenching heat treatment on the spring round steel to obtain a uniform quenched martensitic structure. Wherein the quenching temperature is 860-900 ℃, the quenching heat preservation time is 1-2 min/mm, and cooling (such as water cooling or oil cooling)
Step 2: and tempering heat treatment is carried out on the spring steel to obtain nano-scale NiAl and Cu precipitated phases, and the hydrogen embrittlement resistant high-strength spring steel is obtained. The tempering temperature is 430-470 ℃, and the heat preservation time is 2-3 min/mm. Cooling (e.g., air cooling or water cooling)
In order to further regulate the performance of the spring steel, the heat treatment method can further comprise the following steps:
step 1: and carrying out quenching heat treatment on the spring steel to obtain a uniform quenched martensitic structure. Wherein the quenching temperature is 860-900 ℃, the quenching heat preservation time is 1-2 min/mm, and cooling (such as water cooling or oil cooling)
Step 2: and carrying out tempering heat treatment on the spring steel for the first time to obtain nano-scale NiAl and Cu precipitated phases, and obtaining the hydrogen embrittlement resistant high-strength spring steel. The tempering temperature is 390-410 ℃, and the heat preservation time is 1-2 min/mm. Cooling (e.g., air cooling or water cooling). And carrying out secondary tempering heat treatment on the spring steel to obtain nano-scale NiAl and Cu precipitated phases, and obtaining the hydrogen embrittlement resistant high-strength spring steel. The tempering temperature is 430-470 ℃, and the heat preservation time is 2-3 min/mm. Cooling (e.g., air cooling or water cooling)
The chemical composition requirements of Table 1 were used to co-smelt 3 furnace steels (example 1, example 2 and example 3), and the chemical compositions of examples 1 to 3 and comparative example 1 were shown in Table 1, the heat treatment process parameters of the spring steels are shown in Table 2, and the mechanical properties after heat treatment and the strength degradation rate after charging of the spring steels were measured and the results of the tests are shown in Table 3, were used as comparative steels (comparative example 1) for smelting 1 furnace 55SiCr commercial steels according to the requirements of GB/T1222-2016.
Table 1 chemical compositions of examples 1 to 3 and comparative example 1, mass%, balance: fe (Fe)
| C | Si | Mn | P | S | Cr | |
| Example 1 | 0.38 | 0.05 | 1.40 | 0.006 | 0.002 | 1.28 |
| Example 2 | 0.43 | 0.08 | 1.53 | 0.008 | 0.005 | 1.62 |
| Example 3 | 0.48 | 0.10 | 1.60 | 0.009 | 0.007 | 1.90 |
| Comparative example 1 | 0.58 | 1.55 | 0.78 | 0.008 | 0.005 | 0.72 |
| Mo | Ni | Al | Cu | N | ||
| Example 1 | 0.32 | 2.89 | 0.95 | 1.39 | 0.004 | |
| Example 2 | 0.42 | 3.05 | 1.03 | 1.68 | 0.005 | |
| Example 3 | 0.49 | 3.30 | 1.12 | 1.82 | 0.007 | |
| Comparative example 1 | / | / | / | / | 0.007 |
Table 2 spring steel heat treatment process of examples 1 to 3 and comparative example 1
TABLE 3 mechanical Properties and strength decrease after Hydrogen charging test results for examples 1 to 3 and comparative example 1
The microstructure of the high strength spring steel with hydrogen embrittlement resistance obtained in the examples was characterized by using a TEM electron microscope, and the results are shown in fig. 1. As can be seen from FIG. 1, the matrix structure of the steel samples obtained in examples 1-3 is a lath martensite tempered structure. FIG. 2 shows a TEM morphology and a diffraction pattern of a crystal structure of a precipitated phase of NiAl and Cu after heat treatment of the hydrogen embrittlement resistant high-strength spring steel, which shows that the size of the precipitated phase is 2-10nm, the NiAl structure is B2, the Cu structure is BCC, and the precipitated phase and the matrix are kept in a coherent relation. The steels obtained in examples 1 to 3 and comparative example 1 were tested for tensile strength and yield strength according to GB/T228 tensile test method at room temperature for metallic materials. The test results are shown in Table 3, the carbon content of the steel is reduced by 20-40%, the strength increment is 300-400MPa through the precipitated phases of NiAl and Cu, the strength reaches 1500-2000MPa after heat treatment, and the requirement of a high-strength spring is met. The hydrogen embrittlement resistance of the spring steel is evaluated by adopting the 'GB/T39039-2020 high-strength steel hydrogen induced delay fracture evaluation method' standard, the test result is shown in Table 3, the strength reduction rate of the comparative steel is 30%, and the strength reduction rate of the inventive steel after hydrogen charging is only 13-19%.
From the above examples 1 to 3 and comparative example 1, the hydrogen embrittlement resistant high strength spring steel provided by the invention has excellent mechanical properties and hydrogen embrittlement resistance, and the hydrogen embrittlement resistance can be improved by 30-50% under the same strength.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.
Claims (3)
1. The hydrogen embrittlement resistant high-strength spring steel is characterized by comprising the following components in percentage by mass: 0.35 to 0.50 percent of C, less than or equal to 0.15 percent of Si, 1.30 to 1.70 percent of Mn, 1.20 to 2.00 percent of Cr, 0.30 to 0.55 percent of Mo, 2.8 to 3.5 percent of Ni, 1.3 to 2.0 percent of Cu, 0.9 to 1.30 percent of Al, less than or equal to 0.010 percent of P, less than or equal to 0.010 percent of S, less than or equal to 0.007 percent of N, and the balance of Fe; and Ni is less than or equal to 3 percent of Cu and Al is less than or equal to 1 percent of Cu;
the hydrogen embrittlement resistant high-strength spring steel structure is a lath martensite tempering structure plus NiAl and Cu precipitated phase;
the size of the precipitated phases of the Ni Al and the Cu in the BCC structures in the B2 structure is 2-10nm, and the precipitated phases and the matrix are kept in a coherent relation.
2. A method of heat treating a hydrogen embrittlement resistant high strength spring steel according to claim 1, comprising the steps of:
(1) Carrying out quenching heat treatment on the spring round steel to obtain a uniform quenched martensitic structure; wherein the quenching temperature is 860-900 ℃, the quenching heat preservation time is 1-2 min/mm, and the cooling mode is water cooling or oil cooling;
(2) Tempering heat treatment is carried out on the spring steel to obtain nano-scale NiAl and Cu precipitated phases, and thus the hydrogen embrittlement resistant high-strength spring steel is obtained; tempering temperature is 430-470 ℃, and heat preservation time is 2-3 min/mm; the cooling mode is as follows: air-cooled or water-cooled.
3. A heat treatment method of hydrogen embrittlement resistant high strength spring steel according to claim 2, characterized in that,
tempering is carried out twice in the step (2), wherein the spring steel is subjected to tempering heat treatment once, so that nano-grade NiAl and Cu precipitated phases are obtained, and the hydrogen embrittlement resistant high-strength spring steel is obtained; tempering temperature is 390-410 ℃, and heat preservation time is 1-2 min/mm; the cooling mode is as follows: air cooling or water cooling;
carrying out secondary tempering heat treatment on the spring steel to obtain nano-grade NiAl and Cu precipitated phases, and obtaining the hydrogen embrittlement resistant high-strength spring steel; tempering temperature is 430-470 ℃, and heat preservation time is 2-3 min/mm; the cooling mode is as follows: air-cooled or water-cooled.
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| CN116083851B (en) * | 2023-04-10 | 2023-06-02 | 松诺盟科技有限公司 | Nano composite film for preventing hydrogen embrittlement and preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007031736A (en) * | 2005-07-22 | 2007-02-08 | Nippon Steel Corp | Method for manufacturing high strength bolt excellent in delayed fracture resistance |
| CN111218618A (en) * | 2020-02-27 | 2020-06-02 | 钢铁研究总院 | Hydrogen embrittlement resistant, high strength and toughness stainless steel bar for fastener and method of making same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3254108B2 (en) * | 1995-05-19 | 2002-02-04 | 株式会社神戸製鋼所 | Ultra-high-strength steel sheet excellent in hydrogen embrittlement resistance and method for producing the same |
| JPH0941079A (en) * | 1995-05-19 | 1997-02-10 | Kobe Steel Ltd | Ultra-high strength steel sheet excellent in delayed fracture resistance and its production |
| JPH101740A (en) * | 1996-06-12 | 1998-01-06 | Kobe Steel Ltd | Ultrahigh strength steel sheet excellent in delayed fracture resistance, and its production |
| JP2002146472A (en) * | 2000-11-09 | 2002-05-22 | Nippon Steel Corp | Steel having excellent hydrogen embrittlement cracking resistance and its production method |
| JP6040753B2 (en) * | 2012-12-18 | 2016-12-07 | 新日鐵住金株式会社 | Hot stamping molded article excellent in strength and hydrogen embrittlement resistance and method for producing the same |
| CN109161794B (en) * | 2018-08-31 | 2019-11-22 | 钢铁研究总院 | A kind of anti-delayed fracture high strength steel and preparation method thereof |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007031736A (en) * | 2005-07-22 | 2007-02-08 | Nippon Steel Corp | Method for manufacturing high strength bolt excellent in delayed fracture resistance |
| CN111218618A (en) * | 2020-02-27 | 2020-06-02 | 钢铁研究总院 | Hydrogen embrittlement resistant, high strength and toughness stainless steel bar for fastener and method of making same |
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