Ultra-high strength and high plasticity copper-containing austenitic stainless steel and production method

Abstract

A super-high yield strength and high plasticity copper-containing austenitic stainless steel, the chemical composition and wt% of which are: C: 0.025-0.031%, Si: 0.33-0.76%, Mn: 7.32-13.8%, Cr: 17.3-19.1%, Ni: 0.72-2.9%, N: 0.14-0.35%, Cu: 1.72-3.51%; production method: hot rolling of the ingot after smelting and pouring into a billet; solution treatment; low-temperature cold rolling to product thickness; annealing; natural cooling to room temperature. The present invention obtains not only a yield strength of 1064-1551MPa, but also a tensile strength of 1170-1675MPa, and an elongation of 11.3-30.3% by adding the element copper and utilizing low-temperature rolling combined with low-temperature long-term annealing treatment.

Description

Technical Field

[0001] The invention relates to stainless steel and a production method, in particular to ultra-high strength and high plasticity copper-containing austenitic stainless steel and a production method. Background Art

[0002] Austenitic stainless steel has strong corrosion resistance and excellent plasticity and toughness, and is widely used in various fields as an environmentally friendly material. However, austenitic stainless steel has a low yield strength. As the world's resource and energy consumption issues become increasingly prominent, and the equipment manufacturing industry places higher requirements on the strength and life of various key structural materials, the development of austenitic stainless steel with ultra-high strength and high plasticity is an inevitable choice for the development of the industry and the gradual optimization of the social environment.

[0003] At present, austenitic stainless steel is composed of coarse grains with a face-centered cubic structure, with a yield strength of only 200 to 300 MPa, and it is impossible to improve the strength through phase transformation strengthening during production. In addition, austenitic stainless steel usually adopts a low-carbon / ultra-low-carbon composition design, which reduces the interstitial solid solution strengthening effect of carbon atoms. Nitrogen can also be added to austenitic stainless steel as an interstitial solute atom to improve the yield strength. It is extremely difficult to smelt austenitic stainless steel with a yield strength of more than 700 MPa by adding nitrogen with a mass fraction of more than 1%. Nitriding treatment can increase the nitrogen content on the surface of austenitic stainless steel to 1%, but it has a weak effect on the internal composition and mechanical properties of austenitic stainless steel. Precipitation strengthening can improve the yield strength of stainless steel, but austenitic stainless steel usually avoids the precipitation of carbides to ensure corrosion resistance; the precipitation of nano-scale copper-rich phase particles can improve the strength of austenitic stainless steel, but the copper-rich phase particles precipitated during the aging process can only increase the yield strength by 50 MPa. Deformation strengthening (including surface mechanical grinding, cold rolling, equal-diameter angular extrusion, high-pressure torsion, etc.) can improve the yield strength of austenitic stainless steel, but there are a large number of deformation structures (dislocations, twins and deformation martensite) in the ultra-high strength stainless steel prepared by deformation, which will inhibit dislocation slip and cause a sharp drop in plasticity. Deformation combined with annealing can improve the yield strength of austenitic stainless steel without damaging or less damaging the plasticity. Cold rolling deformation combined with annealing can be used to prepare ultrafine-grained austenitic stainless steel with a yield strength of 700 to 1000 MPa and an elongation greater than 38%. However, if the yield strength of the austenitic stainless steel prepared by the process of this document exceeds 1100 MPa, the plasticity will deteriorate sharply (the elongation does not exceed 10%).

[0004] The document with Chinese patent publication number CN104105805A discloses a "high-strength austenitic stainless steel and its manufacturing method". The document obtains stainless steel with a tensile strength of 2200MPa by adjusting the composition (including less than 1.5% copper) and combining cold rolling (80% reduction). However, after cold rolling with an 80% reduction, a strain-induced martensite structure with a content of 40-60% is generated, which cannot be considered a fully austenitic structure; and the elongation of the steel is not given, and it is difficult to obtain high-plasticity stainless steel by cold rolling deformation treatment with an 80% reduction.

[0005] The document with Chinese patent publication number CN107406934A discloses "High-strength austenitic stainless steel with excellent hydrogen embrittlement resistance and its manufacturing method". This document improves the strength of austenitic stainless steel by adjusting the composition (including less than 1.5% copper) and cooling process to precipitate a large amount of nano-scale carbides in the austenite structure. However, there is no report on the yield strength and elongation of the austenitic stainless steel obtained, and the tensile strength is only 672-755MPa.

[0006] The Chinese patent publication number CN109504911A discloses "A copper-vanadium-containing high-strength and high-corrosion-resistant austenitic stainless steel and its preparation method". The document adds ferrovanadium or metallic vanadium during smelting, and finally precipitates a large amount of nano-scale vanadium carbide in the austenite structure, which improves the strength of austenitic stainless steel. Although it has high plasticity (elongation between 41-47%), its yield strength is only 277-294MPa.

[0007] The document with Chinese patent publication number CN104451082 discloses "A method for preparing 304 austenitic stainless steel with a grain size less than 100nm". The document adopts a three-stage cold rolling-annealing process (cold rolling with a reduction of 33% and annealing at 800℃ for 20 minutes, then cold rolling with a reduction of 35% and annealing at 800℃ for 5 minutes, and finally cold rolling with a reduction of 65% and annealing at 650℃ for 15 minutes) to prepare austenitic stainless steel with a grain size less than 100nm. The yield strength of the stainless steel prepared by this method is 1100-1200MPa, but there is no report on the elongation, and there is still some strain-induced martensite structure remaining in the steel structure, which cannot be considered a fully austenitic structure.

[0008] The document with Chinese patent publication number CN108531817A discloses "Nano / ultrafine grain structure ultra-high strength and high plasticity austenitic stainless steel and preparation method". In this document, austenitic stainless steel containing 0.5-0.9% copper is subjected to cold rolling with a reduction of 60-70% and annealing at 750-800℃, followed by cold rolling with a reduction of 40-50% and annealing at 720-740℃ to prepare austenitic stainless steel with nano / ultrafine grain structure. The stainless steel prepared by this method achieves ultra-high strength and plasticity through fine grain strengthening, back stress strengthening, deformation-induced twinning effect and deformation-induced martensite effect, and its yield strength and elongation are increased to 1150-1320MPa and 39.2-47.3% respectively. However, the heating and cooling rates in the annealing stage of this method need to be strictly controlled within the range of 20-50°C / s and 30-100°C / s, respectively. The ultra-fast heating and cooling rates place extremely high demands on the equipment, and conventional equipment is difficult to meet the requirements. In addition, this method requires multiple cold rolling and annealing, which is not very friendly in terms of energy conservation, environmental protection and cost control.

[0009] The document with Chinese patent publication number CN114622074A discloses "an austenitic stainless steel, its heat treatment process and use of the heat treatment process". In the document, austenitic stainless steel is treated with a total reduction rate of 50-70% cold rolling combined with a 700-750℃ annealing process to prepare austenitic stainless steel with a nano-micron double peak grain structure. The tensile strength and elongation of the austenitic stainless steel prepared by this method are 900-1440MPa and 12-18% respectively, and there is no report on the yield strength of the steel.

[0010] The document with Chinese patent publication number CN113234908A discloses a process for improving the mechanical properties of cold-rolled 304 austenitic stainless steel. In this document, 304 austenitic stainless steel is subjected to cold rolling with a total reduction of 64-78.4% combined with annealing at 400°C for 30 minutes. The yield strength and tensile strength of the austenitic stainless steel produced are 1446-1880MPa and 1573-1896MPa respectively, but there is no report on the plasticity of the steel.

[0011] The Chinese patent publications CN112831639A and 112831640A disclose "A method for producing austenitic stainless steel with a yield strength of ≥700MPa" and "A method for producing austenitic stainless steel with a yield strength of ≥980MPa". In the document, high-nitrogen ultrafine-grained austenitic stainless steel is prepared by cold rolling combined with different nitriding annealing processes. The yield strength and elongation of austenitic stainless steel prepared by this series of methods are 701-1290MPa and 13-46.8%, respectively. However, nitriding strengthening has a certain effect on ultra-thin steel plates with a thickness of only 0.3mm. When the thickness exceeds 1mm, the nitriding strengthening effect of the steel plate is weak, and the yield strength is difficult to exceed 1000MPa. Summary of the invention

[0012] The present invention aims to overcome the shortcomings of the prior art and provide a copper-containing austenitic stainless steel having a yield strength of 1064-1551 MPa, a tensile strength of 1170-1675 MPa and an elongation of 11.3-30.3% and a production method thereof by adding element copper and utilizing low-temperature rolling combined with low-temperature long-term annealing treatment.

[0013] Measures to achieve the above objectives:

[0014] The invention discloses an ultra-high strength and high plasticity copper-containing austenitic stainless steel, wherein the components and weight percentage contents thereof are: C: 0.025-0.031%, Si: 0.33-0.76%, Mn: 7.32-13.8%, Cr: 17.3-19.1%, Ni: 0.72-2.9%, N: 0.14-0.35%, Cu: 1.72-3.51%, and the remainder is Fe and inevitable impurities; the metallographic structure is austenite; the yield strength is 1064-1551MPa, the tensile strength is 1170-1675MPa, and the elongation is 11.3-30.3%.

[0015] Preferably, the weight percentage of Mn is 7.83-12.68%.

[0016] Preferably, the weight percentage of Cu is 2.07-3.45%.

[0017] Preferably, the weight percentage of Ni is 0.78-2.15%.

[0018] A method for producing ultra-high strength and high plasticity copper-containing austenitic stainless steel, comprising the following steps:

[0019] 1) After smelting and casting, the ingot is hot rolled to control the thickness of the hot rolled plate to be 2.75-2.91 mm; then it is naturally cooled to room temperature;

[0020] 2) performing a solution treatment on the hot-rolled slab, controlling the solution treatment temperature at 1100-1150°C, and then cooling to room temperature at a speed of 29-63°C / s;

[0021] 3) Low temperature cold rolling to product thickness, control the cold rolling temperature at -92 to 13°C; each pass reduction rate is controlled at 8.5 to 12%, and the thickness of the steel plate after rolling is 0.96 to 1.13 mm;

[0022] 4) Annealing, the annealing temperature is controlled at 523-652°C, and kept at this temperature for 120-14400min;

[0023] 5) Cool naturally to room temperature.

[0024] Preferably, the cold rolling temperature is between -75°C and 8°C.

[0025] Preferably, the annealing temperature is controlled at 538-641° C., and the holding time is 150-650 min.

[0026] Functions and mechanisms of various raw materials and main processes in the present invention

[0027] C: Carbon is a basic element in steel and is also the most economical and effective strengthening element. In stainless steel, it mainly plays the role of solid solution strengthening and stabilizing austenite. However, this patent requires that the carbon content be controlled at an extremely low level, because cold-rolled stainless steel is very likely to produce a large amount of chromium carbide precipitation phase during long-term annealing at low temperature, resulting in a sharp decline in the corrosion resistance of stainless steel. Therefore, the carbon content is 0.025-0.031%.

[0028] Si: Adding silicon to steel can play a weak solid solution strengthening role. The solid dissolved silicon can also reduce the formation of chromium carbide precipitation phase during low temperature and long time annealing of austenitic stainless steel. The silicon content should be kept above 0.33%. However, when the silicon content is greater than 0.76%, the ductility of stainless steel will deteriorate. Therefore, it is best to control it within 0.33-0.76.

[0029] Mn: It is a commonly used solid solution strengthening element in steel and is relatively cheap. It is a representative element that can also improve economic benefits by stabilizing the austenite phase instead of nickel, so that the steel can obtain an austenite phase structure at room temperature; in addition, adding manganese can increase the solubility of alloying elements such as nitrogen and copper. Therefore, based on economic benefits, the minimum manganese content is 7.32%; but excessive increase in manganese content can easily lead to a weakened ability to form a chromium oxide re-passivation film, resulting in reduced corrosion resistance of austenitic stainless steel. Therefore, the optimal manganese content range is 7.32-13.8%, and the preferred Mn weight percentage content is 7.83-12.68%.

[0030] Cr: It is an essential element to maintain the corrosion resistance and high temperature oxidation resistance of stainless steel. When the chromium content is above 11%, it has the characteristic of spontaneously combining with oxygen in the atmosphere to produce a dense thin layer of chromium oxide several nanometers thick, isolating the surface of the material from oxygen and preventing rust; at the same time, it also has excellent oxidation resistance during long-term annealing at low temperature. In addition, chromium is expensive and is a ferrite phase stabilizing element. When adding a large amount of chromium to austenitic stainless steel, more austenite stabilizing elements need to be added to ensure the stability of the austenite phase. From the perspective of corrosion resistance, high temperature oxidation resistance, phase stability and economy, the optimal value of the chromium content in the embodiment of the present invention is 17.3-19.1%.

[0031] Ni: Nickel in steel is a representative alloying element used to stabilize the austenite phase. Nickel and manganese elements work together to reduce the martensitic transformation point in steel to below room temperature, improving the toughness, weldability and processing performance of steel; the presence of some nickel in steel can also effectively improve the corrosion resistance and high-temperature oxidation resistance of chromium, so the nickel content must be greater than 0.72%. However, the price of nickel metal is extremely expensive. For cost and benefit considerations, the reasonable addition range of nickel content is 0.72-2.9%, and the preferred Ni weight percentage content is 0.78-2.15%.

[0032] N: It is an excellent solid solution strengthening element in austenitic stainless steel, ensuring the strength loss caused by ultra-low carbon content; Nitrogen is also an element that stabilizes the austenite phase, and can replace expensive nickel metal in stainless steel; and nitrogen can improve hardness and corrosion resistance. Nitrogen has limited solubility in steel, and high-nitrogen steel is extremely difficult to smelt; and austenitic stainless steel containing a large amount of nitrogen has a rapid decrease in high-temperature ductility, so its content is controlled between 0.14-0.35%.

[0033] Cu: Copper in austenitic stainless steel is an austenite stabilizing element, especially in the presence of manganese, which can greatly improve the stability of the austenite phase; in addition, copper can form a large number of fine copper-rich phase particles with a lattice distribution during low-temperature and long-term annealing as the interface migrates, producing an excellent precipitation strengthening (precipitation strengthening) effect. However, copper reduces the work hardening rate, so when a large amount of copper is added to the alloy, it will lead to a decrease in tensile strength. For performance and cost considerations, the reasonable addition range of copper content is 1.72-3.51%, and the preferred weight percentage of Cu is 2.07-3.45%.

[0034] The reason why the present invention controls the thickness of the hot-rolled plate to be 2.75-2.91 mm and then cools naturally to room temperature is that if the thickness of the slab is too thin, the compression ratio of the subsequent large-pressure cold rolling process is not enough, resulting in coarse grains in the final product; due to the limited reduction capacity of the rolling mill, it is difficult to obtain the final thin-gauge raw material in the large-pressure rolling process if the slab is too thick. In addition, due to the composition, the steel will not undergo phase change during the cooling process, and for economic considerations, the hot-rolled slab is cooled naturally to room temperature.

[0035] The reason why the present invention controls the solid solution temperature at 1100-1150°C and then cools to room temperature at a speed of 29-63°C / s is that 1.72%-3.51% copper is added to austenitic stainless steel, which can be completely dissolved into the austenite phase at 1100-1150°C; and then cooled to room temperature at a speed of 29-63°C / s, during which copper atoms have no time to precipitate and exist in the austenitic stainless steel as substitutional solute atoms. If the cooling speed is too slow, carbides will precipitate during the cooling process to deteriorate the performance. If the cooling speed is too fast, the plate shape will be deteriorated during the cooling process to affect the product quality.

[0036] The invention controls the low-temperature cold rolling temperature at -92 to 13°C, the reduction rate per pass at 8.5 to 12%, and the thickness of the steel plate after rolling at 0.96 to 1.13 mm. This is because the cold rolling is carried out at a relatively low temperature, which can reduce the stacking fault energy of the steel, thereby promoting the formation of a deformation-induced martensite phase during the rolling process. If the rolling temperature is relatively high, it is difficult to obtain a large amount of deformation martensite, which is not conducive to subsequent annealing to obtain ultrafine austenite grains. If the rolling temperature is extremely low, the production cost is difficult to control and the economic benefit is poor. The reduction rate during the cold rolling process and the thickness after cold rolling are controlled. If the reduction rate per pass is too small, it is difficult to obtain a cold-rolled plate composed of a large amount of deformation martensite, and it will be difficult to obtain austenitic stainless steel with fine grains by subsequent annealing. If the reduction rate per pass is too large, it is easy to damage the equipment, and the deformation martensite generated in the cold-rolled plate is unevenly distributed, and subsequent annealing is easy to form austenitic stainless steel with ultrafine grains and coarse grains.

[0037] The reason why the present invention controls the annealing temperature at 523-652° C. and the annealing time at 120-11400 min and then naturally cools to room temperature is that under the temperature condition, copper cannot be completely dissolved into the austenite phase, and copper atoms have good diffusion ability under the temperature condition, and at the same time, the copper-rich phase is guaranteed to have enough time to move for a long time, and a large number of fine copper-rich phase particles with lattice distribution are formed along with interface migration during the growth of austenite grains. If the annealing temperature is high and the time is short, only a small amount of copper-rich phase precipitates will be generated in the steel; if the annealing temperature is high and the time is long, some dispersed copper-rich phase precipitates will be generated in the steel and the austenite grains will coarsen, resulting in a decrease in yield strength; if the annealing temperature is extremely low and the time is short, the time is not enough to ensure that the copper atoms diffuse a sufficient distance to precipitate copper-rich phase particles; if the annealing temperature is extremely low and the annealing time is extremely long, a large amount of chromium carbide particles will be produced and the corrosion resistance of the steel will be reduced; in addition, since austenitic stainless steel will not undergo phase change during the cooling process, for economic considerations, natural cooling to room temperature is adopted after annealing.

[0038] Compared with the prior art, the present invention forms austenitic stainless steel with submicron-scale and micron-scale austenitic grains and a large number of fine copper-rich phase particles distributed in a lattice inside the austenitic grains by adjusting the composition of austenitic stainless steel and controlling low-temperature cold rolling combined with low-temperature and long-term annealing processes. The submicron-scale / micron-scale grains and nano-scale copper-rich phase particles provide excellent strength through grain refinement strengthening and precipitation strengthening (precipitation strengthening), respectively, and the face-centered cubic structure of the austenite phase and the coherent copper particle precipitation phase also have good plasticity. In the manufacturing process of the ultra-high strength and high-plasticity copper-containing austenitic stainless steel in the present invention, under the joint action of the above-mentioned key control conditions, the strength and plasticity of the copper-containing austenitic stainless steel prepared by the present invention are superior to similar steel grades recorded in other documents and reports. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 TEM morphology of the tissue of the present invention;

[0040] Figure 2 This is a TEM morphology image of the structure of the present invention when it is reduced by 80%. DETAILED DESCRIPTION

[0041] The present invention is described in detail below:

[0042] Table 1 is a list of chemical composition values ​​of various embodiments and comparative examples of the present invention;

[0043] Table 2 is a list of main process parameters of various embodiments and comparative examples of the present invention;

[0044] Table 3 is a table of performance test results of various embodiments and comparative examples of the present invention.

[0045] Each embodiment of the present invention is produced according to the following steps:

[0046] 1) After smelting and casting, the ingot is hot rolled to control the thickness of the hot rolled plate to be 2.75-2.91 mm; then it is naturally cooled to room temperature;

[0047] 2) performing a solution treatment on the hot-rolled slab, controlling the solution treatment temperature at 1100-1150°C, and then cooling to room temperature at a speed of 29-63°C / s;

[0048] 3) Low temperature cold rolling to product thickness, control the cold rolling temperature at -92 to 13°C; each pass reduction rate is controlled at 8.5 to 12%, and the thickness of the steel plate after rolling is 0.96 to 1.13 mm;

[0049] 4) Annealing, the annealing temperature is controlled at 523-652°C, and kept at this temperature for 120-14400min;

[0050] 5) Cool naturally to room temperature.

[0051] Table 1 List of chemical components of various embodiments of the present invention (wt%)

[0052] Example C Si Mn P S Cr Ni N Cu 1 0.028 0.36 7.32 0.008 0.003 18.58 2.90 0.24 1.72 2 0.027 0.39 8.81 0.007 0.005 17.3 2.12 0.33 3.51 3 0.029 0.33 11.52 0.007 0.004 18.1 1.77 0.27 2.09 4 0.031 0.44 13.8 0.010 0.005 18.6 0.72 0.35 1.81 5 0.027 0.45 9.59 0.007 0.009 19.1 1.31 0.14 2.17 6 0.025 0.76 7.71 0.006 0.003 17.9 2.87 0.22 2.46 Comparative Example 1 0.024 0.35 7.34 0.009 0.005 18.9 3.46 0.33 0.07 Comparative Example 2 0.028 0.36 7.32 0.008 0.003 18.58 2.90 0.24 1.72 Comparative Example 3 0.028 0.36 7.32 0.008 0.003 18.58 2.90 0.24 1.72 Comparative Example 4 0.028 0.36 7.32 0.008 0.003 18.58 2.90 0.24 1.72

[0053] Note: The contents of the components in Examples 1-6 in Table 1 meet the following requirements: C: 0.025-0.031%, Si: 0.33-0.76%, Mn: 7.32-13.8%, Cr: 17.3-19.1%, Ni: 0.72-2.9%, N: 0.14-0.35%, Cu: 1.72%-3.51%. The difference in Comparative Example 1 is that the components therein do not meet the copper content requirements of the present invention; the components in Comparative Examples 2-4 meet the content requirements in the embodiments of the present invention, but the difference is that the subsequent processes are different.

[0054] Table 2 List of main process parameters of various embodiments of the present invention

[0055]

[0056] Table 3 List of mechanical properties test results of various embodiments of the present invention

[0057] Example Yield strength / MPa Tensile strength / MPa Elongation / % 1 1300 1335 25.0 2 1417 1455 16.5 3 1551 1675 11.3 4 1377 1403 17.8 5 1367 1454 14.9 6 1064 1170 30.3 Comparative Example 1 797 1048 37.6 Comparative Example 2 964 1140 27.9 Comparative Example 3 618 925 48.5 Comparative Example 4 759 1076 43.1

[0058] It can be seen from Table 3 that the molten steel in the embodiments of the present invention is smelted to obtain products with unchanged contents of various components, and then undergoes a series of rolling heat treatments. The products in embodiments 1-6 of the present invention have good performance in yield strength and tensile strength compared with comparative example 1 with changed chemical composition and comparative example 2 with changed rolling process, especially the yield strength and tensile strength are significantly higher than those of the comparative examples. The yield strength of the products in embodiments 1-6 of the present invention is 1064-1551MPa, the tensile strength is 1170-1675MPa, the elongation is 11.3-30.3%, and the finished product thickness is 0.96-1.13mm.

[0059] Also, see Figure 1 The microstructure of the ultra-high strength austenitic stainless steel prepared in Example 1 of the present invention is composed of submicron-nanoscale and micron-scale austenite grains, and the austenite grains contain a large number of fine copper-rich phase particles distributed in a lattice. The submicron-nanoscale / micron-scale grains and nano-scale copper-rich phase particles provide excellent strength through grain refinement and precipitation strengthening (precipitation strengthening), and the face-centered cubic structure and the coherent copper particle precipitation also have good plasticity.

[0060] It can be seen that during the manufacturing process of the ultra-high strength and high plasticity copper-containing austenitic stainless steel in the present invention, under the joint action of the above-mentioned key control conditions, the strength and plasticity of the copper-containing austenitic stainless steel prepared by the present invention are superior to similar steel grades recorded in other literatures and reports.

[0061] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] This specific implementation is only the best example and is not a restrictive implementation of the technical solution of the present invention.

Claims

1. A method for producing ultra-high strength and high plasticity copper-containing austenitic stainless steel, comprising the following steps: 1) After smelting and casting, the ingot is hot rolled, and the thickness of the hot rolled plate is controlled at 2.75-2.91mm; then it is naturally cooled to room temperature; 2) Solution treatment is performed on the hot-rolled slab, and the solution treatment temperature is controlled at 1100-1150°C, and then water-cooled to room temperature at a speed of 29-63°C / s; 3) Low temperature cold rolling to product thickness, control the cold rolling temperature at -92~13℃; each pass reduction rate is controlled at 8.5~12%, and the thickness of the steel plate after rolling is 0.96~1.13mm; 4) Annealing is performed, the annealing temperature is controlled at 523-652°C, and the temperature is kept at this temperature for 120-14400 minutes; 5) Cool naturally to room temperature; The ultra-high strength and high plasticity copper-containing austenitic stainless steel has the following components and weight percentage contents: C: 0.025-0.031%, Si: 0.33-0.76%, Mn: 8.81-13.8%, Cr: 17.3-19.1%, Ni: 0.72-1.77%, N: 0.14-0.35%, Cu: 1.72-3.51%, and the rest is Fe and unavoidable impurities; the metallographic structure is austenite; the yield strength is 1064-1551MPa, the tensile strength is 1170-1675MPa, and the elongation is 11.3-30.3%.

2. The method for producing ultra-high strength and high plasticity copper-containing austenitic stainless steel according to claim 1, characterized in that: The cold rolling temperature is between -75 and 8°C.

3. The method for producing ultra-high strength and high plasticity copper-containing austenitic stainless steel according to claim 1, characterized in that: The annealing temperature is controlled at 538-641°C, and the holding time is 150-650 minutes.

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