A machining process for high-strength stainless steel pipes

Abstract

The present application relates to the technical field of stainless steel pipe processing, in particular to a processing technology of high-strength stainless steel pipe. The following technical scheme is specifically proposed: S1: preparing Cu@Cu3Pt nanoparticles; melting, casting, hot rolling, and annealing the Cu@Cu3Pt nanoparticles, pure copper, titanium nitride, ice crystal, and rare earth metal cerium to obtain an intermediate layer metal; S2: pre-treating one side of a stainless steel plate, and then performing sputtering treatment on the pre-treated side using pure copper as a target material to obtain a copper plating layer, thereby obtaining a plating layer stainless steel plate; S3: sequentially stacking the plating layer stainless steel plate, the intermediate layer metal, and the plating layer stainless steel plate, with the intermediate layer metal contacting the side of the plating layer stainless steel plate with the copper plating layer; and then sequentially performing hot-pressing sintering, solid solution treatment, hot rolling, and aging treatment to obtain a layered heterogeneous stainless steel plate; and S4: curling and welding the layered heterogeneous stainless steel plate to manufacture a high-strength stainless steel pipe.

Description

Technical Field

[0001] This invention relates to the field of stainless steel pipe processing technology, specifically a processing technology for high-strength stainless steel pipes. Background Technology

[0002] Stainless steel is a type of steel that can withstand corrosion from weak corrosive media such as air, steam, and water, as well as chemical corrosive media such as acids, alkalis, and salts. With the advancement of science and technology and the continuous progress of the metallurgical industry, stainless steel products have been widely used in various fields of life. For example, stainless steel pipes play an important role in industrial transportation pipelines and mechanical structural components in the petroleum, chemical, medical, and light industries. Similarly, with the rapid development of national construction, existing stainless steel pipes are gradually becoming insufficient for previous industry applications, and various industries are placing more stringent comprehensive performance requirements on stainless steel pipes. For instance, stainless steel pipes used in shipbuilding engineering require not only good corrosion resistance but also higher strength.

[0003] To improve the strength of stainless steel pipes, existing technologies typically increase the carbon content, but this reduces the corrosion resistance of the stainless steel. Another approach is to apply a coating to the surface of the stainless steel to improve its strength, but this coating will peel off with increased use, requiring more frequent maintenance.

[0004] To address the shortcomings of current methods for increasing the strength of stainless steel, this invention aims to develop a sandwich-type stainless steel tube that enhances the strength of stainless steel by forming a heterogeneous structure, promoting dislocation formation and dislocation pile-up, and ultimately obtaining a high-strength stainless steel tube. Summary of the Invention

[0005] The purpose of this invention is to provide a processing technology for high-strength stainless steel pipes to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] S1: Prepare Cu@Cu3Pt nanoparticles; then melt, cast, hot roll, and anneal them with pure copper, titanium nitride, cryolite, and rare earth metal cerium to obtain an intermediate layer metal;

[0008] Furthermore, the preparation method of the Cu@Cu3Pt nanoparticles is as follows: 0.01-0.05 mol / L copper chloride solution and 1-3 mol / L sodium hydroxide solution are mixed, heated to 50-90℃, and 0.5-2 mol / L L-ascorbic acid solution is added. The mixture is stirred at 200-600 r / min for 2-6 h. Then, 0.01-0.05 mol / L hexahydroxyplatinic acid solution is added to the solution, the temperature is raised to 90-160℃, and the mixture is stirred continuously for 2-4 h to obtain a precipitate. The precipitate is filtered, washed, and dried to obtain Cu@Cu3Pt nanoparticles.

[0009] Furthermore, in the preparation method of Cu@Cu3Pt nanoparticles, the volume ratio of copper chloride solution, sodium hydroxide solution, L-ascorbic acid solution, and hexahydroxyplatinic acid is 10:10:(2.5~5):3.

[0010] Furthermore, the method for preparing the intermediate layer metal is as follows:

[0011] (1) Pure copper, Cu@Cu3Pt nanoparticles, titanium nitride, cryolite and rare earth metal cerium are placed in a sealed crucible in sequence, argon is introduced as a protective gas, heated to 2000-2200℃ until each component melts, stirred evenly, and cast into an ingot.

[0012] (2) Argon gas is introduced into the heating furnace as a protective gas to heat the ingot to 700-900°C and the surface of the rolling mill is heated to 150-250°C. The ingot is hot rolled into a 0.5-1 mm thick intermediate layer metal pre-finished product at a rolling speed of 30-60 m / min. Finally, the rolled intermediate layer metal pre-finished product is placed in an annealing furnace at 400-600°C and held for 60-100 min. After annealing, it is taken out and cooled naturally to obtain the intermediate layer metal.

[0013] Furthermore, the percentages of each component in the intermediate metal layer are as follows: 95-97% pure copper, 2-5% Cu@Cu3Pt nanoparticles, 0.15-0.5% titanium nitride, 0.01-0.05% cryolite, and 0.01-0.03% rare earth metal cerium.

[0014] The above-mentioned preparation of Cu@Cu3Pt nanoparticles and pure copper melt casting yielded an intermediate copper alloy. The Cu@Cu3Pt nanoparticles effectively modulate the plasticity of the copper alloy, enhancing its mechanical properties. Furthermore, during hot pressing and sintering with 07Cr17Ni7Al stainless steel plates, they better promote the formation of a heterogeneous structure between the stainless steel plate and the intermediate metal after hot rolling. Titanium nitride was added as a heterogeneous nucleating agent, while cryolite was added to lower the melting point of titanium nitride, reducing the reaction difficulty. Both titanium nitride and cryolite possess high strength and do not significantly negatively impact the strength of the prepared copper alloy. Since the stainless steel pipe and sheet prepared in this invention are produced by stacked hot rolling, rare earth metal cerium was added to enhance the plasticity and strength of the copper alloy, preventing damage to the intermediate metal during hot rolling and ensuring the overall performance of the stainless steel pipe is maintained.

[0015] S2: After pre-treating one side of the stainless steel plate, the pre-treated side is sputtered with pure copper as the target material to obtain a copper plating layer, which is then used as the coated stainless steel plate.

[0016] Furthermore, the preparation method of the coated stainless steel plate is as follows: two stainless steel plates with a thickness of 1.5-2 mm are polished to 1000-2000 grit using a polishing machine, ultrasonically cleaned with anhydrous ethanol for 10-20 minutes, washed with deionized water, dried, and placed in a magnetron sputtering chamber, using pure copper as the target material; the magnetron sputtering chamber is evacuated to a vacuum degree of less than 10. -5 Pa, argon gas is introduced as a protective gas for sputtering to obtain a coated stainless steel plate.

[0017] Furthermore, the sputtering power of the magnetron sputtering chamber is 40-80W, the sputtering temperature is 350-500℃, the sputtering working pressure is 0.5-1Pa, and the sputtering time is 10-20min.

[0018] The above-mentioned use of pure copper as the target material to sputter copper onto 07Cr17Ni7Al stainless steel plate is to improve the bonding ability between the intermediate layer metal and the stainless steel plate and avoid hot rolling delamination. In addition, the use of low power and low gas pressure during the sputtering process makes the copper layer more uniform. By controlling the sputtering time, the thickness of the copper layer on the stainless steel plate can be controlled, so as to obtain a coated stainless steel plate with appropriate density and thickness.

[0019] S3: The coated stainless steel sheet, the intermediate layer metal, and the coated stainless steel sheet are stacked in sequence, with the intermediate layer metal in contact with the copper-plated side of the coated stainless steel sheet; then, the sheet is subjected to hot pressing sintering, solution treatment, hot rolling, and aging treatment in sequence to obtain a layered heterogeneous stainless steel sheet.

[0020] Furthermore, the method for preparing the layered heterogeneous stainless steel plate is as follows:

[0021] (1) Grind the intermediate layer metal to 1000-2000 grit with a grinding and polishing machine, and then stack the ground intermediate layer metal on the side of the coated stainless steel plate with copper sputtering. That is, set up the coated stainless steel plate, intermediate layer metal, and coated stainless steel plate in sequence, with the intermediate layer metal in contact with the copper coating side of the coated stainless steel plate.

[0022] (2) Place the stacked materials into a graphite mold, and hot press sinter them in a vacuum at 1000-1050℃ and 30-40 MPa for 1-3 hours to obtain a pre-finished layered heterogeneous stainless steel plate.

[0023] (3) After the pre-finished layered stainless steel plate is cooled in the furnace, the temperature is raised to 980-1050℃, held for 30-60 minutes, and then water quenched to complete the solution treatment.

[0024] (4) Argon gas is introduced into the heating furnace as a protective gas, and the pre-finished layered dissimilar stainless steel plate is heated to 700-900℃. The surface of the rolling mill is heated to 150-250℃ and hot-rolled at a rolling speed of 30-60m / min to roll it into a pre-finished layered dissimilar stainless steel plate with a thickness of 2-3mm. Finally, the pre-finished layered dissimilar stainless steel plate is placed in an annealing furnace at 400-600℃ and held for 60-100min. After annealing, it is taken out and cooled naturally to obtain the layered dissimilar stainless steel plate.

[0025] The above-mentioned process involves stacking and hot-pressing an intermediate layer of metal on the coated side of a stainless steel sheet, followed by a strengthening treatment to obtain a layered heterogeneous stainless steel sheet. The heterogeneous structure created by hot pressing increases the number of dislocations between the two interfaces. Furthermore, under the influence of the heterogeneous nucleating agent titanium nitride, the dislocation density significantly increases. Subsequent strengthening treatments further enhance the strength of the stainless steel sheet, especially during hot rolling, which causes a large number of dislocations to accumulate, drastically improving the strength of the stainless steel sheet.

[0026] S4: Layered dissimilar stainless steel plates are rolled and welded to produce high-strength stainless steel pipes.

[0027] Furthermore, the processing steps of the high-strength stainless steel pipe are as follows: after cutting the layered dissimilar stainless steel plate to the size of the stainless steel pipe sheet, it is transformed into a steel pipe shape using a steel pipe manufacturing machine. Under argon protection, the pipe seam of the stainless steel pipe is welded using plasma welding. After welding, the weld seam is cooled with water to obtain a stainless steel pipe blank. Then, the weld seam is polished with a grinding wheel until it is flush with the base material, and the weld seam is leveled. Finally, after cleaning and drying, the high-strength stainless steel pipe is obtained.

[0028] Furthermore, the stainless steel pipe plate size is any one of the following: 1219mm×2438mm, 1219mm×3048mm, and 1219mm×4000mm.

[0029] Furthermore, the plasma welding current is 275–305A, the arc voltage is 26–30V, and the welding speed is 30–60mm / min.

[0030] The above welding process uses plasma welding, which has the advantages of high arc temperature, good directionality, concentrated arc and no arc ignition impact, and will not cause a large negative impact on the stainless steel plate. Then, water cooling is used to avoid welding deformation. Finally, it is polished, cleaned and dried to obtain high-strength stainless steel pipe.

[0031] Compared with the prior art, the beneficial effects achieved by this invention are as follows: This invention combines stainless steel plates with other metals by stacking them together and hot-pressing them to form a heterogeneous structure. Hot rolling then promotes the generation of dislocations in the heterogeneous structure, resulting in dislocation pile-up, thereby obtaining high-strength stainless steel. The invention introduces Cu@Cu3Pt nanoparticles, which can effectively regulate the plasticity of the intermediate metal layer, enhance the mechanical properties of the copper alloy, and promote bonding with the stainless steel plate. Furthermore, a heterogeneous nucleating agent is added to promote the generation of dislocations and dislocation pile-up in the heterogeneous structure, thereby significantly improving the mechanical properties of the stainless steel plate. Finally, through metal heat treatment, a high-strength stainless steel pipe is obtained. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the following examples, the purity of copper chloride was 99% (CAS No.: 1344-67-8, Jilin Taili Import & Export Co., Ltd.), the purity of sodium hydroxide was 99% (Hebei Nafu Technology Co., Ltd.), the purity of L-ascorbic acid was 99% (CAS No.: 50-81-7, Hebei Mojin Biotechnology Co., Ltd.), the purity of hexahydroxyplatinic acid was 99% (CAS No.: 51850-20-5, item number: qbos2016, Neijiang Luoboer Materials Technology Co., Ltd.), and the purity of pure copper was 99.99% (Guangdong Wengjiang Chemical Co., Ltd.). The following reagents are listed: titanium nitride (99.5%), cryolite (98%), rare earth metal cerium (99%), anhydrous ethanol (99%), 07Cr17Ni7Al stainless steel plate (0.8mm×1219mm×4000%), and argon gas (99.99%).

[0034] Example 1: A processing technology for high-strength stainless steel pipe, comprising the following steps:

[0035] S1: The preparation method of Cu@Cu3Pt nanoparticles is as follows: 0.03 mol / L copper chloride solution and 2 mol / L sodium hydroxide solution are mixed, heated to 60℃, 2 mol / L L-ascorbic acid solution is added, and the mixture is stirred at 600 r / min for 4 h. Then, 0.03 mol / L hexahydroxyplatinic acid solution is added to the solution, the temperature is raised to 130℃, and the mixture is stirred continuously for 3 h to obtain a precipitate. The precipitate is filtered, washed, and dried to obtain Cu@Cu3Pt nanoparticles.

[0036] In the preparation method of Cu@Cu3Pt nanoparticles, the volume ratio of copper chloride solution, sodium hydroxide solution, L-ascorbic acid solution, and hexahydroxyplatinic acid is 10:10:3:3.

[0037] The preparation method of the intermediate layer metal is as follows: pure copper, Cu@Cu3Pt nanoparticles, titanium nitride, cryolite, and rare earth metal cerium are placed in a sealed crucible in sequence, argon gas is introduced as a protective gas, and the mixture is heated to 2000℃ until all components melt. After stirring evenly, the mixture is cast into an ingot. Argon gas is introduced into a heating furnace as a protective gas, and the ingot is heated to 850℃. The surface of the rolling mill is heated to 200℃, and the ingot is hot-rolled at a rolling speed of 50m / min to form a 1mm thick intermediate layer metal pre-finished product. Finally, the rolled intermediate layer metal pre-finished product is placed in an annealing furnace at 450℃ and held for 80min. After annealing, the product is taken out and naturally cooled to obtain the intermediate layer metal.

[0038] The percentages of each component in the intermediate layer metal are as follows: pure copper 96.65%, Cu@Cu3Pt nanoparticles 3%, titanium nitride 0.3%, cryolite 0.03%, and rare earth metal cerium 0.02%.

[0039] S2: The preparation method of the coated stainless steel plate is as follows: Two 1.5mm thick 07Cr17Ni7Al stainless steel plates are polished to 2000 grit using a polishing machine, ultrasonically cleaned with anhydrous ethanol for 15 minutes, then washed with deionized water, dried, and placed in a magnetron sputtering chamber, using pure copper as the target material; the magnetron sputtering chamber is evacuated to a vacuum degree of less than 10. -5 Pa, argon gas is introduced as a protective gas for sputtering to obtain a coated stainless steel plate.

[0040] The magnetron sputtering chamber has a sputtering power of 50W, a sputtering temperature of 400℃, a sputtering working pressure of 1Pa, and a sputtering time of 20min.

[0041] S3: The preparation method of layered heterogeneous stainless steel plate is as follows:

[0042] (1) After trimming the intermediate layer metal and the coated stainless steel plate to the same size, grind the intermediate layer metal to 2000 grit with a grinding and polishing machine; set up the coated stainless steel plate, intermediate layer metal and coated stainless steel plate in sequence, with the intermediate layer metal in contact with the copper coating of the coated stainless steel plate, and stack the three layers together.

[0043] (2) The stacked materials are placed in a graphite mold and hot-pressed in a vacuum at 1000℃ with a pressure of 40 MPa for 2 hours to obtain a pre-finished layered heterogeneous stainless steel plate.

[0044] (3) After the pre-finished layered heterogeneous stainless steel plate is cooled in the furnace, the temperature is raised to 980℃, held for 45 minutes and then water quenched to complete the solution treatment.

[0045] (4) Argon gas is introduced into the heating furnace as a protective gas, the pre-finished layered heterogeneous stainless steel plate is heated to 850°C, the surface of the rolling mill is heated to 200°C, and hot rolling is carried out at a rolling speed of 50m / min to roll it into a 2mm thick pre-finished layered heterogeneous stainless steel plate. Finally, the rolled pre-finished layered heterogeneous stainless steel plate is placed in an annealing furnace at 450°C and held for 80min. After annealing is completed, it is taken out and cooled naturally to obtain the layered heterogeneous stainless steel plate.

[0046] S4: The processing steps for high-strength stainless steel pipes are as follows: After cutting the layered dissimilar stainless steel plate to 1219mm×3048mm, it is transformed into a steel pipe shape using a steel pipe manufacturing machine. Under argon protection, the pipe seam of the stainless steel pipe is welded using plasma welding. After welding, the weld seam is cooled with water to obtain a stainless steel pipe blank. Then, the weld seam is polished with a grinding wheel until it is flush with the base material, and the weld seam is leveled. Finally, after cleaning and drying, the high-strength stainless steel pipe is obtained.

[0047] The plasma welding current is 300A, the arc voltage is 28V, and the welding speed is 45mm / min.

[0048] The dimensions of the high-strength stainless steel pipe are 1219mm × 3048mm × 2mm.

[0049] Example 2: A processing technology for high-strength stainless steel pipe, comprising the following steps:

[0050] S1: The preparation method of Cu@Cu3Pt nanoparticles is as follows: 0.01 mol / L copper chloride solution and 1 mol / L sodium hydroxide solution are mixed, heated to 50℃, 0.5 mol / L L-ascorbic acid solution is added, and the mixture is stirred at 200 r / min for 2 h. Then, 0.01 mol / L hexahydroxyplatinic acid solution is added to the solution, the temperature is raised to 90℃, and the mixture is stirred continuously for 2 h to obtain a precipitate. The precipitate is filtered, washed, and dried to obtain Cu@Cu3Pt nanoparticles.

[0051] In the preparation method of Cu@Cu3Pt nanoparticles, the volume ratio of copper chloride solution, sodium hydroxide solution, L-ascorbic acid solution, and hexahydroxyplatinic acid is 10:10:2.5:3.

[0052] The preparation method of the intermediate layer metal is as follows: pure copper, Cu@Cu3Pt nanoparticles, titanium nitride, cryolite, and rare earth metal cerium are placed in a sealed crucible in sequence, argon gas is introduced as a protective gas, and the mixture is heated to 2200℃ until all components melt. After stirring evenly, the mixture is cast into an ingot. Argon gas is introduced into a heating furnace as a protective gas, and the ingot is heated to 850℃. The surface of the rolling mill is heated to 150℃, and the ingot is hot-rolled at a rolling speed of 30m / min to form a 0.5mm thick intermediate layer metal pre-finished product. Finally, the rolled intermediate layer metal pre-finished product is placed in an annealing furnace at 400℃ and held for 60min. After annealing, the product is taken out and naturally cooled to obtain the intermediate layer metal.

[0053] The percentages of each component in the intermediate layer metal are as follows: pure copper 96.65%, Cu@Cu3Pt nanoparticles 3%, titanium nitride 0.3%, cryolite 0.03%, and rare earth metal cerium 0.02%.

[0054] S2: The preparation method of the coated stainless steel plate is as follows: Two 1.5mm thick 07Cr17Ni7Al stainless steel plates are polished to 1000 grit using a polishing machine, ultrasonically cleaned with anhydrous ethanol for 10 minutes, then washed with deionized water, dried, and placed in a magnetron sputtering chamber, using pure copper as the target material; the magnetron sputtering chamber is evacuated to a vacuum degree of less than 10. -5 Pa, argon gas is introduced as a protective gas for sputtering to obtain a coated stainless steel plate.

[0055] The magnetron sputtering chamber has a sputtering power of 80W, a sputtering temperature of 350℃, a sputtering working pressure of 1Pa, and a sputtering time of 10min.

[0056] S3: The preparation method of layered heterogeneous stainless steel plate is as follows:

[0057] (1) After trimming the intermediate layer metal and the coated stainless steel plate to the same size, grind the intermediate layer metal to 1000 grit with a grinding and polishing machine; set up the coated stainless steel plate, intermediate layer metal and coated stainless steel plate in sequence, with the intermediate layer metal in contact with the copper coating of the coated stainless steel plate, and stack the three layers together.

[0058] (2) The stacked materials are placed in a graphite mold and hot-pressed in a vacuum at 1000℃ with a pressure of 30 MPa for 1 hour to obtain a pre-finished layered heterogeneous stainless steel plate.

[0059] (3) After the pre-finished layered stainless steel plate is cooled in the furnace, the temperature is raised to 980℃, held for 30 minutes and then water quenched to complete the solution treatment.

[0060] (4) Argon gas is introduced into the heating furnace as a protective gas, the pre-finished layered heterogeneous stainless steel plate is heated to 700°C, the surface of the rolling mill is heated to 150°C, and hot rolling is carried out at a rolling speed of 30m / min to roll it into a 2mm thick pre-finished layered heterogeneous stainless steel plate. Finally, the rolled pre-finished layered heterogeneous stainless steel plate is placed in an annealing furnace at 400°C and held for 60min. After annealing is completed, it is taken out and naturally cooled to obtain the layered heterogeneous stainless steel plate.

[0061] S4: The processing steps for high-strength stainless steel pipes are as follows: After cutting the layered dissimilar stainless steel plate to 1219mm×3048mm, it is transformed into a steel pipe shape using a steel pipe manufacturing machine. Under argon protection, the pipe seam of the stainless steel pipe is welded using plasma welding. After welding, the weld seam is cooled with water to obtain a stainless steel pipe blank. Then, the weld seam is polished with a grinding wheel until it is flush with the base material, and the weld seam is leveled. Finally, after cleaning and drying, the high-strength stainless steel pipe is obtained.

[0062] The plasma welding current is 275A, the arc voltage is 26V, and the welding speed is 30mm / min.

[0063] The dimensions of the high-strength stainless steel pipe are 1219mm × 3048mm × 2mm.

[0064] Example 3: A processing technology for high-strength stainless steel pipe, comprising the following steps:

[0065] S1: The preparation method of Cu@Cu3Pt nanoparticles is as follows: 0.05 mol / L copper chloride solution and 3 mol / L sodium hydroxide solution are mixed, heated to 90℃, 2 mol / L L-ascorbic acid solution is added, and the mixture is stirred at 600 r / min for 6 h. Then, 0.05 mol / L hexahydroxyplatinic acid solution is added to the solution, the temperature is raised to 160℃, and the mixture is stirred continuously for 4 h to obtain a precipitate. The precipitate is filtered, washed, and dried to obtain Cu@Cu3Pt nanoparticles.

[0066] In the preparation method of Cu@Cu3Pt nanoparticles, the volume ratio of copper chloride solution, sodium hydroxide solution, L-ascorbic acid solution, and hexahydroxyplatinic acid is 10:10:5:3.

[0067] The preparation method of the intermediate layer metal is as follows: pure copper, Cu@Cu3Pt nanoparticles, titanium nitride, cryolite, and rare earth metal cerium are placed in a sealed crucible in sequence, argon gas is introduced as a protective gas, and the mixture is heated to 2200℃ until all components melt, stirred evenly, and cast into an ingot; argon gas is introduced into a heating furnace as a protective gas, and the ingot is heated to 900℃, and the surface of the rolling mill is heated to 250℃. The ingot is hot rolled into a 1mm thick intermediate layer metal pre-finished product at a rolling speed of 60m / min. Finally, the rolled intermediate layer metal pre-finished product is placed in an annealing furnace at 600℃ and held for 100min. After annealing, it is taken out and naturally cooled to obtain the intermediate layer metal.

[0068] The percentages of each component in the intermediate layer metal are as follows: pure copper 96.65%, Cu@Cu3Pt nanoparticles 3%, titanium nitride 0.3%, cryolite 0.03%, and rare earth metal cerium 0.02%.

[0069] S2: The preparation method of the coated stainless steel plate is as follows: Two 1.5mm thick 07Cr17Ni7Al stainless steel plates are polished to 2000 grit using a polishing machine, ultrasonically cleaned with anhydrous ethanol for 20 minutes, then washed with deionized water, dried, and placed in a magnetron sputtering chamber, using pure copper as the target material; the magnetron sputtering chamber is evacuated to a vacuum degree of less than 10. -5 Pa, argon gas is introduced as a protective gas for sputtering to obtain a coated stainless steel plate.

[0070] The magnetron sputtering chamber has a sputtering power of 40W, a sputtering temperature of 500℃, a sputtering working pressure of 1Pa, and a sputtering time of 20min.

[0071] S3: The preparation method of layered heterogeneous stainless steel plate is as follows:

[0072] (1) After trimming the intermediate layer metal and the coated stainless steel plate to the same size, grind the intermediate layer metal to 2000 grit with a grinding and polishing machine; set up the coated stainless steel plate, intermediate layer metal and coated stainless steel plate in sequence, with the intermediate layer metal in contact with the copper coating of the coated stainless steel plate, and stack the three layers together.

[0073] (2) The stacked materials are placed in a graphite mold and hot-pressed in a vacuum at 1050℃ with a pressure of 40Mpa for 3 hours to obtain a pre-finished layered heterogeneous stainless steel plate.

[0074] (3) After the pre-finished layered heterogeneous stainless steel plate is cooled in the furnace, the temperature is raised to 1050℃, held for 60 minutes and then water quenched to complete the solution treatment.

[0075] (4) Argon gas is introduced into the heating furnace as a protective gas, the pre-finished layered heterogeneous stainless steel plate is heated to 900°C, the surface of the rolling mill is heated to 250°C, and hot rolling is carried out at a rolling speed of 60m / min to roll it into a 2mm thick pre-finished layered heterogeneous stainless steel plate. Finally, the rolled pre-finished layered heterogeneous stainless steel plate is placed in an annealing furnace at 600°C and held for 100min. After annealing is completed, it is taken out and cooled naturally to obtain the layered heterogeneous stainless steel plate.

[0076] S4: The processing steps for high-strength stainless steel pipes are as follows: After cutting the layered dissimilar stainless steel plate to 1219mm×3048mm, it is transformed into a steel pipe shape using a steel pipe manufacturing machine. Under argon protection, the pipe seam of the stainless steel pipe is welded using plasma welding. After welding, the weld seam is cooled with water to obtain a stainless steel pipe blank. Then, the weld seam is polished with a grinding wheel until it is flush with the base material, and the weld seam is leveled. Finally, after cleaning and drying, the high-strength stainless steel pipe is obtained.

[0077] The plasma welding current is 300A, the arc voltage is 30V, and the welding speed is 45mm / min.

[0078] The dimensions of the high-strength stainless steel pipe are 1219mm × 3048mm × 2mm.

[0079] Comparative Example 1: The percentage of each component in the intermediate layer metal is as follows: pure copper 94.83%, Cu@Cu3Pt nanoparticles 5%, titanium nitride 0.15%, cryolite 0.01%, rare earth metal cerium 0.01%, and other components are the same as in Example 1;

[0080] Comparative Example 2: Without the addition of Cu@Cu3Pt nanoparticles, the percentage of each component in the intermediate metal layer is as follows: pure copper 99.65%, titanium nitride 0.3%, cryolite 0.03%, rare earth metal cerium 0.02%, and other components are the same as in Example 1;

[0081] Comparative Example 3: Without the addition of Cu@Cu3Pt nanoparticles and titanium nitride, the percentage of each component in the intermediate layer metal is: 99.98% pure copper, 0.02% rare earth metal cerium, and the rest is the same as in Example 1;

[0082] Comparative Example 4: Without the addition of titanium nitride, the percentage of each component in the intermediate layer metal is as follows: pure copper 96.98%, Cu@Cu3Pt nanoparticles 3%, rare earth metal cerium 0.02%, and other components are the same as in Example 1;

[0083] Comparative Example 5: The 07Cr17Ni7Al stainless steel sheet was not sputtered; instead, the intermediate layer metal was stacked using the 07Cr17Ni7Al stainless steel sheet. Other procedures were the same as in Example 1.

[0084] Comparative Example 6: 07Cr17Ni7Al stainless steel plate was processed into stainless steel pipes of the same size as in Example 1.

[0085] Performance Testing: The stainless steel tubes prepared in Examples 1-3 and Comparative Examples 1-6 were subjected to mechanical property testing. Tensile strength was tested using an electronic universal testing machine according to GB / T 24511-2017 standard. Specific data are shown in the table below:

[0086] Example Tensile strength (MPa) Example Tensile strength (MPa) Example 1 868 Comparative Example 3 805 Example 2 842 Comparative Example 4 823 Example 3 852 Comparative Example 5 827 Comparative Example 1 822 Comparative Example 6 793 Comparative Example 2 828

[0087] The above test results show that the high-strength stainless steel pipe of the present invention has higher strength than the stainless steel pipe made from stainless steel plate, and the strength is significantly improved. The heterogeneous nucleating agents titanium nitride and Cu@Cu3Pt nanoparticles have a significant impact on the strength and significantly improve the mechanical properties of the stainless steel pipe. Sputtering the stainless steel plate enhances the bonding ability between the intermediate layer metal and the coated stainless steel plate, which also has a significant impact on the mechanical properties of the stainless steel pipe.

[0088] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A processing technology for high-strength stainless steel pipes, characterized in that: Includes the following steps: S1: Prepare Cu@Cu3Pt nanoparticles; then melt, cast, hot roll, and anneal them with pure copper, titanium nitride, cryolite, and rare earth metal cerium to obtain an intermediate layer metal; S2: After pre-treating one side of the stainless steel plate, the pre-treated side is sputtered with pure copper as the target material to obtain a copper plating layer, which is then used as the coated stainless steel plate. S3: The coated stainless steel sheet, the intermediate layer metal, and the coated stainless steel sheet are stacked in sequence, with the intermediate layer metal in contact with the copper-plated side of the coated stainless steel sheet; then, the sheet is subjected to hot pressing sintering, solution treatment, hot rolling, and aging treatment in sequence to obtain a layered heterogeneous stainless steel sheet. S4: Layered dissimilar stainless steel plates are rolled and welded to produce high-strength stainless steel pipes; The percentages of each component in the intermediate layer metal are as follows: pure copper 95-97%, Cu@Cu3Pt nanoparticles 2-5%, titanium nitride 0.15-0.5%, cryolite 0.01-0.05%, and rare earth metal cerium 0.01-0.03%. The preparation method of Cu@Cu3Pt nanoparticles is as follows: 0.01-0.05 mol / L copper chloride solution and 1-3 mol / L sodium hydroxide solution are mixed, heated to 50-90℃, and 0.5-2 mol / L L-ascorbic acid solution is added. The mixture is stirred at 200-600 r / min for 2-6 h. Then, 0.01-0.05 mol / L hexahydroxyplatinic acid solution is added to the solution, the temperature is raised to 90-160℃, and the mixture is stirred continuously for 2-4 h to obtain a precipitate. The precipitate is filtered, washed, and dried to obtain Cu@Cu3Pt nanoparticles. The volume ratio of copper chloride solution, sodium hydroxide solution, L-ascorbic acid solution, and hexahydroxyplatinic acid is 10:10:(2.5-5):

3.

2. The processing technology for a high-strength stainless steel pipe according to claim 1, characterized in that: The thickness of the intermediate metal layer is 0.5–1 mm, the thickness of the stainless steel plate is 1.5–2 mm, and the thickness of the layered heterogeneous stainless steel plate is 2–3 mm.

3. The processing technology for a high-strength stainless steel pipe according to claim 1, characterized in that: In S2, the sputtering process is as follows: the sputtering power of the magnetron sputtering chamber is 40-80W, the sputtering temperature is 350-500℃, the sputtering working pressure is 0.5-1Pa, and the sputtering time is 10-20min; the copper plating thickness is controlled by controlling the sputtering time.

4. The processing technology for a high-strength stainless steel pipe according to claim 1, characterized in that: The preparation method of the intermediate layer metal is as follows: pure copper, Cu@Cu3Pt nanoparticles, titanium nitride, cryolite, and rare earth metal cerium are placed sequentially in a sealed crucible, argon gas is introduced as a protective gas, and the mixture is heated to 2000-2200℃ until all components melt. After stirring evenly, the mixture is cast into an ingot. Using argon gas as a protective gas, the ingot is heated to 700-900℃, and the surface of the rolling mill is heated to 150-250℃. The ingot is hot-rolled at a rolling speed of 30-60 m / min to form an intermediate layer metal pre-finished product with a thickness of 0.5-1 mm. Finally, the rolled intermediate layer metal pre-finished product is annealed at 400-600℃ and held for 60-100 min. After annealing, the product is removed and allowed to cool naturally to obtain the intermediate layer metal.

5. The processing technology for a high-strength stainless steel pipe according to claim 1, characterized in that: In S2, the preparation method of the coated stainless steel plate is as follows: a 1.5-2 mm thick 07Cr17Ni7Al stainless steel plate is polished to 1000-2000 mesh using a polishing machine, ultrasonically cleaned with anhydrous ethanol for 10-20 min, washed with deionized water, dried, placed in a magnetron sputtering chamber, and pure copper is used as the target material; the magnetron sputtering chamber is evacuated to a vacuum degree of less than 10-5 Pa, and argon gas is introduced as a protective gas for sputtering to obtain the coated stainless steel plate.

6. The processing technology for a high-strength stainless steel pipe according to claim 1, characterized in that: In S3, the hot pressing sintering temperature is 1000–1050℃, the pressure is 30–40 MPa, and the holding time is 1–3 h; the solution treatment temperature is 980–1050℃, and the holding time is 30–60 min; the hot rolling process temperature is 700–900℃, the surface of the rolling mill is heated to 150–250℃, the rolling speed is 30–60 m / min, and the pre-finished layered dissimilar stainless steel plate with a thickness of 2–3 mm is hot rolled; the annealing temperature is 400–600℃, and the holding time is 60–100 min.

7. A high-strength stainless steel pipe, characterized in that: It is prepared by the processing technology of any one of claims 1 to 6 for a high-strength stainless steel pipe.