Large thin-wall stainless steel ring piece forming method and large thin-wall stainless steel ring piece

Abstract

The invention discloses a large thin-wall stainless steel ring piece forming method. The method comprises the following steps that a stainless steel coil formed by a stainless steel sheet is used as a raw material; the stainless steel thin plate is pulled to the outer side of the ring piece tool, and the upper end and the lower end of the stainless steel thin plate are clamped with the ring piece tool; the ring rolling machine is started, the stainless steel sheet synchronously rotates along with the ring piece tool, and the ring rolling machine radially rolls the stainless steel sheet so that the stainless steel sheet can be attached to the outer wall of the ring piece tool; cutting off the stainless steel thin plate after the stainless steel thin plate circularly moves for a circle along with the ring piece tool, and then welding the butt joint ends of the opposite head end and tail end of the stainless steel thin plate on the outer side of the ring piece tool into a whole; after welding is completed, the ring rolling mill continues to be started to roll the weld joint area in a reciprocating mode, and the welded thin-wall ring piece is obtained; and the ring piece tool and the thin-wall ring piece are subjected to annealing treatment together, and then the thin-wall ring piece is taken down. The method can be used for preparing the large thin-wall stainless steel ring piece with high welding seam strength and high forming precision.

Description

Technical Field

[0001] The invention relates to the technical field of profile processing, and in particular to a large thin-wall stainless steel ring forming method and a large thin-wall stainless steel ring. Background Art

[0002] Ring components, as the key main structural parts of rockets, occupy an important position in aerospace engineering. At present, high-strength aluminum alloy ring components are more common in practical applications. In recent years, with the continuous development and exploration of materials science, some researchers have tried to use stainless steel as the material for preparing ring components. However, such rings made of stainless steel are typical thin-walled weak rigid rings, which expose a series of problems that need to be solved during the forming process.

[0003] Specifically, during the forming process, such rings made of stainless steel are prone to instability. Due to their thin-walled and weakly rigid structural characteristics, they are difficult to maintain a stable shape and structure under the action of processing stress, and are prone to deformation or even damage, which seriously affects product quality and production efficiency. Moreover, after the plate is bent, a large residual stress will be generated. The existence of this residual stress leads to uneven stress distribution inside the ring, forming stress concentration and significantly reducing the mechanical properties and fatigue life of the ring. In addition, the deformation rebound problem causes the size of the processed ring to deviate from the expected design size, making it difficult to meet the high-precision size requirements, which greatly limits its application in actual engineering. Therefore, the forming and preparation of thin-walled stainless steel rings with a diameter of 10m is still a difficult point in research. The existence of the above problems seriously restricts the promotion and application of such large thin-walled stainless steel rings in aerospace and related industrial fields.

[0004] In the prior art, most common thin-walled stainless steel rings are made using a multi-forging welding process, that is, a rolling machine is used to bend the stainless steel sheet into an arc-shaped plate with a certain curvature, and then multiple arc-shaped plates are welded into rings. When such a process is used to prepare thin-walled stainless steel rings with a diameter of 10m, it cannot be directly formed by ring rolling, but a multi-stage welding process must be used, which has a complicated process, an increased number of welds, and an increased number of weak areas of the rings; if other processes such as unwinding and single welding are used, the thin plate will produce large deformation and stress during the bending process due to the high strength and high hardness characteristics of the material, resulting in difficulty in dimensional control. Therefore, the existing preparation processes have technical bottlenecks to varying degrees when facing the manufacture of thin-walled stainless steel rings with a diameter of 10m, and cannot achieve the production of such large thin-walled stainless steel rings with high efficiency and high quality. In view of this, the present invention aims to develop an innovative large-scale thin-walled stainless steel ring forming method to solve the problem of difficulty in manufacturing thin-walled stainless steel rings with a diameter of 10m. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a large thin-walled stainless steel ring forming method to solve the problem of difficulty in manufacturing thin-walled stainless steel rings with a diameter of 10 meters, and to provide a large thin-walled ring with excellent performance.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical solutions: A method for forming a large thin-walled stainless steel ring comprises the following steps: Raw material preparation: stainless steel coils formed from stainless steel sheets are used as raw materials; Pretreatment: prepare the ring tooling, the outer diameter of the ring tooling is the same as the inner diameter of the target thin-walled ring; pull the stainless steel sheet to the outside of the ring tooling, and clamp the upper and lower ends of the stainless steel sheet to the ring tooling; Ring rolling treatment: start the ring rolling mill, the stainless steel sheet rotates synchronously with the ring tooling, and the ring rolling mill radially rolls the stainless steel sheet to make the stainless steel sheet fit the outer wall of the ring tooling; Cutting and welding: After the stainless steel sheet moves in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, and then the head end and tail end of the stainless steel sheet on the outside of the ring tooling are welded together into a whole; Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture together with the thin-walled ring, and then remove the thin-walled ring.

[0007] Furthermore, the stainless steel sheet has a thickness of 3-5 mm, a width of 1000-2000 mm, a tensile strength of >1035 MPa, a yield strength of ≥760 MPa, and an elongation of ≥6%.

[0008] Furthermore, in the pretreatment step, the ring tooling is a steel mold, and the cross-sectional thickness of the ring tooling is 30-70 mm.

[0009] Furthermore, in the ring rolling process, the linear speed of the main roller is 0.8-1.2 m / s, the radial rolling speed is 0.1-0.2 mm / s, and the radial feed time is 15-30 s.

[0010] Furthermore, in the cutting and welding steps, after the stainless steel sheet is cut, the incision is polished and then welded. After the welding is completed, the weld area is 0.5 to 1 mm higher than the main body.

[0011] Furthermore, in the cutting and welding steps, the welding power is 6-12 kW and the welding speed is 0.8-1.5 m / min.

[0012] Furthermore, in the local cold deformation step, the main roll feed speed of the ring rolling mill is 0.05-0.1 mm / s, and the weld area is reciprocated for 3-5 times.

[0013] Furthermore, the annealing treatment is carried out in a heating furnace, the heating temperature is 200-300° C., and the insulation time is 3-6 hours.

[0014] A large thin-walled stainless steel ring is prepared by any of the above methods, wherein the large thin-walled stainless steel ring has a tensile strength of ≥870 MPa, a yield strength of ≥420 MPa, an elongation of ≥12.5%, and an out-of-roundness of ≤0.1%.

[0015] Beneficial effects: The large thin-walled stainless steel ring forming method described in the present invention can use stainless steel as raw material to prepare large thin-walled stainless steel rings with a diameter of 10m. The ring rolling process is used to unwind and combined with stress relief annealing to reduce the rebound stress of high-strength stainless steel plates after large bending deformation; and local ring rolling cold deformation is used to improve the strength of the weld area. In addition, combined with stress relief annealing and other processes, the parameter conditions are strictly controlled to make the prepared large thin-walled stainless steel rings have a tensile strength of ≥870 MPa, a yield strength of ≥420 MPa, an elongation of ≥12.5%, and a non-roundness of ≤0.1%. The performance is excellent and can well meet the needs of aerospace and related industrial fields. The process flow of the present invention is simple, the processing cost is low, and it is suitable for large-scale processing and production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the ring rolling process in the present invention.

[0017] Figure 2 Schematic diagram of the welding process steps in the present invention.

[0018] Among them: 1. Stainless steel sheet; 2. Ring tooling; 3. Main roller; 4. Core roller; 5. Clamping part; 6. Welding area. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0020] Example 1 The forming method of the large thin-walled stainless steel ring described in this embodiment, the diameter of the ring is Φ10m, comprises the following steps: Raw material preparation: The stainless steel coil formed by the stainless steel sheet 1 is used as the raw material. The stainless steel sheet 1 is a 316 hardened stainless steel sheet. The thickness of the stainless steel sheet is 4 mm, the width is 1200 mm, the tensile strength is greater than 1035 MPa, the yield strength is ≥ 760 MPa, and the elongation is ≥ 6%; Pretreatment: 5CrNiMo die steel is used, and a conventional ring rolling process is used to prepare a ring tooling 2 with an outer diameter of 10 mm for standby use. The cross-sectional thickness of the ring tooling 2 is 50 mm. The stainless steel coil is placed vertically, and the stainless steel sheet 1 on the stainless steel coil is pulled to the outside of the ring tooling 2, such as Figure 1 As shown, the upper and lower ends of the stainless steel sheet 1 are clamped with the ring fixture 2 by the clamping member 5 at a distance of 300 mm from the head end of the stainless steel sheet 1; Ring rolling treatment: start the ring rolling mill, the main roller 3 and the core roller 4 of the ring rolling mill drive the stainless steel sheet 1 to rotate synchronously with the ring fixture 3, the linear speed of the main roller 3 is 1.0m / s, the radial rolling speed is 0.12mm / s, and the radial feeding time is 18s; after radial rolling, the stainless steel sheet 1 is fitted with the ring fixture 2; Cutting and welding: The stainless steel sheet 1 continues to move in a circle with the ring tool 2, cuts the stainless steel sheet 1, grinds the cut, and then welds the opposite head and tail ends of the stainless steel sheet 1 on the ring tool 2 into a whole. The weld area 6 is as shown in FIG. Figure 2 As shown; welding power is 10kW, welding speed is 1.2 m / min, after welding is completed, the weld area is 0.6mm higher than the main body.

[0021] Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area 6. The feed speed of the main roller 3 of the ring rolling mill is 0.07 mm / s. The weld area is reciprocated for 4 times to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture 2 together with the thin-walled ring. The annealing is carried out in a heating furnace at a heating temperature of 220°C and a holding time of 4 hours. After the annealing is completed, the thin-walled ring can be removed.

[0022] Example 2 The forming method of the large thin-walled stainless steel ring described in this embodiment, the ring diameter is Φ12m, comprising the following steps: Raw material preparation: stainless steel coils formed by stainless steel sheets are used as raw materials. The stainless steel sheets are 316 hardened stainless steel sheets. The thickness of the stainless steel sheets is 5mm, the width is 1600mm, the tensile strength is >1035MPa, the yield strength is ≥760MPa, and the elongation is ≥6%; Pretreatment: 42CrMo die steel is used, and conventional ring rolling process is used to prepare a ring tooling with an outer diameter of 12m. The cross-sectional thickness of the ring tooling is 50mm. The stainless steel coil is placed vertically, and the stainless steel sheet on the stainless steel coil is pulled to the outside of the ring tooling, such as Figure 1 As shown, the upper and lower ends of the stainless steel sheet are clamped with the ring fixture at a distance of 280 mm from the head end of the stainless steel sheet; Ring rolling treatment: start the ring rolling mill, the main roll and core roll of the ring rolling mill drive the stainless steel sheet to rotate synchronously with the ring tooling, the main roll linear speed is 1.2m / s, the radial rolling speed is 0.15mm / s, and the radial feed time is 25s; after radial rolling, the stainless steel sheet is fitted with the ring tooling; Cutting and welding: The stainless steel sheet continues to move in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, the cut is polished, and then the head and tail ends of the stainless steel sheet on the ring tooling are welded into a whole; the welding power is 6 kW, the welding speed is 1.5 m / min, and after welding is completed, the weld area is 0.8 mm higher than the main body.

[0023] Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area. The main roller feed speed of the ring rolling mill is 0.1mm / s. The weld area is reciprocated for 3 times to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture together with the thin-walled ring. The annealing process is carried out in a heating furnace at a heating temperature of 280°C and a holding time of 5 hours. After the annealing process is completed, the thin-walled ring can be removed.

[0024] Comparative Example 1 The forming method of the large thin-walled stainless steel ring described in this comparative example, the ring diameter is Φ10m, comprising the following steps: Raw material preparation: stainless steel coils formed by stainless steel sheets are used as raw materials. The stainless steel sheets are 316 hardened stainless steel sheets. The thickness of the stainless steel sheets is 4mm, the width is 1200mm, the tensile strength is >1035MPa, the yield strength is ≥760MPa, and the elongation is ≥6%; Pretreatment: 5CrNiMo die steel is used, and conventional ring rolling process is used to prepare a ring tooling with an outer diameter of 10m. The cross-sectional thickness of the ring tooling is 50mm. The stainless steel coil is placed vertically, and the stainless steel sheet on the stainless steel coil is pulled to the outside of the ring tooling, such as Figure 1 As shown, the upper and lower ends of the stainless steel sheet are clamped with the ring fixture at a distance of 300 mm from the head end of the stainless steel sheet; Ring rolling treatment: start the ring rolling mill, the main roller 3 and the core roller 4 of the ring rolling mill drive the stainless steel sheet to rotate synchronously with the ring tooling, the main roller linear speed is 1.0m / s, the radial rolling speed is 0.12mm / s, and the radial feed time is 18s; after radial rolling, the stainless steel sheet is fitted with the ring tooling; Cutting and welding: The stainless steel sheet continues to move in a circle with the ring tooling for one circle, the stainless steel sheet 1 is cut off, the incision is polished, and then the head end and tail end of the stainless steel sheet on the ring tooling are welded into a whole; the welding power is 10kW, the welding speed is 1.2 m / min, and after the welding is completed, the weld area is 0.6mm higher than the main body.

[0025] Stress relief: anneal the ring fixture together with the thin-walled ring. The annealing process is carried out in a heating furnace at a heating temperature of 220°C and a holding time of 4 hours. After the annealing process is completed, the thin-walled ring can be removed.

[0026] Comparative Example 2 The forming method of the large thin-walled stainless steel ring described in this embodiment, the diameter of the ring is Φ10m, comprises the following steps: Raw material preparation: stainless steel coils formed by stainless steel sheets are used as raw materials. The stainless steel sheets are 316 hardened stainless steel sheets. The thickness of the stainless steel sheets is 4mm, the width is 1200mm, the tensile strength is >1035MPa, the yield strength is ≥760MPa, and the elongation is ≥6%; Pretreatment: 5CrNiMo die steel is used, and conventional ring rolling process is used to prepare a ring tooling with an outer diameter of 10m. The cross-sectional thickness of the ring tooling is 50mm. The stainless steel coil is placed vertically, and the stainless steel sheet on the stainless steel coil is pulled to the outside of the ring tooling, such as Figure 1 As shown, the upper and lower ends of the stainless steel sheet are clamped with the ring fixture at a distance of 300 mm from the head end of the stainless steel sheet; Ring rolling treatment: start the ring rolling mill, the main roll and core roll of the ring rolling mill drive the stainless steel sheet to rotate synchronously with the ring tooling, the main roll linear speed is 1.0m / s, the radial rolling speed is 0.12mm / s, and the radial feed time is 18s; after radial rolling, the stainless steel sheet is fitted with the ring tooling; Cutting and welding: The stainless steel sheet continues to move in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, the incision is polished, and then the head and tail ends of the stainless steel sheet on the ring tooling are welded into a whole; the welding power is 10kW, the welding speed is 1.2 m / min, and after welding is completed, the weld area is 0.6mm higher than the main body.

[0027] Local cold deformation: After welding is completed, continue to start the ring rolling mill to reciprocate the weld area. The main roller feed speed of the ring rolling mill is 0.07mm / s. Reciprocate rolling is performed 4 times in the weld area to obtain a welded thin-walled ring, which can then be removed.

[0028] Comparative Example 3 The forming method of the large thin-walled stainless steel ring described in this embodiment, the diameter of the ring is Φ10m, comprises the following steps: Raw material preparation: stainless steel coils formed by stainless steel sheets are used as raw materials. The stainless steel sheets are 316 hardened stainless steel sheets. The thickness of the stainless steel sheets is 4mm, the width is 1200mm, the tensile strength is 935MPa, the yield strength is 560MPa, and the elongation is 8%; Pretreatment: 5CrNiMo die steel is used, and conventional ring rolling process is used to prepare a ring tooling with an outer diameter of 10m. The cross-sectional thickness of the ring tooling is 50mm. The stainless steel coil is placed vertically, and the stainless steel sheet on the stainless steel coil is pulled to the outside of the ring tooling. The upper and lower ends of the stainless steel sheet are clamped to the ring tooling by a clamp at a distance of 300mm from the head end of the stainless steel sheet. Ring rolling treatment: start the ring rolling mill, the main roll and core roll of the ring rolling mill drive the stainless steel sheet to rotate synchronously with the ring tooling, the main roll linear speed is 1.0m / s, the radial rolling speed is 0.12mm / s, and the radial feed time is 18s; after radial rolling, the stainless steel sheet is fitted with the ring tooling; Cutting and welding: The stainless steel sheet continues to move in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, the incision is polished, and then the head and tail ends of the stainless steel sheet on the ring tooling are welded into a whole; the welding power is 10kW, the welding speed is 1.2 m / min, and after welding is completed, the weld area is 0.6mm higher than the main body.

[0029] Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area. The main roller feed speed of the ring rolling mill is 0.07 mm / s. The weld area is reciprocated for 4 times to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture together with the thin-walled ring. The annealing process is carried out in a heating furnace at a heating temperature of 220°C and a holding time of 4 hours. After the annealing process is completed, the thin-walled ring can be removed.

[0030] Comparative Example 4 The forming method of the large thin-walled stainless steel ring described in this embodiment, the diameter of the ring is Φ10m, comprises the following steps: Raw material preparation: stainless steel coils formed by stainless steel sheets are used as raw materials. The stainless steel sheets are 316 hardened stainless steel sheets. The thickness of the stainless steel sheets is 4mm, the width is 1200mm, the tensile strength is >1035MPa, the yield strength is ≥760MPa, and the elongation is ≥6%; Pretreatment: 5CrNiMo die steel is used, and conventional ring rolling process is used to prepare a ring tooling with an outer diameter of 10m. The cross-sectional thickness of the ring tooling is 50mm. The stainless steel coil is placed vertically, and the stainless steel sheet on the stainless steel coil is pulled to the outside of the ring tooling. The upper and lower ends of the stainless steel sheet are clamped to the ring tooling by a clamp at a distance of 300mm from the head end of the stainless steel sheet. Ring rolling treatment: start the ring rolling mill, the main roll and core roll of the ring rolling mill drive the stainless steel sheet to rotate synchronously with the ring tooling, the main roll linear speed is 1.0m / s, the radial rolling speed is 0.12mm / s, and the radial feed time is 40s; after radial rolling, the stainless steel sheet is fitted with the ring tooling; Cutting and welding: The stainless steel sheet continues to move in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, the incision is polished, and then the head and tail ends of the stainless steel sheet on the ring tooling are welded into a whole; the welding power is 10kW, the welding speed is 1.2 m / min, and after welding is completed, the weld area is 0.6mm higher than the main body.

[0031] Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area. The main roller feed speed of the ring rolling mill is 0.07 mm / s. The weld area is reciprocated for 4 times to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture together with the thin-walled ring. The annealing process is carried out in a heating furnace at a heating temperature of 220°C and a holding time of 4 hours. After the annealing process is completed, the thin-walled ring can be removed.

[0032] Comparative Example 5 2219 aluminum alloy sheet is used as raw material, with properties of tensile strength ≥415MPa, yield strength ≥330MPa, and elongation ≥6%. Four curved panels are welded into a Φ10m ring, and the curved panel is rolled into the corresponding size by a plate rolling machine.

[0033] Comparative Example 6 Stainless steel sheets are used as raw materials, with properties such as tensile strength>1035MPa, yield strength≥760MPa, and elongation≥6%. Four curved plates are welded into a Φ10m ring, and the curved plates are rolled into corresponding sizes by a plate rolling machine.

[0034] The performance of the weld of the thin-walled ring obtained in each embodiment and the comparative example and the dimensional accuracy of the ring are tested, and the test results are shown in Table 1. The mechanical properties are tested according to GB / T228.1; the out-of-roundness is calculated according to the following formula: O=[(D1-D2) / (D1+D2)]×100%, where: O—out-of-roundness; D1—actual value of the larger diameter, in millimeters (mm); D2—actual value of the smaller diameter, in millimeters (mm); the out-of-roundness of the ring is defined as the average value of the three groups of out-of-roundness.

[0035] Table 1 Statistics of thin-walled ring performance and dimensional accuracy

[0036] As shown in Table 1, the method of the present invention can solve the problems of high residual stress, deformation springback, poor weld strength, etc. that are easy to occur in the preparation of large thin-walled hardened stainless steel rings by traditional processes, and can produce large thin-walled rings with high weld strength and high forming accuracy, thereby achieving efficient and high-quality production of such large thin-walled stainless steel rings, and the prepared products can meet relevant standards in terms of performance, which can further promote the promotion and application of such large thin-walled stainless steel rings in aerospace and related industrial fields. As shown in the comparative example, in the present invention, the combination of local cold deformation and stress relief is more critical, and the ring rolling process and raw material processing have a greater impact on the results.

[0037] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for forming a large thin-walled stainless steel ring, characterized in that: The steps include: Raw material preparation: stainless steel coils formed from stainless steel sheets are used as raw materials; Pretreatment: prepare the ring tooling, the outer diameter of the ring tooling is the same as the inner diameter of the target thin-walled ring; pull the stainless steel sheet to the outside of the ring tooling, and clamp the upper and lower ends of the stainless steel sheet to the ring tooling; Ring rolling treatment: start the ring rolling mill, the stainless steel sheet rotates synchronously with the ring tooling, and the ring rolling mill radially rolls the stainless steel sheet to make the stainless steel sheet fit the outer wall of the ring tooling; Cutting and welding: After the stainless steel sheet moves in a circle with the ring tooling for one circle, the stainless steel sheet is cut off, and then the head end and tail end of the stainless steel sheet on the outside of the ring tooling are welded together into a whole; Local cold deformation: After welding is completed, the ring rolling mill is started to reciprocate the weld area to obtain a welded thin-walled ring. Stress relief: anneal the ring fixture together with the thin-walled ring, and then remove the thin-walled ring.

2. The method for forming a large thin-walled stainless steel ring according to claim 1, characterized in that: The thickness of stainless steel sheet is 3~5mm, the width is 1000~2000mm, the tensile strength is>1035MPa, the yield strength is ≥760MPa, and the elongation is ≥6%.

3. The method for forming a large thin-walled stainless steel ring according to claim 1, characterized in that: In the pretreatment step, the ring tooling is a steel mold, and the cross-sectional thickness of the ring tooling is 30~70mm.

4. The method for forming a large thin-walled stainless steel ring according to claim 1, characterized in that: In the ring rolling process, the main roller linear speed is 0.8~1.2m / s, the radial rolling speed is 0.1~0.2mm / s, and the radial feed time is 15~30s.

5. The method for forming a large thin-walled stainless steel ring according to claim 1, characterized in that: In the cutting and welding steps, after the stainless steel sheet is cut, the incision is polished and then welded. After welding is completed, the weld area is 0.5~1mm higher than the main body.

6. The method for forming a large thin-walled stainless steel ring according to claim 5, characterized in that: During the cutting and welding steps, the welding power is 6~12 kW and the welding speed is 0.8~1.5 m / min.

7. The method for forming a large thin-walled stainless steel ring according to claim 1, characterized in that: In the local cold deformation step, the main roll feed speed of the ring rolling mill is 0.05~0.1mm / s, and reciprocating rolling is performed in the weld area for 3~5 times.

8. The method for forming a large thin-walled stainless steel ring according to claim 5, characterized in that: The annealing treatment is carried out in a heating furnace at a heating temperature of 200~300℃ and a holding time of 3~6h.

9. A large thin-walled stainless steel ring, characterized in that: The large thin-walled stainless steel ring is prepared by the method according to any one of claims 1 to 8, and has a tensile strength of ≥870 MPa, a yield strength of ≥420 MPa, an elongation of ≥12.5%, and an out-of-roundness of ≤0.1%.

Images