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CN-122012882-A - Method for eliminating precipitated phase of hot-rolled state structure of economic austenitic stainless steel

CN122012882ACN 122012882 ACN122012882 ACN 122012882ACN-122012882-A

Abstract

The application discloses a method for eliminating an economic austenitic stainless steel hot-rolled microstructure precipitated phase, and relates to the technical field of stainless steel material treatment. According to the method for eliminating the precipitated phase of the hot rolled structure of the economic austenitic stainless steel, through carrying out cooperative optimization on chemical components and process parameters, the precipitated phase of the carbonitride does not appear in the hot rolled structure, the binding force of a grain boundary is obviously enhanced, the problem of performance deterioration of the traditional economic austenitic stainless steel caused by the precipitated phase is solved from the root, by eliminating the precipitated phase, the balanced and excellent performance of the material in the aspects of mechanical properties such as strength, toughness and the like is realized, meanwhile, the reasonable proportion of Cr and Ni elements ensures that the material has good corrosion resistance and plastic toughness, the hot rolled structure is pure, the weakening phenomenon of the grain boundary caused by the precipitated phase does not exist, the risks of cracking, breakage and the like in the online processing process are avoided, and the safety and the stability of subsequent processing are greatly improved.

Inventors

  • PEI MINGDE
  • LIU LEI
  • ZOU YONG
  • XING LINA
  • KANG YUXIN

Assignees

  • 山西太钢不锈钢股份有限公司

Dates

Publication Date
20260512
Application Date
20260120

Claims (10)

  1. 1. A method for eliminating precipitated phases of an economic austenitic stainless steel hot-rolled structure, which is characterized by comprising the following steps: S1, selecting materials, namely selecting austenitic stainless steel; Step S2, rough rolling of a casting blank, namely heating the casting blank made of the material to 1200+/-50 ℃, controlling the initial rolling temperature to 1150-1200 ℃ and adopting 5-7 times for rolling; step S3, casting blank finish rolling, namely, performing finish rolling on the casting blank after rough rolling by adopting 5-7 passes, and controlling the finish rolling temperature to be 900-1050 ℃; And S4, hot coil coiling, namely, after finishing finish rolling, pouring laminar cooling, controlling the coiling temperature to be 300-500 ℃ and finishing hot coil rolling, so that precipitated phases in a hot rolled state structure are eliminated.
  2. 2. The method for eliminating the precipitated phase of the hot rolled state structure of the economic austenitic stainless steel according to claim 1, wherein the chemical components of the austenitic stainless steel comprise less than or equal to 0.18% of C, 13.0% -16.0% of Cr, 0.50% -1.50% of Ni, less than or equal to 1.0% of Cu, 0.10% -0.25% of N, 7.0% -10.0% of Mn and less than or equal to 1.0% of Si.
  3. 3. The method for eliminating the hot rolled structure precipitated phase of the economic austenitic stainless steel according to claim 2, wherein the chemical composition of the austenitic stainless steel comprises 0.10% of C, 0.51% of 13.4% of Ni, 0.15% of Cu, 0.20% of N, 9.4% of Mn and 0.4% of Si.
  4. 4. The method for eliminating the hot rolled microstructure precipitated phase of an economical austenitic stainless steel according to claim 3, wherein the cast slab is heated to 1230 ℃, the starting temperature of the cast slab is 1200 ℃, and 5 passes of rolling are adopted.
  5. 5. The method for eliminating precipitated phases in hot rolled austenitic stainless steel according to claim 4, wherein the casting blank after rough rolling is finish rolled in 7 passes, and the finishing temperature is controlled to be 1000 ℃.
  6. 6. The method for eliminating precipitated phases in hot rolled austenitic stainless steel according to claim 5, wherein the coiling temperature is controlled to 480 ℃ by feeding laminar cooling after finishing finish rolling.
  7. 7. The method for eliminating the hot rolled structure precipitated phase of the economic austenitic stainless steel according to claim 2, wherein the chemical components of the austenitic stainless steel comprise less than or equal to 0.14% of C, 13.8% of Cr, 1.33% of Ni, 0.89% of Cu, 0.21% of N, 9.90% of Mn and 0.45% of Si.
  8. 8. The method for eliminating precipitated phases in hot rolled austenitic stainless steel according to claim 7, wherein the cast slab is heated to 1220 ℃, and the initial rolling temperature of the cast slab is 1180 ℃, and 7 passes of rolling are adopted.
  9. 9. The method for eliminating precipitated phases in hot rolled austenitic stainless steel according to claim 8, wherein the casting blank after rough rolling is finish rolled in 7 passes, and the finishing temperature is controlled to 980 ℃.
  10. 10. The method for eliminating precipitated phases in hot rolled austenitic stainless steel according to claim 9, wherein the coiling temperature is controlled to 420 ℃ by feeding laminar cooling after finishing finish rolling.

Description

Method for eliminating precipitated phase of hot-rolled state structure of economic austenitic stainless steel Technical Field The application belongs to the technical field of stainless steel treatment, and particularly relates to a method for eliminating an economic austenitic stainless steel hot-rolled microstructure precipitated phase. Background With the rapid development of social economy, the low-carbon and environment-friendly concept is in deep focus, and the civil stainless steel field has higher requirements on economy, high strength and environment friendliness of materials. On one hand, the conventional austenitic stainless steel is difficult to meet the requirements of high-end civil scenes in the aspects of corrosion resistance, strength and the like, and the conventional austenitic stainless steel is high in cost due to high Cr and Ni contents, so that the large-scale popularization and application of the austenitic stainless steel are limited, and on the other hand, the market is in need of a stainless steel material with low cost and high strength, the material consumption can be reduced by reducing the thickness, the low carbon and environmental friendliness can be realized, the subsequent installation difficulty can be reduced, and the wide requirements in the fields of construction, traffic and the like are met. In this context, economical austenitic stainless steels have grown. The steel has the advantages of reducing the content of noble metal elements such as Cr, ni and the like by optimizing chemical components, greatly reducing the production cost on the premise of ensuring basic corrosion resistance, and simultaneously, remarkably improving the material strength by improving the content of C, N elements and utilizing the effects of gap strengthening and martensitic transformation strengthening, thereby perfectly conforming to the core requirements of the civil field. However, the introduction of high C, N element also brings outstanding technical problems that during hot rolling and subsequent cooling, the carbonitride phases are easy to separate out, and the separated phases are mainly concentrated at austenite grain boundaries, so that the grain boundary binding force can be greatly weakened, the mechanical properties (such as toughness and plasticity) of the material are reduced, the corrosion resistance of the material can be reduced, the on-line processing safety of hot coil is seriously affected, even the rejection of products is caused, and the industrial application of the economic austenitic stainless steel is limited. In the prior art, control of precipitated phases of austenitic stainless steel focuses on high alloy content steel types, the precipitated phases are eliminated through complex heat treatment processes (such as solution treatment), but the method has high cost and high energy consumption, and is contrary to low-cost positioning of economic type stainless steel, and an effective precipitated phase control scheme is not formed for low-alloy and high-C/N content economic type austenitic stainless steel, and the existing hot rolling and coiling processes cannot avoid a precipitation sensitive temperature range of carbonitrides, so that the problem of precipitated phases in a hot rolled state structure exists for a long time, and becomes a key bottleneck for restricting large-scale application of the method. Therefore, developing a low-cost and high-efficiency precipitated phase elimination method suitable for economic austenitic stainless steel becomes a technical problem to be solved in industry. Disclosure of Invention In order to solve part or all of the technical problems in the prior art, the application provides a method for eliminating an economic austenitic stainless steel hot-rolled microstructure precipitated phase. The application provides a method for eliminating an economic austenitic stainless steel hot-rolled microstructure precipitated phase, which comprises the following steps: S1, selecting materials, namely selecting austenitic stainless steel; Step S2, rough rolling of a casting blank, namely heating the casting blank made of the material to 1200+/-50 ℃, controlling the initial rolling temperature to 1150-1200 ℃ and adopting 5-7 times for rolling; step S3, casting blank finish rolling, namely, performing finish rolling on the casting blank after rough rolling by adopting 5-7 passes, and controlling the finish rolling temperature to be 900-1050 ℃; And S4, hot coil coiling, namely, after finishing finish rolling, pouring laminar cooling, controlling the coiling temperature to be 300-500 ℃ and finishing hot coil rolling, so that precipitated phases in a hot rolled state structure are eliminated. Preferably, the austenitic stainless steel comprises the following chemical components of less than or equal to 0.18% of C, 13.0% -16.0% of Cr, 0.50% -1.50% of Ni, less than or equal to 1.0% of Cu, 0.10% -0.25% of N, 7.0% -10.0% of Mn and less than or e