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CN-117046914-B - Method for preparing three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging

CN117046914BCN 117046914 BCN117046914 BCN 117046914BCN-117046914-B

Abstract

The invention belongs to the field of material preparation, and particularly relates to a method for preparing a three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging. The method comprises the steps of (1) surface pretreatment, namely pretreatment of the surfaces of a low-carbon steel rod, a interstitial free steel rod and an austenitic stainless steel rod, (2) mixing arrangement, (3) high-temperature knob at 800-1200 ℃, high-temperature forging, namely high-temperature free forging of a billet, wherein the forging direction is perpendicular to the radial direction, (5) hot rolling, namely hot rolling in the radial direction, (6) low-temperature rolling, namely cold rolling in the radial direction, and (7) heat treatment, namely the heterogeneous steel material consisting of austenite, ferrite and martensite is obtained. The invention has simple process flow, realizes the combination of various steels through a high Wen Xuanniu and forging mode, and forms heterogeneous steels with three-dimensional ferrite, martensite and austenite alternately distributed through subsequent high-temperature hot rolling, low-temperature rolling and heat treatment.

Inventors

  • ZHOU HAO
  • LU CHEN
  • GAO BO
  • XIAO LIRONG

Assignees

  • 南京理工大学

Dates

Publication Date
20260512
Application Date
20230803

Claims (8)

  1. 1. A method for preparing a three-dimensional heterogeneous steel plate by high-temperature torsion and forging, which is characterized by comprising the following steps: The surface pretreatment, namely, the surface pretreatment of the low-carbon steel bar, the interstitial-free steel bar and the austenitic stainless steel bar; Step (2) mixing arrangement, namely, distributing the three different types of steel bars pretreated in the step (1) at intervals, mixing and arranging the steel bars outwards in a spiral manner, and fixing the steel bars by welding; step (3) high temperature knob, which is to carry out knob at 800-1200 ℃; The step (4) of high-temperature forging, in which the billet obtained in the step (3) is subjected to high-temperature free forging, the forging direction is perpendicular to the radial direction, the forging temperature of the high-temperature free forging in the step (4) is 900-1200 ℃, the billet is heated before each forging, the heating temperature is 1100-1200 ℃, the heat preservation time is 10-60 min, and the deformation of the forging is 10-50%; the hot rolling is carried out along the radial direction, the interface combination between steel grades is improved, the hot rolling in the step (5) is carried out at the rolling temperature of 900-1000 ℃, the rolling quantity is 5-10% each time, and the accumulated rolling quantity is 10-50%; The low-temperature rolling step (6) comprises the steps of cold rolling along the radial direction, thinning the microstructure to enable the austenite region to generate stress-induced martensitic transformation, wherein the low-temperature rolling step (6) comprises the steps of rolling at the temperature of 25 oC-400 oC, rolling with the rolling quantity of 1% -5% each time and accumulating rolling quantity of 50% -95%; And (7) heat treatment, namely quenching the steel plate after vacuum heat treatment to obtain the heterogeneous steel material consisting of austenite, ferrite and martensite.
  2. 2. The method according to claim 1, wherein the low carbon steel rod, the interstitial free steel rod and the austenitic stainless steel rod in the step (1) have diameters of 0.5 to 10mm and lengths of 50 to 200mm.
  3. 3. The method according to claim 2, characterized in that the carbon content of the low carbon steel is 0.08-0.25 wt%, the carbon content of the interstitial free steel is less than 0.01wt.%, and the austenitic stainless steel is a 3 series austenitic stainless steel.
  4. 4. A method according to claim 3, wherein the surface pretreatment in the step (1) is specifically to polish the surface of the steel bar by sand paper and to remove oil stains and impurities on the surface by pickling.
  5. 5. The method of claim 4, wherein the number of layers mixed in step (2) is 2-20.
  6. 6. The method according to claim 5, wherein the high temperature twisting in the step (3) is performed by using a torsion forming device, one end of the billet obtained in the step (2) is fixed, the other end of the billet passes through a chuck knob, the rotation speed of the chuck is 10-30 revolutions per minute, and the number of turns of the knob is 1-10 turns.
  7. 7. The method according to claim 6, wherein the heat treatment in the step (7) is specifically performed by subjecting the steel sheet after low-temperature rolling to vacuum heat treatment of 700 oC to 950 oC for a holding time of 1 to 60 and min, and then quenching the steel sheet.
  8. 8. A three-dimensional heterogeneous steel sheet, characterized by being produced by the method according to any one of claims 1 to 7.

Description

Method for preparing three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging Technical Field The invention belongs to the field of material preparation, and particularly relates to a method for preparing a three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging. Background In the development process of the modern industry, steel materials are used as the most commonly used structural materials, and have wide application in the fields of traffic construction, facility equipment, automobiles and the like. However, with the development of technology, new materials are endlessly layered, the service indexes of the materials are continuously increased, and the steel materials are continuously improved and are transformed to functional and light weight. Increasing the carbon content is the most common strengthening means for steel materials, but as the carbon content increases, the steel strength and hardness will increase, but the plasticity and toughness will decrease. Therefore, the improvement of the comprehensive performance of the steel through an effective mode has important significance for popularizing the application of the steel material. The different microstructures of the steel material can lead the steel material to have different performances, wherein the plasticity of ferrite and austenite is better, and the martensitic structure can effectively strengthen the strength of the material. Therefore, by adjusting the microstructure of the steel material, a heterogeneous structure with multiphase composition is formed, so that the steel material has both plasticity and strength and has more excellent performance. Common means for controlling microstructure are plastic deformation, heat treatment, and the like. It was found by search that He et al published a paper titled "Improving ductility by increasing fraction of interfacial zone in low C steel/304SS laminates" on mate. Sci. Eng. A726 (2018) 288-297, which suggested that a stacked structure consisting of martensite and austenite was obtained by combining a low carbon steel and 304 austenitic stainless steel by hot rolling and by subsequent heat treatment after cold rolling, and good mechanical properties were obtained. The technology is characterized in that the technology is simpler, martensite in the obtained three-layer material provides high strength, and austenite provides elongation. However, the technology has the disadvantages that (1) the interface is difficult to ensure good combination in the hot rolling process, and the final mechanical property is influenced, and (2) the preparation of the multilayer structure is difficult. Further searching finds that the invention patent CN 202111370521.2 discloses a preparation method of austenite/ferrite/martensite heterogeneous steel materials, specifically, two steel materials are alternately welded by using a rotary friction welding method, a cylindrical laminated sample obtained by welding is subjected to high-temperature forging, rolling and heat treatment to prepare the heterogeneous steel material consisting of superfine austenite, ferrite and martensite. The technology is characterized in that heterogeneous steel plates are obtained, and interface combination of dissimilar materials formed by friction welding is good. However, the method has the defects that (1) the prepared plate has a heterogeneous interface only on the section, three-dimensional isomerism is not obtained, (2) ferrite and martensite structures are provided by low carbon steel, the multiphase proportion adjustment is limited, and (3) the plate needs to be subjected to multiple friction welding and wire cutting procedures, so that the efficiency is low. Disclosure of Invention The invention aims to provide a method for preparing a three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging. The technical scheme for realizing the aim of the invention is that the method for preparing the three-dimensional heterogeneous steel plate by utilizing high-temperature torsion and forging comprises the following steps: The surface pretreatment, namely, the surface pretreatment of the low-carbon steel bar, the interstitial-free steel bar and the austenitic stainless steel bar; Step (2) mixing arrangement, namely, distributing the three different types of steel bars pretreated in the step (1) at intervals, mixing and arranging the steel bars outwards in a spiral manner, and fixing the steel bars by welding; The step (3) is to turn the knob at a high temperature of 800-1200 ℃; high-temperature forging, namely freely forging the billet obtained in the step (3) at a high temperature, wherein the forging direction is perpendicular to the radial direction; hot rolling, namely hot rolling along the radial direction to improve the interface combination between steel grades; Cold rolling along radial direction to refine microstructure