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CN-122007300-A - Forging process method for eliminating high-nitrogen stainless steel bearing ring forging twin carbide

CN122007300ACN 122007300 ACN122007300 ACN 122007300ACN-122007300-A

Abstract

A forging process method for eliminating twin carbide of high-nitrogen stainless steel bearing ring forging relates to the technical field of metal material forging and comprises the following steps of S1, a preheating stage, S2, a low-temperature heat preservation stage, S3 and a high-temperature heat preservation stage, wherein a blank of the high-nitrogen stainless steel bearing ring is filled when the furnace temperature is more than or equal to 600 ℃, the blank is heated to 840-860 ℃ rapidly, the heat preservation is carried out for 90-150 min, the blank is heated to 1120-1140 ℃ rapidly, the heat preservation is carried out for 80-100 min, S4, the blank is made, and upsetting, blind hole punching, perforation and core rod reaming are sequentially carried out on the blank after the high-temperature heat preservation, so that an annular blank with the wall thickness of S0 is obtained. The forging process method controls the heating temperature, the heat preservation time, the deformation and the cooling mode after forging of the blank, so that the generation of twin crystal carbide in the high-nitrogen stainless steel forging process is inhibited.

Inventors

  • WU DAWEI
  • YU HAIBO
  • HUANG ZHE
  • LAN SHAN
  • CHEN LAN
  • WANG BINGHUI
  • ZHANG LING
  • WEI CHAOFAN
  • LI RUIYUN

Assignees

  • 洛阳轴承集团股份有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (6)

  1. 1. The forging process method for eliminating the twin carbide of the high-nitrogen stainless steel bearing ring is characterized by comprising the following steps of: s1, a preheating stage, namely loading a blank of a high-nitrogen stainless steel bearing ring when the furnace temperature is more than or equal to 600 ℃, and preheating for 30-40 min; S2, in a low-temperature heat preservation stage, rapidly heating the blank to 840-860 ℃, and preserving heat for 90-150 min; S3, in a high-temperature heat preservation stage, rapidly heating the blank to 1120-1140 ℃, and preserving heat for 80-100 min; s4, in a blank making stage, discharging the blank subjected to high-temperature heat preservation, and sequentially upsetting, punching blind holes, perforating and reaming a core rod to obtain an annular blank with the wall thickness of S0; S5, returning the annular blank to the furnace, rapidly heating to 1120-1140 ℃, and preserving heat for 20-30 min; s6, in a rolling stage, discharging and rolling the annular blank subjected to furnace returning and heat preservation to obtain an annular forging finished product with the wall thickness of S, wherein S0 is more than or equal to 1.5S; and S7, carrying out water mist cooling on the finished product of the ring-shaped forging after the ring-shaped forging is rolled.
  2. 2. The forging process for eliminating the twin carbide of the high-nitrogen stainless steel bearing ring according to claim 1, wherein the high-nitrogen stainless steel bearing ring is made of 40Cr15Mo2VN.
  3. 3. The forging process method for eliminating the twin carbide of the high-nitrogen stainless steel bearing ring forging of claim 1, wherein the water mist cooling is completed on a spray conveyor belt, and the surface temperature of the cooled forging is 300-400 ℃.
  4. 4. The forging process for eliminating the twin carbide of the high nitrogen stainless steel bearing ring forging of claim 1, wherein the blank is quickly heated to 850 ℃ in a low temperature heat preservation stage; the blank is quickly heated to 1130 ℃ in the high-temperature heat preservation stage; and in the furnace return heat preservation stage, the annular blank is quickly heated to 1130 ℃.
  5. 5. The forging process method for eliminating the twin carbide forged by the high-nitrogen stainless steel bearing ring according to claim 1, wherein the ratio of the heat preservation time of the low-temperature heat preservation stage, the high-temperature heat preservation stage and the furnace return heat preservation stage is 12:9:2.
  6. 6. The forging process method for eliminating the twin carbide of the high-nitrogen stainless steel bearing ring forging of claim 1, wherein the final forging temperature in the blank making stage and the rolling stage is more than or equal to 900 ℃.

Description

Forging process method for eliminating high-nitrogen stainless steel bearing ring forging twin carbide Technical Field The invention relates to the technical field of forging of metal materials, in particular to a forging process method for eliminating high-nitrogen stainless steel bearing ring forging twin carbide. Background With the increasing use of equipment such as aviation, aerospace, ships and the like in severe environments such as ocean salt fog, rainforest damp heat and the like, the traditional stainless steel bearing is difficult to meet the environmental adaptability requirements such as corrosion resistance, damp heat resistance and high temperature resistance, early failure often occurs, and the use of the equipment is severely restricted. The high-nitrogen stainless steel 40Cr15Mo2VN has the nitrogen content of 0.2wt%, is commonly used as a fully quenched stainless bearing steel, solves the problem that the service performance of the 9Cr18 and 9Cr18Mo steel is poor due to the fact that large-block eutectic carbide is generated in the smelting and solidification processes, greatly improves the corrosion resistance by reducing C and increasing N, has small integral size after heat treatment and is uniformly distributed, so that the high-nitrogen stainless bearing steel can achieve high strength and certain toughness storage proportion, has good wear resistance and heat resistance, and is widely applied to corrosion resistant environments such as aviation, aerospace, ships and the like. As a novel bearing material, the high-nitrogen stainless steel 40Cr15Mo2VN has the advantages that the forging temperature range is narrow (about 100-150 ℃), the metal plasticity is poor, carbides are easy to precipitate along twin crystal boundaries (twin crystal carbides) in the forging process, the twin crystal carbides belong to serious structural defects, the bearing performance is seriously reduced due to the existence of the twin crystal carbides, and early failure and symptom-free fracture of parts can be caused. In recent years, along with the trend of large-scale and multi-variety of the material products, the phenomenon of exceeding the standard of twin carbide after annealing of multi-batch forgings occurs in production practice. In the prior art, the plasticity of materials is generally improved by prolonging the heat preservation time or improving the heating temperature, and other schemes adopt multi-pass forging with small deformation, but the efficiency is low and the twin carbide is difficult to inhibit. Therefore, a method for precisely matching the heating parameters and the deformation process is needed to eliminate the twin carbides. Disclosure of Invention The invention aims to provide a forging process method for eliminating twin carbide in forging a high-nitrogen stainless steel bearing ring, which suppresses the generation of twin carbide in the forging process of the high-nitrogen stainless steel by controlling the heating temperature, the heat preservation time, the deformation and the cooling mode after forging of a blank. The technical scheme adopted by the invention is that the forging process method for eliminating the forging twin carbide of the high-nitrogen stainless steel bearing ring comprises the following steps: s1, a preheating stage, namely loading a blank of a high-nitrogen stainless steel bearing ring when the furnace temperature is more than or equal to 600 ℃, and preheating for 30-40 min; S2, in a low-temperature heat preservation stage, rapidly heating the blank to 840-860 ℃, and preserving heat for 90-150 min; S3, in a high-temperature heat preservation stage, rapidly heating the blank to 1120-1140 ℃, and preserving heat for 80-100 min; s4, in a blank making stage, discharging the blank subjected to high-temperature heat preservation, and sequentially upsetting, punching blind holes, perforating and reaming a core rod to obtain an annular blank with the wall thickness of S0; S5, returning the annular blank to the furnace, rapidly heating to 1120-1140 ℃, and preserving heat for 20-30 min; s6, in a rolling stage, discharging and rolling the annular blank subjected to furnace returning and heat preservation to obtain an annular forging finished product with the wall thickness of S, wherein S0 is more than or equal to 1.5S; and S7, carrying out water mist cooling on the finished product of the ring-shaped forging after the ring-shaped forging is rolled. Preferably, the high-nitrogen stainless steel bearing ring is made of 40Cr15Mo2VN. As a preferable scheme, the water mist cooling is completed on a spray conveyor belt, and the surface temperature of the cooled forging is 300-400 ℃. As a preferable scheme, the blank is quickly heated to 850 ℃ in the low-temperature heat preservation stage; the blank is quickly heated to 1130 ℃ in the high-temperature heat preservation stage; and in the furnace return heat preservation stage, the annular blank is quickly heated to 1130 ℃