Surface quenching

Induction heating surface quenching is one of the methods of using more widely, the former Soviet union on theory and application of the process, the more research, its main application is divided into two categories: one is the induction heating surface quenching of railway bearing, using new materials Ш Х 4 steel ring after induction heating quenching, martensite structure surface is hard and wear-resistant, core for toughness good sorbite, troostite and surface for up to 500 mpa compressive stress, its service life than Ш Х 15 С Г bearing high 1 times, and completely eliminated the ring suddenly when using the phenomenon of brittle fracture, improve the reliability of the bearing, performance and low carbon steel carburizing and quenching are similar, but the cost is much lower than the latter. At the same time, also developed a corresponding special sensors and quenching equipment, and put this material and induction hardening results are generalized to require high wear resistance and toughness of the rolling mill bearings and other heavy-duty bearing; Another application for induction heating surface quenching is oversize bearing heat treatment, reduce the large bearing ring and hardness of quenching deformation inhomogeneity, save equipment investment cost at the same time. Japan the induction heating surface quenching successfully applied to the car after constant speed to the section of the heat treatment, including the ladder shaft, shell inner surface and quenching of raceway are performed by an induction coil, special heating. High frequency heat treatment and the application of cold forging technology has greatly reduced the production cost, greatly improve the reliability of the product also. Laser heat treatment and high energy beam surface is the new heat treatment method developed in recent years, using more CO2 laser beam. 0 is obtained with a laser heating. 25 ~ 2. 0 mm of hardening layer, compared with other methods of surface hardening, it has the depth of hardening layer and the precise position control, without deformation, etc. High carbon chromium bearing steel parts by laser surface hardening after hardening layer of martensite tiny, more uniform distribution of carbides and residual austenite, than ordinary quenching tempering has higher hardness and sliding wear resistance. In addition, laser, such as high energy beam can be used as heat source of surface coating process, a surface hardening and coating process can be completed, especially in recent years the development of nanotechnology, the composite surface treatment processes in precision bearing parts will have broad application prospects.