1. performance requirements for bearing parts:

(1) high hardened and hardenability to ensure evenly on the surface, high hardness, thus ensuring its wear resistance;

(2) high fatigue strength and compressive strength in order to ensure a long service life;

(3) impact toughness and high elastic limit, in order to reduce distortion and accidental impact damage;

(4) to be of adequate size and stability, to keep dimensional changes in use does not occur;

(5) certain of anti-erodibility in order to resist atmospheric corrosion, oil;

(6) a good process to ensure the needs of mass production;

(7) for bearing parts required to work under special conditions can bear high temperature and high resistance to corrosion.

2. thin-walled bearing heat treatment processes:

(1) the main cause of heat treatment deformation

Deformation of bearing rings in heat treatment is one of the main reasons the heating and cooling process, the ferrule and internal expansion and contraction of the surface is and transformation of different thermal stress and more stress. When the ring when an overall plastic deformation occurs, the deformation diameter of swelling or shrinking; when the local plastic deformation is characterized by round or increase of cylindricity error. Due to quenching oil cooling fast, far more than the rings in the furnace of the velocity and low stiffness of thin-walled rings, so most of the deformation are generated during the cooling process.

Many factors affect the deformation of bearing rings in heat treatment, can reduce stress and thermal stress in the process of heat treatment method, you can reduce the deformation of ring. From the viewpoint of heat treatment processes, by reducing the temperature, proper control of the holding time, improving quenching temperature and reduce quenching oil mixing speed, can effectively reduce the deformation of ring. Large outer diameter thin-walled bearing rings, poor because of its stiffness, heat treatment in thermal stress and the organization under stress, may produce large deformations. So, you want to control the deformation, must establish a suitable heat treatment process, control of thermal stress and stress.

(2) the heat treatment process

Original heat treatment process for: quenching temperature 855 ℃, heating time 30min; quenching oil temperature 100 ℃, a circle, car processing Hou increased suitable of to stress annealing; in quenching stage appropriate control quenching heating temperature, and reasonable control quenching cooling speed; quenching heating Qian on oil ditch water glass, and asbestos rope or refractory soil for Jam; used protection atmosphere heating, are can reduced oil ditch crack of produced.

Improving the oil Groove of the structure or the oil Groove shape, avoiding straight oil Groove and cusp effect to control the oil Groove cracking also have a positive effect.