NTN linear motion bearing mechanical seal material surface treatment technology

According to the materials on the relationship between the fracture toughness and other research and analysis on the development process of the crack, it is easy to see that the dn value is high and the presence of circumferential stress, surface modification of high speed steel and low carbon content of the change of the HSS surface hardening depth is of great importance. For this, material surface treatment technology is developed, can enhance the surface hardness, and compressive stress is produced. By the surface treatment of the material has the following features: has good resistance to fatigue crack, the second stage, the expansion of the existing crack speed is low and the inadequate quenching or low carbon content leads to the core of fracture toughness value of materials is relatively higher. Development of this kind of surface treatment processing method includes: with laser and electron beam or the method such as induction hardening less than ordinary HSS local heat treatment quenching, to get the surface hardened layer. Here it should be pointed out that hardening is insufficient in order to improve the fracture toughness. Using chemical heat treatment method for surface hardening layer. This method include carbon or nitrogen infiltrate the common high speed steel microstructure, or small changes in carbon content. Linear motion bearing seal material function is the first element of effective sealing, choose sealing material, if according to the performance of the sealing element, such as used by using temperature, working pressure, working medium and pattern of movement postures and so on. The basic request of sealing material is as follows: 1. NTN bearing wear resistance, erosion of metal; 2. Oxygen resistance and aging resistance, durable; 3. NTN bearing high soft low temperature resistance, high temperature synthesis, softening, low temperature not hardening; 4. Bearing to adapt themselves to the working medium, no swelling, synthesis, hardening, etc. ; 5. Squeeze for deformation small, well elasticity and hardness; 6. Have certain mechanical function, linear motion bearings, such as tensile strength, elongation, etc. ; 7. Easy to forming, low cost;