We can provide free samples . Please contact Email for any inquiries

Hardened steel of undissolved carbide morphology, quantity, size, distribution, which is influenced by the chemical composition and quenching steel before the original organization, but also by the effect of austenitizing condition, related research is less influence of undissolved carbides on imported bearing life. Carbide is hard and brittle phases, in addition to favorable for wear resistance, bearing because of will (especially the carbides are non spherical) stress concentration and crack cause and the matrix, which will reduce the toughness and fatigue resistance. Quenching undissolved carbide in addition to its own influence on the performance of steel, but also influence the carbon content and the content and distribution of Ar quenched martensite, so as to produce additional effects on performance of steel.
Therefore the quenching undissolved carbide and failure resistance comprehensive mechanical properties of steel is more harmful. Appropriate to reduce the carbon content of the imported bearing steel is one of the ways to improve the service life of parts.
Quenching undissolved carbide except the number has influence on material properties, size, morphology, distribution also influence on material properties. In order to avoid the harm of undissolved carbide in bearing steel imports, require fewer undissolved carbides (small number), small (small size), uniform (the size of each other are very small, and the uniform distribution), round (each grain carbides are spherical). It should be pointed out, import bearings steel after quenching and a small amount of undissolved carbides is necessary, not only can maintain sufficient wear resistance, but also obtain the necessary conditions of fine grain cryptocrystalline martensite.
4, the residual stress after quenching and tempering
Imported bearing parts quenched and tempered, still has a large internal stress. The residual stress in the component parts of the advantage and disadvantage of two kinds of state. Steel after heat treatment, surface increases with the residual compressive stress, the fatigue strength of steel increased, and the surface residual stress is tensile stress, makes the reduced fatigue strength of steel. Therefore, the larger pressure residual bearing surface parts after quenching and tempering, is also one of the measures to improve the service life of the.