Steel machining parts , Injection mold or Dies making, Quenching and tempering be required to treat on steel block to make them more hard and with long using life. mold making Quenching and tempering : The heat treatment method of high temperature tempering after quenching is called quenching and tempering. High temperature tempering refers to tempering between 500 and 650 C. Tempering and tempering can make the properties and materials of steel adjusted to a great extent. Its strength, plasticity and toughness are good, and it has good comprehensive mechanical properties. metal fixture Tempered sorbite was obtained after quenching and tempering. Tempered sorbite is formed when martensite is tempered. It can be distinguished more than 500 to 600 times under optical metallographic microscope. It is a composite structure with carbide (including cementite) spheres distributed in ferrite matrix. It is also a tempering structure of martens...