Heat treatment industry often use heat-resistant steel castings.Heat treatment related to heat resistant steel castings basic common sense part 5:
 
5.hardening and tempering
Operation method: high temperature tempering after quenching tempering, the steel is heated to high 10 to 20 degrees than when quenching temperature, the heat preservation after quenching, and then in 400 ~ 720 degrees under the temperature of tempering.
Objective: 1. To improve machinability, improve the processing surface is bright and clean degree; 2. Reduce the quenching deformation and cracking; 3. To get good comprehensive mechanical properties.
Application points: 1. Applicable to the higher hardenability of the alloy structural steel, alloy tool steel and high speed steel; 2. Not only will be the final heat treatment of various important structure, but also can serve as some close parts, such as screw heat treatment in advance, to reduce the deformation.