Explanation

annealing process to obtain ferrite matrix and fine (spherical) carbide structure distributed dispersedly in steel. Uniform microstructure and properties can be obtained by spheroidizing annealing. Improve the cutting performance and reduce the tendency of deformation and cracking during subsequent quenching. spheroidizing annealing is mainly used for eutectoid steel, such as non alloy tool steel, alloy tool steel and bearing steel. medium carbon steel and medium carbon alloy steel can only be used when the hardness is very low and the electrical conductivity is very high. Only spheroidizing annealing is used. Low carbon steel is generally not subject to spheroidizing annealing. Common spheroidizing annealing processes include: ① heating steel to slightly higher temperature for full insulation. Slowly cool (furnace cooled) to 500-650t for cooling out of the furnace. It is applicable to the production of periodic operation furnace and widely used in Dinggu steel and bearing steel; ② Heat the steel until the tip is higher than the temperature for proper time, and then cool it to a temperature slightly lower than the Arl temperature for a certain time before cooling it out of the furnace. It is called isothermal spheroidizing annealing annealing and is commonly used for non-alloy steel and alloy steel cutting tools, cold punching dies and bearing parts.

Classification