The defects caused by improper heat treatment process after forging usually include:
1. The hardness is too high or the hardness is not enough
The reasons for insufficient hardness of forgings due to improper heat treatment process after forging are: ① quenching temperature is too low; ② quenching heating time is too short; ③ tempering temperature is too high; ④ repeated heating causes serious decarburization on the surface of the forging; ⑤ steel Unqualified chemical composition, etc.
The reasons for the high hardness of forgings caused by improper heat treatment process after forging are: ① cooling too fast after normalizing; ② normalizing or tempering heating time is too short; ③ unqualified chemical composition of steel, etc.
2. Uneven hardness
The main cause of uneven hardness is improper heat treatment process regulations, such as too much furnace loading or too short holding time; or partial decarburization of forgings caused by heating.