Mesh carbide of forged flange
When forging steel with high carbon content of forged flange, if the stop forging temperature is high and the cooling speed is too slow, carbides will precipitate in a network along the grain boundary. For example, when bearing steel is slowly cooled at 870 ~ 770 ℃, carbides precipitate along the grain boundary.
Forged reticulated carbides are easy to cause quenching cracks during the heat treatment of forged flanges. In addition, it also deteriorates the service performance of forged flanges.
Defects often caused by improper post forging heat treatment process of forged flange
Defects caused by improper post forging heat treatment process of forged flanges usually include:
The hardness of forged flange is too high or not enough
The reasons for the insufficient hardness of forged flanges caused by improper post forging heat treatment process are: ① the quenching temperature of forged flanges is too low; ② Quenching and heating time of forged flange is too short; ③ Tempering temperature of forged flange is too high; ④ Repeated heating causes serious decarburization on the surface of forged flange; ⑤ Unqualified chemical composition of steel, etc.
The reasons why the hardness of forged flange is too high due to improper post forging heat treatment process are: ① the normalized cooling of forged flange is too fast; ② The normalizing or tempering heating time of forged flange is too short; ③ Unqualified chemical composition of steel, etc.
Uneven hardness of forged flanges
The main reason for uneven hardness caused by forging is the improper heat treatment process of forged flanges, such as too much one-time charging of forged flanges or too short holding time; Or heating causes partial decarburization of forgings, etc.
