Application of forging heat quenching process:
1) The connecting rod produced by forging heat quenching has higher strength and toughness than that by ordinary heat treatment, especially the yield strength ratio of the connecting rod has been greatly improved.
2) The initial forging temperature of 45 steel shall not exceed 1220 ℃ and that of 40Cr steel shall not exceed 1200 ℃, otherwise the strengthening effect of forging heat quenching will be affected.
3) The connecting rod produced by forging heat quenching has high tempering stability. Under the condition of obtaining the same hardness as the ordinary heat treatment, the tempering temperature is higher than the ordinary heat treatment, 20 ~ 30 ℃ higher for 45 steel and 30 ~ 50 ℃ higher for 40Cr steel.
4) During forging heat quenching, the residence time from forging to quenching shall be as short as possible. The 45 steel connecting rod shall be controlled within 20s, and the 40Cr steel connecting rod shall be controlled within 30s, otherwise the strengthening effect will be affected.