Influence of Cryogenic Treatment on Mechanical Properties of Alloy Structure Steel

The effects of cryogenic treatment on microstructure and mechanical properties of 42CrMo steel and 40CrNiMo steel were investigated.The results show that through cryogenic treatment,the microstructure and the mechanical properties at normal temperature can't be further improved,but the impact absorbing energy at-40 ℃ increases.On this experiment condition,the preferable impact absorbing energy at low temperature can be obtained after quenching at 860 ℃+ cryogenic treated at-70 ℃ and tempered at 590 ℃.