30CrNi4Mo钢的组织和冲击疲劳性能的研究

研究了30CrNi4Mo钢不同热处理的组织和冲击疲劳性能。结果表明,30CrNi4Mo钢正火低温回火的组织由贝氏体、马氏体和残余奥氏体组成,淬火低温回火组织为回火马氏体和残余奥氏体。正火低温回火的冲击疲劳裂纹形成寿命高于淬火低温回火和淬火高温回火的冲击疲劳裂纹形成寿命,淬火高温回火的冲击疲劳总寿命高于正火及淬火低温回火热处理的冲击疲劳寿命。分析了多冲击疲劳裂纹扩展的行为,讨论了正火低温回火冲击疲劳裂纹形成寿命较长及淬火高温回火提高冲击疲劳总寿命的原因。

Study on Microstructure and Impact Fatigue Properties of 30CrNi4Mo Steel

Microstructure and impact fatigue of 30CrNi4Mo steel at different heat treatments were studied.The results showed that the microstructure of 30CrNi4Mo is bainite,martensite and retained austenite after normalizing and low-temperature tempering,the microstructure is tempered martensite and retained austenite after quenching and low-temperature tempering.The fatigue crack initiation life of the steel normalized and low-temperature tempered is longer than that quenched and low-temperature tempered and quenched and high-temperature tempered.The total impact fatigue life quenched and high-temperature tempered is longer than that quenched and low-temperature tempered and normalized and low-temperature tempered.The behaviors of impact fatigue crack propagation were analyzed.The reasons for the longer fatigue crack initiation life for the normalized and lowtemperature tempered,and the total improved impact fatigue life for quenched and high-temperature tempered are discussed.