新型贝氏体钢的弯曲疲劳性能

Fatigue Property of a New Bainitic Steel

对新型GDL空冷贝氏体钢进行弯曲疲劳性能试验和微观结构分析。结果表明GDL钢的显微组织是由束状贝氏体和少量残余奥氏体组成,残余奥氏体以薄膜形态分割贝氏体板条而形成超细化亚单元,增加了材料的微观塑性。此外,稀土元素球化钢中的夹杂物、强化晶界,使疲劳裂纹萌生和扩展的抗力增加,该钢在不回火的情况下就具有优异的力学性能。

The fatigue property and the microstructure of new GDL bainitic steel have been tested.The results show that the microstructure of GDL steel is composed of bunchy bainite and a little retained austenitic film which separates bunchy bainite into extra-fine subunits and improves the micro-ductility of the steel.Furthermore RE spheroidizes inclusion in the material,intensifies the crystal boundary and increased the crack initiation and propagation resistance to fatigue.The GDL steel does not need tempering and has an excellent mechanical property after air-cooling.