热处理温度对纳米析出强化钢组织性能的影响

Effect of heat treatment temperatures on microstructure and properties of nano-scale precipitation strengthen steel

开展了一系列热处理(500~750℃保温30 min后空冷)实验,分析了热处理温度对新型纳米析出强化钢组织性能的影响。结果表明:未热处理钢板的屈服强度和抗拉强度分别为510 MPa和620 MPa,显微组织为铁素体+珠光体;热处理温度在500~660℃之间时,屈服强度上升幅度在20~45 MPa之间;而热处理温度在700~750℃之间时,由于形成典型双相钢组织(铁素体+M/A岛),屈服强度仅为350 MPa。热处理温度在500~660℃之间时发生了(Nb,Ti)C的二次析出,且原有的析出物具有很好的热稳定性,宏观上表现为实验钢屈服强度提高。

A series of heat treatment experiments( temperature range from 500 ℃ to 750 ℃,holding time of 30 min) were conducted,and the effect of heat temperature on microstructure and properties of a new type nano-scale precipitation strengthen steel was studied. The results show that the yield strength and tensile strength of hot-rolled steel sheet are 510 MPa and 620 MPa,respectively,and the microstructure is ferrite and pearilite. When the heat treatment temperature is 500-660 ℃,the yield strength of the steel sheet increases by 20-45 MPa. Whereas,when the heat treatment temperature is between 700-750 ℃,the microstructure of steel is a typical dual-phase steel microstructure,which is ferrite and M / A island,so the yield strength is only 350 MPa. When the heat treatment temperature is from500 ℃ to 660 ℃,and the nano-scale( Nb,Ti) C could precipitate again,and original precipitation( Nb,Ti) C has good thermal stability,and the yield strength of experimental steels is improved.