固溶温度对Fe-20Mn-9Al-1.2C低密度钢组织性能的影响

Effect of Solution Temperature on Microstructure and Mechanical Properties of Fe-20Mn-9Al-1.2C Low-Density Steel

为了达到低密度高强钢优异强韧性结合的目的,设计了一种低密度高强钢Fe-20Mn-9Al-1.2C,经冶炼、锻造和热轧后在900,950,1 000,1 050℃下分别进行固溶处理,保温24 min,并快速水淬,采用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射(XRD)、电子探针(EMPA)等试验方法研究固溶温度对试验钢组织性能的影响.结果表明:所设计的新型低密度钢的密度为6.826 g/cm^(3),比常规钢的密度降低约13%.当固溶温度为1 000℃,低密度钢的综合力学性能最佳,其抗拉强度可达1 065 MPa,屈服强度为937 MPa,延伸率为65.3%,强塑积可达69.5 GPa·%,-40℃冲击功(V型缺口)为49 J.

To obtain an excellent combination of strength and toughness,a new heat treatment route of low-density Fe-20Mn-9Al-1.2C steel was designed.After smelting,forging and hot rolling,the steel was treated by solid solution at 900,950,1000 and 1050℃,respectively for 24 min and a water quenching afterward.The effect of solid solution temperature on microstructure and mechanical property of the tested steel was studied by OM,SEM,XRD,EMPA and other methods.The results show that the density of the steel is 6.826 g/cm^(3),which is about 13%lower than the conventional one.When the solid solution temperature is 1000℃,the comprehensive mechanical properties of the steel are the best with the tensile strength of 1065 MPa,yield strength of 937 MPa,elongation of 65.3%,strong strength-ductility product of 69.5 GPa·%,and impact energy(V-notch)at-40℃of 49 J,respectively.