热处理工艺对Fe-Mn-Al-C钢组织和性能的影响

利用SEM、XRD、EPMA等试验方法，对不同退火、固溶以及时效工艺下Fe-Mn-Al-C钢的组织演变规律和力学性能进行研究。结果表明，900～1050℃退火温度对试验钢的组织与性能影响较大，随着退火温度的升高晶粒尺寸增大、碳化物逐渐回溶，强度降低、塑韧性提高，在1050℃保温2 h空冷时抗拉强度为1036 MPa,断后伸长率为39%,冲击功41 J,强塑积40 GPa·%;经1050℃保温2 h水冷固溶后时效处理，试验钢组织为奥氏体+铁素体+κ碳化物，随着时效温度的增高，κ碳化物逐渐析出，使试验钢的强度增加、塑韧性降低。600℃时效时，抗拉强度1145 MPa、断后伸长率22%、冲击功28 J,综合力学性能全部满足设计要求。

Effect of Heat Treatment Process on Microstructure and Properties of Fe-Mn-Al-C Steel

The microstructure evolution and mechanical properties of Fe-Mn-Al steel under different annealing,solution and  aging processes are studied by meansa of SEM, XRD and EPMA. The results show that the 900- 1050 ℃annealing temperature has a great influence on the microstructure and properties of the tested steel. With the increase of annealing temperature,the grain size increases,the carbide gradually redissolved,the strength decreases,and the plasticity-toughness improves. When the annealing temperature is at 1050 ℃ for 2 h air cooling,the tensile strength is 1036 MPa,the elongation is 39%,the impact energy is 41 J and the best plasticity-strength is 40 GPa ·%.The microstructure of the test steel is austenite + ferrite +k carbides after solution treatment at 1050 ℃ for 2 h and water cooling. With the increase of aging temperature,k carbides precipitate gradually,which increases the strength and decreases the plasticity and toughness of the test steel. When aged at 600 ℃,the tensile strength is 1145 MPa,the elongation is 22% and the impact energy is 28 J, the comprehensive mechanical properties all meet the design requirements.