关键词: Fe-Mn-Al-C钢, 退火温度, 时效温度, 力学性能, 显微组织

Abstract: 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.

Key words: Fe-Mn-Al-C Steel, Annealing Temperature;Aging Temperature, Mechanical Properties, Microstructure