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.