Study on Solution Treatment Process of Fe-6Al-4Mn-0.6C High Strength Lightweight Steel

The effects of solution treatment at different temperatures on the microstructure and mechanical properties of hot rolled Fe-6Al-4Mn-0.6C light steel were studied by OM, TEM, XRD, tensile test and fracture observation. The results show that the microstructure of hot rolled Fe-6Al-4Mn-0.6C steel consists of ferrite and a large amount of fine type κ carbides.The microstructure of hot rolled Fe-6Al-4Mn-0.6C steel after solution at 920 ℃is ferrite, martensite, residual austenite and a small amount of type κ carbides. When the solution temperature reaches 980 ℃, the κ carbides in Fe-6Al-4Mn-0.6C steel disappear.Compared with that of the hot rolled test steel, the strength of Fe-6Al-4Mn-0.6C steel in solution state is decreased.Fe-6Al-4Mn-0.6C steel solution treated at 920 ℃has the lowest tensile strength and yield strength of 1012.3 MPa and 824.6 MPa respectively, and the elongation and strong plastic product are the highest, which are 1.5% and 1518.45 MPa·% respectively.