Heat Treatment Effects and Deformation Behavior of 10 Mn α΄+γ Lamellar Structure Steel

Abstract

Heat treatment effects and tensile properties are studied using α΄+γ lamellar structure in cold-rolled Fe-10Mn-2Al-0.2C steel. The 10 Mn steel formed α΄+γ lamellar structure after 4 stages of heat treatment. Microstructures and tensile properties at each stage and deformation behavior of α΄+γ lamellar structure were investigated. The α΄+γ lamellar structure of the 10 Mn steel showed a yield strength of 920 MPa, a tensile strength of 1300 MPa and a total elongation of 20 pct. The tensile properties depended on the volume fraction and stability of the austenite. The third and fourth heat treatment, which are reheating and C partitioning, determined the volume fraction and stability of the austenite. As reheating temperature increased, the amount of martensite transformation increased. As C partitioning temperature increased, austenite stability increased because C atoms moved from martensite to austenite. Tensile tests of the α΄+γ lamellar structure were used to determine the amount of martensite transformation, the transformation sites and the relationship between martensite transformation and work hardening.