Abstract: The effect of austenitizing temperature (t_A) on the microstructure and tensile properties for a hot-rolled high-Mn structure steel with excellent damping capacity after heat treatment with different t_A has been investigated. The results show that when the t_A is up to 600℃， the only recovery occurs in the reversed austenite，and the ε-martensite amount， tensile stress and work hardening rate of the treated steel are higher than those of the rolling state one. When the t_A is over 800℃， the completely static recrystallization of austenite can be observed. Moreover， the austenite size and ε-martensite amount of the steel increase with the t_A， which results in the deterioration of its tensile properties. Furthermore， after treated at t_A=1200℃， the ε-martensite plate becomes very thin，and the fracture along grain boundary is also observed during tensile test owing to the over-sized austenite grains.

Key words: high-Mn steel, austenitizing temperature, ε-martensite, tensile property, work hardening