Microstructure and mechanical properties of a TRIP steel containing 7 Mass% Mn

Abstract

A TRIP steel containing 7 mass% Mn was annealed at various temperature for 10 min and changes in microstructure and mechanical behavior due to different annealing temperature were investigated. Excellent mechanical properties of high tensile strength over 1,200 MPa with high elongation over 20% could be obtained for proper annealing temperature range. Volume fraction and mechanical stability of austenite were highly dependent on annealing temperature, which shows a transition from stable to metastable behavior of austenite. Effects of austenite grain size and solute element contents in austenite grains on stability were discussed.