Effect of Aluminum on Austenite Stability and Mechanical Properties in Medium Manganese Steel

摘要

Microstructure and mechanical properties of medium-Mn steel with and without aluminum addition were investigated in this study.The microstructure results showed that the medium-Mn steel obtained full martensite structure after quenching,and new austenite nucleated and grew between the martensite laths during ART-annealing.Due to addition of aluminum,duplex phase structure was obtained after quenching,and the carbon content of newly formed austenite was higher than that of medium-Mn steel without aluminum.A much larger amount of metastable austenite was found in the medium-Mn steel with aluminum addition,which induced higher ductility.Great total elongation (～41％) and strength-plasticity production 33Gpa· ％ were obtained after long time annealing.