The paper mainly studies intercritically annealed medium manganese steel, which only contains 3.5 wt% Mn. After annealing at different temperature, the microstructure of the experimental steel is composed of ferrite and austenite with different morphology. With the increase of intercritical annealing temperature, a small amount of martensite appears in the microstructure due to the decrease of austenite stability, and the proportion of retained austenite decreases. When the experimental steel is annealed at 700 C, the best matching of strength and plasticity is obtained, which benefits from the appropriate proportion of austenite with different stability. The results show that excellent mechanical properties of 3.5 wt% Mn steel can be achieved by adjusting the intercritical annealing process.

论文主要研究了仅含 3.5 wt% Mn 的临界间退火中锰钢。实验钢经不同温度退火后的显微组织由形貌不同的铁素体和奥氏体组成。随着临界区退火温度的升高，奥氏体稳定性降低，组织中出现少量马氏体，残余奥氏体比例降低。实验钢在700℃退火时，强度和塑性得到最佳匹配，这得益于具有不同稳定性的适当比例的奥氏体。结果表明，通过调整临界间退火工艺，可以获得3.5 wt% Mn钢的优异力学性能。