Analysis of the relationship between microstructure and mechanical properties of intercritically annealed 3.5Mn steel

Abstract

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.