Microstructure and mechanical properties of sub-rapidly solidified Fe-18Â wt%Mn-C alloy strip

High-Mn steels exhibit both high tensile strength and good ductility and have attracted much attention as a promising candidate for next-generation automotive steel. However, there are still problems in conventional production, such as severe slab crack and pronounced element segregation, which restrict their widespread applications. An alternative way to produce this alloy is the near net shape method under a sub-rapid solidification process. We studied the microstructure and mechanical properties of Fe-18Mn-(0.14, 0.50)C alloy thin strip produced by injecting casting at a sub-rapid solidification rate, in which the cooling rate was about 5×103 K/s. The results demonstrated that the formation of cementite particles was suppressed, but apart from the γ-phase, the ε-martensite and α′-martensite also formed in the Fe-18Mn-C thin strips. The lath width of ε-martensite is lower than that of sample produced by conventional method. The mechanical properties of Fe-18Mn-0.50C surpass the Fe-18Mn-0.60C alloy steel processed by hot rolled and heat treated. This paper discusses the relationship between the microstructure and the mechanical properties of the strips.