Twin-roll strip casting: A competitive alternative for the production of high-manganese steels with advanced mechanical properties

In this work, a high-manganese Fe-29Mn-0.3C TWIP steel was produced by twin-roll strip casting and subjected to additional thermo-mechanical treatment. The evolution of microstructure and texture in each processing condition was investigated and correlated with the corresponding mechanical properties. Due to pronounced microsegregations, chemical gradients and an inhomogeneous microstructure in the as-cast and hot-rolled material, regions of strongly varying stacking fault energy caused undesired austenite-martensite transformation and inhomogeneous mechanical properties. The specimens after additional cold rolling and annealing at temperatures as low as 900 °C revealed a microstructure with a homogeneous grain size distribution and significantly reduced microsegregations. The resulting mechanical properties were comparable to those of industrial advanced high strength steels and TWIP steel produced by conventional processing, where energy-consuming homogenization is necessary. Therefore, twin-roll strip casting offers the possibility for cost-effective processing of TWIP steel with competitive mechanical properties.