Investigation of deformation behaviour with yield point phenomenon in cold-rolled medium-Mn steel under hot stamping conditions

Medium manganese (MMn) steels are a promising class of advanced high-strength (AHSS) with potential for application as vehicle panels in the automotive industry. In this study, deformation behaviour representative cold-rolled MMn steel and its dependence on processing parameters studied using uniaxial tensile testing under low-temperature hot stamping (LTHS) conditions, covering austenitisation soaking times 60–600 s, temperatures 500–700 °C strain rates 0.01–5 s?1. A yield point phenomenon is observed first time early stage at such steel, which has submicron grain size. The extent reduced, hardening capability total elongation enhanced, longer times, give coarser-grained microstructures. also tends to be weaker higher lower rates; these both flow stress degree decrease, while insensitive differences conditions. mechanisms test conditions discussed. addition, set unified constitutive equations established calibrated experimental data predict LTHS close agreement experiment, including phenomenon, obtained.