This study investigates a novel forming design, that is, intercritical rolling (IR) + low-temperature rolling (LTR) + short-time intercritical annealing (STIA) + one-step stamping (OSS), to decrease or eliminate the yield point elongation (YPE) in a medium-Mn alloy. Results show that the novel forming design leads to ultra-fine microstructure and excellent mechanical properties in the stamped parts. The dislocation density or austenite mechanical stability may be the underlying reasons for the decreased YPE in medium-Mn steels. This novel forming design can increase the work hardening exponent of experimental samples by increasing the dislocation density in ferrite or decreasing austenite mechanical stability, resulting in a continuous yielding feature in stamped parts.

本研究研究了一种新的成形设计，即临界间轧制 (IR) + 低温轧制 (LTR) + 短时临界间退火 (STIA) + 一步冲压 (OSS)，以降低或消除屈服点延伸率(YPE) 中锰合金。结果表明，新颖的成形设计使冲压件具有超细的微观结构和优异的机械性能。位错密度或奥氏体机械稳定性可能是中锰钢 YPE 降低的根本原因。这种新颖的成形设计可以通过增加铁素体中的位错密度或降低奥氏体机械稳定性来增加实验样品的加工硬化指数，从而在冲压件中产生连续屈服特征。