Research status of TRIP effect influencing factors and strengthening mechanism of medium manganese steel for automobile

Medium-Mn steel has garnered significant attention as a promising advanced high-strength steel for next-generation automotive lightweighting applications, primarily owing to its exceptional combination of ultrahigh strength and superior ductility, which stems from the pronounced transformation-induced plasticity (TRIP) effect. However, significant differences exist in how alloy composition and processing parameters regulate the TRIP effect. This paper systematically summarizes the critical factors influencing of retained austenite (including its chemical composition, grain size, and morphological distribution) and ferrite matrix strength on the TRIP effect, focusing on three key dimensions: alloy design, processing parameters, and heat treatment. Specifically, this review elucidates the strengthening mechanism of heterogeneous microstructures on TRIP behavior, analyzes current scientific and technological challenges in this field, and proposes constructive perspectives for future research.