The present work elucidates the complex interplay between the changes in the microstructural features and tensile properties in a Ni-modified medium manganese steel under the combined influence of cold rolling (CR) and annealing treatment. The annealing temperature within 973 K–1273 K showed a wide range of microstructures, varying from single phase ferrite in CR-973 K to duplex microstructure (ferrite and austenite) in CR-1073 K and to multiphase structure (ferrite, austenite and martensite) in CR-1173 K and CR-1273 K annealed conditions. Additionally, B2 (NiAl) and intermetallic carbide precipitates were also found to be heterogeneously distributed in ferrite matrix of the CR-973 K annealed specimen. However, these precipitates dissolved and concurrently resulted in evolution of the austenite phase at an annealing temperature of ≥1073 K. Apart from the phase transformation, the recrystallization fraction increased and grain size became coarser at higher annealing temperature. The presence of duplex phase microstructure, optimum grain size of austenite and ferrite, and co-occurrence of recrystallized and deformed grains resulted in excellent strength-elongation synergy in CR-1073 K annealed specimen in comparison to the other annealing variants. More importantly, the austenite to martensite transformation during tensile test promoted the transformation induced plasticity (TRIP) effect, which improved the work hardening and ductility of the CR-1073 K annealed specimen. In contrast, the presence of pre-existing martensite in CR-1173 K and CR-1273 K annealed specimens adequately masked the TRIP effect leading to predominant brittle failure in these specimens without rendering any considerable ductility.

目前的工作阐明了在冷轧 (CR) 和退火处理的综合影响下，镍改性中锰钢的微观结构特征和拉伸性能变化之间复杂的相互作用。退火温度在 973 K-1273 K 范围内显示出广泛的显微组织，从 CR-973 K 中的单相铁素体到 CR-1073 K 中的双相显微组织（铁素体和奥氏体）和多相组织（铁素体、奥氏体和马氏体）在 CR-1173 K 和 CR-1273 K 退火条件下。此外，还发现 B2 (NiAl) 和金属间碳化物析出物不均匀地分布在 CR-973 K 退火试样的铁素体基体中。然而，这些析出物在≥1073 K 的退火温度下溶解并同时导致奥氏体相的演变。除了相变外，再结晶分数增加，晶粒尺寸在较高的退火温度下变得粗大。双相微观结构的存在、奥氏体和铁素体的最佳晶粒尺寸以及再结晶和变形晶粒的共存导致 CR-1073 K 退火试样与其他退火变体相比具有出色的强度-延伸率协同作用。更重要的是，拉伸试验中奥氏体向马氏体的转变促进了相变诱发塑性（TRIP）效应，从而提高了CR-1073 K退火试样的加工硬化和延展性。相比之下，