Influence of strain rate on the tensile properties, misorientation distribution, and texture evolution of automotive-grade TRIP-assisted advanced high-strength steel

• Published in: Materials letters 2025-01, Vol.378, p.137612, Article 137612
• Main Authors: Mohapatra, Sudipta, Kumar, Ashish, Kumar, Suman, Poojari, Govardhana, Oh, Min-Suk
• Format: Article
• Language: English
• Subjects: Fe-3.46Al-7.52Mn-0.92Si-0.22C (wt.%); Grain boundary; Microstructure; Strain rate-dependent tensile properties; Texture
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2024.137612

•Higher strain results in higher strength and lower strain rate results in higher ductility.•Lower strain rate leads to a significant reduction in the amount of austenite.•A high intensity Ms-Brass {011}  leads to better ductility at lower strain rates. This study investigates the influence of strain rate on the tensile properties, misorientation distribution, and texture evolution of annealed Fe-3.46Al-7.52Mn-0.92Si-0.22C (wt.%) steel. Tensile tests are performed on the annealed sample at room temperature with strain rates of 3.3 × 10-4 (SR-1), 1.65 × 10-3 (SR-2), and 3.3 × 10-3 s−1 (SR-3). At higher strain rates, a higher amount of austenite is retained and higher weighted average kernel average misorientation (KAM) is observed. SR-1 exhibits a superior ductility (40 %) compared to SR-2 and SR-3 (28 and 18 %, respectively) due to the combined effect of a higher amount of austenite (29.2 %) transformed to martensite, a higher fraction of low-angle grain boundaries, and strong Ms-brass {011}  texture. However, SR-2 and SR-3 show better tensile strength compared to SR-1 due to higher fraction of high-angle grain boundaries and evolution of higher intensity α-fiber RD //  .