Scholarlink

<p>Achieving a favorable strength–ductility balance at ultrahigh strength levels remains a major challenge in medium-carbon low-alloy steels. Constructing a multiphase microstructure that can simultaneously provide high strength and sustained strain hardening is a promising strategy to address this challenge. In this study, a multiphase microstructure consisting of primary martensite, bainitic ferrite, retained austenite, and fresh martensite was successfully developed by sub-M<sub><i>s</i></sub> austempering, delivering an impressive combination of strength and ductility, with an ultimate tensile strength of 2602&#xa0;MPa and a total elongation of 12.8 pct. The superior mechanical properties are mainly associated with microstructural refinement induced by the sub-<i>M</i><sub><i>s</i></sub> transformation route, strengthening from the fine fresh martensite, and transformation-induced plasticity response of retained austenite that sustains strain hardening during deformation. These results provide useful insight into the design of multiphase microstructures for ultrahigh-strength steels.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Sub-Ms Austempering Enables a Multiphase Microstructure that Achieves 2.6 GPa Strength and Large Ductility in a Medium-Carbon Low-Alloy Steel

  • 期刊论文

  • 发表日期：

    2026年7月30日

查看全文
  • Guo-Yang Li,
  • Fei-Long Sun,
  • Pei Li,
  • Xiao-Feng Ren,
  • Gui-Lin Wu,
  • Chao-Lei Zhang,
  • Shui-Ze Wang,
  • Xin-Ping Mao

摘要

Achieving a favorable strength–ductility balance at ultrahigh strength levels remains a major challenge in medium-carbon low-alloy steels. Constructing a multiphase microstructure that can simultaneously provide high strength and sustained strain hardening is a promising strategy to address this challenge. In this study, a multiphase microstructure consisting of primary martensite, bainitic ferrite, retained austenite, and fresh martensite was successfully developed by sub-Ms austempering, delivering an impressive combination of strength and ductility, with an ultimate tensile strength of 2602 MPa and a total elongation of 12.8 pct. The superior mechanical properties are mainly associated with microstructural refinement induced by the sub-Ms transformation route, strengthening from the fine fresh martensite, and transformation-induced plasticity response of retained austenite that sustains strain hardening during deformation. These results provide useful insight into the design of multiphase microstructures for ultrahigh-strength steels.