ABSTRACT Ausforming is being widely used to overcome the kinetics barrier in nanostructured bainitic steels and to enhance its practical industrial applications. It would also affect the microstructural characteristics and consequently the resultant mechanical performance. This article aims to investigate the tensile behaviour of nano bainite obtained from plastically deformed primary austenite at three different heat treatment stages. 10% of ausforming has been implemented and nanostructured bainite obtained after austempering at 300°C for 2, 4 and 6 h in salt bath furnaces. Results indicated that ausforming could successfully increase the volume fraction of bainite within the microstructure and refine the bainite packets sizes. Moreover, it has been demonstrated that higher mechanical stability of retained austenite and therefore more effective TRIP effect could be attained during the tensile test which consequently resulted in elongation improvement without deteriorating the strength properties. This claimed to be beneficial for materials performance during practical applications.

中文翻译：

---

由塑性变形的初生奥氏体获得的纳米贝氏体钢的延伸率改进

摘要 Ausforming 被广泛用于克服纳米结构贝氏体钢中的动力学障碍并增强其实际工业应用。它还会影响微观结构特性，从而影响最终的机械性能。本文旨在研究从塑性变形的初生奥氏体获得的纳米贝氏体在三个不同热处理阶段的拉伸行为。在盐浴炉中在 300°C 下奥氏体淬火 2、4 和 6 小时后，已经实施了 10% 的奥氏体成形并获得了纳米结构的贝氏体。结果表明，奥氏体成形可以成功地增加显微组织内贝氏体的体积分数并细化贝氏体包尺寸。而且，已经证明，残余奥氏体具有更高的机械稳定性，因此在拉伸试验期间可以获得更有效的 TRIP 效应，从而在不降低强度性能的情况下提高伸长率。这据称有利于实际应用中的材料性能。