Abstract

During the past thirty years, two generations of low alloy steels (ferrite/pearlite followed by bainite/martensite) have been developed and widely used in structural applications. The third-generation of low alloy steels is expected to achieve high strength and improved ductility and toughness, while satisfying the new demands for weight reduction, greenness, and safety. This paper reviews recent progress in the development of third-generation low alloy steels with an M³ microstructure, namely, microstructures with multi-phase, meta-stable austenite, and multi-scale precipitates. The review summarizes the alloy designs and processing routes of microstructure control, and the mechanical properties of the alloys. The stabilization of retained austenite in low alloy steels is especially emphasized. Multi-scale nano-precipitates, including carbides of microal-loying elements and Cu-rich precipitates obtained in third-generation low alloy steels, are then introduced. The structure–property relationships of third-generation alloys are also discussed. Finally, the promises and challenges to future applications are explored.

中文翻译：

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在M 3组织控制下开发的第三代低合金钢的最新进展

摘要

在过去的三十年中，已经开发了两代低合金钢（铁素体/珠光体，然后是贝氏体/马氏体），并广泛用于结构应用中。预计第三代低合金钢将实现高强度，并改善延展性和韧性，同时满足减轻重量，提高环保性和安全性的新要求。本文回顾了开发具有M ³的第三代低合金钢的最新进展显微组织，即具有多相，亚稳态奥氏体和多尺度析出物的显微组织。综述总结了合金的设计和微结构控制的加工路线，以及合金的机械性能。低合金钢中残余奥氏体的稳定性特别受重视。然后引入多尺度的纳米沉淀，包括微合金元素的碳化物和在第三代低合金钢中获得的富铜沉淀物。还讨论了第三代合金的结构-性能关系。最后，探讨了未来应用的前景和挑战。