材料期刊网

随着资源、能源和环境压力日益加大，超高强度钢的开发越来越受到世界各国的极大重视。传统的超高强度钢大都是依赖提高碳含量或合金元素含量而获得较高强度的马氏体或贝氏体钢，此种钢存在着焊接性能差、塑韧性低、钢材尺寸受限制和成本昂贵等问题，严重制约了经济的快速发展和现代国防的建设，因此，开发综合性能良好、成本低廉的新型超高强度钢刻不容缓。结合当前纳米科技的发展，介绍了新型纳米强化超高强度钢的设计理念，阐述了以纳米相析出强化为主、多种强化方式结合的强韧化理论，并总结了纳米析出强化超高强度钢在合金设计和工艺优化等方面的初步研究进展，最后探讨了新型纳米强化超高强度钢亟待解决的问题。

In view of the limited material resources and energy supply available together with serious environment impact concerns at the present time, the development of ultra-high strength steels has attracted a great deal of attentions from various countries in the world. As we know, most traditional high strength steels have been developed based on martensitic and bainitic structures with high levels of carbon or high alloy additions. However, these alloys are facing many severe problems, including poor weldabi!ity, low ductility and toughness, fabrication-size limitation, as well as high production cost, all of these resulting in slowdown of the economic and national-defense developments in China. Thus, it is imperative for us to speed up the development of advanced ultra-high strength steels with excellent mechanical and metallurgical properties as well as the low manufacturing cost. In this paper, we present a comprehensive review of the recent development of high-strength ferritic steels hardened by precipitation of nano-scale precipitates. In this paper, we have evaluated all potential hardening mechanisms possibly applied to ferritic steels. Furthermore, the scientific and technical challenges facing this new class of high-strength and low-cost steels will be briefly discussed.