稀土在铁素体不锈钢中的应用

Application of Rare Earth to Ferritic Stainless Steels

近年来,随着镍价的飞涨,奥氏体不锈钢的市场份额有所下降,价格稳定低廉且性能优良的铁素体不锈钢得到了很大的发展和广泛的应用。但铁素体不锈钢韧性、塑性和热敏性能还有待于进一步提高。稀土元素因其具有独特的电子层结构而具有极强的化学活性,在铁素体不锈钢中的应用逐渐引起研究者的关注,主要集中在三个方面:净化钢液、细化晶粒和变质夹杂。本文就近年来国内外研究者对稀土在铁素体不锈钢中的应用及对其机械性能、腐蚀性能的影响进行了系统的总结和阐述,并对稀土在铁素体不锈钢中应用的发展方向进行了展望。此外,还采用FactSage热力学软件计算了铁素体不锈钢中稀土夹杂物的析出顺序,与文献中结果符合的较好。

Recently, the share of the market for austenitic stainless steel has decreased with the increasing price of Nickel. As a result, researches and applications of ferritic stainless steel become more and more because of its low price and perfect properties. Nevertheless, ferritic stainless steel has some disadvantages such as lower toughness, bad plasticity and sensitivity. Therefore, more attentions are paid to the use of rare earth in ferritic stainless steel because of its unique electron configurations and perfect chemical activity and there are mainly three fields of researches： purifying molten steel, refining grain and modifying inclusions. Applications of rare earth and its effect on mechanical, corrosion and antioxidant properties are systematically concluded in this paper, and then, the prospective of development direction for its applications in ferritic stainless steel is also put forward. In addition, the sequence of rare earth precipitates is calculated by FactSage software which shows great agreement with the data in literatures.