不同冶金方法测定双相不锈钢中的二次相析出

Different metallurgical methods for measuring secondary phases precipitation in duplex stainless steels

双相不锈钢(DSS)的铁素体-奥氏体微观结构将良好的机械性能及抗腐蚀性能结合于一体,并且价格也非常具有竞争力。DSS的一个典型性质是其较高的抗点蚀性,这一特性使DSS适用于苛刻环境下的结构应用。然而,DSS的应用受限于危险金属相结构的易感性,从而对其冲击韧性和耐腐蚀性产生不利影响。此析出现象引起了人们的极大关注,并且不同析出次序(σ相,χ相和碳化物)也已被相继提出。本文综述了有关二次相形成的研究,并对最常用分析方法进行比较。对这些析出在连续冷却和等温处理(以定义时间和次序)条件下进行了考察。

The austenitic-ferritic microstructure makes duplex stainless steels （DSS） a good combination of mechanical and corrosion properties with a competitive cost. A typical property of DSS is the high pitting resistance that makes them suitable for structural application in very aggressive environments. However, the application of DSS is limited by their susceptibility to the formation of dangerous intermetallic phases resulting in detrimental effects on impact toughness and corrosion resistance. This precipitation has received considerable attention and different precipitation sequences （σ-phase, Х-phase and carbides） have been suggested.