N含量对S32750双相不锈钢中二次奥氏体析出行为的影响
Effect of N Content on Precipitation Behavior of Secondary Austenite in S32750 Duplex Stainless Steel
吴晓涵 1宋志刚 1何建国 1丰涵 1郑文杰 1朱玉亮1
作者信息
- 1. 钢铁研究总院有限公司特殊钢研究院,北京 100081
- 折叠
摘要
随着行业对双相不锈钢品质及性能要求的提升,二次奥氏体已经成为影响S32750双相不锈钢应用的关键因素之一.二次奥氏体是"温度-冷却速率"共同作用的一种亚稳态产物,与铁素体相呈近K-S或N-W位向关系,且对N有富集作用,可按形貌将其分为针状二次奥氏体和孤岛状二次奥氏体.研究了N含量对二次奥氏体析出行为的影响.通过制备w[N]为0.02%、0.09%和0.17%的试验钢,并借助热模拟及EBSD检测可知,随着N含量增加,二次奥氏体由弯曲羽毛状向板条形针状转变,且奥氏体相的整体比例增加.经计算可知,奥氏体相的析出方式与本征吉布斯自由能相关,即受到成分与试验温度的影响.
Abstract
With the improvement of the quality and performance requirements of duplex stainless steel(DSS)in the indus-try,secondary austenite(γ2)has become one of the key factors affecting the application of S32750 DSS.Secondary austen-ite is considered as the joint product of temperature and cooling rates,which performed near K-S or N-W orientation rela-tionship with the ferrite phase and an enrichment for N elements.Secondary austenite can be divided into needle-shaped austenite(NA)and isolated austenite(IA)by morphology.In this paper,the effect of N mass fraction on the precipitation behavior of secondary austenite was studied by preparing test steels with N content of 0.02%,0.09%and 0.17%.Thermal-Calc simulation and EBSD detection proved that with the increase of N,γ2 evolved from curved feather-shape to needled-shape with the total proportion of austenite phase increased.The precipitation mode of austenite related to the Gibbs free energy,which was namely affected by elements composition and temperature.
关键词
双相不锈钢/二次奥氏体/N含量/析出行为/形核驱动力Key words
Duplex Stainless Steel/Secondary Austenite/Nitrogen Mass Fraction/Precipitation Behavior/Nuclear Driv-ing Forces引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据