双相不锈钢中奥氏体沉淀相的晶粒取向及界面特征分布

Grain Orientation and Interface Character Distribution During Austenite Precipitation Phase in Duplex Stainless Steel

利用电子背散射衍射(EBSD)技术和基于Rodrigues-Frank(R-F)空间的取向差分析方法研究双相不锈钢中过饱和铁素体(α)经1323K沉淀析出的奥氏体(γ)相的晶粒取向和界面(晶界和相界)特征分布。结果表明:α晶粒经ε=2预先轧制变形后,γ析出相具有较强的织构,晶粒内取向差呈现以小角度晶界为主,孪晶界次之的晶界特征分布,这些晶粒与α基体的取向关系满足K-S,N-W和Bain关系的数量基本相当。具有相同取向而未经轧制变形的α晶粒沉淀析出的γ晶粒取向基本随机分布,与基体的取向关系主要以K-S为主;但内部发生孪晶的γ晶粒与基体不再满足K-S关系,其周围的相界约有1/4满足35°/〈110〉的新型取向关系。

The grain orientation and the interface character distribution were investigated forγprecipi-tation from the supersaturatedαduring aging at 1323K in duplex stainless steel by using EBSD tech-nique and misorientation analysis based on Rodrigues-Frank(R-F)space.The results show that sharp texture and the grain boundary character distribution featured by a high population of low angle grain boundary(LAB)and a small number of twin boundaries(TBs)are produced in theγprecipitated from cold-rolled supersaturated coarseαwith pre-strain ofε=2.The precipitated y grains approximately possess K-S,N-W and Bain orientation relationship with theαmatrix equally.For the unstrainedαmatrix of the same orientation,nearly random texture and the grain boundary character predominated by TBs are introduced in theγprecipitation after aging.Most ofγhave K-S relation with theαmatrix.However,twining inγleads to the deviation from typical K-S orientation relationship.And also,one-fourth of phase boundaries alongγgrains containing twins are found to obey a new orientation relationship of 35°/〈110〉with a matrix.