摘要
本文利用扫描电镜(SEM)、透射电镜(TEM)和能谱分析(EDS)技术,研究了奥氏体不锈钢焊缝中δ+γ双相结构的组织形态和显微成分偏析。认为当先析出相为δ铁素体时,在快速冷却条件下,δ→γ转变是块状转变,同时还应考虑短程扩散的作用。铁素体的形态和大小由短程扩散和块状转变决定。当先析出相为奥氏体时,共晶δ铁素体内的成分偏析主要是由于溶质分凝的结果,整个固态转变由扩散控制。
The morphologies and microsegregations of δ+γ two phases structure of austenitic stainless steel weldments are studied by the use of scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Energy—Dispersive Spectrometry (EDS). After the welding, when initial solidification occurs as primary delta ferrite, upon cooling to room temperature, the delta ferrite experiences a massive transformation to austenite, and the short distance diffusion should be considered. The size of the skeletal dalta ferrite and the microsegregation in it are decided by both of massive transformation and short distance diffusion along the grain boundary. When the primary product of solidification is austenite, the microsegregation in the ferrite is a result of solute partitioning during the solidification, and the transformation is controled by diffusion.
关键词
奥氏体不锈钢
焊缝组织
显微偏析
austenitic stainless steel weldment
solidification microsegregation
electron microscope analysis
