308L焊缝中蠕变-疲劳交互行为与σ-相的析出  

Precipitation of σ-Phase and Creep-fatigue Behavior of 308L Steel Weld

作　　者：何君[1] 

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001

出　　处：《热加工工艺》2009年第9期28-29,共2页Hot Working Technology

摘　　要：研究308L焊缝经过焊后热处理其蠕变-疲劳的性质。应用扫描和透射电镜研究了焊态和焊后热处理试样的相变和微观结构。运用EDS探测化学成分的分布。结果表明,焊后热处理能够提高焊缝的蠕变-疲劳抗力。δ-铁素体转变成第二项奥氏体和σ-相。经过高温焊后热处理,δ-铁素体的分解率逐渐减小,这主要是由于Si在γ/σ界面的偏析的减少。The creep-fatigue properties of 308L steel weld after post-weld heat treatments （PWHT） were investigated. The microstructure and phase transformation of the as-welded and PWHT weldments were examined using scanning and transmission electron microscopy. Energy dispersive spectroscopy was used for detecting the elements distribution. The results show that PWHT promotes the creep-fatigue resistance of the weldment δ-Ferrite mainly transforms into secondary austenite and σ-phase. The decomposition ratio of δ-ferrite shows a tendency to decrease after high temperature PWHT. This can be attributed to the reduction of silicon segregation near the γ/σ interface.

关 键 词：Δ-铁素体 相变 蠕变-疲劳 σ-相 

分 类 号：TG441.8[金属学及工艺—焊接]