Precipitation behavior of σ phase in weld metal of a TP321H austenitic stainless steel pipe in a synthetic ammonia reforming furnace
Weld metal of a TP321H austenite stainless steel pipe in a synthetic ammonia reforming furnace,which served up to 2 years at 650℃ has been investigated experimentally in this study.The performance and microstructure of the weld metal were characterized by impact test,optical microscopy (OM),scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD).The results indicated that impact toughness of the weld metal is significantly reduced.Chromium-rich a phase distributed at the Sy interface,companying with the formation of secondary y phase,σ phase appeared blocky and full of secondary cracks.The size of precipitated σ phase ranged from lμm to 5μm.The embrittlement of weld metal is caused by the precipitation of σ phase at δ/y interface.
σ phase Precipitation behavior Impact toughness TP321H Weld metal
Tao Chen Xuedong Chen Zhibin Ai Zhichao Fan Xiaoming Lian
National Technology Research Center on PVP Safety Engineering,Hefei General Machinery Research Institute,Hefei 230031,China
国际会议
成都
英文
445-450
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）