充氚不锈钢焊缝微观组织

Microstructure of Stainless Steel Welding after Tritium Charging

摘要:

用电子显微镜研究了不锈钢电子束、激光束焊缝试样在高温气相充氢氚后断裂的微观行为及显微组织，并用材料试验机测试了其断裂强度。结果表明：不锈钢焊缝试样充氢氚后断裂强度值略有下降，断口组织中出现了明显的氢脆断裂特征:氢脆撕裂岭、准解理断裂形态、沿晶断裂形态和氢致二次裂纹。TEM研究表明，气态氚有与晶界初生析出物交互作用形成氚蚀裂纹趋势；裂纹萌生在形变带和晶界处。

Abstract:

The microstructure and fracture behavior of electron beam and laser beam welded stainless steel samples after charging hydrogen and tritium were studied by electron microscopy and the fracture strength was measured by tensile test. The results show that the fracture strength of the welding charged with tritium decreases a little, and the morphology of fracture surface has the typical hydrogen embrittlement mechanisms such as cleavage fracture, the second cracks and intergranular fracture. TEM observation indicates that there is a tendency to form cracks caused by the interaction between gas tritium and precipitates in grain boundary, and the microcracks initiate along deformation bands and grain boundary.