00Cr17Ni14 Mo2不锈钢高温抗氢脆性能研究

Study of hydrogen embrittlement resistivity for 00Cr17Ni14Mo2 austenitic stainless steel at high temperature

利用光学显微镜、电子显微镜、俄歇电子谱 /二次离子质谱表面分析仪等结合拉伸实验 ,研究了0 0Cr17Ni14Mo2奥氏体不锈钢及其电子束焊缝在 6 5 0℃充氘后组织、微区成分变化与性能的关系 ,以及拉伸应力与氘分布的关系。结果表明 ,高温气相充氘后 ,0 0Cr17Ni14Mo2奥氏体不锈钢及其电子束焊缝抗氢脆性能较明显下降。晶界、孪晶界析出大量的碳化物 ,但拉伸断口形貌并未呈沿晶断裂 ;晶界上未发现S、P等痕量元素的偏聚 ,却产生了富Cr、Mo而贫Ni层 ,这表明晶界成分的变化减弱了晶界析出物对氢脆的影响。电子束焊缝塑性下降 ,拉伸时从该处断裂。

The effects of the microstructure change and the grain boundary composition change of 00Cr17Ni14Mo2 austenitic stainless steel on its resistivity to hydrogen embrittlement are investigated by optical microscopic,SEM,AES,SIMS.The dependence of tension stress on deuterium distribution is also studied,After 00Cr17Ni14Mo2 stainless steel and its electron beam weldings are charged with D 2 at 650℃ for 2 hours,the hydrogen embrittlement susceptibility of them is increased.The tensile fracture surface shows both ductile dimples and secondary cracks,although an amount of carbide particles precipitate along the grain and twin boundaries.Meanwhile,no segregation of S,P,C trace elements occurs in grain boundary,but a Ni-depletive and Cr,Mo-rich region is formed.These indicate that the grain boundary composition change impairs the effect of the grain boundary precipitations on hydrogen embrittlement.The plasticity of electron beam weldings charged at 650℃ is decreased,and the tension sampled rupture from the welding seam.Moreover,the deuterium is richen in the fractures of the tension samples because of static stress.