亚稳态304不锈钢应力腐蚀影响因素探讨

Discussion on Factors of Unstable 304 Stainless Steel Stress Corrosion Cracking

30 4不锈钢通过低温拉伸制得含有不同马氏体相变量的试样 ,由于冷加工将不可避免地导致位错密度大幅度增加 ,利用铁素体测量仪和透射电镜 (TEM )检测并分析 30 4不锈钢位错形态 .上述试样在 4 2 %MgCl2 沸腾溶液中用慢应变速率法 (SSRT) ,结合金相显微镜 ,扫描电子显微镜等表面分析手段 ,探讨了微观组织变化对 30 4不锈钢应力腐蚀的影响 .结果表明 :由于马氏体相和位错缺陷的交互作用 ,影响了 30 4不锈钢在沸腾MgCl2 溶液中应力腐蚀敏感性 ,且在不同变形量范围内 。

The 304 stainless steels were stretched at low temperatures to get different martensite phase transformation.Ferrmagnetometer was used to measure the martensite phase content. It was found that the dislocation density of 304 stainless sted was increased unavoidably with increase of deformation.Transmission electron microscope (TEM) was used to study the distribution of the dislocation.The influence of microstructure change on SCC of 304 stainless steel was discussed by slow strain rate testing (SSRT) in 42% MgCl 2 boiling solution,metallurgical microscope and scanning electron microscope (SEM).The results showed that martensite phase and dislocation flaw act together on the SCC susceptibility of 304 stainless steel in 42% MgCl 2 boiling solution.