Abstract Environmentally assisted cracking (EAC) initiation tests were carried out by subjecting Alloy 800 tensile specimens to 0.55 mol/kg SO42− solution, pH280°C 3, at 280 °C using slow rise-time cyclic loading and in-situ crack detection. EAC, intergranular corrosion (IGC), and pitting were observed. Transmission electron microscopy analysis revealed Ti- and Cr-rich oxides in cracks, and sulfur incorporated in oxide(s) or as sulfide compound(s). This oxide/sulfide film is likely impaired, producing a slip dissolution-type EAC mechanism. For pitting, only a nano-scale sulfur layer was identified at pit-metal interfaces. This high surface coverage of adsorbed sulfur limited oxide nucleation and accelerated metal dissolution.

中文翻译：

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合金 800 中硫辅助降解的高分辨率表征

摘要 环境辅助开裂 (EAC) 引发试验是通过将合金 800 拉伸试样置于 0.55 mol/kg SO42− 溶液、pH280°C 3、在 280°C 下使用缓慢上升时间循环加载和原位裂纹检测进行的。观察到 EAC、晶间腐蚀 (IGC) 和点蚀。透射电子显微镜分析显示裂纹中富含 Ti 和 Cr 的氧化物，并且硫包含在氧化物中或作为硫化物化合物。这种氧化物/硫化物薄膜可能会受损，产生滑移溶解型 EAC 机制。对于点蚀，在坑-金属界面处仅发现了纳米级硫层。这种吸附硫的高表面覆盖限制了氧化物成核和加速金属溶解。