Yeh Chun-Ping, Tsai Kun-Chao, Huang Jiunn-Yuan
Institute of Nuclear Energy Research (INER), 1000 Wenhua Rd., Longtan District, Taoyuan City 32546, Taiwan.
Materials (Basel). 2021 Nov 12;14(22):6834. doi: 10.3390/ma14226834.
Crevice corrosion has become an important issue of the safety of AISI 304L austenitic stainless steel canister when exposed to the chloride environments located in coastal areas. Moreover, dust deposited on the canister surface may enhance the corrosion effect of 304L stainless steel. In this work, white emery was adopted to simulate the dust accumulated on the as-machined specimen surface. To investigate the effect of deposited white emery, chloride concentration, and relative humidity on the crevice corrosion behavior, an experiment was conducted on 304L stainless steel specimens at 45 °C with 45%, 55%, and 70% relative humidity (RH) for 7000 h. The surface features and crack morphology of the tested 304L stainless steel specimens were examined by SEM equipped with energy-dispersive spectrometry (EDS) and electron back scatter diffraction (EBSD). From the experimental results, a threshold RH for the stress corrosion cracking (SCC) initiation of AISI 304L austenitic stainless steel with different concentrations of chloride was proposed.
当暴露于沿海地区的氯化物环境中时，缝隙腐蚀已成为AISI 304L奥氏体不锈钢罐安全性的一个重要问题。此外，沉积在罐体表面的灰尘可能会增强304L不锈钢的腐蚀作用。在这项工作中，采用白刚玉来模拟加工后的试样表面堆积的灰尘。为了研究沉积的白刚玉、氯化物浓度和相对湿度对缝隙腐蚀行为的影响，在45℃、相对湿度为45%、55%和70%的条件下，对304L不锈钢试样进行了7000小时的实验。通过配备能谱仪（EDS）和电子背散射衍射（EBSD）的扫描电子显微镜（SEM）对测试的304L不锈钢试样的表面特征和裂纹形态进行了检查。根据实验结果，提出了不同氯化物浓度下AISI 304L奥氏体不锈钢应力腐蚀开裂（SCC）起始的临界相对湿度。
