Abstract This study investigated the passivation behaviour of wrought 316L stainless steel (SS) and 316L manufactured by the Selective Laser Melting (SLM) process in phosphate-buffered saline (PBS). The 3D printing laser power influenced microstructure, passive film and corrosion resistance of SLM 316L SS were studied, and compared with the results of wrought 316L SS. The results indicated that a smaller corrosion current density and improved breakdown potential (Eb) of SLM 316L SS was associated with a higher proportion of Cr2O3 in the passive film at OCP conditions. The Transmission Electron Microscopy (TEM) proved that the passive film on SLM 316L SS was continuous and compact at 600 mV vs. Ag/AgCl applied potential. The increase in the applied potential resulted in a high content of hydroxide being recorded in the passive film. The results also suggest preferential facets of (1 1 0) and abundant grain/sub-grain boundaries for SLM 316L SS, as well as the increased work of separation and growth rate of the passive film from the substrate. Wrought 316L SS demonstrated preferred facets of (1 1 1)-γ and larger grains. There are confirmed via X-Ray Diffraction (XRD), Electron Backscatter Diffraction (EBSD) and the first-principle calculation.

中文翻译：

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揭示在磷酸盐缓冲盐水溶液中选择性激光熔化的 316L SS 上的钝化膜的卓越腐蚀保护

摘要 本研究研究了通过选择性激光熔化 (SLM) 工艺制造的锻造 316L 不锈钢 (SS) 和 316L 在磷酸盐缓冲盐水 (PBS) 中的钝化行为。研究了 3D 打印激光功率对 SLM 316L SS 的微观结构、钝化膜和耐腐蚀性能的影响，并与锻造 316L SS 的结果进行了比较。结果表明，在 OCP 条件下，SLM 316L SS 较小的腐蚀电流密度和提高的击穿电位 (Eb) 与钝化膜中较高比例的 Cr2O3 相关。透射电子显微镜 (TEM) 证明 SLM 316L SS 上的钝化膜在 600 mV 与 Ag/AgCl 施加电位下是连续且致密的。外加电位的增加导致在钝化膜中记录到高含量的氢氧化物。结果还表明，SLM 316L SS 具有 (1 1 0) 的优先晶面和丰富的晶粒/亚晶界，以及钝化膜与基板的分离工作和生长速率增加。锻造 316L SS 显示出 (1 1 1)-γ 和更大晶粒的首选小面。有通过 X 射线衍射 (XRD)、电子背散射衍射 (EBSD) 和第一性原理计算证实。