The corrosion resistance of the equiatomic CoCrNi medium-entropy alloy (MEA) and its 0.5 atomic % nitrogen alloyed variant in 0.1 M H₂SO₄ solution was investigated and compared with that of the 316 L stainless steel as a reference material. All of the investigated materials showed single-phase face centered cubic (FCC) microstructures, and nitrogen was fully dissolved in the solid solution structure of the CoCrNi MEA. Both the nitrogen-free and nitrogen-doped MEAs showed significantly higher corrosion resistance (lower corrosion currents and rates) than the 316 L steel. Compared to the nitrogen-free CoCrNi, the interstitial nitrogen dissolved in solid solution causes a significant improvement in the pitting corrosion resistance of the CoCrNiN. Under the same testing condition, pitting corrosion was not observed in the CoCrNiN alloy, while the CoCrNi MEA and 316 L steel showed distinct pitting cavities. The better anti-corrosion performance of the CoCrNiN compared to that of the CoCrNi is correlated with a higher fraction of chromium oxide in the passive films.

等原子CoCrNi中熵合金（MEA）及其0.5原子％的氮合金变体在0.1 MH ₂ SO _4中的耐腐蚀性对溶液进行了研究，并与作为参考材料的316 L不锈钢进行了比较。所有研究的材料均显示出单相面心立方（FCC）微观结构，并且氮气完全溶解在CoCrNi MEA的固溶体结构中。与316 L钢相比，无氮MEA和掺氮MEA均显示出更高的耐腐蚀性（更低的腐蚀电流和速率）。与不含氮的CoCrNi相比，固溶体中溶解的间隙氮使CoCrNiN的耐点蚀性得到了显着改善。在相同的测试条件下，CoCrNiN合金中未观察到点蚀，而CoCrNi MEA和316 L钢显示出明显的点蚀腔。