Enhancing on corrosion behavior of selective laser melted CoCrFeNiMn high entropy alloy via hot rolling: A comparative study with 316 stainless steel

This study compares the microstructure, mechanical properties, and corrosion behavior of CoCrFeNiMn high-entropy alloy (HEA) and 316L stainless steel fabricated by selective laser melting (SLM), with a specific focus on the influence of hot rolling post-treatment. The results showed that as SLM-fabricated HEA exhibited a higher microhardness (198.15 Hv) than the 316L, which was further increased to 228.53 Hv after hot rolling due to grain refinement and increasing dislocation density. However, electrochemical testing in 3.5 wt.% NaCl revealed that unrolled HEA had the poorest corrosion resistance, exhibiting severe pitting. Hot rolling improved the HEA's corrosion resistance by eliminating defects and refining its microstructure. In contrast, 316L stainless steel exhibits the optimal pitting corrosion resistance due to its high content of Cr and Mo elements and uniform structure.