Microstructure and corrosion behavior of FeCrNiMnMox high‐entropy alloys fabricated by the laser surface remelting

Abstract In this study, an Nd:YAG laser was used to carry out laser surface remelting treatment on FeCrNiMnMo x ( x = 0, 0.5, 1) alloys. A study was conducted on the potential impact of Mo on the microstructure and corrosion resistance of the laser‐remelted layer. According to the research results, FeCrNiMnMo x alloys were more effective in refining the dendrites, compared with the matrix, whereas the FeCrNiMn alloys' remelted layer exhibited an almost single face‐centered cubic (FCC) structure. In comparison, FeCrNiMnMo 0.5 and FeCrNiMnMo 1 alloys' remelted layer displayed the FCC and σ phase. In addition, the dendrite crystals' microstructure can be clearly refined by Mo alloying. Mo is effective in improving the corrosion resistance of the FeCrNiMnMo x alloys' remelted layer in 3.5% NaCl solution. The pitting resistance of Mo‐containing‐remelted layers is significantly higher, compared with Mo‐free alloy's remelted layer, and the FeCrNiMnMo 0.5 ‐remelted layer shows the most satisfactory corrosion resistance. As revealed by X‐ray photoelectron spectroscopy analyses, the addition of molybdenum promotes the generation of Cr 2 O 3 and enhances the corrosion resistance of the remelted layer.