Excellent corrosion resistance of 316 stainless steel in purified NaCl-MgCl2 eutectic salt at high temperature

•Corrosion behaviors of 316SS were studied in purified NaCl-MgCl2 eutectic salt.•Good corrosion resistance of 316SS was found in purified NaCl-MgCl2 at 600°C.•316SS corrosion rate in purified NaCl-MgCl2 was very low even at 700 °C.•Corrosion mechanisms of 316SS in purified NaCl-MgCl2 were obtained.