Hot corrosion of unwelded and welded 2.25 Cr-1Mo steel coated with a potassium sulphate and sodium chloride mixture is discussed. The coating composition is a eutectic mixture with 40 wt% K2SO4 and 60 wt% NaCl. Weight gain studies were done for welded specimens containing only weld metal and composite specimens containing both weld metal and heat-affected zone. The results indicated that the coated specimens were more corroded than uncoated specimens. Also welded samples showed less attack than unwelded samples. © 1993.