The resistance against erosion-corrosion in wet steam was determined for 58 steels in a laboratory test. Minute quantities of chromium, copper, and molybdenum in-crease the resistance against erosion-corrosion. The erosion-corrosion resistance (R) can be calculated by the regression equation R = 0.61 + 2.43 Cr + 1.64 Cu + 0.3 Mo. Steels from in-service erosion-corrosion failures showed low resistance against erosion-corrosion in the laboratory test. No failures were found in steels with a calculated resistance value R of more than 1.0.