CORROSION-RESISTANCE OF A HIGH-PURITY FE-50 MASS-PERCENT CR ALLOY

High purity Fe-50 mass% Cr alloys containing C and N in a range of 30 to 500 mass ppm were prepared and their corrosion resistance was inves tigated. A field exposure test at a coastal area showed that the decre ase of the C and N content decreases the number and depth of corrosion pits. The alloys containing CS N less than 100 mass ppm did not corro de after 230 cycles of a cyclic corrosion test. The alloy containing 5 00 mass ppm C and N corroded severely. The relation between the genera tion and growth of corrosion pits is discussed on the basis of electro chemical corrosion tests.