... iron oxide is larger) these tend to flake and fall away. Stainless steels contain sufficient chromium to form a passive film of ... chromium oxide, which prevents further surface corrosion and blocks ... , 201, 301, 304, 321, 316, 316L, 309S and 310S Stainless steel pipes, and 1Cr17Ni2, 0Cr13, 1Cr13, 2Cr13, 3Cr13, 4Cr13, 201, 301 ...