EFFECT OF CHROMIUM ENRICHMENT IN THE FILM FORMED BY SURFACE TREATMENTS ON THE CORROSION-RESISTANCE OF TYPE-430 STAINLESS-STEEL

The effect of chromium concentration in the surface film formed by sur face treatments on the corrosion resistance of Type 430 stainless stee l was studied. It was found that the chromium content depends on the s urface treatment method. HNO3 treatments result in a significant enric hment of chromium in the surface film on the Type 430 stainless steel, and the chromium enrichment increases with increasing HNO3 concentrat ion. The pitting potential (E(p)), corrosion potential (E(c)) and pola rization resistance (R(p)) are changed by the chromium enrichment (S-C r) in the surface film formed by treatment. The higher the S-Cr value, the higher the E(p), E(c) and R(p) values. Copyright (C) 1996 Elsevie r Science Ltd.