Effects Of Environmental Factors On The Crevice Corrosion Of Type 304 Stainless Steel

This paper investigated the effects of environmental factors, such as, pH, buffer capacity, the concentration of chloride ions and the concentration of nonaggressive anions, on the crevice corrosion potential (E_cc) of Type 304 stainless steel. The E_c was ascertained by galvanodynamic polarization. In borate or phosphate buffered NaCl solutions with a constant total concentration of borate or phosphate, E_cc increases with an increase in pH. With the increase of the concentration of chloride ions, E_cc decreases markedly in the test solutions. Moreover, the buffer capacity and concentration of nonaggressive anions in the test solutions also exerts some effects on the crevice corrosion of Type 304 stainless steel. Furthermore, the cooperative inhibition effect of the environmental factors on crevice corrosion was investigated. The potential of crevice corrosion (E_cc) shows a strong dependence on a parameter J, which was called as general environmental factor and defined as the product of concentration of nonaggressive anions, pH, buffer capacity and concentration of chloride ions. According to the investigation of the general environmental factor, we can understand the crevice corrosion of stainless steel deeply, and prevent it easily.