Corrosion Resistance to Chloride of a Novel Stainless Steel: The Threshold Chloride Value and Effect of Surface State

To evaluate the corrosion resistance of a novel stainless steel intended for use within reinforced concrete (RC) structures exposed to aggressive environments, the threshold chloride concentration of three stainless steels (316, 2205, novel 2205) and two carbon steels (HRB400, HRB500) exposed to pore solutions of fresh concrete was experimentally studied by means of electrochemical methods. The effect of steel surface state on the corrosion resistance was also experimentally investigated. The results showed that the novel stainless steel has a much higher corrosion resistance than those of the carbon steels and stainless steels when subjected to chloride environments. The presence of surface damage leads to significant decrease of corrosion resistance for carbon steel, however the corrosion can be certainly inhibited with the accumulation of rust on the steel surface. Although the oxide layer was worn, the novel 2205 stainless steel still has a great corrosion resistance.