Influence of HAc Concentration and Temperature on the Electrochemical Corrosion Behavior of Super 13Cr Stainless Steel

Electrochemical techniques were used to investigate the influence of HAc concentration and solution temperature on the passive and pitting corrosion behavior of super 13Cr stainless steel in 3.5% NaCl solution. The results revealed that the addition of HAc lowered the open circuit potential of super 13Cr stainless steel, while did not significantly reduce its critical breakdown potential. In the absence of HAc, the passive film exhibited n-type semiconducting property, whereas changed to n + p type in the presence of HAc. With the increase of HAc concentration, the steady state thickness of the passive film decreased while the concentration of point defects in the passive film increased, which indicated the decline of the protective effect of the film. In the absence of HAc,the width of the passive region decreased with the increase of temperature. However, in the presence of HAc, the width of the passive region kept almost unchanged with the uncrease of temperature.