Study on corrosion resistance of bright annealing treated 304 stainless steel in NaCl solutions

The corrosion resistance of 304 bright-annealing stainless steels in NaCl solutions of 0.01～0.6mol/L was investigated by means of different electrochemical measurement methods,such as stable polarization curves,potentiostatic open-circuit relaxation curves and electrochemical noise.The results show that the pitting broken-down potential E_b of stainless steel exhibits a linear relation with logarithm of Cl~-concentrations.In the solutions with same Cl~-concentration,E_b of bright-annealing stainless steel is about 400～600mV more positive than that of abraded one.It can be also concluded from the results of potentiostatic open-circuit relaxation test and electrochemical noise measurement that bright-annealing treatment can distinctly improve stability of passive film hence ameliorate the pitting performance of 304 stainless steel in NaCl solutions.