Electrochemical Corrosion Behaviour of AISI 304 SS under Plastic Deformation Condition with Bending Tensile Stress in Dilute Sulphuric Acid Solution

The corrosion electrochemical behaviors of 304 stainless steel with tensile stress under plastic deformation condition in dilute sulphuric acid were studied using U-shaped bending specimens. The tensile surface corrosion behaviors of 304 stainless steels of U bend specimens with different strains in 0.5 mol·L-1 H2SO4 solution were studied by polarization curves and impedance spectroscopy. Pitting corrosion protection potentials of the tensile surfaces of U bend specimens with different strains were studied in 0.5 mol·L-1 H2SO4 + 0.2 mol·L-1 KCl. Electrochemical tests show that the larger the plastic strain,the smaller the polarization resistance Rp and the larger the corrosion rate;ΔE=Eb-Ep increased with increasing the strain,indicating that the tensile surface passive film repair ability was poor,and thus susceptible to pitting.