Effect of laser shock peening on corrosion resistance of AISI430 ferritic stainless steel

In order to improve the surface corrosion resistance of AISI430 ferritic stainless steel, laser shock peening(LSP) was used to strengthen AISI430 ferritic stainless steel. Polarization curves and electrochemical impedance spectroscopy were used to study the effect of laser shock processing on corrosion resistance of AISI430 ferritic stainless steel, combined with surface residual stress and corrosion morphology of the specimens. The results show that, residual compressive stress layer appears on specimens surface after strengthening treatment. The maximum residual stress is -339MPa. The depth direction is extended to 900μm in a nearly decreasing manner. Self corrosion potential of the sample in NaCl solution increases from -251mV to -192mV. Corrosion current density can be reduced by 28.18μA/cm^-2 at most. It enlarges the radius of capacitive arc of impedance spectrum. Corrosion pits and strip corrosion are reduced. LSP strengthens corrosion resistance of AISI430 ferritic stainless steel in NaCl solution.