Influence of surface mechanical attrition treatment (SMAT) on the corrosion behaviour of AISI 304 stainless steel

The influence of surface mechanical attrition treatment (SMAT) on the corrosion behaviour of AISI 304 stainless steel in 0.6 M NaCl was studied. SMAT of 304 SS induced plastic deformation, enabled formation of mechanical twins and strain induced alpha-martensite phase, increased the surface roughness and imparted compressive residual stress. SMAT caused a deleterious influence on the corrosion resistance of 304 SS in 0.6 M NaCl. Double log plots of current-time transients at 25 mV((SCE)) indicate formation of defective passive film on SMATed 304 SS. Increase in surface roughness, strain induced martensite and dislocations nullify the beneficial influence of surface nanocrystallization. (C) 2013 Elsevier Ltd. All rights reserved.