Influence of dual shot peening on the enhancement of surface characteristics of duplex stainless steel

The present work aims to improve the surface characteristics of duplex stainless steel 2205 through use of shot peening. Two distinct methods of shot peening were used in which dual shot peening led to significant improvement in the surface topography when compared to the single peened surface. Further, dual peened surface ended with more number of micro indentations than the single shot peened surface. Surface microstructure of DSS revealed severe plastic deformation and grain refinement in both the peened surfaces. Further, the effect of peening was found to be more on the austenitic (gamma) phases than the ferritic (alpha) phases. Shot peening led to work hardening of the surface layers which results in 59% of improvement in the average surface hardness after single shot peening and 139% of improvement after dual shot peening. X-ray diffraction analysis on the peened surfaces showed the presence of highly dislocated surface grains. (C) 2018 Elsevier Ltd. All rights reserved.