Enhancement of Surface Integrity of Binder Jet Fabricated Stainless Steel 316L via Severe Shot Peening

Abstract

This study investigates the effects of heat treatment (HT) and severe shot peening (SSP) on the surface integrity of binder jetting (BJ) manufactured 316L stainless steel. While HT step was chosen for its proven effectiveness in relieving residual stresses in PBF-LB built 316L, it was observed to increase porosity in BJ samples from 2.5% to 7.5%. SSP alone, however, effectively enhanced surface hardness from 145 to 504 HV, introduced beneficial compressive residual stresses reaching −995 MPa at a depth of 91 μm (remaining compressive up to 300 μm), and reduced surface porosity to 0.45%. These improvements indicate a significant enhancement in surface integrity, thus potentially improving wear and fatigue resistance. The findings suggest that SSP is sufficient for optimizing surface properties in BJ components, offering an effective post-processing approach for high-performance applications.