Influence of Shot Peening Pressure on Stress Corrosion Susceptibility of 304 Austenitic Stainless Steel

The surface of 304 austenitic stainless steel sheet specimen was processed by three different shot peening pressure. The thickness of grain refinement layer and refined degree were characterized by SEM, and surface hardness was tested by microhardness tester. The stress corrosion susceptibility of the specimens treated by 0.25,0.30 and 0.40 MPa shot peening pressure was compared through the slow strain rate tensile tests in 5% sodium chloride solution. The results showed that he grain refinement was caused by shot peening treatment in the surface layer and hardness increased; with the rise of shot peening pressure, the thickness of grain refinement layer increased, the surface hardness heightened and the stress corrosion susceptibility index decreased.