Improvement of Residual Stress on Material Surface by Water Jet Peening

Abstract

Cavitation bubbles are generated when highly pressurized water is jetted in water. Surface residual stress is improved remarkably due to the peening effect of extremely high pressure caused by the collapse of cavitation bubbles. This technique is called water jet peening (WJP). WJP is expected to be an effective preventive maintenance technique for the stress corrosion cracking in various components of power plants.
Various specimens are water jet peened to evaluate the fundamental characteristics of WJP and to select the most appropriate conditions for the residual stress improvement.
The test results show that WJP markedly changes the tensile residual stress caused by welding and grinding into the high compressive residual stress and prevents the stress corrosion cracking.