Effect of Laser Peening on Residual Stress and Stress Corrosion Cracking for Type 304 Stainless Steel

Author:  M Obata, Y Sano, N Mukai, M Yoda, S Shima, M Kanno
Source:  Conf Proc: ICSP-7 (pg 387-394)
Doc ID:  1999052
Year of Publication:  1999
Abstract:  
A novel technique in which pulse laser irradiation is used to improve residual stress of material surface has been developed. When a material surface is irradiated by a high-energy pulse laser, the impulsive wave, which is generated by the high-pressure plasma, propagates into the material interior, thereby inducing high compressive stress on the material surface. We call the stress improvement technique using pulse laser irradiation "laser peening". The thickness of a compressive stress layer is much larger than that in the case of conventional peening techniques. The effects of processing parameters and material strength on the stress improvement of cold worked Type 304 stainless steel were investigated. The laser peeningremarkably increases the stress corrosion cracking (SCC) resistance of thermal sensitized Type 304 stainless steel in corrosivse high temperature water. It was confirmed that the laser peening was more effective than conventional peening techniques for improving the residual stress and the SCC resistance of Type 304 stainless steel.