FATIGUE AND SCC LIFETIME ENHANCEMENT OF STEELS BY MEANS OF LASER PEENING

摘要

Laser peening is a technology employed to induce deep levels of plasticity in materials resulting in compressive residual stress to depths of 5mm (0.2 inches) or deeper enabling increased fatigue strength and lifetimes and greatly enhanced resistance to stress corrosion cracking. An advanced in Nd:glass laser technology has enabled high rate, cost effective industrial deployment of the technology that is now being widely used in aerospace and electric power generation applications. Examples of deep levels of compressive stress and resulting improvements in fatigue life and resistance to stress corrosion cracking will be shown. An advanced beam delivery technology incorporating a robotic arm coupled with a video detection/beam alignment system is enabling rapid setup and application in field applications. The technology has been approved and deployed to prevent early fatigue cracking of key structural components on the F-22 fighter jet. It is also being applied to oil and natural gas applications and has the potential to serve a broad base of field applications including oil and gas lines, on-board ship SCC, nuclear power plant SCC, and fatigue and corrosion applications in upstream exploration and downstream oil refining.