Laser peening steams ahead

Siemens Power Generation has started to use a laser peening technology developed by Curtiss-Wright to improve the fatigue strength of titanium blades on some of its advanced steam turbines.

Although laser peening technology has been used for years to strengthen critical titanium components in military turbine engines, the company says that this application represents its first production use in power generation steam turbines.

Curtiss-Wright's laser peening technology is based on a Neodymium glass laser technology, which was originally developed by Curtiss-Wright in conjunction with the Lawrence Livermore National Laboratory.

The laser beam with a peak power output of 1000MW is pulsed and directed at the surface of metal parts to be treated. One million pounds per square inch pressure waves are generated at the surface that compress the metal and leave behind a protective residual compressive stress layer beneath the surface. This compressive stress acts to increase the component's resistance to failure mechanisms such as fatigue, fretting fatigue and stress corrosion cracking, which in turn translates into increased component life and reduced maintenance costs.