R0 Blades Seeing Laser Peening Benefits

Combined Cycle Journal posted a review of the 7F Users Group meeting in 2014.  The issues associated with the engine, they report, are corrosion pitting, blending of the 17th stage discs, upgrade options, and fogging related R0 erosion.  Laser peening is reported to be a “key step in… [making] the enhanced R0 blade erosion-tolerant.”  The review also gives a brief description of the direct material and performance improvements of the blade, indicating that the laser peening of the part imparts a beneficial compressive residual stress “between 50 and 100 mils”.  With laser peening, the enhanced blade measurements were well within damage tolerance after 7000 fogging hours.  Read the CCJ report here.  Even with the improved lifetime of the enhanced R0 blade there was a suggestion to increase the laser peening area to the entire leading edge, which one would conclude is intended to further increase the fatigue life and damage tolerance of the blade.