Ultra-High Pressure Cavitation Peening (UHPCP) was developed by Framatome to mitigate Primary Water Stress Corrosion Cracking (PWSCC) in Alloy 600 and Alloy 182. The effectiveness of UHPCP as a preventive measure against PWSCC initiation was demonstrated previously, but data was still lacking concerning the effect of UHPCP on existing cracks. In this program, PWSCC was generated in actively
loaded 4-point bend specimens and on massive-bend specimens made of Alloy 182, then surfaces were treated by UHPCP and subsequently exposed to simulated Pressurized Water Reactor (PWR) primary water at 360°C. For the larger cracks (1-4 mm depths) in the massive bend specimens, qualitative correlations between
Eddy current measurements of crack advancement, crack morphology on the surface and final crack lengths on cross-sections demonstrate that UHPCP either reduces crack propagation or has a negligible effect on crack propagation. The study of small cracks (~1 mm) in the 4-point bend specimens is detailed in another article (see
“Part 2”).