Ultra-High Pressure Cavitation Peening (UHPCP) was developed by Framatome to mitigate Alloy 600 and Alloy 182 surfaces against primary water stress corrosion cracking (PWSCC). This process creates a compressive membrane stress to a depth of ~1 mm. The effectiveness of UHPCP as a preventive measure against PWSCC initiation was demonstrated previously, but data were still lacking concerning
the effect of UHPCP when applied to surfaces with short preexisting cracks within or just beyond the depth of peening. To investigate this scenario, Framatome sponsored two research projects. In one project, PWSCC cracks were generated on statically loaded massive-bend Alloy 182 specimens (see the “Part 1” paper in this conference), while in the other project described in this paper, actively loaded 4- point bend specimens with in-situ measurement of crack propagation were utilized. A multi-step process was devised and executed to generate a short PWSCC crack with documented active crack growth on 4-point bend specimens. The tensile loaded surface of the specimens was treated by UHPCP, and the specimens were subsequently exposed to simulated PWR primary water at 360°C where crack growth behavior was monitored in-situ using direct current potential drop.