Stress corrosion crack initiation in filler metal 82 in oxygenated high-temperature water

The Stress Corrosion Cracking (SCC) initiation in filler metal (FM) 82 was studied in oxygenated (O2) water at 288 degrees C. Post-test microstructural characterization revealed that cracked grain boundaries (GBs) always exhibited a porous oxide incursion. Some intergranular (IG) cracks exhibited an oxide along the crack walls, which appeared to form after the crack advanced. Furthermore, similar porous oxide incursions were observed at the GBs on the non-stressed FM 82 coupon after oxidizing for a similar duration. The formation of oxide incursions is discussed, and the evolution of crack initiation is proposed.