Abstract
Crack growth kinetics across weld interface between Alloy 182 and LAS (Low Alloy Steel) and that between Alloy 182 and Metals to simulate weld dilution zone was investigated by CBB (Creviced Bent Beam) test. The main objective of this study is to investigate dynamic influence for a crack initiated in Alloy 182 to propagate into LAS. Specimens were subjected to CBB tests for 2000 h each in simulated BWR water with 8 ppm of dissolved oxygen. Mechanics conditions were described by equivalent stress intensity factor KJ values which are J values from elastoplastic analysis. In small-sized specimens of 2 mm in thickness, cracks which initiated in Alloy 182 propagated into Metal21-4 (20%Ni, 4%Cr), while they did not into Metal21-5 (10%Ni, 2%Cr). In moderate-sized specimens of 10 mm in thickness, cracks did advance into Metals and LAS under KJ values more than 80 MPa･m1/2.
