抄録
Fracture toughness and fatigue crack growth rate behavior were investigated using six materiels with different toughness which were taken out of a tubular type reactor and heat treated at different tempering temperatures. Repeated internal pressure tests were conducted using actual size cylinders where the fracture toughness of materials ranged from 67 to 144 MPa √(m). Test results suggest that actual reactors satisfy the leak before break (LBB) condition because of their higher fracture toughness.
