Microstructure and Micro-Hardness of Dissimilar Metal Cladding from a Pipe–Nozzle Mockup for PWR

In this study, the dissimilar metal cladding from a pressure vessel pipe–nozzle mockup for PWR was studied using an optical microscope, scanning electron microscopy, energy-dispersive X-ray spectrometry, back-scattering diffraction, and micro-hardness measurement. The microstructure of SA508 side is non-uniform along fusion boundary, especially at concave convex areas. Martensitic layer (type I type II) boundaries are found boundary area. chemical composition, residual strain, across SA508–309L very complex hence result in complicated distribution.