Diffusion welding parameters and mechanical properties of martensitic chromium steels

To develop and qualify diffusion welding for fabrication of precise high stressed components of fusion reactors, a comprehensive test program was carried out using the martensitic chromium steels OPTIFER-IV and MANET-II. Metallographical and mechanical examinations served to determine the welding quality. The main result is that with a welding pressure of about 50 MPa and a surface roughness of few microns, welding could be produced with a strength and ductility in the range of the base material. Besides, sufficient fracture toughness was achieved when surface machining by wet grinding was replaced by dry milling.