Interfacial microstructure and properties of dissimilar steels joined by high energy beam melting processes

Junctions between austenitic and ferritic steels were produced using two different processes involving melting at the contact surfaces: electron beam cladding designed to improve the corrosion resistance of the joined component, and laser beam welding carried out to obtain mechanically resistant joints. Different processing conditions were adopted in order to determine the beam irradiation parameters, such as incident power density and beam translation speed, suitable for any specific application. Solidified and thermally altered zones were investigated by means of different and complementary techniques: X-ray diffraction, Moessbauer spectroscopy, electron probe microanalysis, metallography and microhardness measurements. The effects of the rapid solidification processes on phase composition, microstructure and properties of clads and welds, are presented and discussed.