A novel weld transition joint by friction surfacing

A novel weld transition joint by solid state friction surfacing method is developed. Weld transition joint between Cr-Mo steel and austenitic stainless steel was developed by depositing series of Ni-alloy coatings between them. These multi-layered coatings with gradual rather than abrupt change in coefficient of thermal expansion between Cr-Mo and austenitic stainless steels are expected to improve the service life of dissimilar metal welds used in thermal and nuclear industries. Metallurgically bonded coatings with minimal dilution were achieved. Grain refinement and increase in hardness were observed in all the coatings due to the dynamic recrystallization.