Effect of dilution on microstructures of dissimilar weld metals using nickel base alloy filler wire

The effect of dilution on microstructure and toughness of dissimilar weld metal of super-austenitic stainless steel using nickel base alloy filler wire was investigated. As the dilution increased, the kind of inclusion was changed from Nb(C,N) to Laves phase and the amount of Laves phase increased because of higher phase stability at dendrite boundaries by solidification segregation. Consequently, the toughness of dissimilar weld metal was lower than that of deposited metal.