Cracking behavior in a dissimilar weld between high silicon nodular cast iron and ferritic stainless steel

Abstract

In this work, the microstructural evolution and cracking behavior of a dissimilar weld between high silicon nodular cast iron and ferritic stainless steel was investigated. An austenitic filler metal (Y309) was employed to produce the dissimilar weld. Microstructural analysis revealed that cracking formed at the unmixed zone (UMZ) and propagated into the partially melted zone (PMZ) in the bond line between the cast iron and the Y309, with hard layers formed around the bond line. The cracking behavior was strongly related to the difference in the melting points of cast iron and the Y309 filler metal, the local liquation of the laves phase, and the constitutional liquation between the graphite and austenite phases in the PMZ.