Liquation cracking in fiber laser welded joints of inconel 617

Abstract

Liquation cracking in the fiber laser welding Inconel 617 joint under different heat input and preheating conditions was systemically investigated. Liquation cracking is prevalent in the necking region of the welded fusion zone. The liquation of the grain boundaries (GBs) is mainly caused by the constitutional liquation of M23(C,B)6 carbides. The continuous (Cr, Mo)-rich phase is re-solidified due to the continuous liquid film along GBs during the solidification. The continuous (Cr, Mo)-rich phase decreases as the heat input and preheating temperature increases. The presence of the GB resolidified phase around liquation cracking is one of the features in the formation of liquation cracking. As well as, liquation cracking in heat affected zone (HAZ) would also decrease with increasing heat input and preheating temperature in the fiber laser welding of Inconel 617.