Hot cracking susceptibility of alloy 617 and modified alloy 617 weld metals

two 617-type filler metals with different carbon and Boron contents were used to deposit tiG all-weld metal. longitudinal Varestraint testing was utilized to evaluate and compare their weld metal cracking susceptibility. hardness, tensile, and impact toughness testing were conducted on the all-weld metal samples, and light optical microscopy as well as scanning electron microscopy, equipped with energy dispersive spectroscopy were adopted for the microstructural inspection of the Varestraint tested samples. computational thermodynamics supported in calculating the solidification interval and predicting the phases formed. Results showed that the modified alloy 617 (617mod.) with higher Boron and lower carbon content is the preferred filler metal, because it showed lower hot cracking susceptibility than the regular version of alloy 617. in addition, the impact toughness of the modified alloy 617 was almost three times higher than for alloy 617 but showed lower tensile strength. in terms of microstructure, the modified alloy 617 disclosed less precipitates along the cracks than the regular alloy 617. these observations were supported by computational thermodynamic calculations.