Weld Repairs of Mar-M247 and Alloy 713C

Precipitation strengthened nickel alloys, such as Mar-M247 and Alloy 713C are severely prone to various types of cracking, which makes weld repair of these alloys difficult. If the aluminium and titanium content of these alloys is above 6%, they are generally considered unweldable. This study investigates the effect of multiple variables within the manual tungsten inert gas (TIG) process on the crack susceptibility of weld repairs of these alloys.

An acceptance criteria is defined and the effect of welding current, heat input, filler material composition (matching and dissimilar), parent material heat treatment and preheat are examined to determine a process window which generates acceptable weldments with a range of geometries, including simple bead-on-plate build-ups, varied groove angles and edge repair of example components.