Statistical analysis of pulsed laser beam welding repair strategies of nickel-base superalloys

摘要

Pulse shaping is a suitable option to adapt energy input and temperature gradients in the base material during filler wire assisted laser beam welding, although the influence on the temperature-depended microstructure and γ'-precipitation strengthening of Nickel-base superalloys as well as the process windows are not sufficiently understood so far. Therefore, the influence of pulse parameters, preheating temperature, hot-wire heating power and wire feeding rate on the deposition process and the resulting macro- and microstructure of similar Nickel-base superalloy joints of Inconel 738 low carbon (IN 738 LC) with Haynes (HS 282) filler are investigated. The statistical analysis of the multidimensional parameter space with respect to the geometric properties of the weld seams (dilution, aspect ratio and wetting angle) and hot-crack formation revealed high reliability and predictability concerning individual choice of suitable parameters in field repair application.