Weldability of Ni-Based Superalloys Waspaloy® and Haynes® 282® - A Study Performed with Varestraint Testing

There is a need for materials with high strength, oxidation
resistance, thermal stability and adequate weldability in order to facilitate
the production of large structural jet engine components. Therefore, the
weldability of Waspaloy® and Haynes® 282® have been evaluated using
the Varestraint weldability test. The experiments reveal that Waspaloy®
has a higher susceptibility to hot cracking compared to Haynes® 282®.
This conclusion is supported by increased total crack length (10 mm or
more) and larger brittle temperature range (approx. 65°C) for Waspaloy®
when compared to Haynes® 282® in Varestraint and Gleeble hot
ductility tests, respectively. The cracking in Haynes® 282® seems to be
connected with a secondary phase which presumably can be associated
with Ti-Mo based MC-type carbide observed in the fusion zone. Also, a
surrounding segregated area is present near this secondary phase as
well as along the grain boundaries. Furthermore, micro-Vickers hardness
results revealed more or less the same weld metal hardness (260-
280 HV) but a difference in the base metal hardness. The weld metal
hardness of Waspaloy® was lower than that of the base metal hardness,
while Haynes® 282® had a higher hardness in comparison.