High-current and heat-input welding conditions
increase the likelihood of problems such
as sensitization and solidification cracking;
therefore, the heat input should be kept at low to
moderate levels. A maximum heat-input recommendation
would be alloy and service-environment
specific; thus, some engineering judgment
is required. The same concerns that lead to the
requirement of relatively low heat input also
necessitate maintenance of relatively low interpass
temperatures. Maximum interpass temperature
recommendations vary between alloys and
manufacturers, but maximum temperatures are
usually between 90 and 200 °C (195 and 390
°F). The low fluidity of nickel-base filler metals
may require manipulation or slight weaving to
avoid steep toe angles that can lead to lack of
fusion defects. Excessive weaving with a low
travel speed produces high heat input and
should be avoided. The low-carbon, low-silicon
nickel-base alloys generally have good resistance
to solidification cracking. The likelihood
of solidification cracking can be minimized by
favoring a convex weld bead crown and low-tomoderate
current and travel speed