| HAYNES® 242® alloy has excellent
forming and welding characteristics.
It may be hot-worked at
temperatures in the range of
about 1800-2250°F (980-1230°C)
provided the entire piece is
soaked for a time sufficient to
bring it uniformly to temperature.
Initial breakdown is normally
performed at the higher end of
the range, while finishing is
usually done at the lower temperatures
to afford grain refinement.
As a consequence of its good
ductility, 242 alloy is also readily
formed by cold-working. All hot or
cold-worked parts should be annealed at 1900-2050°F (925-1120°C) and cooled by air cool
or faster rate before aging at
1200°F (650°C) in order to develop the best balance of
properties.
The alloy can be welded by a
variety of processes, including
gas tungsten arc, gas metal
arc, and shielded metal arc.
High heat input processes
such as submerged arc and
oxyacetalyne welding are not
recommended.
Welding Procedures
Welding procedures common
to most high-temperature,
nickel-base alloys are recommended.
These include use
of stringer beads and an
interpass temperature less
than 200°F (95°C). Preheat is
not required. Cleanliness is
critical, and careful attention
should be given to the
removal of grease, oil, crayon
marks, shop dirt, etc. prior to
welding. Because of the
alloy's high nickel content,
the weld puddle will be
somewhat "sluggish" relative
to steels. To avoid lack of fusion and incomplete penetration
defects, the root opening
and bevel should be sufficiently
open.
Filler Metals
HAYNES 242 alloy should be
joined using matching filler
metal. If shielded metal arc
welding is used, HASTELLOY® W alloy coated electrodes are suggested.
Post-Weld Heat Treatment
HAYNES 242 alloy is normally used in the fully-aged condition.
However, following
forming and welding, a full
solution anneal is recommended
prior to aging in order
to develop the best joint and
overall mechanical properties. |
