The weld deposit matches parent alloy
C276 with Ni-15%Cr-16%Mo-4%W-5%Fe. C and
Si are controlled
to minimize carbide
and intermetallic phase precipitates. Cast versions of the
alloy typically have higher carbon and silicon, but
repair welds are usually solution treated for optimum
corrosion resistance.
Alloy C276 has high resistance to corrosion in a wide
range of acids and salts under oxidizing and
reducing conditions. These include hydrochloric and
hydrofluoric acids, hypochlorites, chlorides and wet
chlorine gas, sulphuric, phosphoric and many organic
acids. Exceptional resistance to crevice corrosion
and pitting in seawater and chloride-induced stress corrosion
cracking, superior to alloy 62.
Excellent properties to below -196°C allow its use for
welding 5-9%Ni cryogenic installations.
Applications include **pumps, valves, pipework and
vessels** for use in aggressive environments in
chemical process plants; also in equipment for flue gas
desulphurization and critical equipment in offshore oil
and gas production." Preheat is not required, interpass temperature
should preferably be kept below 100°C and heat
input restricted to 1.5kJ/mm.
Alloy type
Alloy C276 is a Ni-15%Cr-16%Mo-4%W-5%Fe nickel
base alloy.
Microstructure
In the as-welded condition the weld metal consists
of austenite with some carbides.