Working with Hastelloy® C-22®

Hastelloy® C-22® can be fabricated into a wide variety of process equipment, due to its ductility.

Welding Hastelloy® C-22® is similar to austenitic stainless steels in many ways. It can be readily welded in the shop or field using gas tungsten arc (GTAW), gas metal arc (GMAW), or shielded metal arc (SMAW) welding techniques.

Welding Hastelloy C-22

Although the welding techniques and equipment of 316L and Hastelloy C-22 for orbital welds are similar, there is a difference in the appearance of the welds because of the high nickel in C-22. The weld is still good; this is just a characteristic of the alloy. It resists the formation of any grain boundary precipitates in the weld’s heat affected zone. Nickel-based alloys generally exhibit sluggish welding and shallow penetration characteristics, so the possibility of incomplete fusion increases. Care must be used to ensure that sound welds are achieved. Nickel-based alloys have a tendency to crater crack, so grinding in starts and stops is recommended. Prior to any welding, all foreign matter (grease, cutting fluids, crayon markings, scale) should be removed.

Weld Appearance

Weld appearance can be somewhat misleading when visually compared with any hygienic welds made in 316L stainless steel.