Weld Creations provides Hastelloy welding and fabrication for manufacturers in Los Angeles and Southern California. We TIG weld Hastelloy C-276, C-22 and X using matched nickel-alloy filler metal, a full argon back purge, and the low heat input these alloys demand. It’s the work most general fab shops turn down. Here’s how it’s done right.
What Hastelloy is, and why it’s hard to weld
Hastelloy® alloys are nickel-chromium-molybdenum alloys built for environments that destroy stainless steel. They’re used for hot acids, chlorides, oxidizing and reducing chemicals, and high-temperature service. You’ll find them in chemical processing equipment, pharmaceutical reactors, scrubbers, heat exchangers and pollution-control systems.
The same chemistry that makes them corrosion resistant makes them demanding to weld:
- A sluggish weld pool. Nickel alloys don’t flow and wet out like stainless steel. The welder has to place the filler deliberately, and joint designs typically use wider bevel angles to allow access and fusion.
- Sensitivity to heat input. Excess heat and slow cooling promote unwanted phases in the weld and heat-affected zone, reducing corrosion resistance. That’s exactly the property you bought the alloy for.
- Sensitivity to contamination. Sulfur, lead, phosphorus and other low-melting contaminants from oils, marking crayons, cutting fluids and shop dirt can cause cracking.
- Oxides that don’t self-clean. Root oxidation stays in the joint unless it’s prevented with shielding.
How we weld Hastelloy
1. Confirm the grade and filler. Each grade has a matching filler (AWS A5.14):
| Alloy | UNS | Typical filler (GTAW) | Common service |
|---|---|---|---|
| Hastelloy C-276 | N10276 | ERNiCrMo-4 | Wide range of corrosive chemicals, chlorides |
| Hastelloy C-22 | N06022 | ERNiCrMo-10 | Oxidizing and mixed acids, pitting resistance |
| Hastelloy X | N06002 | ERNiCrMo-2 | High-temperature strength and oxidation resistance |
2. Clean everything. We degrease joints and remove markings, and we use stainless-only brushes and grinding media so no carbon steel particles or shop contamination end up in the weld.
3. Back purge with argon. The root side of the joint is purged before and during welding, so the inside of the weld comes out bright instead of oxidized.
4. Keep the heat low. We use stringer beads with minimal weave, and a controlled interpass temperature, typically held below about 200°F (93°C). Preheat isn’t required, and post-weld heat treatment is not normally needed for the C-series alloys.
5. Inspect. Visual inspection of the face and root, plus any additional inspection your specification calls for, arranged through our partner network.
Welding Hastelloy to stainless and carbon steel
Dissimilar joints are common: a Hastelloy liner in a 316L vessel, C-276 wetted parts on a stainless frame, a nickel-alloy nozzle on carbon steel. These joints are usually made with a nickel-alloy filler such as ERNiCrMo-4 or ERNiCrMo-3, chosen for the service environment rather than simply matching one side. The same rules apply: clean joints, back purge, low heat input and careful dilution control.
If you’re specifying a dissimilar joint and aren’t sure of the filler, send us the service conditions and we’ll recommend options for your engineer to approve.
When Hastelloy is worth it over stainless
Hastelloy costs many times more than 316L, so it earns its place only where stainless will fail. Typical signs are pitting and crevice corrosion from chlorides, attack from hot or mixed acids, stress corrosion cracking, or strength loss at high temperature. A common, cost-effective approach is to use Hastelloy only for the wetted or hot components and 316L or carbon steel for everything else. That makes dissimilar welding and clean material separation in the shop essential.
Where we see Hastelloy
- Pharmaceutical and chemical processing. Reactor and vessel components, wetted parts and process-line components. See pharmaceutical equipment fabrication.
- Scrubbers and pollution control. Components exposed to acid condensates.
- Heat exchangers and high-temperature parts. Hastelloy X, for its strength and oxidation resistance at temperature.
- Repair and modification. Adding nozzles, brackets or replacement sections to existing Hastelloy equipment.
Why Weld Creations
Like Inconel, Hastelloy rewards precise heat control, which is why TIG welding is our core process. We’re AWS D17.1 certified to the aerospace fusion welding standard, which covers nickel-based alloys among others, and we bring that discipline to every exotic-alloy job. We also do sanitary welding in 316L, so mixed-material equipment can be built under one roof. See our capabilities for the full picture.
Request a Hastelloy welding quote
Send the drawing, grade, thickness, quantity and service environment, and tell us whether you’re supplying the material. We’ll confirm the filler and approach and reply within one business day.
HASTELLOY® is a registered trademark of Haynes International, Inc. Weld Creations is not affiliated with Haynes International.