Things to Know when Welding with Nickel Alloys

If you are welding with nickel alloys, the goal is to resist some type of corrosion such as pitting, crevice, and/or stress-corrosion cracking. No post-weld treatment is needed to maintain corrosion resistance when using nickel-based alloys.

Nickel alloys have a low thermal conductivity, resist scaling and oxidation at elevated temperatures, and do not harden without special effort and technique. They can even withstand multiple heating and cooling intervals without compromising the structure or chemical properties of the metal.

Things to be aware of when welding with nickel and nickel alloys:

• Welding nickel is highly susceptible to embrittlement when it comes into contact with sulfur, phosphorus, and lead at elevated temperatures. These contaminants can exist in grease, oil, paint, marking crayons or inks, forming lubricants, cutting fluids, shop dirt, and processing chemicals. So ensure your workstation, the welding wire, and the joint to weld are well-cleaned before work begins. Doing this will also help to prevent porosity and uneven penetration.
• During welding, nickel forms a tenacious viscous oxide, restricting the wettability and flow of the weld metal. Adding helium (25% to 50%) to the shielding gas can help wet the puddle.
• When using nickel-based consumables, open the weld joint wider to allow the molten metal to flow because these alloys retain heat for long periods of time, but be careful not to open it too wide as this can cause solidification or hot cracking.

High-nickel-based alloys are manufactured to withstand very corrosive environments most generally associated with high-pressure environments, and elevated temperatures. You’ll frequently find them used in oil and gas, aerospace, and power-generating industries for joining and cladding. Nickel alloys with higher percentages of copper (CuNi-Gen 413 or NiCu-Gen 418, for instance) are often used to fabricate hardware in marine, chemical, and desalination construction.

Nickle-based alloys can be used with most welding processes, and CWI (Central Wire Industries) Welding Generation 4 manufactures an assortment of nickel-based and high-nickel welding consumables for TIG, MIG and SAW processes. To learn all about our Gen4 welding consumables, visit our website at www.centralwire.com or contact our sales team directly at sales@centralwire.com. Our metallurgical experts are ready to answer your questions!