Checking the Pulse of Welding Inconel

Whether TIG welding in the aerospace industry or MIG welding overlay in a plant environment, successfully welding Inconel can depend on your pulsing capabilities and other new features made possible with modern equipment.

Inconel is a lightweight nickel- and chromium-based alloy used in a number of critical applications for its resistance to corrosion, as well as its ability to maintain its strength even when subjected to high temperatures.

These characteristics make it popular in the aerospace industry for use in engine components and ductwork, certain high-performance automotive components, and as an overlay in chemical plants and other high temperature/corrosive processing environments.

There are two primary welding methods for welding Inconel: Gas Tungsten Arc Welding (GTAW, or TIG) of structural Inconel components, and Inconel cladding as made possible by the Gas Metal Arc Welding (GMAW, or MIG) process.

Both of these are such highly specialized fields that it is difficult to communicate in an article comprehensive best practices or instructions.

One common theme ties both practices together, however, and has benefited from recent technology advances: pulsed welding. In addition to the evolution of pulsing technologies, new features and capabilities of welding equipment have helped improve the processes and given operators more flexibility in dialing in the arc to work for them.

(Note: This discussion is meant to be educational regarding welding technologies and processes and does not supersede established welding procedures. Always work within your welding procedure specification (WPS) or code qualifications.)

MODERN TIG INVERTERS AND HIGH-SPEED PULSED DC TIG WELDING
Inconel, like many nickel-based alloys, is highly susceptible to cracking and warping – especially thin structures. As such, controlling heat input to the part is important, as well as controlling arc starts, providing proper shielding gas protection and averting crater formation at the end of the weld.