Fusion hardfacing is a process by which weld materials, with superior properties than the substrate, are applied to the substrate. Often, two layers total 3 - 6 mm (1/4 - 1/2 in) thick are applied to reduce the surface hardness dilution of the relatively low-cost steel substrates in the expansive cobalt-base alloys. Hardfacing processes are very useful for improving wear and corrosion resistance to selected areas of machinery, such as cutting edges of earth-moving machinery. Common hardfacing techniques include arc, torch, and other processes.

Category	Process
Arc welding	Flux core arc welding (FCAW)
	Gas metal arc welding (GMAW)
	Gas tungsten arc welding (GTAW)
	Plasma arc welding (PAW)
	Shielded metal arc welding (SMAW)
	Submerged arc welding (SAW)
Torch welding	Oxy/fuel gas welding (OFW)
Other welding	Electron beam welding (EBW)
	Electroslag welding (ESW)
	Furnace braze (FB)
	Laser beam welding (LBW)

 

Hardfacings are good for substrate materials that are suitable for welding, such as low-carbon steel. The most common hardfacing materials are nickel alloys and iron/chromium alloys used in wear resistance and high stress abrasion. Common materials for hardfacing are listed as follows:

Metal Alloy	Purpose
Cobalt-base alloys	wear and corrosion resistance
Copper-base alloys	rebuilding worn machinery parts
Iron chromium alloys	high stress abrasion
Manganese steel	wear application
Nickel-base alloys	metal-to-metal wear resistance
Tool steel	tooling, wear application
Tungsten carbide	high stress abrasion