Definition - What does Hardfacing mean?

Hardfacing is a metalworking technique involving the application of a cladding or coating of material designed to resist wear. The welded surface is much more resistant to wear and abrasion. This process improves maintenance costs by providing a longer lifetime for wear parts.

Because hardfacing is a deposition of hard and wear-resistant material on a metal surface by welding, it may be applied to a new part during production to increase its wear resistance, or it may be used to restore a worn-down surface.

Hardfacing is also known as hardsurfacing.

Corrosionpedia explains Hardfacing

Hardfacing is the deposition of thick coatings of hard, wear-resistant materials on a component surface that is subject to wear. The processes generally used to apply the hardfacing layer are:

  • Thermal spraying - Preferred for applications requiring minimal thermal distortion of the component and good process control. Typical hardfacing materials deposited by thermal spraying include cermets. These coatings are applied to a thickness of about 0.3mm.
  • Spray-fuse coatings - Referred to as self-fluxing overlay coatings. The Ni-Cr-B-Si-C alloy system uses a fuse process.
  • Weld hardfacing - Used to deposit very thick (1 to 10mm), dense layers of wear-resistant material with high bond strength.

Commonly applied materials include:

  • Cobalt-based alloys
  • Nickel-based alloys
  • Chromium carbide alloys

Carbon and low-alloy steels with carbon contents of less than 1 percent can be hardfaced. High-carbon alloys may require a special buffer layer. There are several techniques for hardfacing welding:

  • Arc welding of electrodes
  • Filler rod
  • TIG welding
  • Laser welding with powders

After deposition by any of the above welding processes, it is often necessary to finish the component surface.

Hardfacing by arc welding is a surfacing operation to extend the service life of industrial components, pre-emptively on new components, or as part of a maintenance program. Significant savings in machine downtime and production costs has meant that this process has been adopted across many industries such as steel, cement, mining, petrochemical and power.

Share this:

Connect with us