Review on hardfacing as method of improving the service life of critical components subjected to wear in service
A review on hardfacing is presented. Hardfacing involves applying a consumable with desired wear properties over a soft base metal surface to enhance resistance to different wear mechanisms. Substrate materials used for hardfacing are mainly steel, while the alloys of carbide forming elements dominate the surfacing consumables. Powder metallurgy, atomisation and granulation are methods of producing hardfacing alloy powder. Most welding methods were identified to be successfully used in applying consumable on substrate surfaces. Dilution decreases with increase in the number of hardfacing layers. Buffers, butters and build-up metals are used to compensate for composition differences to prevent spalling, overcome welding difficulties and make up for badly worn surfaces, respectively. Waffle, stringer and dot patterns are the existing hardfacing deposit patterns. Benefits of hardfacing include: reduced downtime, inventory and maintenance cost, increased plant availability and productivity, and a good number of service life extensions through timely reparation.
Keywords: Hardfacing, wear, substrate, consumable, service life extension, composition compensation