Surfacing of Materials
Surfacing is the process of depositing filler metal on the surface of a workpiece to obtain desired properties or dimensions.
In this method, the deposited filler metal forms an integral layer with the base metal.
Metals involve in Surfacing
There are many metals that can be surfaced, such as
- Low alloy medium carbon steels
- High carbon steels
- High-speed steels
- Nickel alloys
- Grey and alloy cast iron
- Malleable iron
- Brass and bronze
- Low alloy steels
- Stainless steel
- Whit cast iron
Classification of Surfacing
surfacing processes can be classified as follows:
1-Hardfacing or hard surfacing
Hardfacing is also called hard surfacing. Hardfacing is the process of depositing filler metal on a metal surface to achieve various purposes, such as providing resistance to wear or abrasion, impact, corrosion, galling, heat, corrosion, and cavitation, etc.
Purpose of Hardfacing
The main purpose of hard facing is to achieve desired resistance by depositing metal/alloy on machines and mechanisms to extend the service life of critical (new) parts and assemblies.
In addition, the purpose of hard facing is to rebuild a worn or incorrectly cast/forged part and to repair a component.
Since the metal deposited in this process is usually harder than the base metal, it is called hard facing, but sometimes soft metal is also applied on the base metal, such as bronze layer is also applied on the hard-base metal.
Under the hard-facing process, often Used with alloys containing various percentages of cobalt, chromium, tungsten carbide, chromium-manganese iron, and iron-based alloys such as cobalt, chromium, vanadium, and molybdenum.
These alloys are excellent for extreme abrasion, severe impact, and high-temperature applications.
Classification of Alloys Used in Hard Facing
Hard facing alloys can be classified as follows:
- Copper-based alloys
- Cobalt-based alloys
- Nickel-based alloys
- Low alloys ferrous materials
- High alloy ferrous materials
- Stainless steels
Method of Hardfacing
Following welding process can be used for Hardfacing