Hardfacing is a technique of depositing a layer of wear-resistant, corrosion-resistant or high-strength material on a metal surface by welding, thermal spraying or other processes, mainly used to improve the wear resistance, impact resistance and corrosion resistance of equipment and mechanical parts to extend service life.
Methods of hardfacing welding
Welding Overlay
Cladding is the most common hardfacing method, using techniques such as welding rods, arc welding, TIG, MIG or plasma welding to fuse wear-resistant materials to the surface of the base material.
• Commonly used methods
Manual Arc Welding (SMAW): Suitable for small to medium sized repairs, low cost.
Gas Shielded Arc Welding (MIG/MAG/GMAW): suitable for continuous welding, fast welding speed.
Tungsten Argon Arc Welding (TIG/GTAW): suitable for fine workpieces with good control.
Plasma Transfer Arc Welding (PTA): suitable for high hardness materials, high precision welding.
• Applicable materials
Cobalt-based alloys (e.g. Stellite)
Nickel-based alloys (e.g. NiCrMo)
Iron-based alloys (e.g. high chrome cast iron)
Tungsten carbide composites
Thermal Spraying
The use of flame or plasma spraying to melt and spray powders or wires onto the surface of a substrate to form a mechanically bonded wear-resistant layer.
• Types
Flame Spraying
Plasma Spraying (APS)
High Velocity Oxygen Fuel Spraying (HVOF)
• Advantages
Suitable for large area enhancement
Low distortion, suitable for thin-walled workpieces
Laser Cladding
Laser cladding utilizes a high-energy laser beam to melt and deposit an alloy powder onto the surface of a substrate to form a high-performance coating.
• Features
Precise control of dilution rate
Suitable for high-end parts (e.g. molds, turbine blades)
What are the advantages of hardfacing welding?
• Enhanced wear resistance: suitable for high abrasion working conditions, prolonging equipment life.
• Enhance corrosion resistance: suitable for chemical and marine environments, improving corrosion resistance.
• Reduces maintenance costs: reduces the frequency of equipment replacement and improves productivity.
• Suitable for repair and remanufacturing: can be used to repair worn parts, reducing material waste.
Application cases of hardfacing welding
1. Mining Machinery
• Problem: Crusher hammer head, bucket teeth, etc. are subject to long-term wear and short life.
• Solution: Adopt high chromium cast iron or tungsten carbide hardfacing welding to enhance the wear resistance by 2~5 times.
2. Petrochemical
• Problem: Valve sealing surface is affected by corrosion and high temperature.
• Solution: Use cobalt-based alloy (e.g. Stellite 6) overlay welding to improve corrosion resistance.
3. Metallurgical equipment
• Problem: Roll surfaces were worn, affecting product accuracy.
• Solution: Use plasma transfer arc (PTA) welding to improve wear resistance and extend service life.
Hard surface welding is an important process to improve the wear resistance and corrosion resistance of workpiece, which is widely used in the manufacture and repair of high wear equipment. With the development of automation and intelligent welding technology, hardfacing welding will play a more important role in the industrial field, providing a guarantee for the long-life operation of equipment.
Post time: Mar-05-2025