Application Methods
Colmonoy and Wallex powders are applied in a wide range of thermal surfacing techniques such as:
Plasma Transferred Arc (PTA) Welding
The plasma transferred arc (PTA) process recommends itself due to its ease of automation and thus a high degree of reproducibility of the welded overlays. In addition, because of the highly concentrated heat source, this process benefits from high powder utilization and can achieve a very low level of iron dilution in the overlay.
Because the hard-facing materials are in powder form, it is possible to produce overlays from many different materials and combinations of materials with a wide range of hardness and other properties. For this reason Wall Colmonoy offers the widest range of hardfacing materials for this process.
Main Benefits:
- Can Be Highly Automated
- High Powder Utilization
- Low Dilution
- Very Wide Range Of Hard facing Materials
HVOF
In the HVOF process, powder is introduced axially into a chamber in which a gas flame is constantly burning under high pressure. The exhaust gas exits through an expansion nozzle which produces a high velocity gas stream. The powder particles are heated in this gas stream and transferred by it with kinetic energy to the surface of the work piece, forming a dense coating with excellent bonding properties.
Due to the moderate transfer of heat to the powder particles and to the work piece, which remains relatively cool, there is little metallurgical change to either the sprayed material or work piece.
Spray & Fuse and Powder Welding
Wall Colmonoy powders are gas atomized powders.Spray-Fuse & Powder Welding are available in standard size ranges.
A specially designed Oxy Acetylene torch is used for powder welding. The work piece is heated with the torch. The powder is introduced into the gas stream from the integral powder hopper and then transferred to the work piece through a flame.
This process is similar to the Oxy Acetylene process with the exception that the hard facing takes place at lower temperatures. This minimizes oxidation and distortion of the work piece and enables easy surfacing of edges.
PTA Surfacing (Plasma Transferred Arc)
This is a surfacing method that reduces wear and corrosion on valve seats and ball valves. It is also used in the chemical industry to increase corrosion resistance and reduce mechanical wear.
Laser cladding
This process is used for renovating critical industrial components such as shafts, bearings and sealing surfaces. Laser cladding creates coatings, while having a minor thermal effect on the base material.
For more information please contact us.
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