Welding Resurfacing
Welding is a technique for applying layers of resistant materials to metal parts to improve their resistance to wear, corrosion, and other forms of degradation. This method extends the service life of industrial components by strengthening their surfaces exposed to harsh conditions.
Welding Processes:
1. Torch-Rod Welding:
Description: This method involves heating the surface of the part with a torch flame and depositing a filler metal in the form of a rod. Deposit thicknesses typically range from 1.5 to 3 mm. This technique is particularly suitable for demanding environments or high-temperature applications, as it minimizes dilution of the stellite with the base metal, ensuring a high-quality coating layer.
2. Sprayfuse Powder Coating:
Description: This process involves spraying molten metal powders onto the surface of the part, forming a coating with a thickness between 0.6 and 0.8 mm. The powders are melted and sprayed onto the target surface, creating a uniform, adherent coating. This method is effective in improving the wear and corrosion resistance of treated parts.
Benefits
Benefits of Welded Overlays:
– Improved Friction: The applied coatings reduce the coefficient of friction, which reduces wear and extends the life of moving parts.
– Anti-Corrosion Properties: The overlay layers provide effective protection against corrosion, even in harsh environments.
– High Temperature Resistance: Some overlay processes allow parts to withstand high temperatures without significant degradation.
– Mechanical Strengthening: The coatings increase the mechanical strength of the parts, making them better able to withstand high loads and stresses.
– Adaptability: The coatings can be applied to various part geometries, including hard-to-reach areas, ensuring uniform protection.
Features
Very good resistance to metallic abrasion and corrosion up to 800°C.
Good resistance to thermal and mechanical shock.
Good polishing and machinability.
Very good weldability, good slag detachment, and a regular bead.
Typical application
– Oil and Gas Industry: Components such as piston rods, liners, valve seats, and check valves are coated to improve their performance and durability.
– Mechanical Industry: Parts such as bearings, bushings, and pump shafts are hardfaced to resist wear and corrosion.
– Food Industry: Equipment such as metering pumps and sealing jaws are protected against wear and contamination.
– Textile Industry: Components such as transfer rollers and glue rollers are coated to improve their performance and lifespan.
The choice of hardfacing process depends on various factors, including part geometry, operating conditions, and required coating properties. Selecting the most appropriate method for each specific application is essential to ensure optimal performance and effective protection against wear and corrosion.