Spray coating component repair

Thermal spraying is not only a "magic tool" for repairing worn bearing positions. With advantages such as wear resistance, corrosion resistance, high-temperature resistance, and precise repair, it has become a core technology for extending the lifespan and reducing costs of industrial equipment, and its applications cover multiple key fields:

1. Repair of shaft parts

Apart from bearing positions, thermal spraying can also quickly repair worn, scratched, or oversized transmission shafts, crankshafts, camshafts, rolls, agitator shafts, etc., restoring their precision and strength.

2. Repair of molds and tools

Injection molds, stamping dies, and die-casting molds are prone to wear, erosion, and cracking. Thermal spraying can enhance surface hardness and wear resistance, extend mold life, and reduce replacement costs.

3. Valves and pump components

Valve sealing surfaces, pump shafts, impellers, cylinder liners, etc., which are subject to long-term erosion, corrosion, and cavitation, can significantly improve their corrosion and wear resistance by spraying alloy and ceramic coatings.

4. Power and energy equipment

Steam turbine blades, boiler pipes, fan impellers, etc., which are prone to wear in high-temperature and dusty environments, can be protected against high temperatures, wear, and corrosion through thermal spraying.

5. Mining and construction machinery

Hammer heads, liners, bucket teeth, conveyor rollers, etc., in crushers and excavators wear out extremely fast. After thermal spraying reinforcement, their service life can be doubled.

6. Petrochemical equipment

Pipes, flanges, sucker rods, reactors, etc., which are exposed to acid and alkali corrosion and medium erosion, can effectively delay aging and reduce leakage risks by spraying anti-corrosion coatings.

7. Ships and marine engineering

Propellers, shaft systems, seawater pumps, steel structures, etc., which are prone to corrosion by seawater, can be protected with long-lasting anti-corrosion effects by spraying aluminum-zinc alloy coatings.

The coating thickness in thermal spraying is not a fixed value. It is determined based on the wear amount, workpiece accuracy, and force conditions. Here are the most commonly used and practical thickness ranges for you:

I. Conventional repair and wear-resistant coating thickness

Minimum commonly used thickness: 0.1 mm

Used for minor scratches, small dimensional deviations, and only for wear resistance and corrosion protection.

Most commonly used thickness: 0.3 - 1.0 mm

This range is typically used for bearing seat wear, journal repair, bushings, and roller surfaces.

Maximum commonly used thickness: 1.0 - 3.0 mm

For deep wear and when more dimensional recovery is needed, it generally does not exceed 3 mm.

II. Why are thicker coatings rarely used?

The thicker the coating, the greater the internal stress, making it more prone to cracking and peeling.

The greater the thickness, the larger the subsequent grinding allowance, resulting in higher costs.

If the thickness exceeds 3 mm, it is generally recommended to first perform a base weld and then apply the coating for fine finishing.

III. Typical thickness for bearing seat repair

Minor wear: 0.2 - 0.5 mm

Moderate wear: 0.5 - 1.2 mm

Leave a grinding allowance of 0.1 - 0.3 mm after spraying to achieve the standard size.

A simple rule of thumb:

0.3 - 1.0 mm is the most stable for daily repairs. Be cautious if it exceeds 2 mm.