HVOF – Replacement of hard chrome plating

On May 31, 2013

Hard chrome plating (HCP) has been a trusted industry solution for wear, erosion, corrosion resistance and dimensional reclamation for many years. It can be applied at a reasonable cost per unit of surface area, but has limitations on thickness build-up, part size, and in some instances performance in service

reasonable cost per unit of surface area, but has limitations on thickness build-up, part size, and in some instances performance in service.

Hard chrome plating utilizes chromium in the hexavalent state which is known as Carcinogen (a factor to cause cancer) As a result, the Environmental Protection Agency (EPA) has issued stringent air emission standards for hex-Cr and the Occupational Health and Safety Administration (OSHA) has established permissible exposure limits (PEL) for hex-Cr in the workplace at significantly reduced levels.

As a result, it is estimated that the cost of compliance for hard chrome plating facilities to upgrade their equipment to meet the standards will significantly increase the cost of hard chroming and will result in a number of plating facilities closing down operations.

HVOF (high velocity oxy-fuel) process has proven much superior to HCP for wear & corrosion resistance application as per the conclusion of many researches done in this field. This process uses Oxygen-fuel (LPG/Hydrogen) combustion for melting of material & compressed air for atomisation of that semi molton material. Oversprayed carbide particles can be simply trapped by using spraybooth with dust collector.

Following are the advantages of HVOF :-

Increased wear resistance & service life
Improved corrosion resistance
Higher bond strength
Higher hardness
No physical distortion
Controllable thickness variation
Grinding as post treatment can be done
Environmentally safe process
Can be done in-house as well as on-site.
Less no. of steps included in the process
The most important is variety of available coating materials This means that coating materials can be successfully tailored to specific applications in various operating environments where electrolytic hard chrome would not perform well or in fact, may not be considered at all.

Following are the some of applications where Hvof coating has replaced hard chrome plating :-

Valves – metal to metal ball valves & gate valves
Hydraulic cylinder rods
Landing gear
Paper mill rolls
Mandrels
Pump housing & impellers etc.

MEC (Metallizing Equipment Co. Pvt. Ltd.) offer its model HIPOJET 2700 & XPOJET 5000 for applying hvof coatings. Using its experience & expertise of more than 45 years this company may offer you complete technology transfer for getting HVOF facility in-house at your works.

For more information
Metallizing Equipment Co. Pvt. Ltd.
E-101, M.I.A., Basni II phase, Jodhpur 342005 India, Rajasthan.
Tel : +91-291-2747601/02, Fax : +91-291-2746359
Web: www.mecpl.com

Metallizing Equipment Co. Pvt. Ltd.