Hard chrome coatings have been established for many years as the most reliable and economic solution for the salvage of worn parts, combining high hardness (65HRc) with low co-efficient of friction and fair resistance to corrosion.
The coating is applied on the surface of new metal objects for protection, as well as of worn ones, after proper mechanical treatment (grinding). Thus, dimensional restoration and extended service life of the workpiece is achieved. The coating can be deposited allover the part’s surface or just on a specific area (e.g. bearing journals). In case of subsequent grinding, a maximum thickness of 0,4mm can be obtained, whereas, without the need for a final grinding, the maximum permissible thickness is approximately 0,04mm.
Application examples of hard chrome coatings are:
Hydraulic cylinders, printing cylinders, piston rods, cylinder jackets, rolls, tubes, valve spindles, rotor shafts, moulds and draw dies, crankshafts, transmission yokes, engraving rollers, shock absorber rods, pins, housings, etc.
A special application is hard chrome plating of marine diesel engine’s (SULZER, MAN B&W, PIELSTICK, MITSUBISHI, etc.), piston crown ring grooves. “METALCHROM” has designed and developed a proprietary system/process of rotational plating of piston crowns that is been granted as a patent (No 1000555/14-2-92, Int. Cl5. C25D 7/04), at the Industrial Property Organization (OBI).