When Is Hard Chrome The Right Surface Treatment For A Part?
Not every worn or high-abuse part needs the same coating. Use the following list as a pre-specification check list for use of Hard Chrome Plating.
Check the Wear and Load Type
Hard Chrome Plating is typically used to harden components that are subject to sliding abrasion, metal-to-metal contact or continuous reciprocating motion. Hydraulic rod wear, shaft wear and press tool wear are typical applications for Hard Chrome Plating. However, if a part is subject to impact loading rather than sliding wear, then a tougher thermal spray coating would be more suitable.
Check the Base Material
Chrome plates well to steel, cast iron, and most other materials, but is very difficult to bond to aluminium, titanium, and some of the stainless steels. In these cases, the process can be made to work, but great care and much surface preparation is required. Consult with your plater in these cases.
Check the Dimensional Tolerance
Chrome is typically deposited in a controlled thickness from 25 to 500 microns. After plating it can be ground back to a tight tolerance for final dimensions. Allow for the post plate grinding in terms of cost and lead time.
Check the Geometry
Chrome plates better to edges and corners than to recessed areas, such as blind holes, and areas of complex sections such as holes within holes. External cylindrical surfaces are ideally suited for chrome plating, however areas of complex sections are better suited to alternative coatings such as electroless nickel.
Consider the Regulatory Position
As chrome is deposited using hexavalent chromium, it is covered by HSE guidance on hexavalent chromium at work. This must be adhered to by all platers. Some sectors are also looking at alternative coatings to hard chrome under the REACH regulations.
For Hard Chrome Plating, see poeton.co.uk/advanced-treatments/apticote-100-hard-chrome.
If most of the points have been answered positively for your part, chrome will be a good coating. For several points answered negatively, however, there will be a coating much better suited for your part.
