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Advantages/Disadvantages of nickel-CHROME

We have a customer who is inquiring about the advantages and disadvantages of nickel-chrome plating versus nickel plating. I know that most of the advantages of chrome involve better rust protection but I was looking for a list of advantages/disadvantages I could go over with them. Does anyone have any suggestions? We are plating mild steel wire material.

Thanks,

Chris Ballew
- Newport, Tennessee

Ni- Cr will be harder deposit compared to Ni ( 1000 Vickers against about 500 Vickers) The surface finish can be better with Ni- cr The co efficient of friction will be less for Ni- cr.

Payal [last name deleted for privacy by Editor]
- Charlotte, North Carolina

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Chromium deposits will measure 1000 Vickers, but thin deposits of 1-3 millionths of an inch deposits over 0.0001 inch nickel won't materially change the hardness. I imagine the wire will only be receiving a plating of (total) a few tenths of a mil.

For thin deposits, a soft coating will measure harder due to the "anvil effect" of the indentor pushing through the soft layer and bouncing off the harder layer underneath.

Does this wire get an organic coating? Where is the wire used? How thick is this wire, Is it round or square in cross section? Does it get drawn after plating?

  
Tom Pullizzi
Falls Township, Pennsylvania

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Hi Chris:

You already had some opinions about the advantages of chrome added to the nickel but the advantages of eliminating the chrome I think are on your side as the plater, rather than your customer's. Chrome is a lot more toxic and difficult to dispose (I mean the hexa which is the harder and more tarnish resistant one).

Guillermo Marrufo
Monterrey, NL, Mexico

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Nickel will tarnish over time and has a slightly yellow color. Chrome over nickel stops any tarnishing and has a slighly bluish color. As far as actual corrosion goes the chrome is always cracked and therefore corrosion cells are set up which will corrode the nickel, eventually leading to corrosion of the steel underneath

Geoffrey Whitelaw
- Port Melbourne, Australia
 

Geoff, What is Salt Spray Test life for Ni-Cr Vs Ni plating with a plating thickness of 2.5-5.0µ. Can any one answer this for me please. Izhar

Mohammed.Izhar-ul-haq
- Singapore