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Corrosion in zn plated steel wire rods

2004

Dear Friends,

Goodmorning/evening to all

We are using a high carbon steel wire rods for specific purposes. To improve a corrosion resistance we have done a zn plating by salt spray method. Eventhough we found that the zn plating is getting rusted interms of days itself. so please someone answer what are all the reasons for getting rusted/corroded. plating must withstand interms years. but what can be done to prevent this ?

Loganathan Palaniyappan
Mirco Lab - Chennai, Tamil Nadu

The length of time that zinc will last in a salt spray test is going to depend on the quality of application, the thickness applied and the chromate conversion coating that the plated part is treated with. Basically, electroplated zinc will last only hours in a salt spray test. Remember that this is an accelerated corrosion test, not a real world test. Zinc is a poor choice for very long term corrosion resistance. Look at electroless nickel for a far superior coating. Obviously, a thick gold coating would be optimum. This begs the quesion, what is the end use and is using stainless, possibly a hardenable high nickel alloy be a better solution to the problem.

James Watts
- Navarre, Florida
2004