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Striations on a Substrate that was Electroless Nickel Plated

We have a landing gear cylinder with striations on the surface. These striations are only found in the area where the part was electroless nickel plated. The striations almost look corrosion related. These striations are in parallel in nature and seems to be oriented in every direction, and some times follow a swirl like appearance. In some instances you can see the striations under the electroless nickel plating. However, the part we have has been stripped of the nickel plating. Question: Has anyone out there seen or experienced such a phenomena. The substrate is 300M steel.

Thomas P [surname deleted for privacy by Editor]
aircraft industry - Long Beach, California, USA
2003

A wild guess. Honing scratches that were slightly opened up by the etch process in plating. 300M is no fun to plate, so are you sure that it was not stripped and replated one or more times?

James Watts
- Navarre, Florida
2003

I have seen this condition on EN plated parts.I think it is something that occurs from stress in the deposit.It has been primarily witnessed on thicker deposits(+.003" thick) that have been plated in a older solution.(greater than 5 MTO) I think the corrosion occurs after the fact because the cracks (striations) go down to the substrate allowing corrosion to occur.I too have seen the mirror image of the striations on the substrate after stripping. Suggest replating parts in a compressively stressed solution,at a slower plating rate (.0004" /hour,less than 4 MTO) and post plating heat treat according to metallurgy of substrate.

Tom Newberry
- Georgetown,Ontario
2003