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High Phosphorous Electroless Nickel Plating failing in 15W40 motor oil during thermal cycle

Has anyone experienced a high phos electroless nickel plating failing (flaking) in an oil bath of motor oil (Mobil Super Delvac 15W40) during a thermal cycle (-50 °C to 150 °C, 30 min ramp, 90 min dwell for 25 cycles). The base material being plated is a 4140 hardened to Rc of 32-40. To narrow down the possibilities, I conducted additional tests with a cycle 25°C to 150 °C to reduce any thermal stresses and placing two samples in the 15W40 motor oil and an additional two in mineral oil. The results proved that the failure is a function of the additives of the 15W40 since the samples in mineral oil survived.

Laurence Borst
Solenoid Valves - Florham Park, New Jersey
2006

The quickest check would be to have 3 sample parts done by 3 different shops and see if anybody's pass. There is an outside possibility that they might need a quick nickel strike, electrolytic, and then EN. It could be that it is not being adequately cleaned or etched (or over cleaned/etched) prior to plate. That is a wicked test. It could be that the outside is expanding/contracting faster than the core leading to failure. The more part mass, the worse the effect.

James Watts
- Navarre, Florida
2006

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Congratulations!

The well-paid engineers and formulation scientists at the cutting-edge research facility of the world's most profitable company (Exxon Mobil) developed an engine oil meeting the CI-4 requirements of the American Petroleum Institute (API), plus various ASTM and engine manufacturer (Caterpillar, Cummins, Mack, VolvoMack) specifications, and yet you've been able to prove that its additives damage electroless nickel.

To what specification was the electroless nickel plating certified? Also, please peruse letters 20081, 37638 and 40223.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2006