Metal finishing Q&As since 1989

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Electrophoretic paint and hydrogen embrittlement

I have a torsion spring application where cyclic fatigue is critical. The salt spray requirement is 96 hours. Our vendor is recommending a electrophoretic paint finish but I am concerned about hydrogen embrittlement. Hydrogen embrittlement quite often is the cause of spring failure. Is hydrogen embrittlement a concern in electrophoretic painting? And how important is type of cleaning in minimizing the risk of hydrogen embrittlement. What is the typical electrophoretic paint process? Does it include a bake operation at the end?

Thanks,

Tim Zwit
- Spring Lake, Michigan
2003

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2003

Hydrogen embrittlement is not an issue in electrophoretic coating. Two reasons: One you deposit an organic layer therefore hydrogen does not get entrapped in the metallic lattice. Two the coating is cured at 170 °C. The process involves pre treatment to obtain a phosphate coating followed by E-coat and baking.

Hope that helps.

Gurvin Singh
Mohali, Punjab, India