Metal finishing Q&As since 1989

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Supplemental Coating for Ferritic Nitrocarburizing Steel Components?

Hi!

My name is Jillian Nondorf and I am a Materials and Process Engineer with a truck manufacturer.

We have had steel cylinders that are ferritic nitrocarburized, that meet the specification of 0.001" min. compound zone thickness start to red rust after a short period of time. Our current process is Ferritic Nitrocarburizing with a subsequent quench and polishing operation that seals the compound layer with an oxide to provide a level, although typically considered low, of corrosion protection.

Is there a supplemental coating that could be applied to the surface that would provide extended corrosion prevention and control? The compound zone of the nitrided layer could then perform its job as a wear coating and the supplemental coating could provide the brunt of corrosion prevention and control. If no supplemental coating is available are there any other coatings that could be used in place of the ferritic nitrocarburizing?

Thank you.

Jillian Nondorf
Materials and Process Engineer - Oshkosh, WI
2007

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Nitriding rather than carbonitriding may provide the surface hardness you require and good corrosioin resistance too.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2007

Can you explain to me why nitriding would be a better option? Will I still get the wear and corrosion protection?

Jillian Nondorf
- Oshkosh, Wisconsin
2007

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Nitriding will provide a wear and corrosion resistant surface. Will it be good enough for you application? I have no way to know as you've given no information about your requirements.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2007