AISI 4340 machining, heat treating and Tungsten Carbide coating Help needed for Process Idea

[ParthZala]

Hello All,

I'm working on a part that will be made out of AISI 4340 and will have tungsten carbide coating as finished surface.

It will be machined, hardened and coated and surface finished to get mirror surface roughness. Can any one suggest which grade should be used for machining? What's the usual hardening process and what dimensional change I should expect? Plus information on Tungsten Carbide coating, like surface preparation, coating thickness, different options and limitations etc. I've no idea on the coating and what effect it will have on the steel during process. Somewhere I saw temperatures are too high in the process.

thank you in advance for any help. I need resources to go through accurate information. The only think I could find was different companies providing coating service but none of them had proper information expect running around and saying they do coating.

Thank you

 

[EdStainless]

How thick does you coating need to be?
How are you applying it? HVOF? Flame spray? Arc spray?
With any coating system you will end up with minor surface imperfections.
Do you have any idea how many and what size can be tolerated?


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P.E. Metallurgy, consulting work welcomed

 

[mfgenggear]

Parthzala

best bet is to draw a preliminary drawing and send it to vendors who do this type of work (very few and expensive). and get their advice.
with more details like a blue print can't give any better advice. heat treating 4340 is very common. depending on the coating final dimensional requirements
it has to be ground with diamond, unless it can be a liberal dimensional tolerance.