440C fastening to Aluminum, Induction Hardening 1

[Mandrill22]

I'm making a shaft that looks like a shoulder bolt. It needs to be hard and have a tight tolerance.

I'm planning to induction harden it. It will have an M4 male threaded end, which mates to a female thread on a 6061-T6 aluminum machined part. There will regularly be torsional pressure on the threads.

I'm concerned about corrosion due to unlike metals. Does anyone have any idea how they might react? Would 18-8 do any better? The environment will be indoor and controlled.

 

[EdStainless]

Will they get wet in use, storage, or cleaning? If not then don't worry about corrosion.
I would worry about the stripping of the Al threads and galling.

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P.E. Metallurgy

 

[Mandrill22]

.I would worry about the stripping of the Al threads and galling.

I'm not terribly concerned about stripping, as the components should, theoretically, never need to be taken apart after installation. I'm just worried about the integrity of the aluminum and the possibility of the part slipping out.

 

[TugboatEng]

If there is any concern, silicone greases and thread locking adhesives are both excellent at preventing dissimilar metal corrosion.

Galling can happen during assembly, too.

 

[blacksmith37]

You will want some anti-gall like moly sulfide if you plan to turn the bolt more than once . Corrosion no problem unless you are in seawater or similar environment.