300M machining environment

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Does anyone have a TO for the machining environment of 300M or 4340? I am looking for specifics in temperature and humidity for optimum machining tolerances, as well as corrosion prevention from machining through assembly.

 

[NickE]

(I dont know what a TO is but heres some general things I know about corrosion prone steels and how to prevent pitting/surface rust.)

The steel will corrode most easily when hardened and on freshly ground surfaces. VCI Paper will be very beneficial for storage, you can also oil/grease/etc.. if necessary.

We pack parts of 1095 (HRc 54) in a rust preventative called "Drytouch" (or maybe Tectel 900, I'm not sure). "Drytouch" will dry on the surface over time and is very thin, and doesnt attract dirt.

We also use a water based corrosion preventative called MACCO. You rinse clean steel parts in it at the right concentration and then dry it on the surface. This works good for light handling w/ gloves and decent environments. (60-80F, <50%RH, Non-condensing if temp drops) It will not protect you if RH goes up or water condenses on your parts. Nor will it protect from fingerprints.

Your coolants for machining should have corrosion preventative in them.

You can also clean them with something like simple green, be careful dont let it dry on the surface, rinse well with water, then pack in Nitrogen. (Only do this if you cant use any type of coating.)

As far as glove go you must wear barrier gloves, that means vinyl or latex. Its easier and safer to wear a cloth glove over the barrier glove. (This might seem extreme, but you have to do it right)

For corrosion prevention:

1: keep it clean.
2: wear gloves when handling
3: Warm, Dry. (70F, 15%RH)


Nick
I love materials science!

 

[swall]

As MickE mentioned, many of the coolants for machining have rust preventitives in them. I know from experience that some of the synthetics will provide ample rust protection for indoor storage when left on the part and not removed until final assembly.