TempTabs in Vacuum Furnace

[Tchuang]

Hello,

At work we have this vacuum furnace and I used Orton Temptabs to map the temperature uniformity in the furnace. I am pretty sure they made my parts oxidize and turn blue. Does anyone have insight as to why this would be happening or have any resources that I should check out. The Temptabs are supposed to be pretreated so that binders will not burn off in the oven but something is still causing oxidation. Thank you so much for your time.

Sincerely,
Troy

 

[IRstuff]

Seems like you could trivially test your theory by running parts without the Temptabs and see directly.

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[Tchuang]

I have and they were not oxidized or blue. Do you have any idea why this would be the case? Thanks for your reply!

 

[IRstuff]

What material are your parts? Have you had the coloration tested? Color is usually indicative of an oxide.

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[MintJulep]

Outgassing.

 

[EdStainless]

The temptabs are meant to survey a furnace, not to run as monitors.
I would expect them to outgas, and leaving discoloration would be the result.
Just because the tabs function in vacuum doesn't mean that they should be run in vac with parts.

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P.E. Metallurgy, Plymouth Tube

 

[Tchuang]

My parts are stainless steel 316, inconel, and yellow zirconia. Do you guys have any idea what exactly in the temptab would be outgassing? Thank you all for your time.

 

[metengr]

Why not ask the manufacturer of TempTabs?

 

[EdStainless]

Or heat some and measure the gasses coming off using a MS or RGA.

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P.E. Metallurgy, Plymouth Tube

 

[Tchuang]

Cool thanks I have emailed the manufacturer. What is a MS? RGA is a residual gas analyzer? Thank you all for your insight and time. I truly appreciate it.

 

[EdStainless]

RGA, residual gas analyzer which is a limited range mass spectrometer (MS).
When I was running vac fce we would take new material (product or fixtures) and bake them in a small vac oven and use our RGA to see what was out gassing.

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P.E. Metallurgy, Plymouth Tube

 

[Tchuang]

Cool, thank you so much edstainless, metengr, and IRstuff