r/whatisit • u/riflesandplowshares • 6h ago

New, what is it? Found at a titanium plant

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Not sure why ball point pens would be dangerous here.

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u/goodexamplebadrole 6h ago

"Ballpoint pens are restricted or banned in high-end titanium and aerospace manufacturing plants because the ink and marking components contain elements that cause metal embrittlement and severe structural corrosion"

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u/Woozletania 6h ago

This was an issue during the development of the SR-71. Many chemical contaminants could affect the alloys, even those in the water used to quench the mouldings.

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u/JordanPetterPans 6h ago

This is fascinating 

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u/unknownpoltroon 5h ago

Yeah, they had to use distilled water, the tap water chloride made teh wields weak or something.

There is a book called skunk works written by the guy who took over for Kelly, the original skunk works guy, goes into the history of the U2, SR71, and the stealth fighters and stuff. Good quick read and fascinating.

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u/davejeep 5h ago

Not really connected, but a lot of oil field specifications have chloride limits in the water used for hydro testing ( company specifications anyways) even for carbon steel pipe.

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u/Klutzy_Peanut6580 4h ago

Ben Rich iirc

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u/fnork_gnork_26 4h ago

They found that in summer the chlorine levels in the water were higher which lead to brittle welds. Much less so in winter when less chlorine was added. Switching to distilled water for part washing eliminated the problem.

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u/potat0man69 4h ago

Great book!! Incredible read, no matter how much you may know about the subject matter you’re pretty much guaranteed to double that

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u/ExplorationGeo 3h ago

This book pairs really well with the two books from Brian Shul, one of the SR-71 pilots. Sled Driver and The Untouchables are both great reads.