Hydrogen Embrittlement

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tornitore45
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Hydrogen Embrittlement

Post by tornitore45 » Mon Oct 16, 2017 10:58 am

I got a big wrench and a handful of wood brace auger bits I was planning to de-rust electrolytically. Then I read about Hydrogen Embrittlement and paused.
A rusty bit always cuts better than a broken one.

How pronounced would be the phenomenon after an overnight de-rusting bath?
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Russ Hanscom
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Re: Hydrogen Embrittlement

Post by Russ Hanscom » Mon Oct 16, 2017 2:53 pm

Probably not an issue for that period of time. Also depends on the steel, harder ones are more susceptible. A night in a warm oven should help any hydrogen diffuse.

Harold_V
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Re: Hydrogen Embrittlement

Post by Harold_V » Mon Oct 16, 2017 3:32 pm

What Russ said, although I'm not convinced that time is much of a factor. A few hours of hydrogen generation is likely more than enough to create issues. Hardened steel readily absorbs (and retains) hydrogen, which is suspected of interrupting the slip plane of atoms, thus causing breakage. A roast in a relatively warm oven (375° F) for a few hours should disperse the hydrogen, with no ill effect.

H
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tornitore45
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Re: Hydrogen Embrittlement

Post by tornitore45 » Mon Oct 16, 2017 6:17 pm

Thanks. I knew expert answer would come.
Mauro Gaetano
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10 Wheeler Rob
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Re: Hydrogen Embrittlement

Post by 10 Wheeler Rob » Fri Oct 20, 2017 12:08 am

I ran into it with some plated split lock washers that would crack in two when tightening the bolt. Spec said they should be capable of being bent to 90 degrees. The manufacture had not baked them after plating.

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Re: Hydrogen Embrittlement

Post by Harold_V » Fri Oct 20, 2017 3:07 pm

10 Wheeler Rob wrote:I ran into it with some plated split lock washers that would crack in two when tightening the bolt. Spec said they should be capable of being bent to 90 degrees. The manufacture had not baked them after plating.
A good example of how little time it takes for the hydrogen to be absorbed.

H
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Bill Shields
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Re: Hydrogen Embrittlement

Post by Bill Shields » Fri Oct 20, 2017 6:14 pm

Ever hear of Hydroformers in refineries?

find about on Google and be horrified.

When I worked in Saudi in the 1970's we STILL had one running (the last in the world).
Too many things going on to bother listing them.

John Hasler
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Re: Hydrogen Embrittlement

Post by John Hasler » Fri Oct 20, 2017 10:59 pm

What's horrifying about hydroforming (either the metal working process or the petrochemical process)?

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Bill Shields
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Re: Hydrogen Embrittlement

Post by Bill Shields » Sat Oct 21, 2017 6:42 am

in the petroleum industry, hydroforming is a very different concept from using hydraulic pressure to form metal.

In a refinery, HYDROFORMING is (was) a process which while popular in the 1940's has totally disappeared from the business.

Technical description:

"a process for producing high-octane gasoline or aromatic hydrocarbons (as toluene, xylenes) by dehydrogenation and aromatization of petroleum naphthas usually containing a high ratio of naphthenes in a stream of added hydrogen and in the presence of a catalyst at elevated temperature"

Short description:

Basically, you put hydrocarbons inside a PRESSURIZED vessel, ADD HYDROGEN and heat the outside with an open flame.

Hydrogen embrittlement would cause the steel pressure vessel to de-laminate and leak hydrogen / hydrocarbons to the outside (flame) area

The resulting explosions were nothing short of spectacular (if you were several miles away).

Conversion of the process to steam heating was somewhat successful (less efficient) but the embrittlement problem continued (along with the hydrogen leaks).

https://www.youtube.com/watch?v=PEL_TfVSYyQ

IIRC, there were something like 12 of them built. 5 exploded (Whiting was the most in-famous), 7 were shut down for safety reasons once they finally figured out exactly what was causing the failures...
Too many things going on to bother listing them.

John Hasler
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Re: Hydrogen Embrittlement

Post by John Hasler » Sat Oct 21, 2017 5:16 pm

> ...in the petroleum industry, hydroforming is a very different concept from using hydraulic pressure to form metal.

Yes, that's why I mentioned both.

Hot pressurized hydrogen (and often uglier things) is common in chemical industry processes. Ammonia manufacture is the primary example. Hydrogen embrittlement is pretty well understood these days. The hydroforming process seems to still be in widespread use, though it is usually called catalytic reforming.

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Bill Shields
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Re: Hydrogen Embrittlement

Post by Bill Shields » Sat Oct 21, 2017 6:18 pm

I am pretty sure that the use of Hydrogen in the petroleum catalytic process has been discontinued....

as I mentioned, the last refinery where I worked (in the middle east), had the last running hydroformer in existence - and we shut it down while I was there (in the 1980s).

Unless something new has started since then...
Too many things going on to bother listing them.

John Hasler
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Re: Hydrogen Embrittlement

Post by John Hasler » Sat Oct 21, 2017 6:42 pm

Lots of references disagree. Example: http://nptel.ac.in/courses/103107082/mo ... cture6.pdf

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