Hydrogen Embrittlement & Plating
#2703812
10/04/19 01:11 PM
10/04/19 01:11 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
OP
If you can't dazzle em with diamonds..
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OP
If you can't dazzle em with diamonds..
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So I suspect i learned something yesterday. Fabricated/tig welded a pair of CM suspension arms. Had them post weld heat treated and shot peened. I like powder coating, bit felt a yellow zinc plating prior to powder coating might be the best long term solution, no pun intended. However solution plating in the harder materials has the potential downside of hydrogen embrittlement. The solution then is a prompt after plating 375F 4 hr minimum bake cycle to drive out the trapped hydrogen. One issue in my design, there was lapped gusset reifnorcement that could not by design be welded closed. I was certain it was going to trap liquid , whatever small amount.. My thinking was, with the added bake cycle, no liquid could survive, and it would not be an issue. I was wrong. What I found out was, the bake cycle is not at the end, but more mid process, as later solution immersions trap later solutions, unbeknownst to me. So I mocked up the part, fitted it, put it on the shelf, for a month and two days ago inspected it and found leakage corrosion around the lapped metals, and then called the plater. and was told about the real sequence of the bake cycle. Baking after final plating would "blow off" the plating. Who knew?
Last edited by jcc; 10/04/19 01:12 PM.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Hydrogen Embrittlement & Plating
[Re: Stanton]
#2704057
10/05/19 10:23 AM
10/05/19 10:23 AM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
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If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
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Is my process overkill, yes, is the part a non redundant potentially catastrophic suspension part of the chassis, yes, and to think I resisted additional cyro treatment because I thought that would be a bit much. Maybe I was exaggerating a bake cycle "blowing off" a plating. Maybe a better description would be the final finish would lose luster and the plater doesn't want to hear complaints about finish color/sheen. Yes the part expectedly trapped one or part of all the solutions after the baking process, leading to the corrosion noticed after time. And yes, I am certain I am not 100% knowledgeable on this process, and why I am here. Now that I think about it, not sure the 375F? is critical, as maybe a bake cycle at say 250F but for a much longer time might achieve the same beneficial results with no degrading of the final plating. But because of cost/time, the plater may elect for the higher temps to get product out the door. I don't know. On the chrome plating, I was also under impression another chrome plate downside was, it had the potential to also "cover" initially developing fatigue cracks.
Last edited by jcc; 10/05/19 10:31 AM.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Hydrogen Embrittlement & Plating
[Re: jcc]
#2704146
10/05/19 05:43 PM
10/05/19 05:43 PM
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Joined: Oct 2005
Posts: 8,870 Ontario, Canada
Stanton
Don't question me!
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Don't question me!
Joined: Oct 2005
Posts: 8,870
Ontario, Canada
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Is it possible to drill a drain hole for the solution that was being trapped?
It was once explained to me that chrome moly can be a problem to put any kind of coating on other than oil simply because the "moly" is actually a lubricant that can't be completely removed. One of the reasons I think most high end race cars these days are left bare metal. If you do see a painted cage, its probably made from mild steel. I'd say build your CM parts then wipe 'em down with WD40 and forget the "pretty".
Last edited by Stanton; 10/05/19 05:50 PM.
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Re: Hydrogen Embrittlement & Plating
[Re: jcc]
#2704147
10/05/19 05:57 PM
10/05/19 05:57 PM
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Joined: Jan 2011
Posts: 4,785 Utah and Alaska
astjp2
master
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master
Joined: Jan 2011
Posts: 4,785
Utah and Alaska
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375 will not affect the plating. I build airplane parts and its not an issue to bake.
1941 Taylorcraft 1968 Charger 1994 Wrangler 1998 Wrangler 2008 Kia Rio 2017 Jetta
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Re: Hydrogen Embrittlement & Plating
[Re: Stanton]
#2704155
10/05/19 07:35 PM
10/05/19 07:35 PM
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Joined: Dec 2005
Posts: 11,551 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,551
Fulton County, PA
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Actually on Funny Cars and Dragsters, it's for weight and for ease of inspection for cracks and repair. Pro Stock and most everyone else are painted or powder. I prefer paint for ease of fixing and/or adding stuff (welding) and then fixing the finish. Plus guys are still concerned with appearances.
NHRA hasn't allowed plating (chrome) on cage components for years. Paint and powder only.
If the results don't match the theory, change the theory.
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Re: Hydrogen Embrittlement & Plating
[Re: CMcAllister]
#2704207
10/06/19 12:38 AM
10/06/19 12:38 AM
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Joined: Jan 2003
Posts: 3,504 DFW
mr_340
master
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master
Joined: Jan 2003
Posts: 3,504
DFW
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http://www.galvanizeit.com/uploads/ASTM-B-633-yr-13.pdfhttp://imf-co.com/wp-content/uploads/2015/12/Website-Eliminating-Hydrogen-Embrittlement-per-ASTM-B633.pdfhttp://imf-co.com/wp-content/uploads/2015/12/Website-Eliminating-Hydrogen-Embrittlement-per-ASTM-B633.pdf
Floyd Lippencott IV
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Re: Hydrogen Embrittlement & Plating
[Re: astjp2]
#2704333
10/06/19 01:36 PM
10/06/19 01:36 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
OP
If you can't dazzle em with diamonds..
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OP
If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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375 will not affect the plating. I build airplane parts and its not an issue to bake. At what temp have you found temp to be a problem, and in my case I'm talking yellow zinc? I have discolored yellow zinc when doing typical powder coat temps. I only have the platers word to go on here, and the 375F is from my memory , I could be wrong. And yes, the drain hole if possible is the proper solution, and my part had needed drain holes for other areas.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Hydrogen Embrittlement & Plating
[Re: dthemi]
#2705736
10/10/19 10:49 PM
10/10/19 10:49 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
OP
If you can't dazzle em with diamonds..
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OP
If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
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"A note about electroless nickel and hydrogen Electroless nickel (EN) generates hydrogen as a part of the deposition reaction. Therefore Hydrogen embrittlement of high-strength steels can occur. What is different about electroless nickel deposits, you ask? Remember that electroplated deposits are crystalline. That is they have grain boundaries from which hydrogen can escape during the baking process. Electroless nickel is virtually amorphous (without grain structure). Since there are no grains, it is very difficult for hydrogen to pass through electroless nickel deposits, particularly thicker deposits where there is little or no porosity." http://www.plateworld.com/editorial65.htm
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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