Should I worry about hydrogen embrittlement when hard-chroming gun parts?

[IMtheNRA]

I know that hydrogen embrittlement can occur during the chrome plating process. I'm wondering if there are any significant negative implications of this condition when plating gun parts such as hammers, AR bolts, slides, frames, etc.

Do we have any in-house experts who would like to offer their opinions?

 

[Cesiumsponge]

I would be worried that hydrogen embrittlement would reduce the strength of the steel and it would fracture at a lower stress level than otherwise expected at whatever hardness those parts are treated at. I believe you can use (relatively) low level heat and drive off any absorbed hydrogen impurities from the grain structure by baking it.

Found this "ask the expert" Q & A on a metal finishing resource dealing with the subject. A lot of other stuff turns up under hydrogen embrittlement treatment/baking/treatment/prevention on Google when dealing with chromium platings. You can probably get a fairly decent idea by absorbing all the information and averaging the bake times.

http://www.nmfrc.org/crarchive/jun06a.cfm

 

[dfariswheel]

Most all gun platers take steps to limit or eliminate embitterment problems.

If it was really that serious a problem, there'd be plenty of people on the gun forums telling us about broken parts and failures.

 

[steveno]

to prevent Hydrogen embrittlement the parts have to be baked to a certain temperature for a period of time otherwise there will be problems. if the platers know what they are doing they are aware of this

 

[BobCat]

Bake the plated parts at 350ºF for four hours and air cool. All done.

You can find the ASM Metals Handbook in any University Library and look this up, or probably find more than you want to know on the Web.

Regards,
Andrew

 

[IMtheNRA]

That's all there is to it? So, is it OK to bake the parts for what is possibly the second time just in case the plating service, like Tripp for example, did not take that step?

 

[BobCat]

Baking twice will not hurt; the temperature is we below any reasonable tempering temperature for the steels in question, so you will not soften them.

No one here wants a lecture so I'll keep quiet, but there is a ton of information about steels, heat treating, fracture modes / mechanisms, and so forth out on the internet. It is really fun.

Just for fun, check out http://www.steelynx.net/

Have fun!

Regards,
Andrew