"Lee Michaels" wrote in message
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"Proton Soup" wrote in message
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On Sun, 20 Feb 2005 14:54:51 -0500, "Lee Michaels"
wrote:


"Harold and Susan Vordos" wrote in message
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"Ignoramus29737" wrote in
message
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snip--------

[the article above is a PDF file from a barbell manufacturer that
claims, among other things, that chroming a barbell causes "hydrogen
embrittlement"].

I think that there is a possibility that the article is not true. He
is saying that a relatively quick process of chroming is going to
affect deep layers of steel inside the handle. I am doubtful that
this
is indeed the case. I am xposting to rec.crafts.metalworking to see
what they say.

i

That tends to be a problem only for heat treated items, but it is
true.
Hydrogen embrittlement can be a serious problem under that condition.

I am no expert in these matters. And I don't know who at the metal
working
forum would be such an expert either.

But as someone who has worked extensively with small gym equipment
manufacturers, the universal truth by this group is that bars covered
with
chrome are of low quality. They feel that way for a reason. I trust
their
judgement. This was long before I heard of hydrogen embrittlement.

While we're on the subject of chromed bars, I've got one (just happens
ot be for standard sized weights), and the chrome is starting to wear
away where the clips to hold the weights slide on and off. And oddly
enough (to me at least), the metal underneath the chrome appears to be
copper, not steel. Now I'm pretty damn sure the bar isn't solid
copper (it'd be too expensive and bendy), so it must be a plating that
is applied before the chrome. But why? Is it to help the chrome
better adhere (decent chrome job, btw, no flaking) or some other
purpose, like limiting the aforementioned hydrogen embrittlement?


Don't quote me on this.

But my understanding is that the steel is coated with nickel. And the
chrome adheres to the nickel.

But most of my chrome knowledge comes from watching American Chopper.

High-volume jobs, like old car bumpers, had a flash plating of nickel; a
thick plating of copper; a thin layer of nickel; and then the chrome.

I don't remember what the functions were, exactly, but nickel gets better
adhesion to steel than either copper or chromium. One function of copper is
to fill in imperfections.

That's a decorative chrome job. Hard-chrome plating of bearing surfaces (the
"hard" part really just means "thick") is done without the copper, and,
sometimes, without the nickel.

I knew this stuff cold 25 years ago. Sorry, the memory is going. d8-)

--
Ed Huntress