Re: chrome and steel

[Regan Dale Copple <copple@xxxxxxxxxxxxxxxxxxxxxx>]

Norm,

On Tue, 1 Dec 1998, Newigi@domain.elided wrote:

>An interesting note on chroming parts is someone brought up the subject
>that chroming may make steel brittle, does anyone else have any inputs on
>this?  I am interested in having the steel wheels chromed and there are a
>lot of other style steel wheels out there that have been chromed.  But
>one would not want
>brittle wheels would they, any inputs?

	The first thing you should have asked them is why would it make
the steel brittle?  Is it something about the process?  Or does the chrome
itself actually change or lower the ductility of the steel that it's
sitting on top of.  Speaking from a materials science perspective these
are the only two things that could possibly do it.  If you have a steel
alloy and it is exposed to an unnaturally high heat, say one outside the
normal operating range of the component, then you will have altered the
composition of the steel by heat treatment.  Steel is one of those funny
things, it has all of these different forms, add a little more carbon to
Austenite which is a relatively ductile steel, take it up to about 1100
degrees Celsius, quench it relatively quickly by dunking it in a vat of
water, and presto change-o, you now have a hard, brittle steel called
Martensite.  You can change all kinds of characteristics by adding
various other elements besides carbon.  Most common are tungsten, nickel,
vanadium, chromium, molybdenum, manganese, and even silicon.  And there
are other forms of steel like perlite or cementite that have different
characteristics than that of austenite or martensite.  So I would have say
that since chromium is added usually to increase the hardness penetration
that it might embrittle the steel a little, but not enough to matter.  And
from my knowledge of chroming something, I believe it's done by
electro-plating the chrome on, not sure though because chrome is an alloy
and sometimes mixtures don't react or respond the same way as an element
does.  I hope this helps, any more questions, just send them in.  Ciao!

						Typing with five fingers,
						Regan Copple
						79 Spider-black
				(coming soon)-->72 Montreal-silver
						73 Montreal-black

"It is amazing how complete is the delusion that beauty is goodness."
					-Lev Nikolayevich Tolstoy

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