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Brent, A heavy coat of a molybdenum-based anti-seize compound to
threads prior to applying a nut will go a long ways to avoiding galling.
This is a big concern on valves in nuclear systems as they stainless steel and
have a threaded cap that covers the valve stem and packing…galling was of
particular concerning in these cap threads. R/Jay Respectfully, Jay K. Jeffries Andros Is., Bahamas As scarce as the truth is, the supply has always been in excess of
the demand. -Josh Billings From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent
Hartwig I trust all you Submadmen are having a
great day. Just don't try to go shopping today. As for me
it's all about the quality of the snow shovels, and gas for the snow blowers. Properties
"High oxidation-resistance in air at ambient temperature
are normally achieved with additions of a minimum of 13% (by weight) chromium, and
up to 26% is used for harsh environments.[7]
The chromium forms a passivation layer of chromium(III) oxide (Cr2O3)
when exposed to oxygen.
The layer is too thin to be visible, and the metal remains lustrous. It is
impervious to water
and air, protecting the metal beneath. Also, this layer quickly reforms when
the surface is scratched. This phenomenon is called passivation
and is seen in other metals, such as aluminium and
titanium.
When stainless steel parts such as nuts
and bolts are
forced together, the oxide layer can be scraped off causing the parts to weld together.
When disassembled, the welded material may be torn and pitted, an effect that
is known as galling.
This destructive galling can be best avoided by the use of dissimilar
materials, e.g. bronze to stainless steel, or even different types of stainless
steels (martensitic
against austenitic,
etc.), when metal-to-metal wear is a concern. In addition, Nitronic alloys
(trademark of Armco, Inc.) reduce the tendency to gall through selective
alloying with manganese and nitrogen."
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