Hello Jim,
You have not really read my story very good. I have tried to explain
only what a normal use of liquid nitrogen is, and that I do not
believe in this process… What the Swiss are doing with there watch
part is to prevent them from aging. This means, the changing material
properties over time. The balance wheel and arbours are often made of
Bi-metals, or from invar (has a very low nearly zero thermal
extension.). This is only for expensive watches $10.000 and more.
These parts need to be very precise form fit and do not allow microns
of size differences. Normal al things including metal parts, change
and deform over time. How ever it is very difficult to measure this,
also metal evaporate over time. So if you want to deliver these watch
parts, after say 100 years, you want to supply the customer with new
parts. Making watch parts is very expensive, if you make just a few,
not in big series. So they never want to make these special parts
again, and it is cheaper to store them for 500 years. How can you
store them more safely than in liquid nitrogen or in a ever freezing
cave. Watch part do not take a lot of space so storage is relatively
cheep.
I understand, as you claim, the trick is a very slow warming process.
To release stress in steel like materials, you want to divide the
molecules and crystals so homogenic as possible, than you have no
internal stresses. This process will only work if the atoms are
vibrating and can move to vacancies ( gabs) ,The normal way of stress
releasing is 50 degrees Celsius above the recristalistion temperature.
When you cool material down, the movement of atoms is slower, so the
process of moving and homogenising is slowing down. Maybe I am to
conservative, but come up with some real proof and testing reports. If
you can proof to me that this process works, I can supply you with
some interesting things from Warsila to work on.
Martin Niemeijer