Re: sec:unclassified Coil Spring Metallurgy (a little long)

[bearbvd@domain.elided (Greg Hermann)]

At 9:29 AM 2/19/03, Reid, Warren wrote:

The danger of this "technique" is that it can alter the metallurgical
structure of the steel, where in a Spring steel (which has a relatively
high carbon content) you can get diffusion of carbon to the grain
boundaries which amongst other things can make the steel brittle and more
likely to fail.

Grain GROWTH (due to heating) is yet another factor in causing the above
described troubles.
>
>Alfa content: Alfa 105's were notorious for the rear ends sagging over
>many years. This may have been compounded (me speculating again) by the
>fact that Alfas engineers would have been trying to make the rear springs
>as soft (from a Force/deflection view point) as possible due to the heavy
>rear axle.

More likely the rear springs were so soft because of the rather high rear
roll center. The designers made the springs soft so that the rear roll
stiffness would not be excessive in relation to the rear roll couple (short
distance between Cg and roll center translates into rather small roll
couple).

Nice description of what goes on, though.

Greg
>
>Warren Reid (MApp Sc - Physical Metallurgy)
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