stihl chain hardness

[1953greg]

That deck screw could have set the cutters back into them self?

dang sure did. rolled the leading edge back. even after removing the rolled edge bout 1/8" of the tooth still zinged w/ the file!!! held the edge pretty good though.
nails wil just dull the cutters. deck screws practically destroy them!!!!!

 

[Big Woody]

Shot Peening

At least some of you guys are on the right track.

http://www.metalimprovement.com/shot_peening.php

What edge packing dose is makes a denser structure

Since plastic deformation in metals is incompressible (volume conserving)
this would be impossible. The interatomic distances in metals aren't effected by what part of the stress strain curve your on, at least on this planet.

 

[Hard Knocks]

Why is this not work / strain hardening?

If the leading edge of a dull cutter has been rolled and flattened has it not been taken past it's yield point to achieve plastic deformation? Is strain hardening not achieved when loading is carried beyond the yield point requiring the load to increase for additional strain to occur?

 

[ShoerFast]

Since plastic deformation in metals is incompressible (volume conserving)
this would be impossible. The interatomic distances in metals aren't effected by what part of the stress strain curve your on, at least on this planet.

This is from the class that believes that a jar full of golf-balls if full! And the test, if you push in another golf-ball, one will pop out.

I'm not here to argue a point on this, as there are some that are not meant to understand this, but if I may?

Steel is a gift!

There would be no reason to roll steel, cold or hot, if we were happy with the grain structure the way it was plucked from trees (ore were ever it came from) here is a simple sketch of the hot-rolling processes.

The idea that
"The interatomic distances in metals aren't effected by what part of the stress strain curve your on".
Is about the same idea that keeps the jar of golf-balls full.

This idea has stumped Scientists for decades, but the true solution was known by Blacksmiths for centuries. Steel has flaws and inclusions.

The words I chose, "denser structure " may not be as good as the words grain structure. But it dose bring back the idea of jar full of golf-balls, yes, it is full of golf-balls , but will still hold a few hand fulls of bird-shot, and a few handfuls of fine sand, and again, maybe a cup or 2 of coffee. Steel is made up of several different elements. But that is at the molecular level, not interatomic, as was mentioned.

The real nutz to edge packing, as an old world term, or work-harding or shot-peening, is the parentage of Body Centered Cubic (bcc) compared to the amount of Face Centered Cubic (fcc) and the strength they have. (That is also what determines the hardness)

It is not possible to move metal (within it's self) with out changing this. That's why we are hearing descriptions of "zig-zaging" files and hard to sharpen chains, now that we look in to it, IMO.



(ref: http://www.cashenblades.com/articles/lowdown/lowdown.html , very fine Bladesmith)