# The intentional creation of banding in the forging process



## rick alen (Jul 8, 2014)

This is for the forgers out there.

I was reading on Ed Fowler's site here: http://www.edfowler.com/index.php?option=com_content&view=article&id=61&Itemid=67
In it Ed says that the extensive forging and reduction his blades go thru create "banding," which he indicates is a desirable thing [in a purely functional knife], which Ed seems to emphasize as the primary element in his knife-making philosophy.

Banding is a dishomogination of structural elements within a metal, and so far as I have read serves no functional purpose but to degrade a metals strength. It does serve to give wootz steal its patterned appearance, but that is not exactly functional.

So what if anything am I missing here?


Rick


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## XooMG (Jul 8, 2014)

I am not a metalworker, but I'm curious about the claim. It seems that segregation happens in initial cooling and is present in pretty much all steels; hot working like rolling or forging may move the segregation boundaries into more organized bands that correspond to the direction of working. Within such bands, there may be differential hardenability and carbide formation, which might be useful if said bands intersect with the edge. I do not know how significant an effect it might be.

The way I imagine it is a bunch of microscopic dendrites getting smooshed into more or less parallel bands via hot working. I don't think forging or other general hot work "creates" the segregation; rather they organize it into a macroscopic banded pattern.

Like i said though, I'm an ignoramus when it comes to steel, so don't take what I say seriously.


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