Decarburization of 1095

[Bo T]

I plan on using a kiln for normalizing/austenizing 1095. Do I need to worry about decarburization? Should I pack in vermiculite?

 

[sunshadow]

You will have some decarb, it's a surface diffusion thing, grind it off, just allow yourself 10-20 thousandths of an inch and you'll be fine. To minimize decarb in my kiln I throw a couple of chunks of lump charcoal in just before I put my blades in, that generates CO which takes any free oxygen out of circulation which minimizes the decarb (doesn't eliminate it but reduces it)

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[sunshadow]

Oh leave the vermiculite in the garden. The last thing you want to do with 1095 is slow cool it. Trust me, scratch that, actually don't take my word for it,

http://www.bladeforums.com/forums/showthread.php/673173-Working-the-three-steel-types.

1095 is Hypereutechtoid

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[Bo T]

OK. Thanks for the information and reference. 2 things though.

First, as I understand it, I don't want to take to long going from the normalization temperature to the lower austenizing temperature as undesirable effects can occur. About how long should it take going from 1625 F to 1475 F?

Second, The heating process is difficult to control in a kiln due to the blade heating faster than the kiln. How do I shield the blade? How can I better control the heating process in a kiln?