w1 heat treat

[JCWalker]

Should I use water or brine to HT w1? If I make brine is it just water with all the salt it can take? Do I heat the blade to non magnetic? Thanks

[JCWalker]

I am going to attempt an edge quench in either brine or hot oil. not sure yet though, edge is still kind of thick so warpage is not a huge concern I hope...

[JCWalker]

i used brine and cracked the blade, gotta start over and will use oil this time...

[RedNeckLeftie]

Hi JC,

 

Sorry to hear of the loss! I guess, though, you figured out nix on the brine... From everything I've read, seen and experienced, brine is too harsh for most all decent blade steels (I know someone out there will swear by it of course).

 

I have not done any edge-quenching, but have done a boat load of water quenching. I do not believe water (or brine) is a suitable edge-quenching medium. There's just too much trouble with the formation of a vapor jacket, which will inhibit the quench effectiveness and uniformity--it may not even harden. Those with more experience please chime in.

 

For edge-quenching, oil is the only medium I have heard of, other than perhaps the polymers (Parks 50?). And by oil, I mean fine-grade mineral oil, vegetable oil or tranny fluid--not the leftovers from the last oil change.

 

For full-submersion water-quenching, I use normal, garage-temperature (softened) tap water, ~60-88F. BUT, the one piece of 1095 I did got quench-cracks, and 1095 is very roughly comparable to W1. More recent info suggests one should use ~120F water and an interrupted-quench with the higher-carbon stuff.

 

Oh yeah, the heat before quench: 15-50F above non-magnetic should be fine.

 

Thanks,

Brian K.

[Tom Demitras]

I did my first interupted quench on my razor last night and it worked out wonderfully. I highly recommend that method. Just stick it in til it looses color, pull it out let it air cool till the sizzling of water slows down to near nil then plunge it back in. Thats how I did it and there was no dreaded ping.

[Doug Lester]

If I wanted to do differential heat treating with brine, I'd do a full quench and a selective draw back on the temper, if that. The reason that I say "if that" is, according to Verhoeven, with shallow harding steels, such as W1, martinsite will only form to twice the depth of hardenablility for a combination of steel, quenching medium, and temperature (twice the depth comes from the fact that the hardening depth is measured from both sides of the blade). Beyond that thickness, the blade is pearlite and bainite. With shallow hardening steel there is an automatic differential hardening unless the entire blade is twice the depth of hardening or thinner. The other part of "if that" is the fact that differential hardening is not always desirable or at least necessary to the design of the blade.

 

Doug Lester

 

P.S. (This will teach me to read the WHOLE article before posting) The above depends on how fine the grain of the steel is. Large grains facilitate hardenability, however, if we reduce the grain size to increase the toughness of the blade the above does apply with shallow hardening steel.

Edited November 28, 2008 by Doug Lester