HT info

[NRunals]

I stumbled across this web page today and the HT described here is a bit different from other methods I've used/read about.

They say that the cooling from 1500f to 900f should take 1-2 seconds (which is normal). The main difference is that it is recommended that the cooling from 900f to 125f should take about 15 minuets... Anyone HT this way? Does it really make for a better edge?

[Steve Sells]

this method is often referred too as an Interrupted Quench, to reduce stress in the metal from thermal shock.

[basher]

That is pretty much the most confusing Ht advice I have ever seen .
and is a very odd way to go about things (in my opinion) , All the information is routed in fact its just a not very controlable way of going about it and leaves a lit to chance/Intuition.
the site is advocating an interupted marquench . Brine first and then air .
Marquenching a far more controllable way of doing this. By quenching into heated salts or marquenching oil at a known temperature (say 200to 250C) . You quench into hot oil and the martensite formation is slowed down .The real advantage of this method is that you get time to straiten warped blades whilst they are hot ,before the meta austenite in them has fully turned to martensite.Also warping is less likley .
This method is used in industry for complex parts that are liable to warp . For us metal bashers swords come to mind .
For most applications simple oil quenching is just fine.