Yes I've had and excess of time to think lately, but it spent all morning raining so I should be able to fire up my forge soon.
Anyway, I went from thinking on torsion and charpy to wondering about the differences in differential quenching and differential tempering and this led obviously to which results in a tougher knife all else being equal?
As I understand it, differential quenching, either clay-coat or edge quench, will give a hard martenistic edge with a soft perlite spine. (I suppose the spine may be some combination of perlite/martensite and perhaps with a little bainite). A differential temper on the other hand will still have the hard martensite edge with a softened marteniste spine.
So if someone was chasing that elusive ideal knife, which would be a better choice and if you can why?