Hardness after interrupted quench vs full quench?

[P.Brewster]

Suppose we have knife A and knife B, both made from the same steel (say 1095), both are in the oven at the same time and temp.

Knife A is removed from the oven and given a brief (say 5 to 7 second) quench. Perhaps it is 600° when removed from the quench, then it is air-cooled to ambient.

Knife B is removed from the oven and given a lengthy quench. It is cooled down to ambient in the oil.

Now knife A and B are hardness tested. Will we see the same reading?

 

[mete]

Steel quenched down to ambient will be harder than one going through a slower quench .The quench to ambient will have higher stresses therefore will be harder.

 

[Stacy E. Apelt - Bladesmith]

Additionally, after 5-7 seconds of quench, the blade is probably still 800-900F. In still air it may not hit 400F for 20-30 seconds. The drop to 200F may take another 30 seconds. This will cause auto-tempering and some austempering.

 

[P.Brewster]

Great, this is what I expected. Thank you!