1.2519 fast or slow quench

John mc c

John mc c

Joined
Aug 23, 2018
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3,079
Hey guys
I've HTed a couple of 1.2519 blades using canola oil with good results but on further reading I see some use parks 50,think specs wise it falls between fast and slower quench
So what's everyone using for this steel
Thanks in advance
 
It is an oil quench steel. It has enough manganese to fully harden in Canola oil. Parks #50 works fine, too.

Austentize at 1475-1500F (800-815C)
Soak for 8-10 minutes.
Temper twice at 350 to 400F ( 175-195C)

DON'T normalize, anneal, or cycle this steel. (It can form carbides and structures you don't want). It has very fine grain right from the mill.
Using the lower austenitization temps will make a better blade at high hardness. With a 350F/175C temper you should get Rc 62-64.
 
Thanks Stacy
So what would you recommend after forging?
I done my usual Kevin cashen routine
871
801
801 quench
690 × 2 hours
 
Not needed with this O-7 clone. I would just quench it from 800C/1475F.
I assume the 690C temper you gave is a typo, and should be 190C ?
 
Sorry Stacy I wasn't clear at all
After forging
871c for 10 mins and cool
801 c for 10 mins and cool
801c for 10 and quench
690 c for 2 hours to anneal
So after forging how would I go about grain refinement and annealing?
 
On 1.5mm 1.2519 after welding san mai on 1200 celsius I get grain size back with this protocol ...i did not anealed it.
870 celsius 5min.
850 Celsius 5min.
830 Celsius 5min.
830 Celsius 5min. QUENCH in oil!
another one san mai /same protocol for grain refinement/ from 800 Celisus i quench it in warm water .....
 
Your close.
Your first cycle with a slow cool is a stress relief cycle. It does not reduce grain as much as quenching does. Any cycle that does not end in a quench will not reduce the grain as significantly. It is in the quench that new grain boundaries are formed, creating more and smaller grains.


Try this protocol:
870 for 10 minutes and air cool to black ( stress relief)
870 for 10 minutes and quench (first grain refinement)
800 for 10 minutes and quench (second grain refinement)
690 for two hours and air cool to black before quenching. (sub-critical anneal)
After clean-up and drilling -
800 for 10 minutes and quench ( hardening)
190 for one hour, quench in water, 190 for one hour, quench in water. ( tempering)
 
Last edited:
Stacy E. Apelt - Bladesmith said:
Your close.
Your first cycle with a slow cool is a stress relief cycle. It does not reduce grain as much as quenching does. Any cycle that does not end in a quench will not reduce the grain as significantly. It is in the quench that new grain boundaries are formed, creating more and smaller grains.


Try this protocol:
870 for 10 minutes and air cool to black ( stress relief)
870 for 10 minutes and quench (first grain refinement)
800 for 10 minutes and quench (second grain refinement)
690 for two hours and air cool to black before quenching. (sub-critical anneal)
After clean-up and drilling -
800 for 10 minutes and quench ( hardening)
190 for one hour, quench in water, 190 for one hour, quench in water. ( tempering)
Click to expand...
So triple quench is not myth ?
From Kevin Cashen site ............
Normalizing

The very name of "normalizing" best describes what this operation does; it brings everything inside the steel back to a normal or equalized state. By everything I mean grain size, carbide size and distribution, dislocation densities and stresses resulting from the strain of working or thermal effects. The idea is to heat the steel above the recrystallization temperature in order to reset the austenite grains, evenly soak at a temperature sufficient to dissolve large carbide concentrations and in the process wipe out any strain energy that could be in the structure. The most important consideration in normalizing is that the heat is as even as possible and that the cooling is as even as possible, but not too slow and not too fast. If one were to cool from normalizing heats too slowly the carbide would diffuse out in rather coarse structures and in places that you may not want them, and thus you would not be normalizing but annealing instead. A slightly faster cooling rate will also promote finer structures, so air cooling is the method used for normalizing, Any faster than this and you are hardening. Normalizing is used after forging the blade to even out all the chaos inflicted by the hammer. Industry specifies much higher heats for normalizing than many bladesmiths, 1600oF.-1700oF., and I always start out with a higher temperature to be certain that I put things into solution. At this first stage I am not so concerned about how fine the grain is but that they are all the same size, uneven grain size can be worse than larger grains, so using the high heat levels out the carbide/grain size and actually "normalizes" the inside of the steel. I then follow this heat with two or three more normalizings at subsequently lower heats to step down and refine the sizes of those constituents.
Click to expand...
13.00 min.
 
Last edited by a moderator:
Triple quench as taught by certain cowboy knifemakers is not what we are talking about. That is a myth .. or at least misinformation ... claiming to magically improve the blade hardness and quality an unbelievable amount. That person was also using a very different steel than we are discussing.

On a stock removal or minimally forged blade in 1.2519 you would only do the hardening quench and tempering.

What I am giving John is a normalization and grain refinement protocol for a forged blade in 1.2519. If the steel was not forged, none of this would be useful, and might even make the grain less fine than it was as received from the supplier.
The first heat and moderate rate cool relieves the stress along the grain boundaries and "normalizes the structure. Upon slow cooling below Ar-1 it becomes coarse pearlite. It is cooled off in water then to stop the cooling.
The second heat at the same temperature followed by a quench dissolves the structures and re-crystallizes them as more and finer grains.
The third heat at the austenitization target will do the refinement to a finer degree. You could skip this step and would still have good results.
The final heat and quench is at the target temp and forms the finest grain you are likely to get for this steel. Once cooled to ambient it is immediately tempered twice to remove the stress and convert any retained austenite.

Now, some additional info:
On every blade I forge, after the last heat I heat the blade to bright red/orange ( 1600-1800F) and let it cool to black. I do this a couple times and then cool the blade in the slack tub. This leaves the blade stress free and soft. This means I don't have to do it when doing HT .
If the blade was heated very hot in forging, I would make the last heat cycle a quench to re-set the grain. I might even do it twice if the forging was long and hot with many heats.
Then, at HT time I only need bring to the target temp and quench.
 
Last edited:
Stacy E. Apelt - Bladesmith said:
Triple quench as taught by certain cowboy knifemakers is not what we are talking about. That is a myth .. or at least misinformation ... claiming to magically improve the blade hardness and quality an unbelievable amount. That person was also using a very different steel than we are discussing.

On a stock removal or minimally forged blade in 1.2519 you would only do the hardening quench and tempering.

What I am giving John is a normalization and grain refinement protocol for a forged blade in 1.2519. If the steel was not forged, none of this would be useful, and might even make the grain less fine than it was as received from the supplier.
The first heat and moderate rate cool relieves the stress along the grain boundaries and "normalizes the structure. Upon slow cooling below Ar-1 it becomes coarse pearlite. It is cooled off in water then to stop the cooling.
The second heat at the same temperature followed by a quench dissolves the structures and re-crystallizes them as more and finer grains.
The third heat at the austenitization target will do the refinement to a finer degree. You could skip this step and would still have good results.
The final heat and quench is at the target temp and forms the finest grain you are likely to get for this steel. Once cooled to ambient it is immediately tempered twice to remove the stress and convert any retained austenite.

Now, some additional info:
On every blade I forge, after the last heat I heat the blade to bright red/orange ( 1600-1800F) and let it cool to black. I do this a couple times and then cool the blade in the slack tub. This leaves the blade stress free and soft. This means I don't have to do it when doing HT .
If the blade was heated very hot in forging, I would make the last heat cycle a quench to re-set the grain. I might even do it twice if the forging was long and hot with many heats.
Then, at HT time I only need bring to the target temp and quench.
Click to expand...
Ok , Stacy ........i found hundreds yours post where cool to black is recommended by you .And I found thousands topic about grain refinement ........and not in single one is recommended quenching between cycles , only cool in still air to black ?? And how I get invisible to eye grain size with my way if it is wrong ?
Did you read Quote in my previous post from Kevin Cashen ?
So is this something new we don t know or what ? Or this is only for 1.2519 steel ? You confused me well with that quenching between cycles..... I thought I learned something here :D
 
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