O1 quenching

Read about fifteen different info sheets on O1. For stress relieving I have seen everything from equalizing, one hour, and 2 hour soak times at 1200 and furnace cooling or still air. Nothing about pulling out at 900f. Is an hour enough? I am not doing anything thicker than 5/32". I don't imagine it needing that long to heat all the way through.
 
I run 100 01 clamps at one time in my electric kiln. I've run several thousand of them finally coming to the the 1200 @ 2 hrs ramped up to 1600, cool to black 1525, cool to black, 1450 cool to black. I do the previous because it has proven itself to work consistently with no breakage or warping.

Steel cycling is all about time @ temperature, when you find something that works, stick with it.

Regards, Fred
 
Fred.Rowe said:
I run 100 01 clamps at one time in my electric kiln. I've run several thousand of them finally coming to the the 1200 @ 2 hrs ramped up to 1600, cool to black 1525, cool to black, 1450 cool to black. I do the previous because it has proven itself to work consistently with no breakage or warping.

Steel cycling is all about time @ temperature, when you find something that works, stick with it.

Regards, Fred
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So I ended up running the stress relief cycle for 2 hours at 1200 and let the blades kiln cool. I will be hardening today and let everyone know how it turned out. I would like to add that all the blades were straightened and surface ground dead flat before any HT was performed. Results coming soon. Thanks everyone
 
Ok. After two hour stress relief yesterday at 1200 and let kiln cool over night, today I ran my hardening cycle. Put blades in kiln, ramp to 1250, soak for 20 min, ramp to 1490, soak for 30 min, quench in 135f peanut oil. 6/7 blades warped, 2 terribly warped, three with a little warp, and 2 with slight warp. I am at a loss. I was super careful not to bump the blades.
 
also, when people say "cool to black" during normalizing, does that mean the blade is no longer red hot? also, quenching during stress relief... is that necessary? can't I just kiln cool it? thanks
 
I wouldn't let em cool with the kiln. pull out and air cool. Normalizing cycles work very well at preventing warping.

I'd clamp them 'straight' to a flat bar and temper. Should be fine.
 
As Don states, remove the blades from the kiln. When your cycling the steel in an electricj kiln it's getting it to temp thats needed. Leaving the steel in the kiln and letting it slowly cool will increase the grain size. I cool blades quickly when normalizing, once they loose their color it goes in the water. It won't warp once the colors out of it and the quick cooling gets the steel through the soft structures faster, which is a good practice. Blades are so thin they take little soak time when the come to temperature.[/B]
 
Fred.Rowe said:
As Don states, remove the blades from the kiln. When your cycling the steel in an electricj kiln it's getting it to temp thats needed. Leaving the steel in the kiln and letting it slowly cool will increase the grain size. I cool blades quickly when normalizing, once they loose their color it goes in the water. It won't warp once the colors out of it and the quick cooling gets the steel through the soft structures faster, which is a good practice. Blades are so thin they take little soak time when the come to temperature.[/B]
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ok, that makes sense. thanks.

I would also like to add that the warping that I am having trouble with is not always noticeable by looking down the blade but apparent when placed on a flat surface and looking for light peeking through or pushing on the ends (point/pommel) and watching the opposite side lift. The more severe warping is obvious when looking down the blade (2/7 blades today)

I notice that a lot of the blades are warping where I stamp my logo. I bend all the blades dead straight and surface grind to make sure they are within .001" consistent in thickness after stamping yet still the problem persists.

does anyone see anyone see any problems in this HT regiment?

Stress relief:
place blades in cold kiln without anti-scale compound
1200F 2 hours, cool in still air

Hardening:
Place blades in coolf kiln, no anti-scale compound
RAMP to 1250, soak for 20 min
Ramp to 1490, Soak for 30 min
quench in 130f Peanut oil
remove from oil when 130f
sit flat on wood bench until at room temp (when all the blades are done being quenched)

go inside the house

Tempering:
400f 1 hour x3
unless I am fixing warps (and I am all day)
clamp to flat plate using a penny to use as a point to bend against the warp for 30 min of heating until room temp and then checking for straightness.

I'd really like to not have to guess when the right time is to pull the blade from oil to bend by hand. Honestly it seems there is too much room for error, but I am probably wrong. I am definitely frustrated and tired of spending entire days straightening blades. I tried heating to 400F and bending in vise but it didn't seem to actually do anything to straighten them
 
Thanks everyone who has replied and been patient. I am obviously still learning a lot about knife making (specifically heat treating) My knives hold an edge well and I am happy thus far with their performance, I am just trying to minimize my frustrations and make knives faster and more efficient.

Also, I would like to know (in detail please) how to normalize. I'm not quite getting the "cool to black" thing.

I am assuming that it means heat to the temp 1600F, 1550F, and 1500F and let air cool (pull out of the kiln) until it is no longer red hot?

Should I be using antis-scale to minimize decarb? Will anti-scale compound stay on the knife through the entire HT (normalizing, stress relieving, hardening, tempering) or does it have to be reapplied? Any recommendations on a good anti-scale?
 
Just ordered parks AAA from maxim. Going to try an interrupted quench. I am considering using quench plates to bring it down to room temp.
 
With regards to anti-scale, The only two I've been able to find are PBC powder and ATP641. They will only stay on for one heat cycle in my experience. I have had blades come out cleaner with PBC, but I like how easy it is to apply the ATP.

I'd be interested to hear how it goes with an oil quench using antiscale, and then going to the plates. Seems like the antiscale pops off in some places, sticks on in others, you might end up causing more warp.
 
TILLER said:
With regards to anti-scale, The only two I've been able to find are PBC powder and ATP641. They will only stay on for one heat cycle in my experience. I have had blades come out cleaner with PBC, but I like how easy it is to apply the ATP.

I'd be interested to hear how it goes with an oil quench using antiscale, and then going to the plates. Seems like the antiscale pops off in some places, sticks on in others, you might end up causing more warp.
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so far I am not sold on the anti-scale. It was just part of my inquiry. Honestly worried about warping more than anything else. But I see your point. thanks
 
The liquid anti scale PBC from Brownell's is good to use through stress relief and normalizing and yes it needs to be re-applied between cycles. It does stick much better after the first cycle.
Do not use it on the entire blade during quenching, it will affect the hardness. It can be used for hamons on steels like W2, its great for this.

I apply the PBC to the ricasso area which is close to finished when quenched. The bevels will be ground after heat treatment so no need to cover. If you can get the racasso and plunge area to come out clean, you are far ahead of the game.
 
I used to stamp my blades and now that you mention it I do recall that I was having a similar problem as you . I don't stamp anymore because I have a etcher now but sometimes its the little things. Also have you tried getting your steel from another vendor ? Might help to rule that out too .
 
Marko3 said:
I used to stamp my blades and now that you mention it I do recall that I was having a similar problem as you . I don't stamp anymore because I have a etcher now but sometimes its the little things. Also have you tried getting your steel from another vendor ? Might help to rule that out too .
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You know I was also considering that as a possible issue. I have a fair amount of the steel left so I will use it all up. It works out because that supplier is dried up and I had to get a new source. I love down the block from a supplier Amtek Tool. They have a huge selection of O1 and from what I hear the quality is great. Hopefully the new steel, parks AAA, and an interrupted quench will solve the issue. I am considering adding a plate quench to the tail end of the oil quench. A lot of makers I know swear by it.

Thanks for all the help so far. If anyone has other suggestions or info I would appreciate it.
 
I would wait until after HT to stamp the blade, it may be putting added stress even with normalizing. Also when I HT, I found that if I lay my blades flat after quench, there is more of a chance to warp so I now hang them by the pin holes after the quench. Ive only had one minor warp doing that.
 
I put this in another currently running O-1 thread. It has some O-1 and general eutectoid info that may help:


A good medium speed oil and proper HT regime should take care of most warp issues in O-1.

O-1 and the other eutectoid steels have a much slower cooling curve than most folks think. You have plenty of time to straighten any warp. Pull it out after a count of 5, straighten, and put back in the oil to cool down below 200F.

The TTT of eutectoid steels gives you lots of time:
1 second to clear the nose at 1000F,
5 seconds to get to 800F,
1 minute to get to 600F,
2+ minutes to reach 450F ( Ms)
1/2 hour before it stiffens too much to straighten safely (50% martensite)
You have several hours before it has to get to 200F(Mf)

Eutectoid TTT chart : http://blog.ub.ac.id/okkyardiansyah...mation-Diagram-for-a-1080-Eutectoid-Steel.jpg

During the two minute time between 800F and 400F, you can twist, bend, hammer, etc. with no fear. A wooden mallet and a wooden plank on the anvil will keep cooling rate down when whacking out twist and warp. Even with taking all that time, the as quenched should be around Rc64.

To see how long two minutes is, go to a football field. Start at one goal post and walk to the other. Turn around and walk back. That took about two minutes at a leisurely stroll. Math is 3-4MPH walking speed = 100 yards per minute.
 
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tattooedfreak said:
I would wait until after HT to stamp the blade, it may be putting added stress even with normalizing. Also when I HT, I found that if I lay my blades flat after quench, there is more of a chance to warp so I now hang them by the pin holes after the quench. Ive only had one minor warp doing that.
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I like the idea of hanging them, i will do that. However if I stamp my logo after hardening I will probably just break my stamp.
 
Yes you will ruin your stamp .. Stacy put some good info there. Like posted above try hanging them . I have 5 gallons of quench oil and when I quench I check for straightness and hang from a rod in the oil until I am ready . I don't know if any of this matters but sometimes its just little things that ruin a good knife. I have only got a few years under my belt but I use a lot of O1.
 
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