Quench speed

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Apr 12, 2006
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I've dug around on here and other forums for a while and haven't turned up the answer, so my apologies if this specific question has been answered.

I've been using canola oil for quenching my 5160 with pretty good results, but I'm wondering if I could bump the edge holding a bit with a faster quench. I'm thinking of trying the 11 second quench oil from McMaster-Carr. I've had good results with their 28-second stuff on my 4140.

But, I haven't been able to find anywhere how many seconds quench canola is. I know the number of seconds comes from how quickly it will drop a particularly-sized ball of nickel from one particular temperature to another particular temperature.

So is canola oil (assuming it's fresh and appropriately pre-heated) going to be a faster or slower quench than the McMaster 11-second stuff?
 
Is there any faster line in CCT for 5160? Does it give more HV than value that you get? If no, then quenhinch speed is not the key. You can allways try to make grain smaller.
 
I would think you'd get better results quenching slower than canola. You have almost 5 seconds to get it below 900F and you should be at around 1525F when you quench, unless you have the ability to hold an accurate soak. 5160 needs a slow oil... preferably, an engineered 11 sec or greater oil. I have and still occasionally use(when the situation permits) canola. But I always think of Kevin Cashen's post when I do.
 
My limited experience tells me that the difference between 11-13 second oil and 7 second oil like #50 is much greater than say the difference between the 11-13 and the 28 second stuff. I may be wrong, but by oil standards, Parks #50 is a fairly "violent" quench whereas the Tough Quench, McMaster-carr, etc, not so much. With that said, the only time that I have ever had a problem with room temp #50 even with deep harding steels is with thin blades.
 
McMaster-Carr 11 sec. works great on 5160. I have the 11 sec. oil and Parks #50. I use the #50 on 10XX steels and W series steels and 11 sec. oil for everything else.
 
Not to knock anyone, but I still don't know whether canola is slower or faster than the 11 second quench. :)

Idaho - I do a triple normalization cycle prior to hardening to refine the grain already.

Karburized - I don't have any Rockwell numbers. My customers seem happy with the edge retention, but if I can push a few more cuts out of it by changing oil, why not?

Rick - I think the pertinent part of the post you linked to was in the picture that is no longer there. I re-read Kevin's post several times to make sure I wasn't just missing what he was saying. Could you summarize what the picture showed?

And while I have your attention, what were you quenching in for your 80CrV2 testing? Some kind of Sasquatch oil? (The first is a serious question, but the treaty that keeps Texas from invading Canuckistan [aside from the cold y'all have been attacking us with this winter] means I have to ask in a snarky way.)

Jdm61 & Darrin - Interesting. I need to look into the Parks 50's applications more, see what steels benefit the most and if any are the ones I use.
 
You won't gain toughness by speeding the quench unless the quench is too slow for the steel type. If the steel is 5160, the canola is doing all it needs already. As Rick said, an engineered slow quenchant might gain a tad, as it allows a smoother conversion. I doubt you could tell, though.

I haven't seen reliable numbers, but from what I have seen and read, canola falls somewhere between 11 second oil and 7 second oil...closer to the 11 second mark.

The short and sweet of it all is that if you are trying to assure top quality on blades you sell, use top quality quenchant. Canola works fine for the hobby maker .... Heatbath/Parks/Brownell's /etc. works better for the professional.
 
Rick - I think the pertinent part of the post you linked to was in the picture that is no longer there. I re-read Kevin's post several times to make sure I wasn't just missing what he was saying. Could you summarize what the picture showed?
Kevin summarizes better than I...
"The real point of this post is that making a real quench oil isn’t all that simple and testing it is even less so, believe it or not these are just rough preliminary tests and not all that exhaustive. I hope this gives somewhat of an insight as to my perspective when I express my doubts about all the homemade and improvised quenchants some folks feel work “just fine”, and I hope it gives pause to those of who feel carefully formulated quenchants are unnecessary."

He also points out the fact that the common things knifemakers test for(file skating, edge flex test, etc...) are not always indicators of what the true internal structure of the steel is.
And while I have your attention, what were you quenching in for your 80CrV2 testing?
I quench in HQ-K(roughly equivalent to P50.) and canola for non-critical stuff like strikers... or when I'm doing a demo at a site where environmental issues come up. I messed around with multiple quenches and extended soaks. In the end, I treated the 80CrV20 like 1080 with some added alloying. I gave it a 10min a soak at 1500F and everything checked out well with penetration testing. I still have the test coupons from the experiments but never got around to sending them out for micro-graphs.
 
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We use parks 50 for all 10xx steels and 80crv2, then we use 11sec McMaster carr for most everything else..I tried 52100 in parks "once" It broke cleanly in two with a .030 thick edge. Ive used canola a lot myself and I don't think the 5160 is going to get any harder than what your getting it. You may get a smoother transition from 11 second oil but I don't think you will get any more hardness.
 
Thanks everyone! There is so much to heat treatment that I'll never know, but I appreciate getting to pick the brains here. :)

Stacy - I know that the canola vs. engineered oil debate has been hashed through and am not trying to open any old wounds, but what would you say makes the engineered oils better for the professional? The greater stability?

Rick - Ah, got it. You weren't wanting to show the results of that particular test, but the fact that there's more to a quenchant than most folks realize. :)

Kentucky - Interesting. I'm about to be playing with 80CrV2 myself and will keep that datum in mind.
 
I agree, after heat treating 100+ 5160 knives with both canola and 11 second oil... you will get a slightly tougher knife with 11 second oil. I'd bet the canola is faster by a margin after testing many blades.

5160 can also hit a somewhat high hardness out of quench, sometimes it needs a higher temper temp than usual depending on your heat treat regimen.
 
Engineered oils are not just one oil. They are made from oils and other chemical things that have different attributes. The total package is where the engineering comes in.

What is the difference:
Better quality quench - The difference in the quench results of most all non-commercial quenchants is normally less than the results from the proper commercial quenchant for that steel. The slower the steels CCC, the less this matters. In the fast quenching 10XX steels, it can matter a lot. The only home quenchant oil I ever suggest is canola, which is pretty good for most steels.
Much longer life - degradation and other oxidation issues are taken care of by buffers, retardants, and oils selected for the blend. These things will also prevent the oil from burning/scorching and reduce flare-up.
More stable life - part of the above, but the oil will not slowly degrade, and thus slowly change its quenching parameters. Its life should be many thousand blades with no appreciable change in quench results.
More reliable results - The commercial oils are tested thousands of times, and the results can be relied on. No so much with any home brew or even canola. The consistent and reliable results are the commercial quenchants life blood, and they are very carefully checked. As need changes, these oils are re-balanced and improved upon to keep up with industry changes and new steel types.
Variable cooling curve - This is the biggie. The cooling rate changes as the structure of the steel does. Faster in the drop through the pearlite nose, and slower as it reaches the Ms. Canola will have one rate only.
This is what the different speed oils are about. It is not just how slow the oil cools the steel, it is how evenly and at what rate thorough out the entire quench.
 
If you quench a thin blade of some deep hardening steel in #50, you may find that it magically blows the hell up! :D
So parks #50 isn't the magical oil for every steel like I've seen many others say?
 
heere is the magic quench the steel you want to use as fast as you can without cracking it . once you get the steel as hard as it an be you cna tempe it to the specs you need it.
 
heere is the magic quench the steel you want to use as fast as you can without cracking it . once you get the steel as hard as it an be you cna tempe it to the specs you need it.

Translation

Here is the magic:
Quench the steel you want to use as fast as you can without cracking it .
Once you get the steel as hard as it can be, you can temper it to the hardness and toughness you need it at.
 
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I like Butch's original encrypted code better, Stacy ... it's more open to interpretation.
 
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