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what about quenching into 400 degree oil??


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what about quenching into 400 degree oil??

would that lend the same effect as the marquench salt?? I was thinking of using O1 for this as the harding curve is pretty generous. What say you guys? I have oil with a very high flash point made for quenching.

I temper in 400 degree oil why not quench??

Plus I have such a bloody blister on my fingers from the Cashen patent "ouch test" its begining to get well ..... wierd from my girlfriends point of view.

thanks-Ian

Please disregard what I have just written,

Ian

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I've been wanting to experiment in this area too. Basically I think you'll marquench and form bainite if you quench austenized steel into 400-450 degree oil and hold it there for several hours. Of course i'm talking in generalities, exact temps and soaks will be dependent on the specific steel. I think what your aiming for is quenching to a temp just above where the steel will form martensite and holding it there for a period. I think Jesse Frank said he was doing his bainite swords this way in peanut oil.

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Yes , it all depends on the steel. For that you need a TTT diagram. Marquenching quenches to just above the Ms temperature . For example the Ms for 1095 is just above 400F and for 52100 is 480 F.If you can get to just below the Ms that will help too in reducing quenching stresses.If you are trying to austemper for bainite you have to be just above the Ms and hold it there until the bainite transition is complete. For some alloys this time is excessive and they are not suitable for austempering.

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Yeah, use peanut oil. That seems to have the highest flash point.

 

Incidentally, I've through hardened W1 marquenching @425f in peanut oil. Much of your success will depend on your ability to control your austenitizing temp and soak time.

 

It's fun playing around with the different effects you can get with different combinations of quench temp and austenitizing temp.

Rósta að, maðr!

 

http://jfmetalsmith.com/

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what about quenching into 400 degree oil??

would that lend the same effect as the marquench salt?? I was thinking of using O1 for this as the harding curve is pretty generous. What say you guys? I have oil with a very high flash point made for quenching.

I temper in 400 degree oil why not quench??

Plus I have such a bloody blister on my fingers from the Cashen patent "ouch test" its begining to get well ..... wierd from my girlfriends point of view.

thanks-Ian

38951[/snapback]

 

 

From the little I know about it, if your martinsite finish point is say 400F for the steel you are using and you quench at say 425F and hold for a little while and then air cool or quench to room temp you are surposed to get a better, or more martensite transformation ( less retained austenite ). If you want bainite, now this is for crucible L6, you would quench at about 650F and hold for about 30 min and then air cool to get about 50 Rc, which would be a good spring. If you wanted to get say 57 Rc you would quench at about 400F and hold there for about 15 hours and then air cool. The TTT curve diagram that I have for L6 looks like you could get a harder bainite if you could hold at the quench temp for longer, say 90 hours at350F fot about 59 Rc, but thats where the chart ends so anything else is speculation, plus I was told that the top end of bainite was around 57 Rc. So I really don't know any more about it. But for a good normal heat treat quench into a bath a little higher then the martisite finnish point, hold for a few minutes and then air cool. This is what I've learned from listening to Howard Clarke and from the TTT curve chart I got from Crucible for thier L6. Please feel free to correct me on any of this if I'm wrong, as I have never tried any of this out, since I do not yet have salt tanks. :wacko:

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I have not done this with L6 either but if I read the chart correctly you will be below the Ms point at 400f....the chart shows that Martensite begins to form at just below 450f. Maybe 435 or so?

 

I have done this a lot (marqenching, austempering) with 5160 and if you quench below the Ms point but above the Mf point you will get a significant amount of transformation to Martensite. It ends up being autotempered and tough as hell (good stuff for knife and sword blades!) but a slightly different product than Bainite. It doesn't seem to take the abuse quite like Bainite and it does not flex or yield quite the same. It does end up harder and a bit more abrasion resistant. In 5160 and O1 the characteristics are rather distinct whether I quench just above Ms or just below.

 

I wouldn't argue with Howard about it as I'm sure he knows a hell of a lot more about it than I do. B)

 

But I have always found that if I marquench (the desired product being Martensite) I can quench a deep hardening, low alloy steel either just above Ms or even all the way down to about 350f or so and the blade will get full hard as it cools to ambient. If I wanna do Bainite, I quench and hold the same steel distinctly above Ms and hold for the length of time it takes to get transformation at that temperature. The higher the quench and hold temp. the shorter the transformation time.

 

I'm skeptical that quenching L6 to 350f will result in a primarily Bainitic structure (I'd bet on mostly autotempered Martensite) but then Mete, RK, or Howard may be able to enlighten me to the contrary.

 

Brian

"Imagination is more important than knowledge" - Albert Einstein

 

"The innovator is not an opponent of the old. He is a proponent of the new."

- Lyle E. Schaller

 

http://home.mchsi.com/~hermits/BrianRVanSp..._Edged_Art.html

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You guys have lots of time on your hands and lots of money for energy if you want to hold long hours for bainite . About 10 hours for L-6, that's a long time ,make sure the benefit in properties is worth it !..I'm not sure what happens when L-6 would be quenched for long times at 350F, probably a martensite/bainite mix. But that alloy is pretty tough with just martensite.

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  • 3 months later...

Peanut oil is a good choice - as is canola oil. Both have really nice cooling curves, with a high boiling temperature and flash.

D. Scott MacKenzie, PhD

Heat Treating (Aluminum and Steel)

Quenching (Water, Polymer, Oil, Salt and Mar-Tempering)

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Hi Dr. MacKenzie,

 

Welcome to the forum, and thanks for the info!

 

Do you know where I can get hold of any charts or other info on the cooling rates of Veg. oils?

 

Thanks!

 

I believe that CHTE (Center for Heat Treating Excellence) at WPI has some information on their page. If not there, then you can try some of the recent ASM Conference proceedings on Heat Treating. If not there, I may have some that we have done - specifically Canola Oil. If fact we have a product that we sell that is manufactured from Canola Oil that does a wonderful job - except it is expensive. One of the troubles with using salad oil that you buy from the grocery store, is that it has a quantity of water in it that changes the cooling curve. This can cause soft spots, or potentially cracking - depending on the water content. I may also have it on my "Information for Heat Treaters" page, under the topic "Advances in Quenching".

 

I will see what I can find... maybe I will figure out how to attach stuff.

 

BTW - I go by Scott..... :D

D. Scott MacKenzie, PhD

Heat Treating (Aluminum and Steel)

Quenching (Water, Polymer, Oil, Salt and Mar-Tempering)

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