Oil based quenchants - mete and Kevin?

F

Fox

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Feb 6, 2000
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For many years I have used veterinary grade mineral oil as a quenchant achieving good results with O1, 5160, 52100 and 1084. However, the more I study the scientific side of metallurgy the more I realize that industry formulated quenchants are the appropriate medium. Mete and Kevin, your writings and the egghead books have definitely corrupted me! [:D]

My question concerns how to choose an appropriate quenchant for given steels. In front of me are data sheets for Chevron 70, Texaco Quenchtex A, B, C and MM, the entire Parks line and Exxon's Fenso series. Brownell's Tough Quench is another choice, but I could not find specific data for that product. What are the important factors in choosing a quenchant? How do I decipher things like viscosity index, Kinematic Viscosity vs. Saybolt Viscosity? How important is advertised quench time and what is its relationship to a particular steel? I recognize that there is probably not a single quenchant that is the panacea for all four of the steels used in my shop, but, how do I choose the appropriate quenchant for the steels noted above? I like the idea of Brownell's because it is readily available in small quantities. Comments by Roger, Nick Wheeler and Don Fogg lead me to believe that it is generally a very good choice for oil and water hardening steels. I guess the bottom line is: are there better choices that will make an appreciable difference? All comments and advice welcome.
 
Quenching is much, much more complicated than most want to admit. Factors that come into play are vapor point, flash point, viscosity, thermal conductivy and thermal stability. Most spec sheets will specify whether the oils was designed for shallow hardening (water quenchable steel) or oil hardening alloys.

You are correct that ther is no "one size fits all" oil. I am unfamiliar with a wide range of the oild out there because i found ones that work very well foe me and just stuck with them. I used one many years ago called Ammo-quench that worked very well on oil hardening blades and would throw a nice temper line on the shallow hardeners. which would indicate that it was probably a tad slow for these steels, according to industry. I now use the salts for oil hardeners and Park #50 for the shallow hardening stuff. I have some Park AAA for oil hardening steel and use it when I have some specifiac applications that the salts will not address. I have worked with some other oils in other shops and when "roughing it" have settled with some home made concoctions. The difference between most of these others and the Park oils is like night an day.

It is really wonderful the first time you quench into a perfectly clear oil and can actually watch your blade cool below the surface. Not flames no heavy smoke and no boiling turbulent shroud around the steel. When you notice how fast the blade drops below 900F. , and then the cooling slows as you approach Ms, it becomes very obvious some serious engineering and science went into the stuff. It is pretty cool :D
 
Some of the factors are more important for production use .F lash point is important for safety especially if you are differentially quenching. It also depends on what you are doing ; are you looking for hamon ? have you had quench cracking problems ? warping problems ? O1 in thin sections can be air hardening, that in hardenability would be followed by 52100, then 5160 ,then 1084.How many oils do you want to buy/experiment with ? You say Brownell's is available in small amounts, are you using enough to properly agitate ? Five gallons should be minimum, and the life is going to be more a matter of times quenched rather than just age. You should be able to do fine with just two oils a light one for 1084 and 5160 and a heavier one for O1 and 52100. Perhaps others can give specific suggestions for which ones to try.
 
I'm no expert, but the way I understand it is that Texico Type A is esentialy a heavy mineral oil, may be a few additives. I do notice a slight differance between blades quenched with one or the other, but the acutal quenching itself they seem to react the same to me as far as flame up and such.

Also you can change quench speed to a small degree by changing the quenchant's temp, the hotter the oil the faster the quench, to a certain point.
 
Thank you, gentlemen.

Kevin, in looking at all of the data sheets, none of them discuss vapor point or thermal conductivity, but most discuss flash point, fire point, pour point, viscosity index and quench time in seconds. I am guessing that when Texaco Quenchtex "C" gives a quench time of 10.5 seconds that there must be some industry standard part of specific size and steel that achieves hardenability in 10.5 seconds? Occasionally, as in the case of Chevron 70, the sheet specifically states that it is for deep, uniform hardening. That leads me to believe that the Chevron product is probably superb for the deep hardening steels, but not as viable for the 10xx series. Texaco gives nothing but numbers; no descriptive text of any kind. I guess I am just surprised that the data sheets, at least those available on the Net in *.pdf format, do not usually specify whether the product is for deep or shallow hardening steels. I guess I was looking for more of an industry guide of the quenchant qualities desired for various types of steels. Interestingly enough, the Texaco and Chevron products are much closer to the Parks 400 series when comparing just the numbers on the data sheets. Brownell's seems to match up well with the Parks AAA.

Mete, no, I am not looking for hamons necessarily, although I do differential quenching. One of the beauties of the veterinary grade mineral is the high flash point, which is nice for the differential quench. The mineral oil has worked well for me and I have no problems with O1 warping. I have not had a blade crack in several years. I do use a five gallon container with agitation and heat to 140F. By "small quantities" I was referring to less than a 55 gallon drum, which seems to be the industry standard. None of the local bulk plants will sell me less than that. I do not have the resources to experiment with too many quenchants. As I mention in the first paragraph, I was hoping there might me more of an industry guide for specific steels, not brand-name specific, but something listing the desirable oil qualities in terms similar to the data sheets. However, the more I read, it just is not that simple as real world application seems to play a prominent role in how a part is treated. I destroyed a 52100 blade this weekend that was quenched in the mineral oil and it passed the ABS tests that I threw at it, including the bend test, so I have to assume that the mineral oil is at least adequate for 52100 and O1. The grain in the 52100 reminded me of the grain in a freshly broken Nicholson file. I think the answer is definitely two oils, I just need to choose a second.

Will, I notice that the flash point of the Texaco "A" is up near some of the marquenching oils, but the viscosity is lower than the Chevron and Texaco "C" products. It must have a lot of flash retardants.
 
Thermal extraction rates fall under the measurement of quench times. For quenchants quite often the "H" value is quoted for quench severity, this is the quench speed in relation to water. Water =1 in H value so it is kind of like measuring specific gravity. Oil may have a .3 H value and brine could have a value of 2.

The quench time in seconds that you read, most often refers to the industry standard as measured by the nickel ball test. This is a test in wich a 7/8" nickel ball is heated to a high temp and then quenched in the oil. The time it takes for the ball to reach the currie point of nickel and become magnetic again is then measured and indicted in the "seconds" that you have seen. So this is what I was getting with thermal conductivity, it would be clearer to say thermal extraction rate, since convection can play a large part as well.
 
I knew I had more detailed information abot that ball test and I finally found it :)

The nickel ball (it can also be nichrome) is heated to 1625F. and then quenched with the time measured to 670F. (Currie temp). Another test I found consists of heating a silver cylinder that has a thermocoupler inserted in the center and then quenching.
 
Those last two posts clarify things a bit. Assuming that "Quench Time, s", which is in most of the sheets, refers to the nickle ball test, then the times specified should give me a benchmark for the relative quench speeds among the various quenchants.

My data sheet does not show the quench times for the Parks line. Kevin, do you happen to know what the times are for AAA and #50? With those two I should be able to work out some reasonable extrapolation of what each quenchant is best suited for, at least for my world.
 
I looked at the Park website too. It's interesting that the AAA is designed to cool at a rapid rate to get past the pearlite nose then has a slower rate as it gets to the martensite range .Olive oil isn't designed to do that !! Why don't you contact Park ? They ought to know their quenchants better than anyone.
 
mete said:
I looked at the Park website too. It's interesting that the AAA is designed to cool at a rapid rate to get past the pearlite nose then has a slower rate as it gets to the martensite range .Olive oil isn't designed to do that !! ...
Click to expand...

That was my reaction, except I, didn't read it, I experienced it. I had been using another oil, then the first time I used the AAA I put on my gloves and prepared to interrupt the quench at around Ms. I had gotten quite used to the time it takes to reach this point with other oils, so just by habit I pulled the blade out at the usual interval and grabbed it with my gloved hands. I let go real quick too :eek: ! It had to be above 600F. still. That oil got it from 1500F. to 850F. (through the vapor blanket stage and vapor transport stage) as fast as any other oil I had worked with, but then slowed the process way down during the liquid cooling stage for a gentle martensite transition. Made a beautiful blade, almost ruined my gloves :(

Olive oil isn't designed to do that, indeed! I have no problem with folks using whatever they can for quenching, it keeps things interesting. I do, however, have a problem when they try to say there is no advantage to using a real oil designed to do that job. That is just silly, when you have seen what some of these good oils can do.

I have worked with some quenchants that I could believe are just glorified mineral oils, but the good ones have had some serious science and engineering thrown into them. Heck Park #50 can give some affects that many swear can only be achieved with water. In the winter the stuff will crystalize like water. Not just get sluggish, I am talking acicular, needlike crystals that would make you swear that it is amber colored water (preheat is a must for many reasons with this stuff)
 
Fox said:
My data sheet does not show the quench times for the Parks line. Kevin, do you happen to know what the times are for AAA and #50? With those two I should be able to work out some reasonable extrapolation of what each quenchant is best suited for, at least for my world.
Click to expand...

I have some papers on them somewhere. All I can say is that I will let you know if I find them, but I wouldn't hold my breath for anything being found in my office :eek:
 
Thanks again, guys. I emailed Parks through their web site but have not heard back yet. If I do, I will post the information here on the board.
 
Your comments about the HT oil crystalizing in the winter reminded me of a past train of thought. Have you ever experimented with Water/oil emulsions as quenchents? With a strong emulsifier such as a strong detergent you might be able to emulsify a heavy oil in water. Have you ever used a satuarated solution of Sodium Hydorxide (Lye) as some old shop manuals recomend as a severe quench? Many thanks, I always appreciate your postings.
 
I have led a boring life. I have not played much with mixing quenches, and have never had a use for something as extreme as lye, due to the steel that I prefer.

I do have this quote from the ASM book "Quenching and Martempering":

"Water- Oil Emulsions: As indicated by the comparison of cooling curves presented in Fig. 18, emulsions of water and soluble oil combine the worst features of water and oil quenchants. The center cooling curves of an emulsion consisting of 10% soluble oil and 90% water at 75 and 125 F. clearly show that massive vapor envelopes are formed at the beginning of the quenching cycle. Thus, the higher bath temperature, the initial severity of quench is reduced below that of a conventional oil. Cooling in the latter stage is essentially the same as in water. For emulsions containing 90%soluble oil and 10% water, cooling rates are lower all the way down, compared with conventional oil. For these reasons, oil and water emulsions generally are inferior to other quenchants."

The question I always have to ask myself whenever I start to thing of mixing up my own concoction is "why? Is there somethign lacking in my current quenchants?". This usually brings me back you a happy satisfaction with my current setup.

The above quoted book has loads of information on just about every quench medium you could imagine (includeing sodium hydroxide) and would probably be very useful in your research. I just got it last year and it has all of the information that I have been collecting for years inside of one cover. I would give you and ISBN but it is not listed. I believe this book would put any bladesmith miles ahead of many others when it comes to quenching, and leave all those who read it permanently cured of the homemade magic potion quenches. I can't recommend it enough.
 
Kevin R. Cashen said:
I do have this quote from the ASM book "Quenching and Martempering":
Click to expand...


Kevin, is this the book you mention?:

Title:
Quenching and martempering, by the ASM Committees on Quenching and Martempering.
Author:
American Society for Metals. Committee on Quenching.
American Society for Metals. Committee on Martempering.
Published:
Metals Park, Ohio, American Society for Metals [1964]
Subject:
Steel --Quenching.
Series:
ASM monographs on heat treating
Material:
xiii, 277 p. illus. 19 cm.


:)

-Darren
 
Yes that is the book Darren. Hey, you should get a few copies and some of Parks oils and sell them as a package! :D Everything a guy needs to get started heat treating like the pros! :D ;)
 
Ok so now that I'm convinced about switching to a comercial quench oil, where can I get some Park's #50? Preferably in smaller quantities than 55 gallons, but well I'll take what I can get.
 
For small quatities of Parks products contact Stephanie Gregoire at sgregoire@heatbath
I just purchased 5 gal of #50 and 5 gal of AAA with shipping for $135 using this contact. I believe the minimum transaction at Heatbath is $100.

BTW, Seth Howard did the leg work on this.

thanks,
dms
 
Kevin Cashen ( who I one day want to shake hands with and thank for all the help, information, and inspiration ) gave me the info I needed to get in touch with the right people at Heatbath.


Seth
 
I just tried to send an email to Stephanie at that address about three days ago, and I got an automated response that that email address is no longer in service at HeatBath.

Any other ideas?
Nick
 
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