Quenching 52100 in Parks 50?

C

coldsteelburns

Joined
Aug 2, 2010
Messages
1,611
I was wondering what the drawbacks of quenching 52100 into parks 50 are. I'm going to HT 3 blades tonight and I don't have enough canola oil to disperse all the heat, on have a small bread pan full, so the oil will basically be too hot right after the first blade, not to mention I am going to normalize and thermocyle them with one quench each during the decending cycle heats prior to the actual quench so that won't help either. I usually only do one blade at a time but I made 3 similar blades and am doin the same stage on each of them at the same time. I do have 5 gallon of P50 though (maxim shipped it to me in a blue 5 gallon PLASTIC bucket), but I normally just use a 1 gallon paint can that I filled up with my P50 for single blades. (On a side note: Would it be dangerous just quenching 3 smaller sized blades with the oil still in the plastic bucket they sent it in?)

Is the drawback to not using a slower quench like canola oil for example for 52100 just that there is more chance for warping and cracks? Or does it cool it too fast that in some way inhibits it from fully hardening or reaching its potential? Just so you guys know what I'm dealing with, the 3 blades are ground only about a third of the acual bevel height and I left the edge about .040" thick. I'm sick of screwing up blades after HT which had perfect grinds ect. by taking too much off tryin to fix my grinds due to slight warpage or for w/e reason because I'm still teaching myself to freehand, and when I achieve a good bevel I don't like messin with it, cause 90% of the time I'll mess it up... So I decided this time to leave a good amount of meat and do most grinding post HT, but still establishing the bevel pre HT. The steel is Aldos 52100 and it's .110" thick and the widest part of the blade itself is 1" and I ground a bevel about .315" or about 1/3 of the way up the blade, and like I said left a thicker edge at about .040" for doing most the grinding post HT.

It has always confused me when I see guys at home doin larger batches of blades and HT them all at the same time using the same quench bucket, you would think, or at least I do, that each blades HRC for perfomance would turn out different do to the oil getting much hotter afte each blade, so the cooling rate would change and not be consistant. Is this a reasonable thing to be confused about? :confused:

Anyway if you guys can give me any advice on this subject I'd appreciate it a bunch :) Thanks!

-Paul
www.youtube.com/Lsubslimed
 
Probably too late, but a trip to the grocery store would find a couple gallons of canola on the cooking isle. You need a lot more than a bread pan of oil for any quench. 2-3 gallons is what I consider the minimum...especially for multiple quenching of three blades. While you might get away with #50 and 52100, it is faster than needed.

TIP:
Take a couple empty one quart plastic milk jugs [/I, fill them with tap water, and freeze them. When the oil gets too warm from quenching, wipe a frozen bottle off ( to keep condensation moisture out of your oil) and stir it around in the quench tank. It will drop the temp a lot faster than sitting around waiting for the oil to air cool.
 
On a similar topic I like to edge quench my 52100 knives(in Texaco type A) and the 24" long pan only holds a little more than a half gallon of

oil do you think this is a problem for hardening my knives? At present I only do about two knives at a time.

Thanks
 
I have no problem quenching 52100 in Parks 50. I don't do it any longer, as I like to save the Parks for the steels that need it. Some steel require a really fast quench, which Parks 50 is certainly that. Steels like 1095, W2, W1, 1084 should have a really fast quench. You have like about a second to get under the pearlite nose. But 52100, with it's alloy content, hardens quite well in canola...so I would do as Stacy suggested and hit the cooking oil aisle at the local grocery store! Funny, I just did a 52100 blade yesterday, debating to myself whether I wanted to use the P50 again or canola. Decided with the canola. The plastic bucket Maxim ships the oil in....I did quench a few in it, but I was worried about accidentally dropping a screaming hot blade down in there, and it "eating" thru the bottom. I don't know if the steel would remain hot enough to do that once it hit the bottom, but I put a metal plate down there just in case. Then I got even SMARTER (hold on.....look out) and put half of it in a steel pot, deep enough to do any quenching. The other half is kept stored in the plastic container in case the other half gets too "old". Is there quantitative data on that stuff? Like a half life or something? :) I always heat the canola to 130F. Depending on the amount of quench oil you use at any given time will determine how much rise in temp you'll get after so many numbers of quenches. The more oil...the less rise in temp. Mr Rohde....maybe someone else can give better advice...but without knowing exactly how big of a blade, I would think a half gallon is not enough. But it just depends on how much mass you are trying to quench in that half gallon. If the edge is getting hard for you...then you have enough oil! And Paul, I see you like to quench on your thermal cycles. I've been wondering about quenching vs air cooling only, and after much discussion with some of the well known heat treat gurus out there....I usually only allow them to air cool, after normalizing and after each thermal cycle. The thought there being that the air cool is fast enough to keep the carbon there, without the possible risk of microfracture inside the steel structure. While it might be true that quenching during each cycle might refine the grain a bit more, the difference not being enough for most smiths to risk the micro-cracking possible with blades quenched many times. Especially if one quenches on that first normalizing heat of 1650F. Aldo's 52100 is great stuff to work with, and makes for a FINE blade.
 
I have quenched 52100 in fast oil. It does not need it, and there is risk of fracturing the steel. Interestingly, the datasheet lists oil quench at the higher austentizing temps, and water at the lower end of the range.
 
Daniel Rohde said:
On a similar topic I like to edge quench my 52100 knives(in Texaco type A) and the 24" long pan only holds a little more than a half gallon of

oil do you think this is a problem for hardening my knives? At present I only do about two knives at a time.

Thanks
Click to expand...

Yes, I think there is a problem with hardening your knives....but it is the edge quench. Fully hardening the blade and drawing the spine softer is a better method metallurgically.
If you decide to do edge quenches, I would use a smaller volume than for regular quenches, as you will destroy the quenchant much faster, and need to dump it and refill the tank with new oil much more often. Quenchants like #50 will degrade fast with repeated scorching and flare-ups.
Additionally, the edge may be severely auto-tempered by the spine heat in an edge quench on a hyper-eutectoid steel, and not achieve full hardness.
 
Hope this isn't off topic- how do you tell when Canola is no good anymore? Does it look different?

What is it that changes, and how do those changes affect the quench?

When to use it to warm the shop and go to the store for new stuff?
 
Canola Oil is an organic oil. It is a mixture of fatty acids,(saturated, and mono/poly unsaturated), and a bit of erucic acids. With exposure to air it degrades. With exposure to air at 1000+ degrees, it burns and degrades rapidly.

Commercial quench oils are mineral oil, and are much more stable. Air exposure doesn't do much to it.

Both will degrade with burning/overheating, so a full quench to place the 1000+F blade under the surface...and away from oxygen.....is how to make it last.

As it degrades oil will darken. Just like your deep fryer, when the oil gets too dark, or the canola starts smelling foul, it is time to replace it. I have used a tank of parks#50 for many years before discarding it.
 
Daniel Rohde said:
On a similar topic I like to edge quench my 52100 knives(in Texaco type A) and the 24" long pan only holds a little more than a half gallon of

oil do you think this is a problem for hardening my knives? At present I only do about two knives at a time.

Thanks
Click to expand...


Where are you getting Texaco A?
I thought it was discontinued some time ago.

edge quench my 52100 knives(in Texaco type A)
Click to expand...
That sounds like an Ed Fowler potion

There are much much better sources of info.


For example you develop full strength in fully hardened blades.
More important to me than flippy floppy bending.
 
12345678910 said:
Where are you getting Texaco A?
I thought it was discontinued some time ago.


That sounds like an Ed Fowler potion

There are much much better sources of info.


For example you develop full strength in fully hardened blades.
More important to me than flippy floppy bending.
Click to expand...
to a point I agree that bending a knife back and forth allot does not make sense
it was discontinued I actually got my oil from Ed(who bot allot of the last stuff...he sold me a gallon when I was out there).

Thanks Stacy I will be looking into the full hardening and spine drawing.
 
You must log in or register to reply here.
Back
Top