Triple quench secrets to be revealed?(or not)

Status
Not open for further replies.
Seth good Idea.

And also If temp can't be judged accurately by eye then
how are you supposed to get even remotely close on the grain size? If we want a "sientific" test then the samples should be sent to a Metalurgy labratory for a complete analysis. Things like grain size and carbon loss and wheather or not there is any retained austenite cannot be judged by eye. Although you can see if there is a big difference in grain.
 
That might be best then. Can someone send me a couple sample pieces of 5160 cut from the same bar stock that has not previously been hardened??

RL
 
You know, I never really paid that much attention to the methods of HT the multiple quench guys use until this thread. Now I am noticing more and more that the ones that promote it are forge or torch heaters. One of the best I treated was double quenched. Yes, from my little home made gas forge. I am just about of a mind that these multiple quenches have more to do with inconsistant heating than multiple quenching. I said this before a little earlier here but I have been paying more attention to how multiple quenchers austenitize since then.

How well, anyone want to send me some 5160 or should I go with the O1 I have?? I have some D2 but I hate to have to grind deep decarb since that will make it more difficult to keep each sample consistant (because of varying heat caused by grinding). Even with O1 I will need to grind off decarb for the diamond penetrator to give a consistant depth. The O1 decarb will not be that deep though and there will be less grind heat and work on it. What I complain about may be academic in that I may not be able to resolve the difference on the tester dial caused by inconsistant grinding heat and work between samples. However, I think it best to go with a shallow decarb temperature rather than a air/oil quench steel that requires higher aust. temps.

RL
 
Guys, I am quite positive, as a metallurgist, mete is not expecting rlinger to make a grain size "number" presumption. Just a simple inspection to prove a point. Which can be plenty effective for the said test.
I did a similar test once and all my "eyeball" methods varied from very fine to coarse and I tried single, double and triple methods. Also, the levels of hardness, hardenability and toughness ranged too much. My kilns on the other hand, nailed them perfectly consistant every time, with every intended effect. I was stunned, enlightened and will never go back. Also, all single quenched. The steels I tried in those tests were both 1084 and 1050 back then.
And saying that, lastly, I'd like to say, back in the day (pre-metallurgists), nobody new any better and steel was inferior and inconsistant in quality, compared to today. These days we have premium steel and premium methods producing them... so, why go backwards and use less than precise HT methods to accomodate these advances?
 
This discussion sounds promising!
Men planning real tests.

I have a comment to the tests, in fact two.
Tests can scientificially thinking be best as you planned.

However, most practical smiths are relying on Ed Fowler's triple quench and test done by rope cutting.

If test is made in laboratory it is convincing to many but MOST of the smiths say: "Nonsense, they studied factor x and factor y in laboratory, in fact unknown factor z makes blades better with triple quenching, they did not make a real test which is a rope cut as Ed did."

To my understanding this is a key point.
If only lab tests done, metallurgists are convinced but they are already.
Smiths are not convinced as they are not this moment.

In fact we wasted time.

I understand that the rope cut test is difficult.
Should we recryte a baseball team to swing knifes?
In the Ed's Blade magazine and book documented tests it did take hunders of swings to cut ropes.
A triple quenched blade did take about 130 rope cuts to dull, and he had many test blades of all types.

Also 5160 is a must for the same reason, Ed used it and said other steels can be different.

To Graymaker: You were smiling at me triple times ':D' ':D' ':D' (suits to the theme, tough). It is easy now to smile at Finns when the summer temperature in Finland is above liquid nitrogen. But the winter is coming for sure and Finnish knifes will outperform all American blades.

Then it is not only a blade which is frozen it is your smile too. Think about that! ':eek:'


pig
 
Unfortunately I am retired and no longer have access to a lab, otherwise I would do a proper ,complete investigation. Jason is right the fracture surface would give you a comparative idea of grainsize not a number. I hope someone will supply rlinger with some 5160.At the proper hardening temp and the short times involved grain growth and decarb will not be a problem. It should be obvious who I am on sword forum if you read the postings -Robert C . H.Clark and K.Cashen are VERY knowledgeble smiths, skilled , experienced,know their metallurgy, you can learn a lot from their postings.
 
Pig,

You make some very good points in your last thread. I would like to add a few if I may since Ed Fowler’s results have been brought into the mix.

1- Ed fowler uses used John Deere Load Control Shafts as his source of 5160 steel. These are round stock ranging from around 3/4" to 1 1/4" in diameter. I have been able to find these for free at the local John Deere shops just by asking. I have half of a shaft left that I will donate to the cause if Roger is willing to forge it.

2- Tempering is not necessary after each quenching cycle when using Ed’s guidelines. The blade is quenched and left in the oil to cool to room temperature and then placed in the freezer overnight followed by two more cycles of the same before any tempering cycles are completed. I know that this will be frowned upon by some of you but it’s what Ed recommends and it’s what I have been doing and I have had no problems just exceptional results.

3- Just for the record, Ed uses a magnet to determine when a blade is at the proper temperature. It seems like someone in an earlier post mentioned the need for pyrometers to determine proper quenching temp’s. Although it’s not as precise as a pyrometer can be, a magnet never needs calibration either. So far a magnet has been everything that I have ever needed or wanted.

Since Ed is being used as a reference, are we going to be using Ed’s methods of forging and heat treatment for the triple quenched blade or are we going to keep this as controlled and clinical as possible to measure only one facet of heat treatment results i.e. grain size and carbon loss?

Rick
 
RL. e-mail me your address and I will send you some JD load shaft material that has been forged in the manner that Ed has used in the past. I have a shaft that is already forged out to about 1/4 by 1 inch. It has not been anealed or normalized though so I will have to do this before I can send it. I can forge to a thinner cross section if you prefer before the normalizing and anealing. and I will surface it to a uniform thickness also.
 
Finns when the summer temperature in Finland is above liquid nitrogen. But the winter is coming for sure and Finnish knifes will outperform all American blades

Now wait a minute pig!!!This thread was enjoyable until you started knocking American knives. You don't know the whole story!!!

While we do triple quench, it is not needed. The truth is that REAL AMERICAN KNIFEMAKERS heat the blade with a bolt of lightening and quench in a clap of thunder. The reason we do it three times is because it was so damn much fun the first time!:eek: :D :eek: :D :eek:
 
Bill, great. I sent you an email. When you know the final thickness mete can specify soak time based on that.

Roger
 
rlinger, 5160 in the freezer ? I don't see the logic there either. The tests should be done with similar size pieces ~ 1/8".
 
METE..

I read in Knife Talk by Ed Fowler about putting the blade in the freezer, but he only says it in passing, and not like he actually thinks we all need to do it,,...

I dont think ANYONE has ever found if this was good or bad for the knife. The idea is a good one for me only because it helps me remember where my knife is...
(although here in North Dakota for most of the year my shop is cold enough to be called a freezer.)

I also hope you guys test just 5160 as this is the steel I try to make most of my knives from and I could use all the advice you can come up with as to why some Heat treating things work, why some things dont, and why some things might seem to work from time to time...

last night I started a new 5160 blade out in my forge. The steel came from Texas Knife maker supply I think. I did the many dunkings in cold oil thing again like Ed Fowler wrote to me about.
I think as I forged down the tang I must have dunked about 7-12 times in cold oil before I started to do that next step where I heat 2 times to watch the color changes, etc, etc,etc
 
Now wait a minute pig!!!This thread was enjoyable until you started knocking American knives. You don't know the whole story!!!

While we do triple quench, it is not needed. The truth is that REAL AMERICAN KNIFEMAKERS heat the blade with a bolt of lightening and quench in a clap of thunder. The reason we do it three times is because it was so damn much fun the first time!
Click to expand...

Peter: I am not knoking American knifes! Those are the second best and a silver medal is nice too, nothing to be shamed for.


We must really test this also to be sure, you send me your best American knife and I compare it with a Finnish "winter time outdoor frozen" knife BY TRYING TO CUT A CAKE BAKED BY WIFE. I quess this makes you think, and speak more carefully! :confused:



pig
 
Mete,

I talked to Rex Walter, today and we discussed the freezer thing. He told me that he had thought as you do that a freezer would not be cold enough to make any difference in the steel. He then told me that recently he was doing some kind of testing (I can't remember the name), where you take piece of steel and heat it up in a holding fixture and when at temp a stream of water is directed at only one end. After cooling Rockwell readings are taken every 3/8ths of an inch down the length of the bar. after doing the standard test for the company he took the bar home and put it in the freezer overnight. The next day on his lunch break he retested the same bar as close as practically possible to the previous test points. What he found was that his readings were at least a point higher through out the bar after it had been frozen at -20 for twelve hours.

Rex also reafirmed what I wrote above about the triple quench tests that he did.
 
Bill emailed me that it will be a few days before he can forge and anneal the 5160 and send it out to me. Because O1 is not what is wanted tested I am not going to bother with the O1. I will wait for the 5160. Bill is also sending a sample piece of his own receipe. I think that is a real good idea. I can test all four samples (my three and his one) with the same Rockwell tester. Remember guys, all I"ll be doing after HT is Rockwell and grain; no wear or edge retention tests. I can ship the samples to any of you that want them after that.

mete, you need to specify whether I should plug in a 'equalize' cycle in the HT. I would. However, I want to stay out of the HT specs so that I can remain unswayed by my own biases. You specify. I'll HT.

Please advise. RL
 
Bill...was there any idea as to what was going on?

Take a guess,,Let us just say that putting a forged blade in a freezer helps the blade in some way,,,HOW could such a thing happen?

Although I dont know anything about Rockwell hardness numbers, it seems to me that if you test a blade at say...30 hardness before any heat treatments, then you test it after your heat treatments and come up with a number like 52, Then freeze it for a day then re-test it getting a number like 54, then I would guess that whatever happens in steel during the normal heat treatments to bump the hardness numbers up from 30 to 52 would somehow still be going on in the freezer ..correct?
 
guy's cryo is effected by time as much as temp. More time, less cold can get similar results to very cold and shorter times. Balance, as with so many things in metallurgy.
 
Status
Not open for further replies.
Back
Top