heat treating hype and reality

[Matthew Gregory]

I don't know about beards, but maybe a good 'beer gut' would help by mellowing the resonance of the hammer blows-- making such blows more 'sympathetic' to the harmonic predisposition of steel atoms. :thumbup:

That and an XXL magnetic bracelet strapped around the horn of your anvil and you're all set!

Jim Siska told me I'll never get good at grinding until I develop a "Biological Tool Rest"... he plants his elbows into his belly to steady himself, so there's got to be SOME merit to it!

... come to think of it, he doesn't have a beard. He doesn't forge knives, it's all stock removal. Maybe he doesn't forge because of not having a beard?

 

[JCaswell]

Resonance of the blows ? They just tore down a bridge here .When they were undercutting the concrete of one of the supports they hit the resonant frequency of the truss.!! The whole truss vibrated, a shower of debris came off it and the sound was very obvious - a low frequency pulsing !!! The photo shows the truss just as it came down, the whole thing resonated just before !!

It's high time we harness the energy of harmonic resonance in forging!!!

Nurture and respect that 'beer gut.'

 

[JCaswell]

Maybe he doesn't forge because of not having a beard?

Actually the connection is very clear between beards and superior forging:

We all know that a beard is often comprised of relatively course, WIRY hair.

It is also well known that electricity seems to come in WIRES. Further, we make antenna out of WIRE.

Ergo, the beard serves as an antenna, collecting the subtle impulses (messages) radiating from the heated workpiece. This provides the smith with a certain undefinable 'sympathy' for the material's needs.

 

[scottickes]

One of the reasons that I have volunteered to put together the Technical Heat treating chart for knife steels is because technical report writing and preparing technical documents is part of my "real" job. I do this kind of thing on a day to day basis, so after all of the information is gathered and verified as accurate by the various experts, creating the document will be easy for me. It's also something that I enjoy doing, being of an "engineering" (<<<read 'geeky engineering type' mentality here) person.

 

[Deweyknives]

Actually the connection is very clear between beards and superior forging:

We all know that a beard is often comprised of relatively course, WIRY hair.

It is also well known that electricity seems to come in WIRES. Further, we make antenna out of WIRE.

Ergo, the beard serves as an antenna, collecting the subtle impulses (messages) radiating from the heated workpiece. This provides the smith with a certain undefinable 'sympathy' for the material's needs.

Hey!! It's all clear now! After a day at the forge,my face is dirty. It must be the magnetic field around my beard that attracts the charcoal dust!! If I hang a chain around my neck and let it drag on the floor like a ground cable, will this interupt the magnetic field? Or will this interfear with the impulses and render my forgings to mere non-bearded levels? This could lead to some intense testing! Maybe I can get a government grant?? :thumbup:

 

[Deweyknives]

On the serious side,Scott,charts like that could change the learning curve for up 'n comming makers.But it could turn into a larger undertaking than any of us can imagine.I'de be interested in seeing the progress if it should become reality.

 

[Kevin Davey]

...

I'm thinking each knife steel type could be broken down into types of knives, with a suggested heat treat process for each of those types. With a resulting Rc throughout the process. Such as Rc after hardening and tempering.

Which maker are you going to listen to?.....


Hardness after quenching can be related to how sucessful the quench was, that in turn will relate to tempering temperatures, and final performance.



My 2 cents..... the Rc hardness ''number'' is the last thing one needs to be concerned about...First, experiment and test knives to find the optimum hardness for the task its going to be used for (edge retention, sharpening, flex etc).....When satisfied with the performance and the performance is consistant then find out what the Rockwell hardness is, and use this as a benchmark.

 

[Phillip Patton]

If I hang a chain around my neck and let it drag on the floor like a ground cable, will this interupt the magnetic field? :thumbup:

What will happen is you'll trip on the cable, and your beard and anvil will become unified.

 

[Kevin R. Cashen]

It appears to me that a "steel usage chart for custom knives" would be a great benefit to all of us, especially us newbies! Has anyone thought of creating a chart of this type? Or is one already available?...

...As I stated, I'm willing to gather all of the information and create a document for us. How many of you would like to contribute to this kind of a project?

A source for ideas in making a tmeplate could be had from the old Carpenter matching method (you can find it in their literature or in Luerson's "Tool Steel Simplified"). It covers a wide array of applications but it gives an idea as to how desired alloying can be determined by heat treating methods and applications. They include speed, heat resitance, tough impact and wear resistance. A knife chart would simplify things down to impact and wear resistanse. Hypo eutectoids in impact and hypereutectoids in wear resistance, with alloying creating exceptions and subcategories.

I was always trying to come up with a definitive chart like this for my Intro class but always ran into snags in heat treating considerations and those blades that could fall in either category because of it. Then I am sure a good many students in the future would encounter other smiths that would say my categories are crazy. Getting two knifemakers to agree on what knife perforamnce should be is darned near impossible, much less getting a concensus on what steel will meet those needs.

 

[scottickes]

I don't propose creating a "definitive" chart of absolutes. Instead I propose creating a general guideline, that would take the knowledge of the best of us and put it into an easily readable and useable form. I just want to create a "starting" point. My starting point was the "machinist handbook". The heat treating guidelines in that reference book are for tool steels, etc. If you follow the guidelines in that book for W2 steel, you'll end up with one heck of a hard blade, at Rc 70 or higher. It would be a blade that is hard to sharpen and brittle. I don't want to create a "bible" of knife steel heat treating, but instead I want to create one of those little 4 page leaflets you find in airport and restaurant men's rooms that talk about the "bible" of knife steel heat treating.

 

[JCaswell]

Hey!! It's all clear now! After a day at the forge,my face is dirty. It must be the magnetic field around my beard that attracts the charcoal dust!! If I hang a chain around my neck and let it drag on the floor like a ground cable, will this interupt the magnetic field? Or will this interfear with the impulses and render my forgings to mere non-bearded levels? This could lead to some intense testing! Maybe I can get a government grant?? :thumbup:

Actually, one could fashion a 'beard' from aluminum foil--sort of like a Santa-beard. If you attach it to your aluminum cap (also useful for mitigating government mind-control, BTW), I suspect you'd have the next best thing to a real beard for communing with those electromagnetic impulses.

 

[JCaswell]

I don't propose creating a "definitive" chart of absolutes. Instead I propose creating a general guideline, that would take the knowledge of the best of us and put it into an easily readable and useable form. I just want to create a "starting" point. My starting point was the "machinist handbook". The heat treating guidelines in that reference book are for tool steels, etc. If you follow the guidelines in that book for W2 steel, you'll end up with one heck of a hard blade, at Rc 70 or higher. It would be a blade that is hard to sharpen and brittle. I don't want to create a "bible" of knife steel heat treating, but instead I want to create one of those little 4 page leaflets you find in airport and restaurant men's rooms that talk about the "bible" of knife steel heat treating.

I think a consolidated guide for knifemakers would be handy.

You could eliminate a lot of guesswork (and subjectivity) by using data already available and well documented from industry. Just concentrate on the relevant alloys and put the info in one handy guide!

The job of such a guide wouldn't necessarily be to tell someone what a knife should be, just what the steel can do.

 

[scottickes]

Exactly!!!!!!!

 

[HomeBru]

What percentage of forgers have beards and do they make better knives ??

I'm not a forger, but my beard is much to course to make a fine-grained steel. 'sides, it tends to smoulder and curl up at much less than non-magnetic heats!

J-

 

[Daniel Koster]

I'd be interested in such a chart.

Something to keep in mind...I use 1095 for my kitchen knives...and I've heard others using it for camp knives. The heat-treat is going to be different. And maybe neither is the "ideal" use of the steel....

If I do too much grinding before HT...the edge of my blade literally blackens in the 3/10s of a second it takes for me to remove it from my oven and stick it in the oil.

I'm not trying to unnecessarily complicate things...just wanted to add some comments.

Please continue with your study - I wish you the best and I want a copy when it's done!



seems every time I get "comfortable" about my heattreat I either have a failure (had first one in almost a year this morning) or I come on here, do some reading and realize I know NOTHING....

 

[Daniel Koster]

And yes, I do have a beard. But stopped forging after injuring my hand.

 

[Ed Fowler]

Kevin:
You area absolutely correct when you state that Rc is not as significant as performance. Another factor is that temperature is not as relevant as the condition of the steel, this is why the magnet is the most significant indicator we have. I believe actual temp requirement may change, but the magnet is always measures what we want it to. Again I speak only about 52100,5160 and sometimes L6

 

[KnifeHead]

Kevin:
You area absolutely correct when you state that Rc is not as significant as performance. Another factor is that temperature is not as relevant as the condition of the steel, this is why the magnet is the most significant indicator we have. I believe actual temp requirement may change, but the magnet is always measures what we want it to. Again I speak only about 52100,5160 and sometimes L6

Again...a great beard and he knows how to use it

 

[IronWolf]

Mr Fowler, could you elaborate on what you meant by temperature is not as important as the condition of the steel? This does not fit in with what I have studied. there is a propper austinizing teperature for each steel, and for all but a few steels the austinizing temperature does not match the non-magnetic temperature. Different alloys will change the the temperatures and soak times that you need. Are you speaking of grain size? A very fine grain size can move the pearilite nose to the left, making it more difficult to get a full hardening, but I have not come across grain size changing the austinizing temp.

Ken Nelson

 

[Ed Fowler]

I do not have high precision insturments to measure temperature. The temp of my quench tank is measured by the same thermometer I have used for over 30 years. Is its 165 f. actually 165 f or maybe a little different. It does not matter, it is the same each time. I evaluate the results by performance not the recorded temp. This may be a simple explanation, but this is how I work.

I use my Paragon to soak billets at critical temp. I coach the temp up until the steel just looses its magnetism. I look at the stated temp on the read out and record what it says. It does not matter if the thermal couple is absolutely accurate, the magnet provides the information we need. The temp predicted by the thermal couple is simply a number for me, a reference point that is the same and I know it is the same by the nature of the steel at that reference point. That is all that matters, the alloy may or may not become nonmagnetic at the exact temp in reference books, I know where I am by the magnet and that is all that matters to me.

At one time I had a friend shoot temps of blades we were quenching using a recently calibrated optical pyrometer. According to it, critical temp seemed to vary when other variables were manipulated. We worried about it for some time, then came to the decision that the exact temp did not matter all we needed to knwo was the point when the magnet said the steel was hot enough (in this case critical temp).

Some experimental blades seem to drop down through critical at different rates when doing what I call the bladesmith flash normalize. We have fooled around with a stop watch to check this theory out and have not reached a definate conclusion. In reality it does not matter, heat uniformly to critical, verify with a magnet and watch it cycle down. Again the actual temp and time down does not matter, it is the cycle that is significant.

I do believe that temperatures and heat times (conductivity) may vary with grain refinement, can I prove it? No. Does it matter? Not really.

We could spend some money on instruments that could shed some light on these questions, but is it worth it? Maybe to some and the questions and answers may be of value to someone in another application.

At this time we are working on reduction ratios and the influence of higher temperatures at the start of reducing steel by forging. This is kind of interesting because we will know how far a bladesmith can push this steel starting from a billet of smaller volume.

You mentioned full hardening, I believe several extensive volumes could be written seeking a comprehensive evaluation of full hardening, add what for to the question and another lifetime could provide another answer or two.

Anyone who in interested in working with these variables is welcome to join and work with us. I sincerely appreciate your questioning what I said, there is a lot to learn, this is why we will never know it all. (I hope)