"True Damascus"

Fletcher hawke

Fletcher hawke

Joined
Jun 14, 2000
Messages
71
I was wondering is any of the Smiths here had seen the article in January's SCIENTIFIC AMERICAN about a possible discovery of how to make "true" damascus (wootz as opposed to pattern-welded). I'm curious about the Pros' opinions on this.

For the record (and anyone who hasn't seen the article) the author, one John D. Verhoeven reports that he and a Floridian Bladesmith, one Alfred H. Pendray believe to have rediscovered the technique for forging "true" damascus steel.

The really short version of the technique is that the patterns of the steel are cultured like bacteria.

A more informative summary: An ingot of steel is formed, intentionally containing several trace impurities--the author particularly indicating vanadium and molybdenum as being conducive to the process--in an enclosed crucible. As the ingot, about the size of a hockey puck, is shaped into a blade, it is naturally heated repeatedly. During the process, the impurities segregate themselves. Where the impurites are found, the crystals of the steel are slower to disintegrate during heating; so a veining of harder steel forms throughout the bar around the impurities, where the crystaline structure never fully breaks down during forging. And so a composite is formed that holds a remarkable edge and, when etched with acid, shows a beautiful pattern of varying grades of steel.

So the harder steel is induced to "grow" throughout the softer; as opposed to pattern-weld, where differing metals are, in effect, "woven" together.

I'm very curious to hear thoughts on this.
 
I had a chance, last fall, to watch a set of four video tapes from the Florida Artist Blacksmith Assc. annual conference ('97 I believe) featuring Mr. Pendray demonstrating forging techniques for his wootz. It seems to be really finicky to forge, as the working temperature range is only about 200 deg. He said if you overheat it, the suspended carbides will go back into solution and it will look like plain old steel and if you try and work it below the forging temperature it tends to crumble. As far as I know, he's the only one in the US to make the stuff! BTW, welcome to the forums!
Bob
 
There's two other people/groups in the world who actually make wootz. One is in russia. The other, Heimo Roselli, is a well-known bladesmith from Finland who works together with a university professor of metallurgy to make this stuff. It is expensive, hard to forge and has some interesting abilities.

There are some interesting writings on the net about it. Just do a search for wootz steel.

Achim
 
There's also a Metallurgy Professor at Stanford named Oleg Sherby that is thought to have rediscovered damascus. Except that it's being calling "super plastic steel." Lawrence Livermore Labs, Caterpillar and North Star Steel were very interested in the results of Sherby's study. There was an LA Times article about it from about 6 years ago. I'm looking at it right now.

Also, Verhoeven and Pendray had an article in "The Anvil's Ring" Summer '94. I've got that one also. And another in "The Iowa Stater" from May '94.

I'm glad I keep all these articles!

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Glen AKA Centaur
"I'll be your Huckleberry."
- Doc Holiday

[This message has been edited by Centaur (edited 01-09-2001).]
 
Welcome to the Forums!!!!! Sounds interresting I'll have to go track down some more info.
Centaur...you keep a lot of articles man.

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Mykl
Anxiously awaiting my BM 42A
 
Thanks for all the input everyone. I'll have to look up these other sources as soon as I have some time.
 
Mykl -

Yeah, I know... Whenever I see an article pertaining to knives, swords, blacksmithing, damascus, (and so on) I try to keep a copy. At least my Wife tolerates my "library." Thank goodness she tolerates my forging & grinding as well.

I got the arcticle from the "Iowa Stater" from a friend who's Mother knows Mr. Verhoeven.

------------------
Glen AKA Centaur
"I'll be your Huckleberry."
- Doc Holiday
 
I just read this article and was also wondering on the thoughts of others on the reality of it. i was thinking about contacting pendray myself but wanted some objective input on the subject.
My main question is how well does it perform compared to today's great steels and if it still dominates, why dont others try to pick up forging it. Any ideas???
thanks
james
 
After reading two articles on the process, it seems that the steel is great for swords. Samples have a low RC according to one article. I would think that the steel is not hardenable (in the standard way) since raising the temperature beyond a critical point, Acm, (the point at which the carbides dissolve) looses the carbide banding.
<q>
"The carbide bands of the wootz Damascus steel are destroyed by a complete austenitization at low temperatures (just above the Acm temperature) followed by cooling at all rates, slow or fast. However, if the steel is then repeatedly cycled to maximum temperatures of around 50-100°C below Acm, the carbide bands will begin to develop after a few cycles and become clear after 6-8 cycles."
</q>
Clearly if Acm is below the temperature required for hardening a carbon steel then you would loose all the properties created by the process. Perhaps wootz Damascus does not need to be hardened, much like cobalt-based materials.

The jury is still out on how it replaces materials used in other cutting applications, i.e., knives. But perhaps understanding the process will lead to other innovations!

As to why nobody is forging this way yet...well, it's pretty new at the moment. In addition, the number of forging cycles is in the range of 50 times! Much more than for pattern-welded Damascus.

In any case, a fascinating process.

Jeff Jenness

[This message has been edited by jeffj (edited 02-13-2001).]
 
I did just read the article today and found it intriguing. The knife depicted on the first page appeared flawless and according to the caption was created in the 1600's?

I am spellbound by the craftsmanship and quality of the past, constantly showing up modern technology. Best of Luck
 
for Jeff J,

There is some confusion in your post. Acm is the temperature at which *all* carbon is put into solution in the austenite. The usual practice for hardening is to go to some temperature above Ac1, and pput only part of the carbon into solution in the austenite in the case of steels with more carbon that you need to achieve the as quenched hardness that you desire, while still retaining some carbides undissolved in the matrix.

Example 52100. Ac1 is low, and the material will harden some from temperatures as low as about 1350F, with more carbon going into solution as you increase the austenitizing temperature. MOst sources reccomend heating 52100 to 1550F, which puts aprox. .6% of the available carbon into soution. Acm in 52100 is clear up at about 1850F.

Wootz is indeed hardenable, though the hardenability of it is quite low (I heat treated several blades for Alfred and JDV as part of an experiment that they included me in).

MOst of the old swords are not hardened and tempered as we think of it today. The vast majority of them are in a condition that has the matrix as fine pearlite, not martensite, and the hardness of them in HRC is not all that high (usually high 30's to mid 40's).

It is peculiar material. And it is not common because it is a great deal of work and trouble, and like pattern welded steel, things can go wrong right at the end, leaving you with nothing for all that work.
 
You are right, Howard. I don't have much of an experience with this material right now, but after making some and handling and forging it into a blade i can tell that i never handled a steel similar to wootz. You have to concentrate on your work in an extremely manner from the beginning to the end. One heat to hot and you end up with a piece of simple high carbon steel. Hit it too hard or too cold and it will crumble and break. It is definitely not for the beginners in the forge.

Achim
 
Thanks Howard! You are right there was confusion. The papers that I had were not very clear on the temperature ranges and the quote is from one of the papers. It never did tell what that temperature was, so it left me confused about what might happen in other applications. This is certainly exciting times! It's hard to wait until you fellers get some of this stuff in knives and get some experience with it. Please, keep us posted.

Jeff
 
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