Viking Swords and Wootz

[Pukka Bundook]

Hi David, and;
Happy New Year!

Yes, I read this somewhere recently.
It appears even the genuine blades were made over a few generations.

Only thing I question here, is there seems to be the idea that the 'Vikings' made these swords, and I think it has been established beyond serious doubt that these blades are Frankish.
Still, I was not aware that the Franks or whoever were using crucible steel.
Are not the Vlfberht blades made with a pettern-welded core?
...would appear unnescessary with crucible steel.

I find it very refreshing, that new information is still forthcoming!

All the best,

Richard.

[Richard Furrer]

Hello All,
This will be rough, but its from memory.

I can not speak for Dr. Williams, but I was in India when he first presented this paper in 2007 (later published in Gladius I think). It is my recollection, as I do not have the paper in front of me, that Dr. Williams tested 13? Ulfberht blades of the 30-60? known and four or so (all with "Ulfberht" spelled the same by the way) turned out to be slag free in the body of the blade and it is this lack of slag and the carbon content which led to the idea that it was forged from a crucible steel product. I can see no flaw in that argument.
The only other way to obtain slag free steel is to be lucky enough to have some form as a liquid in the bottom of an open reduction process and use this to forge a sword, but I have not ever seen a large enough single piece to make a sword (a small knife perhaps, but not a sword). There was no evidence of a weld line in the slag free blades tested...this does not mean that there was no weld, but id does mean that none was seen. I would think that this could be proven one way or another by sectioning the entire blade in many directions, but I doubt this would ever be allowed to occur.

Where the crucible steel came from is up for debate as it is almost impossible to trace the origin of such things.

BUT,
The article referenced above is more sensational then the original as one would expect such in a popular newspaper.

Do keep in mind that Dr. Williams also gave us the "Knight and the Blast-furnace" some years ago...which was no small task either.

What this slag free finding shows me is that the old smiths were far more clever then we think and perhaps trade was far more widespread then what was previously assumed. This also illustrates the matter of discovering craftsmen's work and viewing it with tools which allow us to appreciate their accomplishments.

Ric

[kisak]

I wonder a bit about the "fake" part. While such most likely did exist in considerable numbers, I wonder if we can really with just this rule out that Ulfberth made swords from local steel as well, perhaps when there wasn't enough imported steel to be found, or perhaps as the "budget line".

A very interesting discovery in any case.

[Lee]

Williams, Alan R., 'Crucible Steel in medieval swords', Metals and Mines: Studies in Archaeometallurgy (London, 2007), pp. 233 - 241.

ULFBERTH will be spelled various ways between different examples; apparently those with high carbon content and a microstructure suggesting crucible steel have, so far, all been spelled the same way. Exciting stuff; I am most curious to see what trend emerges as more swords are analysed.

[Gonzalo G]

The article seems incongruent to me, but I have no much knowledge of the subject. Swords made with iron would not shatter like that, unless having many impurities and inclusions, and hardening them in cold water would give only a very small hardness to the iron. On the other side, they don´t mention "wootz", only crucible steel. Swords were made with crucible steel not being wootz, but with this carbon content they would be very brittle. I understand that toughtness of wootz with it´s carbon content is due to the fact that it has a perlite matrix. The "Viking solution", as I recall, consists in making blades with an iron body, and only the edges, mechanically welded to the body, were made of steel. That would not make a fragile blade. Please correct me if I am wrong.
Regards

Gonzalo

[Jeff Pringle]

Like most newspaper items on esoteric subjects, there is often a bit (sometimes quite a bit ) of error introduced between the interview and the page, so don’t be surprised the facts seem ‘off’ in the Guardian article.
The Viking period spans a few hundred years, and the era includes some pretty radical improvements both in sword design and in steel making, so it would be a mistake to think there was just one way to make a sword during that era. Plus, swords made locally vs. swords made in an ‘industrial’ center & exported will add a layer of difference.

You can get more info on the fake issue and start forming your own theories on which ones were ‘fake’ from reading “The Vlfberht sword blades reevaluated” by Anne Stalsberg, she did a signature analysis of ~135 Ulfberhts, and there are two variants of the signature (the two most numerous) she concludes are probably authentic.

Below is a Williams quote from 2003, when he was starting to develop this concept - note he is saying higher slag content (not quenching!) can lead to brittleness:

Some early medieval swords in the Wallace Collection and elsewhere
David Edge, Alan Williams
Gladius XXIII, 2003 pp. 191-210
http://gladius.revistas.csic.es/inde...rticle/view/50

“….
It should be observed that yet another blade with a similar inscription has been found by one of the authors to consist of a totally different metal. That «Ulfbehrt» sword was made of an air-cooled hypereutectoid steel of around 1.0%C (Williams, 1977). Since that account was published, a great deal more information has become available about the crucible steel industry of Central Asia (e.g. Craddock, 1995 and Feuerbach, 1997) and it seems likely that a cake of such a steel was the raw material for that blade; being virtually slag free and of hardness around 300 VPH, it must have been an exceptionally serviceable sword, and one which would keep its hard edges permanently. The maker of our «Ulfbehrt» sword had made what must have seemed to his customers at the time like a very good copy, with an edge hardness of over 460 VPH. Prolonged use might have altered their opinions; the cutting edge is only 6mm deep, and could have been removed by a few years of regular sharpening on a grindstone. It is also distinctly higher in slag content, and therefore more likely to fracture on impact.
….”

[Gonzalo G]

Jeff, thankyou for your information on this subject, and also on the wootz thread. I found very interesting and useful your comments.
Regards

Gonzalo

[Chris Evans]

Hi Jeff,

Originally Posted by Jeff Pringle

... It is also distinctly higher in slag content, and therefore more likely to fracture on impact.
….”

Informative post.

Without knowing much about Wootz, in wrought iron slag inclusions enhance toughness by acting as a crack arrestor. It is my understanding that the core of Japanese swords is often high in slag content with a similar effect.


Cheers
Chris