Viking Swords and Wootz

[katana]

Hi everyone,
read this brief article which you may find interesting....

http://www.guardian.co.uk/science/20...-vikings-sword

Wootz, Fakes and burial swords ....plenty for a discussion

Happy New Year

Regards David

[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

[Jens Nordlunde]

Here is a picture of Viking swords found in Nydam Mose in Denmark, the book is from 1863, and reprinted in1970.

[Jeff Pringle]

Jens – those look a bit pre-Viking to me, I think they stopped throwing stuff in the lake at Nydam around 450AD.

After having a chance to read “Crucible steel in medieval swords” by Alan Williams, it is no surprise to find it is a much more coherent & reasonable article than the Guardian would lead one to believe. That said, Mr. Williams makes a few unsupported statements which I feel should not go by unquestioned. In the section introducing Damascus steel (wootz in this context), he says:
“The blade so formed needed no further heat treatment
to harden it, although some attempts might be made.”

Obviously, heat treating wootz is a big kettle of fish which is full of unresolved questions (hinted at in the end of that sentence), but by saying it does not need to be heat-treated, he sets himself up for this:
“…it would have been very tempting to
try to counterfeit these valuable blades. One way, perhaps,
was by welding small pieces of bloomery steel onto a billet
of iron, and forging that into a blade before quenching it.”

Perhaps? He is talking about the state-of-the-art swordmaking here, THE USUAL METHOD by which swords were made at the time, yet it is put forth as a possible means to counterfit a small number of unusual blades?????
He then goes on to say:
“The sharp edge that could be formed might well deceive the
less discerning customer, but with a depth of only a few millimetres
it would not have survived many sharpenings.”

By his own measurements a few years before, six millimeters, over a quarter inch – I think this is the major blunder from which the other questionable theories have grown. If the Viking period warrior used his sword as often as the modern GI, mercenary or policeman uses his gun, or even if it was twice as often, or ten times as often, that would still equate to ALMOST NEVER, and six mm of hardened steel would last generations- as many swords of the era with much later hilts attest to. Again, it was the usual way to make a sword for almost a thousand years, it seems weird to make it the fake rather than the odd Ulfberhts which may be introducing a new method.

[Jim McDougall]

I have been entirely fascinated by this thread, which has produced a discussion that offers most readable and beautifully explained aspects of a subject that I have always had difficulty relating to, metallurgy. While obviously of utmost importance in studying edged weapons, I always preferred to focus on typology, styles, markings and motif and the history of use. Most material concerning metallurgical subjects has, to me,been a bit too technical ( the appearance of complex terminology and numeric formulas sends my mind into sleep mode but reading the dialogue you guys have put together here is great!
Thank you David, for posting the original article, and everyone for the great input, and links, which I was able to read with far better understanding thanks to the footing given by your discussions.
Jens, thank you for the great illustration and reference to this early resource. These earlier references are fantastic at adding perspective, and adding that benchmark to all this material was a great addition.

I thought this extremely informative thread should be placed in the sticky column, for its outstanding reference potential.


All the best,
Jim

[Chris Evans]

Hi Jeff (Pringle)

Nicely put. All valid observations.

Cheers
Chris

[katana]

Not being a metallurgist but extremely interested in the forging of blades, could someone please help explain....
....am I correct in thinking that if a billet of wootz is forged, normalised, quenched and tempered the structure of the wootz is altered and the surface pattern lost...would that mean that crucible steel forged in the same way as sponge iron ( as perhaps viking smiths would have done) the resulting blade would also not have the same crystalline structure. (assuming wootz and crucible steel are not the same)

If so ...would the quality of the blade suffer, now that the structure of the crucible steel or wootz is much more homogenised after repeated hammering and folding ?

Would the carbon content of the crucible steel increase with the repeated heating in a charcoal forge ....if so wouldn't the higher carbon content make the blade increasingly brittle?

Thank you

Regards David

[kisak]

From my understanding, it would be entierly possible at least to obliterate the patterns seen in wootz and similar steels if you work the material "wrong". One of the things you want to achieve with the treatment you give to bloomery iron is to even out the chemical composition, while in patterned crucible steels those differences are what gives us the pattern. The "dangerous" part here is probably the extensive forging. The heat treatment (normalising, quench and temper) could leave the primary ferrite or carbides that form the pattern intact, in theory at least.

As for the properties, the impression I've gotten is that it's uncertain whether or not the grouped nature of the "pattern forming" parts in wootz and similar truly gives a benefit (it wouldn't surprise me if it was the other way around actually, fine scale and evenly distributed are often good ideas). Assuming that the austenitisation is done at the right temperature, it should be entierly possible to get the same amount of carbides out of the steel even after the pattern has been destroyed, they will just be more evenly distriburted in the blade.

[Chris Evans]

Hi David,

Your question covers a lot of territory defying short explanations that I may come up with and which could be readily understood - Keep in mind that sometimes it is said that those who understand the metallurgy of steel understand all of metallurgy because iron-carbon is so complex. Jeff Pringle can probably do beter, though in the meanwhile I suggest that you wrestle a bit with this paper: http://www.tms.org/pubs/journals/JOM...html#Verhoeven to better understand pattern yielding Wootz, which the authors call Wootz Damascus.

I should mention that swords made from bloomery iron (sponge iron) were forged at higher temperatures and I have read a number of accounts that later era European swordsmiths who managed to obtain Wootz cakes could not forge it successfully as they did not know that a lower temperature was a requisite.

Cheers
Chris