Viking Swords and Wootz

[katana]

I would like to thank you all for the VERY informative posts ....I have certainly learnt a few things A special thank you to our 'metallurgical guru's' for all the added 'background'

Kind Regards David

[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

[Gonzalo G]

All depends on which europeans, and in which timeline. In Spain wootz was imported and forged to the mid 19th Century. You can see some references here:

http://forums.swordforum.com/showthread.php?t=80073

Sorry if I cannot follow in real time this discussion, but I don´t have many chances to get into internet.

In fact, there are many articles form Verhoeven online, and some of them are posted in forums, as you can´t find them on Verhoeven´s page anymore, but the last word on the antique wootz heat threatments and wootz blade quality (as the steel, it´s forging and the resulting sword cannot be separated completely), is yet to come from other sources and more extenisve studies of old blades. I believe there are more discoveries to make.

There are also other many sources about wootz, in english and in other languajes. Srinivasan and Ranganathan are some of them, but you can also find articles from the publications of the Indian National Science Academy, among others, here:

http://www.insa.ac.in/html/home.asp

The excellent work from Verhoeven "Matallurgy for Bladesmiths and Others...", is not very indispensable to the specific study of wootz, unless you want a deep comprehension of it´s chemical characteristics and structure, and it is a heavy reading for those not interested in learning metallurgy and forging and heat threating blades. But is a great treatise on this last subject, which I love and appreciate very much. It provides, neverthless, with the necessary understanding of general steel inner structures and how they are produced.
Regards

Gonzalo