True Combat Value of Wootz

[Jeff Pringle]

...they could not analyze for carbon, nor knew about its critical role;

I think we have to be careful here: yes, they did not have a scientific understanding of carbon and it's specific role in how steel behaved in the quench. However, they had generations of empirical knowledege that said things like 'steel that looks like this, behaves like so;' to such a degree that when metallurgy and metallography became the way to understand steel they were checking the new theories against the eyeballing of fracture surfaces by the old foundry guys. They could give you the carbon content down to tenths of a percent or better just by looking at a quenched and broken surface. All that knowledge dissappeared in the last hundred years, but I think it's safe to assume it went back a thousand or more, and they had a good idea of how to treat the hypo- and hyper-eutectoid steels as they came from the furnace, if not precisely why.

[Chris Evans]

Hi Jeff,

Originally Posted by Jeff Pringle

I think we have to be careful here: yes, they did not have a scientific understanding of carbon and it's specific role in how steel behaved in the quench. However, they had generations of empirical knowledege that said things like 'steel that looks like this, behaves like so;' to such a degree that when metallurgy and metallography became the way to understand steel they were checking the new theories against the eyeballing of fracture surfaces by the old foundry guys. They could give you the carbon content down to tenths of a percent or better just by looking at a quenched and broken surface. All that knowledge dissappeared in the last hundred years, but I think it's safe to assume it went back a thousand or more, and they had a good idea of how to treat the hypo- and hyper-eutectoid steels as they came from the furnace, if not precisely why.

I absolutely agree with you that they had lots of empirical knowledge, but perhaps not quite as much as we may think. I am open to be persuaded to the contrary, but would like to know more of their methods.

All the same, they were very good. For one, I never cease to be astonished as to how Japanese swordsmiths managed to identify the high carbon steel for the edges - It was done as you say, by breaking bits of steel and examining their surface. However, we must remember that good steel or swords were the exception and not the rule, which strongly argues for a lottery factor in their methodology.

Carbon was identified as an element at the end of the 18th century and from that point on the metallurgy of steel advanced in leaps and bounds. Once an accurate analysis could be made, all sorts of indirect qualitative tests could be standardized against laboratory results and this is how those very savvy tradesmen did their seemingly unbelievable assessments. For example, if one has a good collection of steel samples of known composition then with a simple grinder spark test one can identify an unknown sample with astonishing accuracy. But without those reference samples it becomes much more difficult.

With bloomery steel made by solid state reduction, the resultant was nearly pure iron which had to be carburized. This was done by heating in a carbon rich environment and the iron absorbed the carbon. My suspicion is that although they did not know what exactly they were doing, they could correlate the end result with carburization time. But in the absence of accurate temperature and furnace atmosphere control, it must have been an uncertain process.

Here is an interesting link onto 18th century steel making:

http://www.staff.hum.ku.dk/dbwagner/....html#Heading1

Cheers
Chris

[Ann Feuerbach]

And of course their were good smiths and less good smiths. Plus add in those who have been working along with their father since they were very young, or at least around 12 years old, they would/could have a great amount of hands-on knowledge passed down for generations. Whereas others, may not have had as good training, didn't care, or simply weren't that talented.

[Chris Evans]

Hi Ann,

You make very valid points. The quality of smithing must have varied enormously.

As well, we must remember that in the absence of patent rights, the empirically hard won advances were jealously guarded and not shared as we might expect. There is the story of the Japanese swordsmith's apprentice who put his hand in the quenching water and had it cut off by his master. Perhaps apocryphal and with different interpretations as to why the youth was treated so savage; But a Japanese friend, also a metallurgist and very knowledgeable on their sword making opined that probably the young man was trying to find out the temperature of the quench water, something that his master wanted to keep a secret.

Cheers
Chris

[Chris Evans]

Hi Folks,

I would like to draw your attention to two most interesting pos by Zifir (22&25) under the thread of Fencing With Sabres. He presents quotes from William Elton, esq., A Survey of the Turkish Empire, London, Printed for T. Cadell, jun. and W. Davies, 1799. on Turkish sabers.

It states that Turkish swords were both hard and brittle, capable of cutting through an iron nail thick as a finger, and strongly suggesting that they were hardened by quenching and tempering.

Cheers
Chris

[Emanuel]

Hi Chris,

Many thanks for your explanation. I had simply understood austenite to mean a high-grain crystal structure, as per Carlo's informative pictures. I understand my mistake now. I also found this good site http://www.metal-mart.com/Dictionary/dictlist.htm with quick definitions for metallurgical terms.

So temperature control is more or less the whole secret to good forging, correct? Now, would an European smith with comparable levels of knowledge and experience to a top Indian/Persian smith be able to create wootz/pulad ingots and forge a watered blade from European iron ore? Or is the precise mix of iron/carbon of Indian ore important? Gt.Obach, is your home-forged wootz chemically the same as the traditional Indian ingots?

Carlo, besides splitting kindling with an axe and cutting bread, it's true I've never cut anything Some training would indeed be recommended.

Regards,
Emanuel

[Chris Evans]

Hi Emanuel,

Originally Posted by Manolo

Hi Chris,
So temperature control is more or less the whole secret to good forging, correct?

You certainly identified correctly one of the most important factors. But there are many others such as the chemical composition of the steel, that of the fuel, atmosphere control, `soaking' time and temperature. Metallurgy involves the successful management of quite a number of variables.

Now, would an European smith with comparable levels of knowledge and experience to a top Indian/Persian smith be able to create wootz/pulad ingots and forge a watered blade from European iron ore? Or is the precise mix of iron/carbon of Indian ore important?

Forging Damascus Wootz with the tell-tale surface pattern was considered a lost art until very recently. Have a read of that paper that I gave the link to in my post early on, No8 in this thread. It will probably answer your questions. One of the big problems, as I see it, is that we do not even have a clear consensus as to what we are talking about, that is what exact type of steel, forging and heat treatment we are specifically interested in. For my part, I am happy to settle for any pre modern crucible steel, but others apply a much tighter definition. For example, in the above link, one of the swords was declared not to be true Wootz Damascus because it had a lower carbon content.

Cheers
Chris