Hi Ann. Welcome back. :)

So, it sounds like the much more accurate term would simply be "crucible steel"? How about the term "balut"?

Thanks Ann.

Hope the conference was enjoyable, informative and productive. Like Andrew, I would welcome your suggestion for a better term than wootz. Look forward to hearing your views about the possible significance of these fine sub-micronic structures that have been described recently.

Regards,

Ian.

Hi all,
Bulat is good, but pulad (phulad) is better, because bulat comes from pulad or a related term and variations of the word pulad can be found in many languages. I did an etymological study of the words. The earliest use of the term pulad is a 6th century AD text. It may have originally came from Sanskrit or Avesten (which had a common root language). In sanskrit languages the prefix pu means pure or purify, while there are hundreds of words for iron in the languages of India including loha, lauha, etc. Pu loha (meaning pure or purified iron) or such was probably the origin for the word. I have checked this theory out with Sanskrit scholars and they agree with this.

I have no problem with the use of the term wootz when refering specifially to Indian steel, but the word assumes a geographic location, which can be inaccurate and assuming. I prefer the term crucible Damascus steel to prevent assumptions.

On a related note: If I read one more reference in the news, including the Nature article and National Geographic news (where the author even contacted me but took no notice to what I said) to the process being only from India, being lost, and references to crusaders and Damascus, Syria I am going to scream!
:eek:

I think what we have here is a cultural issue. I grew up in a commpunity (Asia/Eastern Europe) where "bulat" novadays simply means steel. Any steel. Even if you buy almost any translational of any old text, you will see that translator uses word "bulat" with no regard for the original text, i.e. assumes that it simply means steel. This is why you occasionally see russian works on bulat that pronounce that you know what (since we don't know how to call it ?), was used by Roland, prince Igor and virtually every other historic person, because the author did not check the manuscript's original for the exact _original_ wording.

Even in XIXth century, per Anosov, bulat meant any steel with a pattern, whether it is mechanical, you know what, or something even more simple.

The "wootz" word for me is a slang and I think we need such a word to clearly identify what we are talking about.

Hi Folks,

Rivkin very kindly sent me a copy of that paper that was published in Nature. He is indeed a gentleman and a scholar and my sincerest thanks go to him

I hurriedly read it and the thing that immediately struck me is is the claim that Wootz had superior qualities, without telling us which exact attributes were being talked about. After all, in the context of swords, there are a number of mechanical properties that are considered desirable, most having to do with hardness and toughness. Hardness, is relatively simple, but toughness has many aspects.

The most often mentioned advantage of Wootz is its supposed combination of hardness and ductility resulting from the presence of carbides and nearly pure iron in its microstructure. The simplistic logic appears to be that the hard carbides do the cutting and the soft near pure iron provides the toughness. This paradigm is contrasted by that of conventional quenched & tempered Martensitic steels in which the same homogenous microstructure embodies both attributes.

Whilst true to some extent, I have a lot of trouble in accepting the above line of reasoning as a justification for declaring Wootz to be a superior steel. After all, it is well known that steel obtains its optimal hardness and toughness in the quenched and tempered Martensitic state, though I hasten to add, that work hardened Pearlitic steels, such as piano wire, can also be both surprisingly tough and hard. Whether Wotz swords were ever work hardened to to the same extent as modern piano wire, I have yet to find out.

A theoretical evaluation, from first principles, of Wootz is very difficult because the very large number of variables to be considered and all this has to be done in the context of various sword, the design of which introduces yet more variables.

Based on the papers that I read, most Wootz blades were not Martensic, rather work hardened Pearlitic with additional iron carbide embedded in it, though GT Obach did make the very important observation that partially quenched Martensitic blades, where the edge was expected to do the cutting, as well as fully quenched, were not uncommon. However, here we have to remember that once the carbon content of Martensitic steels exceeds 0.8%, the surplus carbon precipitates out as iron carbide, which can have detrimental effects on toughness, depending on its microstructure and localization. Whilst this effect can be minimized with very careful heat treatment, it is extremely unlikely that the ancients would have had the means or knowledge to achieve this.

So where does this leave us in relation to carbon nanotubes and which properties did these influence? I am at a loss.

Just looking at the evidence that so far I have managed to lay my hands on, it would appear that in centuries past Wootz acquired its formidable reputation more than anything else on account of the fact that it was melted during firing.

Unlike primitive steel, Wootz was free from insoluble inclusions, such as slag, which would float to the surface -The presence of coarse lumps of impurities in primitive steel could greatly weaken it and hence the need to remove these and disperse uniformly what remained - This was done by the process of extensive hammering and folding. But the presence of these impurities could only be minimized, never eliminated, and as such, primitive Martensitic steel always had a question mark against it. Also, during the process of hammering and folding, often the welds were incomplete due to poor technique or bad luck, introducing additional flaws.

To complete this rambling, I should reiterate that the great disadvantage of primitive Martensitic steel, in contrast to Wootz, was its variability due to the then poor understanding of metallurgy, as well as the presence of slag like impurities.

Of course, Wootz was good steel to start out with, but the forging process could very easily ruin it and the end product was not necessarily any better than that made from primitive steel. I think, that by sheer chance, it was possible to make a sword out of primitive Martensitic steel that was every bit as good as those made from Wootz, for in the end, all that was required was a correctly heat treated blade of about 0.8% carbon (optimal) and largely free from slag inclusions; But given the then extant incomplete knowledge of metallurgy and on the balance of probabilities, the odds lay with Wootz to deliver a superior blade.


Cheers
Chris

This gives me the possibility to highlight again that in order to evaluate
the "true combat value of wootz" as this thread is named, we should consider
the SMITH too.

Assuming (and i'm only saying ASSUMING) that the wootz is no better then
other western steels, we get only half of the equation's result. Might be the
great performances that the wootz is assumed to have are due to the
abilities the smiths achieved in working this material.
May be both were only slightly superior in front of western ones but adding
such slight superiorities we get a not-so-slight superiority.
The smith factor is overlooked in this thread making it a debate about
sheer composition of the steel, not the qualities he can achieve with
proper and skillfull smithing. "Nanostructures" of rough material can be
useless to a crappy smith.

I'd completely agree with that.. ... very good points..

i will add... something here..

if you look at one factor in steel such as grain size... if you have a large grain size, the steel won't be as tough and can crack easier..... Now... the same steel with a very small grain size will be much tougher and resist cracking

now... if you look at the 2 processes... when you forge weld steel, the temperature is very very high (yellow to white heat) and tends to grow the size of grain in the steel...... if you do not take steps to Normalize the steel.... you will have a steel that is weakened due to large grain... ... an experienced smith should know how to make the grain small again..!

The wootz forging process must be done at a lower heat.... from red to orange.... because any heat higher than that and you are very close to melting some of the components of the ingot... .. it is strange... but some components of the ingot matrix start to fall apart and the whole cake will become mushy/crumbly....
-- so by the very nature of wootz... it will force you to keep the grain structure small......

its something i'm familiar with having forged a few blades.... but i never seen it written about in the old historical accounts..


don't worry though..........if you have a patternwelded blade.... with a small grain structure .... it will be very tough steel aswell......

So it does boil down to....... a well made patternwelded or wootz blade, involves many people... if all these people do their job very well...... you'll have a very tough and beautiful sword...

Greg

Exactly Greg.
Michael "Tinker" Pierce is of the same advise as per the attachment
hereunder. I add a table about the temperatures at which you should get the
several structures (showed at microscope) too :

Hi Folks,



1. What Carlo and GT Obach say about the input of the smith is absolutely correct and cannot be emphasized sufficiently. These days we concentrate a little too much on the potential of the basic steel and tend to disregard the process of forging and heat treatment, which in the old days was of equal or greater importance. We have to keep in mind that the ancients had no accurate means of measuring temperature and worse still, had little or no idea as to why things turned out (metallurgically) the way they did. Theirs was an entirely empirical process.

2. GT Obach: Did you ever do a metallographic examination of your quenched Wootz blades? If so, what was the carbide distribution like?

3. Carlo: Thank you for those illustrations of grain sizes and microstructures. For those who would like to read a little more, here is a good article, albeit a little heavy at times.

http://www.osti.gov/bridge/servlets/...pb9/861397.PDF


Cheers
Chris

Hi,

Here is something that I picked up, written by Dr. John Verhoeven:

There is a general myth in some of the popular literature that genuine Damascus steel blades possess outstanding mechanical properties, often thought superior to modern steels. This idea was shown to be incorrect as long ago as 1924. A famous Swiss collector, Henri Moser, donated 4 genuine Damascus steel swords, one with a non typical carbon content and microstructure, to B. Zschokke, who performed extensive careful experiments including metallographic and chemical analysis in addition to mechanical testing [15]. A series of bending tests compared samples from the swords to a pattern welded blade and a cast blade from the famous German knife center in Solingen. The 3 good Damascus blades showed significantly inferior bending deflection prior to breakage than the 2 Solingen blades in spite of the fact that the Brinell hardness of the 3 ranged from only 193 to 248, compared to 347 and 463 for the pattern welded and cast Solingen blade, respectively. This is not too surprising in view of the now well known fact that toughness of high carbon steels is inherently low; the Solingen blades had carbon levels of 0.5 to 0.6% compared to 1.3 to 1.9% for the 3 Damascus blades. The reputation of Damascus steel blades being superior to European blades was probably established prior to the 17th century when European blades were still being made by forge welding of carburized iron. It is hard to avoid embrittlement of such blades due to imperfect welding during the forging process as well as difficulty with the carburizing process.

The full article is here: http://bronksknifeworks.com/historical.htm

I don't know how representative the samples studied were, but the above observations further support the view that Wootz was only outstanding when compared to the primitive steels of olden days. However, here is another article that puts things into a somewhat different perspective:

http://www.llnl.gov/tid/lof/documents/pdf/237566.pdf

Cheers
Chris

Here is my two cents, extract from my PhD...
"The ductility of Damascus blades was one feature that distinguished it from other types of steels. Damascus steel blades typically contain spheroidal/globular cementite in a ferrite/pearlite matrix. Metallurgical experiments conducted by Ebner and Maurer (1982) on steel concluded that toughness and ductility coincide with a spheroidization of carbides. They also noted that additional tempering decreases the strength whereas toughness and ductility vary only slightly (Ebner and Maurer, 1982). Thus, the microstructure of hypereutectoid Damascus steel is optimum for ductility."

I think trying to determine which is the "best quality" sword is like trying to determine what the "Best" car is...American made? Japanese? German? Italian? British? depends on your needs, even the most expensive ones can produce a "lemon", while a cheaper car may perform very well for a long time, plus personal experience, preference, and how much you can afford. :)

Hi

oddly... i do have abit that is suppose to be looked at.. and hopefully i'll get some good pic's from it...

but that is the problem right there... my steel is a modern crucible steel... and there is no way to make a connection a solid connection to the past.. .. i try to use the old recipes that are out there... .... ..it's like baking a cake with a list of ingredients and process... made by a person who is a casual observer..... ..... so there are alot of pieces missing to the puzzle..

i've read about the Zschokke swords and have real difficulty with some of the study..... such a narrow sample generalized to a whole sword population should be taken with a grain of salt.... it totally overlooks low carbon wootz... and other types of wootz...its not all made the same way..
-- also ... there are many ways wootz can be hardened... i'd like to hear about martensite... seemingly overlooked for some bizarre reason ?

actually what we really need is a series of studies.... from blades in crucible steel producing areas... and other regions... ... also the studies must be done by people who arent' going to benefit financially from the study..
( i know i'm asking alot... but i can dream )

onto my homebrew
I've said this in the past... that my steel functions much like a 1080 carbon steel... so i've never seen magic properties, just a very decent knife steel.....

oh by the way... if you want to read more about uhcs, det, detwad... theres tonnes of patents on the stuff... back in university i used to love to read it...

http://patft.uspto.gov/netacgi/nph-P...S=PN/5,445,685

check the references..... and click on the blue links for more.... also look at the studies...
-- enough superplasticity to boggle the mind

oh and by the way... i just did a little tutorial on SFI about my forging process... . but be warned... I went picture crazy and the download might bore you to tears..

http://forums.swordforum.com/showthread.php?t=74040

take care
Greg

From Greg: "actually what we really need is a series of studies.... from blades in crucible steel producing areas... and other regions... ... also the studies must be done by people who arent' going to benefit financially from the study..
( i know i'm asking alot... but i can dream )"

No dream, I have put in a grant for such a study (and have been gathering data on this for years) cross you fingers I get the grant! I do hope to gain financially from the study (in the form of a book) but have no hidden agenda's of what the outcome of the study should be. Just need: time, money, and samples! :)

Chris Evans: thank you very, I appreciate your words, however wootz is not my specialty so here I am not a scholar.

Because of this topic I have consulted my library extensively in the past two months, with just a single conclusion - hell knows.

First of all there were collosal number of experiments performed on wootz blades starting with XIXth century (Moser collection, russian cavalry experiment, the most recent experiments by Tavadze and so on), with exactly opposite conclusions. In order to keep it "in bay" I would just address the russian part. all said below is my personal opinion.

Stage I - during russian-caucasian and russian-ottoman conflicts of early XIXthe century general Patto writes that the enemy's yataghans and shashkas are better than russian weapons. Assumption is made by the ministry of finance that this superiority is due to crucible damascus (wanted to say wootz) nature of the swords. Massive expeditions are mounted in all directions (central asia, caucasus, west) to find the secret.

Stage II - the expidition send to Caucasus collects various techniques and comes to a conclusion that neither shashkas nor yataghans are made of crucible damascus (too long, "crud" from now on), but rather - from mechanical one. Report is presented to the minister of Finance, supervising the effort. In the same time in Zlatoust georgian Revaz makes wootz weapons repeating indian patterns, but no one can reproduce his results by using his technique, so he is declared to be a crook.

Stage III Anosov publishes his techniques of "bulatization". Interesting notes:
1. He claims historical attribution of super-powers to bulat based on the literature (prince Igor) which never contained "bulat" in the original, the term was used in later translations.
2. He makes a few blades, repeating the "best" pattern of indian and khorasani swords, with very good cutting properties. The problem - the blades do not nearly match the chemical decomposition of indian blades they are compared with.
3. No one is able to reproduce any of his processes after Anosov's death (Chernov and others).

Stage IV - persian bulat blades completely fail the russian army test on bending. As a results all persian blades are given special standards, 3-4 times "lighter" than for other blades (i.e. 1/13th of a "line" rather than 1/4th of a "line" bending angle to be used in testing).

Stage V. Russian government nearly completely abandons the research.

Chris, thanks for the link. This is another one that, even if referred to
japanese swords only, is of high interest to the ones that are interested in
metallurgy. Many information of general interest :

http://xoomer.alice.it/tsubame/ZZZZZZ_DOWNLOADS.htm

Click on Tatsuo Inoue Swordsmithing file.

You've to download it.
Sadly it is no more on line and I've stored it into my website to preserve
the info from oblivion.

You're right Dr. Ann.
This thread switched from "True combat value of the wootz" to "in order to produce swords is crucible damascus better then european steels in later times ?".
Whether, after the info provided, we can answer at the original topic
"wootz had good and true combat value", at the second question which the
thread has switched to, due to the almost exclusively western info provided
we can only reply the way you made : "depends on...".

GT Obach and Ann,

I have been wondering about Martensitic (quench hardened) Wootz. I imagine that the practical difficulty would have been the avoidance of re-dissolving the iron carbides whilst Austenitizing and then upon quenching ending up with retained Austenite, as well as Martensite, which is a trait of high carbon steels and potentially disastrous to toughness.

I suppose that this could have been minimized by keeping the Asutenitizing temperature as low as possible, but in the absence of modern temperature measurement apparatus and knowing how to deal with the problem, I just cannot see how the ancients managed to get over it. Any thoughts?

Cheers
Chris

FYI, Personally, I have not come across any blades with Martensite. I would be interested in any metallurgical studies of antique blades that do have Martensite, so references please. :)

1. I could not agree more with the importance of smith's qualifications.
2. So do we move from wootz to "crucible damascus" or we stay with "wootz" ? I like wootz more - it is shorter.
3. The problem is also "what is wootz ?". For example, a lot of people do not believe that what Anosov made was anything similar (besides patterns) to traditional wootz.
4. While the subject is heavily obscured by myths and so on, it seems that comparison wootz vs. others were repeatedly made with different results (i.e. Anosov's bulat seemed to be of really high quality).

FYI, I have held the blade that Anosov made for Faraday. It had a light sham-like pattern, however, the blade was overcleaned and that may be why the pattern was faint and only visable near the handle.

The patterns - no problems. But is it true that their chemistry/structure is usually very different than the swords they were supposed to imitate ? Again, I guess you know this material, while I just read some papers, so I would really appreciate to be corrected here.

Hi Dr. Feuerbach.

NihonTo (japanese blades) have martensite. A very high quality work my Dr. Tatsuo Inoue
was online but it is now available only downloading it by my site here under the title "Tatsuo Inoue Swordsmithing file":

http://xoomer.alice.it/tsubame/ZZZZZZ_DOWNLOADS.htm

I believe that "Control of inclusions in japanese ancient iron and steelmaking"
(available in the same link) can be of some interest to you too...

Hi

retained austenite is alway a problem with high alloys... especially with chromium.. .. I know Achim made a wootz with stainless levels of Cr ... and he did maintain it was tough... so i don't know .... if you reach the temp for martensite finish ... you should have good conversion... that why i like to undercool my blades abit... (just me being paranoid )


with the martensitic wootz.... you don't have an extended soak time as you would with other high alloy steel... I just treat it as a plain carbon steel with a very short 4 min soak at non-mag... ... basically, i don't want the large macro carbides to go into solution... just the steel matrix..... i know its abit bizarre.... just the opposite of modern heat treatments for high alloy steels... in the modern case you want the carbides to be dissolved
-- take for example A2 .... with 5% Cr needs 30 to 45 min at 1750 to 1800F for proper heat treat....

-- if you think about it..... part of the forging of the barstock is the growth of these macro carbides........ basically dissolving little ones and adding to the big.. .... through all those heat cycles......... from a black heat up to orange etc


also....... alot of the pattern of wootz has to do with how slow the cool time is from liquid charge to solid.... and.... combined with the roast time (anneal ) afterwards.......both time and temperature ...


just my opinion
;)

Martensite
 

Can't find better words then the Ted Tenold's ones to describe the following pictures that shows the grouped martensite called "Nie" in japanese swords :

quote...

Nie is basically "spheroidal martensite" which are clumps of martensitic growth propogated by long high heat and maintained in a rapid agressive quench.

...unquote.

pictures by Keith Larman ( http://moderntosho.com ) :

http://i118.photobucket.com/albums/o...ame1/jinie.jpg

close-close-close up :

http://i118.photobucket.com/albums/o...me1/jinie2.jpg

Hi Ann,

Neither was I aware that they existed until that earlier post by GT Obach and also this paper by Verhoeven and Pendray, available here:

http://met.iisc.ernet.in/~rangu/text.pdf

So would I, but apart from the above, unfortunately I cannot help. I hasten to reiterate that as far as Wootz is concerned, I am a beginner on a steep learning curve.

I imagine that there must have been attempts to quench harden, as opposed to work harden, Wootz blades because of the superior hardness/strength attainable, but we do know the problems associated with quenching hypereutectoid steels. Perhaps quenching from the lowest possible temperature, established empirically would have minimized the problems to an acceptable level. Maybe, by sheer chance every now and then they managed to turn out a martensitic blade that wasn't badly flawed and performed superbly; I just cannot see the ancients regularly turning out superb Martensitic Wootz blades - Just my thoughts as an informed layman on the subject.

If I may impose on you a little: What is the highest measured hardness of a historical blade that you are aware of? And how was it tested (Brinell, Rockwell, Vickers)?.

I suspect that herein resides the original question of this thread. If Wootz swords were not quench hardened, merely work hardened, then I very much doubt that they could have ever been able to cut through armour, never mind wrought iron chains. And as such, whilst serviceable, their legendary reputations must have been based on gross exaggerations.

Cheers
Chris

GT Obach,

Thanks for that information. I have no doubt that with modern pyrometry and metallurgical know-how, we can get around the problems of producing Martensitic Wootz that performs - After all, you obviously did, as amply demonstrated by that cutting through wrought iron.

However, the question remains whether the ancients could do the same and to answer this, we need historical samples.

Cheers
Chris

Hi Chris

you got it
-- we really need to test more ancient samples..... ... despite the couple studies that were done... i still have hope for some good martensite structures.....(i've been optimistic about it for years... ;)

there are a couple of accounts that talk about oil quenching... ( yes, i know words are not proof enough for either of us...but they are interesting to read. )

Massalski account : "When the blade has cooled, it is quenched in boiling hemp seed oil. Some armourers add a little grease and bone marrow. The wooden tub which contains the oil is sufficiently large for the blade to go in easily. The oil is heated by plunging two or three pieces of red hot iron into it. During this time the blade is given a heat between red and white hot, and then plunged into the bath. If it is a dagger it is held flat; if it is a sabre, it is quenched little by little, beginning by the end of the cutting edge, holding the latter toward the bath. This manoeuvre is repeated until the oil stops smoking, which proves that the blade has cooled. After quenching the blade is always soiled with burnt oil. This dirt is removed by heating it enough to set light to a piece of wood, and by rubbing with a rag from a bedsheet. It is at this time too that imperfections are corrected and the blade is straightened if it is out of true. After 5 or 6 heats the blade leaves the fire quite ready, i.e it then only has to be cleaned with sand, polished with emery and mottled by pickling in iron sulphate. "


I've got others just got to dig them up...

also... one last thing... I'm really not sure that the air quenched wootz would be able to cut a cannon chain... but i could be wrong..... it may cut flesh well but i'm not sure about the other... what i do know is that air cool wootz is much much harder to get a nice even etch on... ...


take care
Greg

Hi Greg,

Many thanks for that account. It certainly cannot be ignored and is food for thought as it does support the case for Martensitic Wootz. Not being familiar with the author, when was it written?

As far as work hardened Pearlitic Wootz is concerned, my guess (based on modern similarly hardened products) is that the equivalent of 45Rc should be readily attainable. And this hardness level is that of many 19th century military sabres, so is quite serviceable, but not outstanding.

Cheers
Chris

Just as a pointer...

Chris, the text in PDF you linked is not an article from Verhoeven and Pendray, but an extract (only the main text, without the figures, nor the frontpage, foreword and acknowledgements) of a book written by a couple of Bangalore (India) researchers, Dr. Sharada Srinivasan and Prof. Srinivasa Ranganathan, from the National Institute of Advanced Studies and the Indian Institute of Science, respectively. I think these institutions acted as the publishers, also. The title of this work is "India's Legendary Wootz Steel: An Advanced Material of the Ancient World". It was commissioned by the company Tata Steel, and came out in 2004. The rest of the book can also be found in the same page (which is Prof. Ranganathan's, by the way, would anyone be concerned about Intellectual Property issues). The first pages are HERE, and the figures are HERE.

Good discussion, Gentlemen :)

Sorry to be a pain, but where in the book do they mention a historical crucible steel blade with martensite? I have had a look and can not find it. Plus is GT Orbach's one from replication or an historical object? I remember doing a survey of all known published historical crucible steel objects, and I do not remember any with martensite, but I could have missed it. :shrug:

Rivkin, As far as I recall, the information of Anasof's experiments, published by Bogachev, does suggest that his processes were comparable to traditional crucible steel ingredients and processes.

Hi

Metallographic examination of two damascene steel blades... by Jerzy Piaskowski... 1978

no mention of Martensite but sorbitic matrix...

SORBITE:

Structure of steel, resulting from the tempering of martensite. In a truly sorbitic structure, the cementite is completely dispersed in the matrix. The trend is to call this structure tempered martensite.

this can be confusing... because i don't know if people still use that term sorbite... .. i know the bladesmiths all call it tempered martensite..


Look on pg 9 in the " discussions "
-- the structure of both blades is very uniform along the whole of the cross-section. The measurements of hardness showed identical values for each of the swords which, in turn, points to the fact that the blades were subjected to quenching and tempering, according to the descriptions by J. Barker and Massalski, who travelled in the Near East.


so... .. I was wrong...... as their is some evidence.....

thank you...
:D :D :D


Greg



another quote from the study..

" strips of carbides are visible to the naked eye on the blades surfaces and appear in the form of light coloured bands typical of the damascus pattern, whereas the dark background of this pattern forms a sorbitic matrix "

You're right. Sorbite is martensite tempered at high temperatures (600°)
for quiet a long period and is known as tempered martensite.

Hereunder two exaples from my HD :

Typical structure of oil quenched martensite :

http://i118.photobucket.com/albums/o...martensite.jpg

Sorbite (martensite quenched in oil and tempered at 600° C for 2 hours) :

http://i118.photobucket.com/albums/o...e1/Sorbite.jpg

Very interesting. I thought for example Anosov used graphite instead of traditional materials such as coal/wood. But taking in mind that I have no idea how smithing works, it well may be that I am saying that simple shocks the present in its ignorance :).

Usually graphite is found in cast (pig) iron being connected with a too much
high carbon content (2,8%-3,8%). I wonder if the burning of graphite
in these experiments can be connected with transferring some carbon to
steel or simply because it achieve the needed temperature in a faster
way or it can hold such temperature longer (only supposing about these two
last properties of graphite).

Japanese smiths transfer carbon to the blade using vegetal fiber wrapping
in certain stages of the smithing. Might be that putting steel into a
burning graphite bed is intended to the same aim to compensate the
carbon loss during the smithing ? Are wootz/crucible steel blades
folded many times as the japanese ones, meaning a loss of carbon in the
process and so needing a trick to maintain high the carbon content ?

Hi Ann,

First I must thank Frank for his correction and the supplementary links.

I found that link late in the night and read it too hastily. The authors were most certainly not by V&P - My mistake, for which I apologize.

In my haste, I did not read the work in full, just did a global search for the words `quench' and `Martensite'. However, it appears to me that the author links the hardening of Wootz with quenching and tempering, but I add, none too clearly for me, especially when we get to Pg 87.

On page 29/90 under the heading of Steel Processing: Reference to Indians smiths quenching swords into banana trees and worse :eek:

Pg 86/90: Reference to work by Kochman and colleagues in which a historical blade was examined for microstructure and bits of Martensite were found. The full article can be read here:

http://www.crystalresearch.com/crt/ab40/905_a.pdf

I found it interesting that: a) Martensite was formed in the 1st place, as this usually requires quenching of some sort, b) that there appears to be little Cementite near the very edge and c) the rather obtuse angle of the edge, which suggests something or another.

Pg 87/90: Elaboration on the idea of high carbon Martensite decomposing.

Cheers
Chris

Thanks loads Chris for the link. I did not have a copy of the article.
Ok, let me add some more murkiness to the mud.....

From Samuel's Optical Microscopy of Carbon Steels, 1980, ASM, P 26-28.
"Sorbite....It was subsequently shown that these constituents often were merely fine lammellar pearlite, but unfortunatly the terms were also indiscriminately used to refer to tempered martensite. This duality or origin was in fact recognized in the original ISI definition......." The text goes on in detail (sorbite was named for Sorby if anyone is interested).

From what I gather, there is primary and secondary sorbite: Primary from the eutectoid transformation process (and perhaps very important for pattern discussion) and secondary sorbite which is tempered marteniste.

Now all that said, my brain hurts and I am no more the wise. :shrug:

Hi Ann

yes.. you are correct and note... that it seems that sorbite... is a confusing term.. ... due to it being used for both tempered martensite and pearlitic sorbite ...

i've read more that a couple times that its an old term that seems to be out of style...lol

I had to reread that study i quoted several times before i realized they were talking about tempered martensite...... the term sorbite had fooled me at first

you see... he mentions sorbite that is produced in the case of these two swords were made according to the Massalski and Barker accounts..... In the Massalski account ... this is definitely an oil quench and that would make martensite ...

if it was pearlitic sorbite... then you wouldn't need an oil quench nor a temper cycle afterwards....... just air cooling


Greg

Hi Folks,

1. I am beginning to think that we are rapidly reaching an impasse because of a lack of what can be considered sufficient studies on enough samples to be representative of Wootz swords - Especially those that were more than just eye candy. Nevertheless, we can state with some confidence the following:

a) In the absence of new knowledge, the quench hardening of hypereutectoid (>0.8%C) Wootz would have presented the ancients with enough problems to render the process quite haphazard - Whilst it is conceivable that some smiths could consistently estimate the lowest Austenitization temperature by the colour of the heated steel, a bit too much heat and some of the carbides re-disolved leading to retained Austenite after quenching (very undesirable);

b) That whilst unquenched hypereutectoid Woots can be work-hardened, the hardness obtainable would have been insufficient to produce swords capable of cutting through armour, or for that matter, knives and tools (say woodworking or stone cutting) with a sufficiently keen/hard edge to be truly functional;

c) Quenching/tempering and the attendant superior qualities thus attainable were sufficiently well known in antiquity, for Indian and Middle Eastern smiths to ignore and be satisfied with the inferior alternatives; And

d) there are too many instances of quenching being mentioned in olden times.

2. Other thoughts on this matter:

Why are we concentrating on hypereutectoid Wootz and exclude hypoeutectoid (<0.8%C) as representative of the kind?

What I am getting at is that there is no real difficulty in obtaining excellent Martensitic steel from hypoeutectoid stock, and tempered Martensite is the preferred microstructure for a sword that cuts by impact.

If the Indians could reliable produce hypoeutectoid crucible steel then the problem of how to obtain truly great hardness&toughness disappears. I imagine that it may have even been possible to arrive at a hypoeutectoid steel by de-carburizing hypereutectoid crucible steel stock. At this point of my deliberations, the only real advantage that I can see for hypereutectoid Wootz, apart from appearance, is a lower melting point which facilitated the crucible reduction process.

Greg could be right, as per his posts elsewhere, that our current day definition of what constitutes Wootz is unreasonably narrow by restricting it to hypereutectoid steel. For example, Vehroheven&Pendray decided that one of the swords they studied was not Woots Damascus because it did not contain the expected carbides. Ands yet, the term Wootz is said to be the Anglicization of the Kannada word for steel (any steel or crucible steel?). Of course they added the appellation `Damascus' to their definition, but then why go looking for mechanical attributes that may have have been the property of swords exclusive to this definition?

I think that it is fairly safe to say that when ancient chroniclers recorded that some swords performed remarkable cutting feats, that they did not class them by their carbon content, rather their origin, and even that very broadly.


Cheers
Chris

Hi Chris,
You are right. I have been arguing that hypoeutectoid crucible steel (producing ferrite/pearlite banding pattern) should not been seen as inferior. I am SURE that both were made in the same workshop, and were in the furnace next to each other, to control a difference between >0.8% and <0.8% would have been difficult to control. I am sure that cast iron was occasionally made as well.

Also, when I did my PhD I found that only 18 blades had been studied, which is why I am trying to increase that "database". How can we base any theories on such a small sample base? Plus, where the sample was take on the blade is also a concern when it comes to microstructures etc.

Just a note to say that I am not against any quenching/tempering of ancient blades, just the lack of evidence, but as mentioned above, could be due to sampling. :)

Hello,

This is a wonderful discussion, thanks to all the metallurgists for the great information!

In "Armes blanches du monde Islamique" by Alain Jacob, I think, I recall an account by a French officer in Napoleon's army who commented on Mamluk sabres. He gave an account of the way Mamluks trained: they would ride at full speed towards a block of wood on which was placed a turban. They would have to slice the turban in half without displacing it off the block, careful not to hit the block of wood as it would break the sword and cause great shame. I don't recall if he characterized the blade as Damascus, but the passage indicates that these blades could hold a magnificent edge, but were extremely brittle. Would such blades exhibit a high austenite content?

Regards,
Emanuel