A question about blade materials

not2sharp · 17th March 2006, 03:44 AM

We put a premium on weapons that show evidence of a pattern welded or wootz blade; but, when we are talking about a preindustrial manufacturing process, what other kinds of steel were there? Weren't these techniques used to raise the carbon content of iron to levels that were suitable for edge weapons; and, if so wouldn't the same process have been used for most edged weapons? Could the difference between wootz and other contemporary weapons be simply one artifact shows a clear pattern while the other has the pattern obscured by oxidation and patination?

n2s

Rivkin · 17th March 2006, 05:20 AM

Uneducated imho: "wootz" is when you have distinctive iron carbide and austenite, while sham is when you have ferrite/pearlite structure.
"Differential" tempering willl produce a small region with martensite on top of a simple ferrite. In addition to this, the properties will depend on various impurities - vanadium, molibden, sulfites etc., and on geometry - uniformity and thickness of layers.

In short all of these are not techniques to enrich carbon context, but more of a final result of different processes. The properties of wootz, mechanical damascus and differentially tempered weapons are also going to be drastically different, whith no sure way to say which one is better until very late XIX century when I think european steel simply became vastly superior to anything else - experiments with Moser collection, experiments done by russian and english cavalry weapons at least seemed to show this.

PUFF · 17th March 2006, 07:29 AM

Quote:

Originally Posted by not2sharp

what other kinds of steel were there?

Surface carbourizing & Folding for Chinese & SEA (and other part of the world) blades...

Forge welding/folding for Japanese blades...

IMHO, these are not in "pattern" welding catagory

katana · 17th March 2006, 05:40 PM

My understanding of Wootz is this,

Wootz is a matrix of almost pure iron and iron carbide particles.
It is created like crucible steel in a sealed (airtight)crucible.
The trick to getting wootz instead of regular high carbon steel is in the
melting and cooling cycles. (very, very slowly)
As the metal cools at just the right rate it crystalizes into a dendritic
structure .
Wootz is considered far superior to any laminated steel , but is extremely difficult to produce predictably.
Wootz is characterized by the incluson of carbides in a more ot less concenrtic pattern that follows the shape of the crucible..This orientation is changed as the material is forged out.And will align itself in the direction of the forging.
A great deal of care must be taken that the material is not allowed to
overheat as the carbides will then be made homogenous within the iron.
The properties of a wootz blade are they are strong, and are able to keep a keen edge to the blade. Due to modern industrial processes, good quality steel is available that has similar structural qualities but does not have the beautiful and interesting patterns of wootz.

not2sharp · 17th March 2006, 10:26 PM

I am not necessarily trying to get at the metalurgy; but, rather trying to understand the underlying economics which were in play during the last several centuries with respect to ethnographic blades. The steel had to produce somewhere by some process, relative to each area of edge weapons manufacture. I am not convinced that the average smith would have access to multiple sources of steel produced under a diverse set of technologies. That would imply a steel grading system, branding, and distribution system much like what we have in a post industrialized world. Most likely the smiths made knives according to tradition using the time tested methods repetitively; so if a knife is made in region A from layer forged steel, it would be safe to assume that all knives from that region, at that point of time, were made with the same technology.

The implication would be that even if two examples outwardly resemble each other, they could not date from the same region, nor the same period if the chemistry of the blade is materially different. On the other hand, knives which may outwardly seem very different could be very closely linked, so as to have been made by the same people.

n2s

Rivkin · 18th March 2006, 01:12 AM

Imho, I would completely disagree with almost everything said above.

1. Most smiths were buying steel/iron. In Caucasus in XIXth century for example they used iron files, rails and even needles. Before, it was not unusual for a smith to receive metal from a customer, either as an old sword to be completely reworked or simply as nails etc. It was also not unusual to buy iron/steel from caravans, including those from China and India. Therefore the same artisans could work with drastically different materials, even through each of them had their own preferences.

2. B. Zschokke, Du Damasse it des Lames de Damas, Rev. Met. vol. 21,635-69(1924) shows that wootz sword have neither hard edge (since it is not martensite but a very high carbon steel), neither as flexible as modern (XXth century) steel. It is also inferior to modern mechanical damascus.

Sincerely yours,

Kirill Rivkin

not2sharp · 18th March 2006, 02:34 AM

Quote:

Before, it was not unusual for a smith to receive metal from a customer, either as an old sword to be completely reworked or simply as nails etc. It was also not unusual to buy iron/steel from caravans, including those from China and India.

Wouldn't one technology eventually replace the other? If you had a good source of steel coming along a trade route wouldn't that soon replace local steel production? Keep in mind that every time you switch steels the smith has to experiment to find the correct hardening and tempering process.

n2s

Rivkin · 18th March 2006, 03:28 AM

Technology to some extent is a matter of taste and skill - some people like differential tempering, some mechanical damascus and some like wootz. It is hard to say for certain which one was better even in XVIIth century because skill is more of a determining factor than technology. Concerning trade routes - they were never stable. The profit for a typical caravan was very significant, but highly risky - virtually anyone could simply attack it for the cargo. At the same time even if people relied to some extent on some source of iron, different people had different preferencies concerning how they are going to make _their_ steel - how much camel's urine and how much blood of a sacrificial lamb they would use in their recipe (seriously). In short - same region, Caucasus, same village - Amazga, same timeframe will have everything - wootz, mechanical damascus, differential tempering, fully tempered steel etc. etc. The sources for ore would be everything from old weapons, western supplies, captured russian guns, India etc.

17th March 2006, 03:44 AM	#1
not2sharp Member Join Date: Jun 2005 Posts: 210	A question about blade materials We put a premium on weapons that show evidence of a pattern welded or wootz blade; but, when we are talking about a preindustrial manufacturing process, what other kinds of steel were there? Weren't these techniques used to raise the carbon content of iron to levels that were suitable for edge weapons; and, if so wouldn't the same process have been used for most edged weapons? Could the difference between wootz and other contemporary weapons be simply one artifact shows a clear pattern while the other has the pattern obscured by oxidation and patination? n2s

17th March 2006, 05:20 AM	#2
Rivkin Member Join Date: Dec 2004 Posts: 655	Uneducated imho: "wootz" is when you have distinctive iron carbide and austenite, while sham is when you have ferrite/pearlite structure. "Differential" tempering willl produce a small region with martensite on top of a simple ferrite. In addition to this, the properties will depend on various impurities - vanadium, molibden, sulfites etc., and on geometry - uniformity and thickness of layers. In short all of these are not techniques to enrich carbon context, but more of a final result of different processes. The properties of wootz, mechanical damascus and differentially tempered weapons are also going to be drastically different, whith no sure way to say which one is better until very late XIX century when I think european steel simply became vastly superior to anything else - experiments with Moser collection, experiments done by russian and english cavalry weapons at least seemed to show this.

17th March 2006, 05:40 PM	#4
katana Member Join Date: Jan 2006 Location: Kent Posts: 2,653	My understanding of Wootz is this, Wootz is a matrix of almost pure iron and iron carbide particles. It is created like crucible steel in a sealed (airtight)crucible. The trick to getting wootz instead of regular high carbon steel is in the melting and cooling cycles. (very, very slowly) As the metal cools at just the right rate it crystalizes into a dendritic structure . Wootz is considered far superior to any laminated steel , but is extremely difficult to produce predictably. Wootz is characterized by the incluson of carbides in a more ot less concenrtic pattern that follows the shape of the crucible..This orientation is changed as the material is forged out.And will align itself in the direction of the forging. A great deal of care must be taken that the material is not allowed to overheat as the carbides will then be made homogenous within the iron. The properties of a wootz blade are they are strong, and are able to keep a keen edge to the blade. Due to modern industrial processes, good quality steel is available that has similar structural qualities but does not have the beautiful and interesting patterns of wootz.

17th March 2006, 10:26 PM	#5
not2sharp Member Join Date: Jun 2005 Posts: 210	I am not necessarily trying to get at the metalurgy; but, rather trying to understand the underlying economics which were in play during the last several centuries with respect to ethnographic blades. The steel had to produce somewhere by some process, relative to each area of edge weapons manufacture. I am not convinced that the average smith would have access to multiple sources of steel produced under a diverse set of technologies. That would imply a steel grading system, branding, and distribution system much like what we have in a post industrialized world. Most likely the smiths made knives according to tradition using the time tested methods repetitively; so if a knife is made in region A from layer forged steel, it would be safe to assume that all knives from that region, at that point of time, were made with the same technology. The implication would be that even if two examples outwardly resemble each other, they could not date from the same region, nor the same period if the chemistry of the blade is materially different. On the other hand, knives which may outwardly seem very different could be very closely linked, so as to have been made by the same people. n2s

18th March 2006, 01:12 AM	#6
Rivkin Member Join Date: Dec 2004 Posts: 655	Imho, I would completely disagree with almost everything said above. 1. Most smiths were buying steel/iron. In Caucasus in XIXth century for example they used iron files, rails and even needles. Before, it was not unusual for a smith to receive metal from a customer, either as an old sword to be completely reworked or simply as nails etc. It was also not unusual to buy iron/steel from caravans, including those from China and India. Therefore the same artisans could work with drastically different materials, even through each of them had their own preferences. 2. B. Zschokke, Du Damasse it des Lames de Damas, Rev. Met. vol. 21,635-69(1924) shows that wootz sword have neither hard edge (since it is not martensite but a very high carbon steel), neither as flexible as modern (XXth century) steel. It is also inferior to modern mechanical damascus. Sincerely yours, Kirill Rivkin

18th March 2006, 03:28 AM	#8
Rivkin Member Join Date: Dec 2004 Posts: 655	Technology to some extent is a matter of taste and skill - some people like differential tempering, some mechanical damascus and some like wootz. It is hard to say for certain which one was better even in XVIIth century because skill is more of a determining factor than technology. Concerning trade routes - they were never stable. The profit for a typical caravan was very significant, but highly risky - virtually anyone could simply attack it for the cargo. At the same time even if people relied to some extent on some source of iron, different people had different preferencies concerning how they are going to make _their_ steel - how much camel's urine and how much blood of a sacrificial lamb they would use in their recipe (seriously). In short - same region, Caucasus, same village - Amazga, same timeframe will have everything - wootz, mechanical damascus, differential tempering, fully tempered steel etc. etc. The sources for ore would be everything from old weapons, western supplies, captured russian guns, India etc.