Myths About Damascus - Edge Retention, Sharpness, and History

Larrin said:
There are potential complications with toughness testing including the potential introduction of impurities, in certain scenarios (layer count, orientation, etc.) there can be an increase in toughness due to energy required for delamination, and there is somewhat of a refinement of the carbide size of 154CM. Also if you remember my microchipping article the crack initiation may be reduced by the 154CM carbides potentially making the AEB-L less effective at increasing toughness (especially with unnotched). In summary there are a lot of factors and the specific variables of each test are important. I know that in tensile testing of a 420/302 stainless steel laminate that it behaved as a composite in terms of strength and ductility.
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Wow, never expect that pattern welded can increase the toughness. I always thought that laminated area is a weak point.
 
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Hi Larrin, that wasn't bad at all. Thanks for putting out some correct info on Crucible Steel. There is only one thing that I would add to what you have written there.

Doing an edge comparison between crucible steel and specific steel formulas is so ambiguous to be almost ridiculous. Wootz steel is not a formula steel, it is a very general grouping that encompasses several thousand years and different elemental profiles of many different patterns and steels. We can't make a specific statement about an undefined and general group of steels and then compare the performance of one example of that general group against a specific formula steel such as 52100 or 1095 and expect our findings to be taken seriously.

Wootz has carbon contents varying between 1 and 2% carbon with the average falling around the 1.4 to 1.6 mark. This carbon content affects the performance of the edge and the ability to chip when hard. The way it is forged determines how tough the steel is and if it is more or less likely to chip and this way of forging can also effect the pattern the blade. The wootz steel cross section sample that was shown in your article was not well forged and it was not an example of the best wootz steel. The cluster sheets of carbides were not parallel lines in cross section as all the good blades have in them from the old days.

Abbott from the 1800s in his account mentioned that the edge holding and durability of wootz was posessed by only a very few blades and that most of the countries that supplied wootz swords did not make good quality steel blades. This was because of the methods of heat treating and forging of the ingots.

Much of what is said about wootz today is wrong, thankfully things are slowly getting better and I appreciate you doing your bit to set the record straight.

Cheers,
Tim.
Buffalo River Forge.
 
The wootz cited was made by Al Pendray and John Verhoeven and was tested against blades forged by Al P. And Howard Clark. All leading researchers of wootz damascus. I’m pretty sure they know what they are doing.

Hoss
 
Thanks Hoss for pointing out the authors, I didn't catch that. Al Pendray knew what he was doing, he was my mentor and started me on the road to making Wootz almost 20 years ago. But that gives me cause to wonder about that specific sample, the orientation of the carbides is all wrong for Al's steel the way he forged it, oh well perhaps I should put in a request for the paper to get the finer details. I know that they would have done a good job on the study. John Verhoeven is pretty thorough, I know him personally too. I am surprised that I missed this paper in my collection of papers and research.

Notwithstanding that, my comment about making a general statement about how all Damascus Crucible Steel performs stands. Al's steel was good, but it still doesn't represent all DCS steel samples of all different carbon levels and all different chemistry from all times that Crucible Steel was made. DCS was not one steel type but many. There were many alloying elements depending on the process used and the ingredients that they added. Manganese was added in quantity in some Damascus Crucible Steel recipes and Chromium was added in others as well as Magnesium and even Silver... and there were others.

It is kind of like saying that because W1 performs one way then 1095 performs the same way because they are both carbon steels. Both steels have different elemental profiles because of the ore bodies that they come from and other things which are added. Analyzing the performance of the edge of one and saying that it represents all carbon steel blades is just as ridiculous as making a generalization about the edge performance of Wootz etc.

I am not trying to be a pain, there have been way too many generalisations and lies spread about Crucible Steel over the years and we have to be specific if we want things to improve.

Cheers, Tim.
 
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Hi Larrin, I gather you are suggesting that I am using the "no true scotsman" line of reasoning. If that is your suggestion then you don't really understand the history or variety of Crucible Steel. All modern alloy steels are the results of the original efforts of trying to replicate Crucible Steel. Just as modern alloy steels which have more nickel or more chromium or more manganese in order to change the characteristics of the steel or the blade made from it; Wootz / Pulad / Bulat which all are general names for crucible steel, also had different elements added in order to increase toughness, edge hardness etc. A person cannot make a general statement about Crucible Steel and it's edge holding abilities or it's toughness or it's flexibility, from the results of one kind of Crucible Steel. These conclusions or findings only apply to a specific type of crucible steel with a specific elemental profile, not to another kind of crucible steel with more chromium or with silver or with more manganese. These things change the edge performance as well as the blade flexibility and durability of the edge, I am not even talking about the way that it is forged affecting the characteristics, which is a totally different set of variables. Each kind of crucible steel must be tested separately and if the findings are all the same, it is then and only then that we can make generalisations about Crucible Steel and be correct.

This is a matter of academic method and making accurate statements from research.

This is something that I know something about having made and researched Crucible Steel in all aspects since around 2001.
 
Kevin McGovern said:
"you can't make a general statement about crucible steel, except that ALL modern steel is an effort to recreate it."... Riiight.
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Kevin, you misquoted me. What I actually said is "All modern alloy steels are the results of the original efforts of trying to replicate Crucible Steel"

This is a matter of modern metallurgical record. The first steel alloys in the modern era, in the west, were the results of investigating wootz and trying to replicate it. All the modern alloying of steel has it's roots in the search to replicate crucible steel and we wouldn't have the modern research without the original search that birthed what we have today. This is something that any metallurgical historian will readily admit.
 
Larrin said:
Once you have shown with research that wootz can cut better than in the study let me know. Until then we will use the knowledge we have.
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Of course I support you using the knowledge that you have, just so long as you are honest with what that knowledge represents and what it doesn't. More research should be done, especially on the old blades but unfortunately the really good ones are in collections and will never be released for this sort of testing. Even using modern day crucible steel doesn't give a good representation of how the old blades would or would not have performed. I wish it was different but unfortunately it is not. We have a tiny tip of the iceburg that we have good research on in regards to historical Wootz. Hopefully with the increase of non invasive neutron analysis etc. that body of information will grow.

Anyway Larrin, happy studying and all the best.
 
I find wootz to be fairly uninteresting. It doesn’t perform better or look better than other modern steels. Pattern welded steel is more appealing for looks and performance.

Except for the nostalgia of the ancient material, I find it doesn’t bring the returns as other materials do.

Al Pendray was such an interesting person that it added greatly to his knives.

Hoss
 
Wootz is a particular taste for sure and it is not for all people and the patterns are often more subtle than with pattern welded steel and that is fine. Everyone has their interests. The modern steel formulas do perform better than the average Wootz blade, but it is kind of like the Japanese steels, they aren't all around steels and as they say if you chip a traditional Japanese knife you were not using it correctly. It is expensive to make and therefore expensive to buy and you are right the market is not the same for it as with other steels. It is kind of like a boutique steel off to the side of other steels but can have great beauty and a bit of mystery by itself. Sometimes people buy it for the process and not for it's all round performance, similar to the Japanese steels.
 
Tim Mitchell said:
Kevin, you misquoted me. What I actually said is "All modern alloy steels are the results of the original efforts of trying to replicate Crucible Steel"

This is a matter of modern metallurgical record. The first steel alloys in the modern era, in the west, were the results of investigating wootz and trying to replicate it. All the modern alloying of steel has it's roots in the search to replicate crucible steel and we wouldn't have the modern research without the original search that birthed what we have today. This is something that any metallurgical historian will readily admit.
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I fail to see your point. Discovery begets discovery.
 
My point is that without the search to replicate crucible steel and to find out what made it tick our understanding of the microcrystaline nature of steel and the modern understanding of alloys would never have happened. The search for replicating wootz was the generating spark of our modern metallurgy. Our modern alloys are the results of that search.
 
Tim Mitchell said:
My point is that without the search to replicate crucible steel and to find out what made it tick our understanding of the microcrystaline nature of steel and the modern understanding of alloys would never have happened. The search for replicating wootz was the generating spark of our modern metallurgy. Our modern alloys are the results of that search.
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Could you provide sources for these claims, please?
 
Interesting discussion gentlemen. I’m going to just interject an opinion, after reading Devins comment about wootz vs pattern welding. Only an opinion.....please don’t crucify me here. It is amazing the designs that are capable of being made by pattern welding (modern day so called “Damascus” steel). But this is usually done with modern processed steels of completely different alloying content. For example 1084 and 15n20, or O1 and L6, which are welded together and folded to create the desired controlled pattern. Even as a knife maker, and a relatively new one at that, “pattern welding” has never appealed to me. Well, maybe for a few months at the very beginning of my interest in metallurgy and knife steel processing it did. The overall look of the blade is “too busy”, for my taste and lack of a better term. And after all, it’s just two (or more) steels of varying alloy content combined together to form the pattern. Patterns from random to ladder to Texas flags!!?? And the resulting patterns can be beautiful, no doubt about it. And I am by no means diminishing the talent it takes to do such. Please. I get it.

But for my simple and relatively uneducated tastes, real historical wootz steel is in a whole different area of cool. It’s not 2 different steels, but “one” of very high Carbon content, which has small alloying elements (vanadium) that is specifiallly processed in a certain manner to show off the “banding” (if I may be allowed to say that is the correct term for what’s going on). And what really got my “goat”, wootz steel was never quenched, like modern steel and so called “damascus/pattern welded” steel must be.

I’m in no means speaking of one is superior to the other in performance, but rather aesthetics, and more to the point, what was more valued at the time, and what catches my eye today.

Just an opinion!
 
samuraistuart said:
Interesting discussion gentlemen. I’m going to just interject an opinion, after reading Devins comment about wootz vs pattern welding. Only an opinion.....please don’t crucify me here. It is amazing the designs that are capable of being made by pattern welding (modern day so called “Damascus” steel). But this is usually done with modern processed steels of completely different alloying content. For example 1084 and 15n20, or O1 and L6, which are welded together and folded to create the desired controlled pattern. Even as a knife maker, and a relatively new one at that, “pattern welding” has never appealed to me. Well, maybe for a few months at the very beginning of my interest in metallurgy and knife steel processing it did. The overall look of the blade is “too busy”, for my taste and lack of a better term. And after all, it’s just two (or more) steels of varying alloy content combined together to form the pattern. Patterns from random to ladder to Texas flags!!?? And the resulting patterns can be beautiful, no doubt about it. And I am by no means diminishing the talent it takes to do such. Please. I get it.

But for my simple and relatively uneducated tastes, real historical wootz steel is in a whole different area of cool. It’s not 2 different steels, but “one” of very high Carbon content, which has small alloying elements (vanadium) that is specifiallly processed in a certain manner to show off the “banding” (if I may be allowed to say that is the correct term for what’s going on). And what really got my “goat”, wootz steel was never quenched, like modern steel and so called “damascus/pattern welded” steel must be.

I’m in no means speaking of one is superior to the other in performance, but rather aesthetics, and more to the point, what was more valued at the time, and what catches my eye today.

Just an opinion!
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I strongly encourage you to make some wootz and some interesting pattern welded material and then report your findings.

Hoss
 
The first person who looked at a specimen of steel under a microscope in order to look at it's structure was Pavel Anosoff. It was his work on trying to recreate crucible steel and looking at it under a microscope which began the microscopic study of the microcrystaline structure of metals and which led to the creation of Phase Diagrams.

Concerning the influence of crucible steel on alloying of steel, Faraday was considered the father of alloys and he began his studies with Stodart trying to work out the secret of crucible steel which he incorrectly attributed to silica and aluminium oxide. They tried alloys of nickel, silver and other noble metals which showed him that the addition of these metals did harden steel. There is a good general summary of how crucible steel study has influenced our modern metallurgy at this link: https://www.researchgate.net/publication/226262307_A_tale_of_Wootz_steel
It does miss several very important things but it gives the general picture.

Breant also did extensive experiments not long after this of alloying all sorts of metals in an attempt to recreate wootz. He did at least 300 experiments of alloying to try and recreate crucible steel.

I hope that helps.
 
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