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Ross Vosloo

This can't be right, right?

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Posted (edited)

We all know wikipedia is a bit hit and miss, but whilst reading this article I couldn't help but feel that who ever wrote this has no idea... unless of course it's a case of it sounding so far fetched because it's true. 

So here's the quote, taken from a wiki page on the Roman Galdius, under the manufacture heading.

 

"The Vetulonian sword was crafted by the pattern welding process from five blooms reduced at a temperature of 1163 °C. Five strips of varying carbon content were created. A central core of the sword contained the highest: 0.15–0.25% carbon. On its edges were placed four strips of low-carbon steel, 0.05–0.07%, and the whole thing was welded together by forging on the pattern of hammer blows. A blow increased the temperature sufficiently to produce a friction weld at that spot. Forging continued until the steel was cold, producing some central annealing. The sword was 58 cm (23 in) long.[15]"

 

 

So, from my understanding, the carbon content seems way too low, even for antiquity. then theres the placement of highest and lowest carbon content billets. And then we come to the process of welding by hitting hard enough to generate welding temps. That can't be, can it??? This article seemed to be very clued up until I read that. 

Edited by Ross Vosloo

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Nope.  :lol:  Sounds like he has read just enough to get it backwards.  Gladii were often low carbon, but cold hammering work-hardens it rather than anneals it.  And no, you can't get a friction weld by hammering alone unless you're working in a vacuum, which is hard on the lungs, not to mention unavailable to the ancient Romans.

I've seen some pretty stupid statements like that even in archaeological reports.

Some "experts" forget there are still people doing this stuff. :rolleyes: 

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1 hour ago, Alan Longmire said:

I've seen some pretty stupid statements like that even in archaeological reports.

Oh man no good there.

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Posted (edited)

At least they had the decency to write 'Pattern Welding' rather than this term 'Pattern Damascus.'  I want to scream when I hear that term for some reason.  Two processes so different from each other historically and regionally:angry: and AHHH!

 

Not looking to start a debate. I'm just glad someone wrote pattern welding. :D

Edited by Daniel W

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I had/have a book primarily on ancient iron/steel making.  The author mentioned that he found one (1) sword blade in a museum out of a few that he was allowed to check for carbon content that the core steel was higher in carbon than the edge steel.  That leaves me to believe that smiths of the early iron age hadn't a clue what carbon was let alone what it did when you added it to iron.  He, by the way, also mentioned that all the sword blades that he tested were inconsistent in carbon content throughout the blades.

Another problem with the original article that Ross sited is that just because Pattern Welding uses Forge Welding not everything that is Forge Welded is Pattern Welded.  It's just how rods of iron/steel had to be built up into a flat bar.

Doug

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A little off topic, but when is it generally accepted that carbon content was deliberately used in hardening? There would be the unintentional results of carbon in alloying that contribute to toughness, etc. without heat treating compared to steel closer to pure iron on the spectrum, but that doesn't mean they were trying to get martensite. Also different alloys (carbon, phosphorous) would create visually distinct patterning without hardening, so that might not have been the original contributing reason for intentionally using different material layers. Is there a definitive or even vague period where the transition went explicitly into 'using higher carbon steel because it hardens'? Just a curiosity from a modern perspective...


John

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10 hours ago, Alan Longmire said:

Nope.  :lol:  Sounds like he has read just enough to get it backwards.  Gladii were often low carbon, but cold hammering work-hardens it rather than anneals it.  And no, you can't get a friction weld by hammering alone unless you're working in a vacuum, which is hard on the lungs, not to mention unavailable to the ancient Romans.

I've seen some pretty stupid statements like that even in archaeological reports.

Some "experts" forget there are still people doing this stuff. :rolleyes: 

i thought so. funny how an article which people will read and take as truthful fact can be so wrong. but even the guy writing it, a little common sense should have told him that you cant hit steel to make it hot enough to weld

6 hours ago, Doug Lester said:

I had/have a book primarily on ancient iron/steel making.  The author mentioned that he found one (1) sword blade in a museum out of a few that he was allowed to check for carbon content that the core steel was higher in carbon than the edge steel.  That leaves me to believe that smiths of the early iron age hadn't a clue what carbon was let alone what it did when you added it to iron.  He, by the way, also mentioned that all the sword blades that he tested were inconsistent in carbon content throughout the blades.

Another problem with the original article that Ross sited is that just because Pattern Welding uses Forge Welding not everything that is Forge Welded is Pattern Welded.  It's just how rods of iron/steel had to be built up into a flat bar.

Doug

i wonder if age and decay have anything to do with this. i wonder if the the outer edges were high carbon, but due to 1000's of years of decay, have lost that carbon when compared to the edge. 

why i wonder this is because, if your smart enough to know not to use iron, and smart enough to know how to forge weld, im sure your smart enough to realize that some steel gets harder than other steel, and even if you dont know that its carbon, you do know that it belongs on the edge of the blade. just a theory

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Having the "high" carbon edges eroded away is a distinct possibility.  I doubt that the museums that the author had contacted were going to allow him to do destructive testing on their best specimens

Yes, smiths did eventually learn that parts of iron/steel blooms of a certain appearance, or maybe taste did produce a harder steel.  Take for example the Japanese bladesmiths.  I still think that they were clueless about carbon; I believe that it was sometime in the 1700's before it was "discovered".

As far as quench hardening and tempering were discovered you could really start an argument over that.  Then there's the fact that if the carbon content was around 0.3%-0.4% you might get away with quench hardening without tempering.  From what I have read on these forums, that main thing that made iron hard was a high phosphorus content.

Doug

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Several good points here, it did not occur to me he may have been talking about "piled" construction rather than actual pattern welding.  I too have read about some early blades with higher carbon in the core than the edges, and it was not because the edges were gone.  I suspect it had to do with pattern manipulation or the smith wanted the tougher-to-forge stuff in the core where it make a stronger blade, by some theories.

Phosphorus does make a harder iron, and is more common the farther north you get.  This is due to the ores, it is not a deliberate addition.

BUT: we all can tell the difference between forging mild steel and something like a railroad spike with 0.35% carbon.  With bloomery material the difference is even more noticeable.  The smiths knew what hard steel felt like versus soft iron, and even knew how to run a smelt to get the desired end product.

And ah, the quenching debate!  Evidence suggests the first centuries A.D., but all the evidence has not been tested as of yet.

Finally, the discovery that it was carbon that made steel hardenable was indeed the product of the (very) late 1700s.  Prior to that steel was thought to be the purest form of iron, in which all the non-iron stuff had been cooked out by lots of time in a reducing charcoal fire...

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Posted (edited)

Very interesting stuff, thanks for the insight gents! I'll never cease to be fascinated by the depth of society that humanity has created and being able to look in on our past as though it were the history from another world for all its mysteries :rolleyes:

Edited by John Page

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On 8/6/2018 at 11:01 AM, Doug Lester said:

Having the "high" carbon edges eroded away is a distinct possibility.  I doubt that the museums that the author had contacted were going to allow him to do destructive testing on their best specimens

Yes, smiths did eventually learn that parts of iron/steel blooms of a certain appearance, or maybe taste did produce a harder steel.  Take for example the Japanese bladesmiths.  I still think that they were clueless about carbon; I believe that it was sometime in the 1700's before it was "discovered".

As far as quench hardening and tempering were discovered you could really start an argument over that.  Then there's the fact that if the carbon content was around 0.3%-0.4% you might get away with quench hardening without tempering.  From what I have read on these forums, that main thing that made iron hard was a high phosphorus content.

Doug

 

22 hours ago, Alan Longmire said:

Several good points here, it did not occur to me he may have been talking about "piled" construction rather than actual pattern welding.  I too have read about some early blades with higher carbon in the core than the edges, and it was not because the edges were gone.  I suspect it had to do with pattern manipulation or the smith wanted the tougher-to-forge stuff in the core where it make a stronger blade, by some theories.

Phosphorus does make a harder iron, and is more common the farther north you get.  This is due to the ores, it is not a deliberate addition.

BUT: we all can tell the difference between forging mild steel and something like a railroad spike with 0.35% carbon.  With bloomery material the difference is even more noticeable.  The smiths knew what hard steel felt like versus soft iron, and even knew how to run a smelt to get the desired end product.

And ah, the quenching debate!  Evidence suggests the first centuries A.D., but all the evidence has not been tested as of yet.

Finally, the discovery that it was carbon that made steel hardenable was indeed the product of the (very) late 1700s.  Prior to that steel was thought to be the purest form of iron, in which all the non-iron stuff had been cooked out by lots of time in a reducing charcoal fire...

is it possible that the carbon could leech out? ok, thats bad terminology, i should say decarborization. is it possible that over centuries or even millennia, the carbon has simply left the steel? or is it a case of once its in the steel, its stays there unless heat is brought to bear upon it?

and yes, i realize that this does sound rather silly. i just have this belief that people of antiquity were a whole lot smarter than we often give them credit for. 

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1 hour ago, Ross Vosloo said:

 

is it possible that the carbon could leech out? ok, thats bad terminology, i should say decarborization. is it possible that over centuries or even millennia, the carbon has simply left the steel? or is it a case of once its in the steel, its stays there unless heat is brought to bear upon it?

and yes, i realize that this does sound rather silly. i just have this belief that people of antiquity were a whole lot smarter than we often give them credit for. 

No, the carbon can not move through the iron at cold temperatures. It's firmly fixed in place. You need to get to at least normalizing temperatures to get the carbon to be able to move as I understand it.

With regards to when they started to harden steel, that was at least 500BC in Europe, from which the oldest firesteels are found. The point isn't when did they start to harden steel, but when did they find out how to temper it. I've not seen any evidence of hardened steel swords at least until the late iron age, eventhough various swords with high enough carbon contents are found. I haven't read all available analyses yet (which is still limited) though.  

Having forge welded stuff, I know just how easy it is to get the edge material on the wrong side of the blade. It's a mistake very easily made. Aside from that, a smith may also have been unaware that some of the iron he had was actually higher in carbon. While he may have had steel made specially for hardenable edges, for lower quality swords he may have been using random material that can have any amount of carbon in it, or a large variation throughout.

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13 hours ago, Jeroen Zuiderwijk said:

I know just how easy it is to get the edge material on the wrong side of the blade.

There's that, that's for sure a possibility. There are more than a few historical examples where the ancient smith got it "backwards" by modern thought. Then there's Alan's point about 

On ‎8‎/‎6‎/‎2018 at 4:56 AM, Alan Longmire said:

the smith wanted the tougher-to-forge stuff in the core where it make a stronger blade, by some theories.

I mean it's completely conceivable that there were two distinct camps on this subject, much like modern smiths have their personal debates about venturi vs. forced air forge burners. I can definitely imagine a couple of ancient smiths debating the merits of one way or another.

Sven: You want the hard stuff in the core so the blade doesn’t bend when it gets smacked on the side parrying an axe.

Snorri: No, you don’t. The hard stuff holds an edge way better than the soft stuff. You want as sharp and durable an edge as possible for longer battles.

Sven: That doesn’t do much good if the edge chips and falls apart in the first fight you toad brain.

Snorri: That soft stuff will get blunt in the first fight. You might as well take a club into battle you troll.

(then the fist fight ensues)

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Ah the polemic duality of Man. It makes perfect sense. I recall a period of stimulated debate over "bend or break" in knives meant for "serious"work. The theory was that a blade that will bend will do so under less pressure than it takes to break one that will break instead . All kinds of "but if....." in that one.

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