A more recent look at alloy and hardness of some Merovingian Swords, spears & etc.
http://www.tms.org/pubs/journals/jom/0508/Ehrenreich-0508.html

Hi Jeroen...

Sorry if I gave the idea that I believed pattern-welding was only decorative or even mostly decorative. In my post above I was trying to give some expert opinions which would be much more meaningful than my on feelings.

My own personal feelings on the matter (for whatever that may be worth compared to Tylecote's and Gilmore's work) is that in many cases, in their original state before over a thousand years of aging and corrosion, many if not most of these pattern-welded core blades did have a noticable increase in toughness and resilience. As I mention earlier, I think this is why it became a hallmark of relative superiority and was included as inlay and veneers in the twilight of medieval pattern welding.

What I really wanted to emphasize in the above post, is that, to me, it is more amazing that these dark age swordsmiths could forge such fine and thin layers of steel into the edge of the blades for the full length of a 30 inch blade than that they could forge weld a bundle of twisted billets together in the core. Also I wanted to suggests that even if we were to accept the most extreme view that pattern welding was only decorative then, in terms of superiority, we still must deal with the issue of these welded on edges and especially the layered sandwich type edges with high carbon steel cores. Who is going to say that this is only decorative? It is clear to me that this was obviously meant to be functional and the experts seem to agree on this point. So... If we were to ask if there was a natural superiority in function with these pattern welded prestige weapons the answer would be yes, even if the patterns were only "bling bling." :D

Jeroen Zuiderwijk wrote:

...Well, the general idea I get is that the smiths tried to create a harder edge, and a tougher core. The latter can be done in various ways, one of which is by creating nice looking torsion damast. While the patterns may be decorative, and the same effect could have been achieved by other methods, that doesn't mean the patternwelding was only decorative.

Great point... And to add to it (and probably open another can of worms): The very fact that they are experimenting with so many "various ways" and patterns in the core would suggest that they are trying to increase some functional aspect. If someone countered that the variety was simply the ever increasing desire for the "new" in decoration then, in IMHO, they don't understand the ancient mind. The obsessive "quest for the new" is a modern condition. The ancients were much more conservative. They believed, and I say this in very general terms, that old was good (tested and proven) and new was bad (unproven and chancy)... just the opposite of the modern tendency. That would explain why decorative trends, as well as technological status quo existed for centuries or longer. For instance with pattern-welding designs, it may look as if they had tried every pattern that could be imagined. However there seems to be some patterns that have not been found as of yet but would have a really nice look. As a matter of fact it was on of these patterns I really liked when designing the reconstruction of the Fetter Lane sword. It involves billets side-by-side twisted in the same direction and offset on each side of the core. I will try to post an image.

It gives a very nice decorative effect but was so unperiod that Barta reversed the outer billets to be more in keeping with period patterns.

take care

ks

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One can read that article with several interpretations. Only one sword showed signs of optimal quench hardening.

In general terms, understanding of the metalurgy and tempering process did not really become established until 10th century.

Pattern welding of swords supposedly peaked around 11th to 12th century, with mass production of superior (more homegenous steel) becomming very well known in very early 14th century in central Europe.

Thanks Jeff!

I had been looking casually for some time regarding evidence of steel and heat treatment in an early period central European sword. It is fantastic to have something concrete to reference. I can't read many specifics in the link, and would appreciate it if you could tell the forum a little about it (estimated age, region it came from, anything else cool.)

Seperately, if you know of any evidence of early bloomery steel production in dark ages central Europe, please share it. It is hard to find through simple internet searches, if it has been written about at all.

My "theory" on why Saxons pattern welded could be totally bunk. I still desire a rational or understanding of why saxons would have utllized a particularly difficult technique (such as pattern welding) for several centuries. It becomes even more mysterious if they did not do heat treat after going through all of that work.

Some researchers have done analysis on surviving wootz and pattern welded swords and concluded that the results were not as good as modern steel (inconsistent carbon content and structure, more prone to ductile bending failure, etc.) but still exceptionally good for pre-modern steel.

I am wondering if the basic process of diffusion during welding would have accidentally imparted semi-effective spring temper (many examples are low hardness such as 30 to 35 Rockwell C) , or if many swords were tempered but have never been assessed archeologically to prove the issue. Modern pattern welders specify a fairly simple heat treat process (often something like heat whole blade to 1400 for 15 minutes, quench in 150 F bath of oil or brine for 30 seconds.) This seems well within reach of a dark age Smithy's capabilities.

There is another enigma of Saxon pattern welding. FLUX.

Forging higher carbon steels and iron together requires a specialized flux (chemical that prevents oxidation from ruining the welds but still permits fusion.) Modern artisan pattern welders use mixtures that are composed predominantly of Borax (sodium borates.) As far as I know, there are no “naturally occurring” alternatives to Borax that are adequate for the pattern welding technique. Alternate chemicals exist, but are products of advanced chemical synthesis. There are only two known regions where naturally occurring mineral deposits of Borax occurs; Turkey and the U.S. Mohave desert town named Borax. Today, some Borax sold for welding is chemically synthesized, but something like 60% of it is still mined, primarily in Turkey.

The Turkish deposits were known and utilized for glazing in ancient China and even found in mummification in ancient Egypt. The actual name for it is based upon Persian “buraq”. It was utilized throughout the middle-East regions also known for production of fine Damascus - wootz swords, which also are accepted as known centers of crucible production of the highest carbon steels available during the “Dark Ages.”

So here is the enigma… If the Saxons produced their pattern welded swords entirely from local mineral resources what were they using for flux? Where did they get it? Did they also have advanced chemical capabilities in addition to high carbon steel production not yet discovered by archeologists?

They could have acquired all of the non-native materials and the processing technology required for pattern welding and heat treatment on a single trade stop during the 9th century either in the mid-East or far-East. This is about the time pattern welding really becomes significant for “Vikings.”

All this information is helpful, but I think relation to my original question about sword production in regions outside Roman influence we need to look at the swords in Britain before the Roman conquest compared to those on the continent. I find it hard to belief that quality deteriorated in the far North of Britain, perhaps in Ireland as there was a sea seperating the two islands. What do you think?

About the sand...

Nobody claims to be certain how ancient pattern welding was done, but several modern pattern welders recycle excess flux by letting it run off into a bucket of sand. They later reclaim it and reuse it. Today they are picky about sifting and separating the sand out though. As far as I know, sand will not act as a flux itself. Smooth grinding and close surface contact between the metal layers prior to forge welding is actually critical. The sand is a "bad thing" in terms of the quality of the composite blade's strength and integrity of the welds.

I honestly can not say I have heard of anyone attempting sand as a flux, although people have been intensly experiementing with reinventing how to do it for almost half a century now, and insist that the flux is critical and needs to be more than 90% Borax. Fluxes containing significant carbon powder will actually bond iron to spring grade steel, but these types of fluxes nearly destroy the cosmetic quality of the pattern welding and are not representative of the few surviving blades that have been assessed metalurgically.

Sand could possibly stop oxidation and diffusion loss of the carbon, and might also have been used as a protective layer during heating, or to protect sections of a heated blade not being prepared for the immediate section of forging. Sand is also a constituent impurity of crucible steel, which I am "theorizing" would have been the source of appropriate carbon content steel in these pre-modern blades that resemble steel. Sand inclusion was generally not a problem in pure iron production.

If someone does have a naturally occurring working alternative to Borax flux that still produces the beautiful patterns of classic pattern welded blades with dependable forge welding characteristics, it woulud be considered a major discovery by dozens of major artisans who have devoted their life careers to experiementing with and advancing the art of pattern welding.

Jeff,

If I only speak English, is there a workable technique for Googeling in another language? At present I am using Firefox which may disable some functions. It seems to be good at stopping "pop ups" though......

Thanks Jeff and Peter. I think you have convinced me.

This link illustrates the method Peter described with quartz sand as flux. I was able to find it after searching for quartz as a welding flux. http://www.metmuseum.org/toah/ho/06/eue/hod_55.46.1.htm

This museum link describes a sword as made from "alternating rods of steel and iron." http://users.utu.fi/mikmoi/construction.htm
I suspect the museum description is misleading and that the rods would be better characterized as varying grades of iron. So far, I have not found evidence of steel in NorthWest European regions other than "bog" or low carbon wrought iron and mild carbon (0.7% or less) however it was produced. Some crucible steel was traded out of Syria to the Genoese in Italy, but evidence is not conclusive before the 12th century.

It is supposedly very difficult to weld plain low carbon steels or iron to higher carbon "alloy steel". Particularly so as you begin to introduce nickle, vanadium, chromium, and elements of stainless steels into the alternating layers to really make the contrast distinct. This is where specialized flux becomes necessary, and what modern pattern welders are doing to make the layers show up with beautiful contrast. I suspect that this is closer to what we see in some of the fantastic examples by Barta, who appears to have a sort of a blast furnace or bloomery forge for production of iron and steel. What seems to be characterized in the metallurgy of the Dark Ages non Eastern blades is "mildly carburized iron", ranging from 0.3% to 0.7% in better cases. This is still not alloy steel, but is impressive if carbon is being achieved through piling and simple hearth forge facilities. If all rods were actually low grade iron, they might be welded with a good forge using no flux at all. This would still have a beautiful look where the slag lines would reveal the look of the twisting and lamination of layers performed as part of the forging. I doubt you could get a spring temper from it though.

I got the above links backwards. They are the correct ones though...