Thread: Wootz and stuff

Perhaps either Mike Blue or Joe Chandler will chime in here. They both have experience with Wootz and pattern welded damascus steel.

http://straightrazorpalace.com/show-...ler-wootz.html

I don't remember if I posted any info about CATRA testing. But, wootz is a very interesting material. Ten years ago or longer a machine was invented in the UK that would put a known force into an edge to test cutting performance. Down force, slicing forces etc could all be measured. Probably more inventive was the development of a graded abrasive paper that would provide a known quantity of resistance and wear. The machine pushes straight down into the paper and then slices. Not a shaving motion.

In the hardened state, at this time, 52100 outperformed all other steels. That steel has been made famous as ball bearing steel. It's quite good, but is particular about how it's heat treated. When it's done well, it's a very good material. Some wootz was compared to this steel. The wootz was from Alfred Pendray and John Verhoeven's labs/shops. In the hardened state, the wootz was slightly inferior to the 52100. Where it got strange was that in the UN-hardened state, wootz out cut everything else by a wide margin.

As to razors, the razor doesn't cut on the side of the bevel, it cuts at the edge. Where the wootz advantage of hard carbide in a soft pearlite matrix takes over is the abrasion resistance along the sides of the edge like in the CATRA testing. You don't need a razor edge to keep cutting successfully, when all those retained carbides are hanging out like saw teeth in that type of cutting action. So the wootz intuitively looks good as a cutting instrument in one form but I don't think it readily translates to razors that way. There is an experiment of sorts under way even now though.

Personally, the razor in wootz I've shaved with, is as good as any steel. And these two examples I know of are hardened and the edges highly polished/honed. I think any advantage of wootz maybe lost compared to any other good steel treated the same.

John Verhoeven provides the most metallurgically sound discussion of ancient wootz. That material is not stainless. I would argue that it maybe better to call any modern stainless reproduction something like stainless crucible steel rather than wootz. I don't have any control of how someone wants to market something they've done, but it's imprecise at the very least. Stainless steel did not exist in the days when wootz was common. A lot of smelted materials can be pushed to develop some of the appearance features of wootz dendrites, but if it's not the same chemistry, it's hard to argue that it is wootz.

I think you were referring to Achim Wirtz, a fine smith. Some of his work has been printed on the net in Russian. He's certainly experimented with a number of different steel types and their manufacture.

Originally Posted by Mike Blue

I think you were referring to Achim Wirtz, a fine smith. Some of his work has been printed on the net in Russian. He's certainly experimented with a number of different steel types and their manufacture.

Are you referring to bulat here?

For those of us not familiar with it: Bulat steel - Wikipedia, the free encyclopedia

Originally Posted by Kees

Are you referring to bulat here?

To some degree I can't avoid comparison. There is not enough evidence to completely separate bulat, pulad, wootz (all other names for the same stuff) from each other. It may wind up being only a semantic difference (nomenclature). Either way it's a steel manufactured in a crucible. There are a lot of things that can be manipulated in the crucible. Without knowing that exact recipe, it's difficult for me to comment on what Achim's doing. He may well be using an Eastern method, where in the US, we'd tend to follow the documents we have available through John and Alfred (western). Until I have a chance to talk to him and watch, I will remain respectfully and eagerly curious. All I see in the video is forging something that could be any steel. If he says it's stainless bulat, that's good enough for me. I have to admit I don't know everything about what he did though.

Here's another reference. David Boye, who helped considerably with his book on knifemaking get me started, has done some work with cast stain resistant materials, even cast cobalt alloy. Those blades show dendritic formations. They are not considered wootz or bulat.

Boye Knives

I think a cobalt razor would be a pretty cool item too.

Here's some more on the archeology of wootz: Home Page

Wiggamore,

I believe the article I was referencing is on the website that Kees just linked in the above post, but I don't know where the article is on that site, it may be in one of the links or it may be elsewhere.

But the essence of what it said, and as Mike confirmed above, is that "traditional" wootz is not heat treated as common steels are and that process leads to different performance characteristics.

The "traditional" Wootz was steel that reached a melting temperature inside a crucible, then allowed to cool very slowly which allowed for the formation of dendrites and highly segregated carbides within the steel matrix. The resulting steel was then forged at low temperatures so as not to reach Austenitizing temperatures that would alter the carbide/dendrite features, which means that it can't be heat treated like modern steels are since that requires full Austenitization. The final blade had those super hard carbides that would be exposed by the softer steel being worn away from the cutting action and thus act like a saw.

It seems like the modern heat treatment makes the Wootz blade's edge a good deal smoother but eliminates those "traditional" characteristics in the process.

Here is a guy that did his dissertation on recreating wootz. Pretty awesome.
Replication of Wootz