Damascus question

I may be wrong but I don't think it will ever become a homogeneaus billet unless you melt it down and repour it. But after multiple folds the layers will get so small they may not be decernible. don't know just how far you can go but some 1000 layer count damascus has some real fine lines.
Stan
 
In my experience, once you get to about 1000 layers things start to get pretty fine. That said I've seen some 3000 layer steel that had a visible (if very subtle) patterning.

It also depends on what is going into the billet, and how it's constructed. There are Japanese style swords where claims of folding 13 times, etc have been made, which is perfectly reasonable, and assuming that your layer count starts with one layer (the bar after being welded together from tamahagane) that would give you 8000+ layers. There is still visible patterning when polished, but it is quite subtle. That same level of folding would likely result in a less subtle (but will VERY fine) pattern if high-contrast steels were used as we tend to do in modern pattern welding.

Are thinking towards a specific project? If so, a little more detail on what you're planning might help get you a better answer.

-d
 
here is a picture of a blade that has 132,000 layers in it.
standard.jpg
 
Lets define homogeneous. If you mean as one piece of steel, one fold. If not, the more folds, the less definition in the pattern. I generally dont ever go over 500 layers.
 
just curious when it gets to the point of diminishing returns. Won't it either be just one big weld, or so fine you won't tell it's damascus?
 
I understand your question completely. Its not so much a matter of exactly how many times it can be folded, but rather how many times it can be folded under the correct circumstances, and what materials to use. The answer is going to be different for each individual, depending on their shop setup, and their experience level. The alloys utilized the in the billet are also going to place a key role.

Example: If you choose two alloys that greatly differ in carbon content, say 1080 and 1018, carbon migration (as well as other alloys) will occur in a shorter number of "heats" than say a billet of 1080 and 1075.

Several years ago I did a series of experiments, and had the results spectrographed. What it reveled FOR ME, was that when mixing high/low carbon alloys, things started to meld around 300-400 layer count....the thicker the starting pieces of the billet were, the closer it came to 300 layers, and the thinner the starting pieces, the closer it came to 400 layers. I can only surmise that because I was starting with a higher layer count initially(with the thinner stock), and exposing the billet to less heat/duration than was require with the thicker starting material, carbon/alloy migration was lessened.
Just to be clear...these were the results I achieved, in my shop, with my tools and my methods. The fella that did the testing for me made it very clear that these results applied to me particularly.
Basically the tests reveled that those billets created with 1/4" thick pieces (1080 and 1018) Came out with an overall carbon content of approx. .55-.60 throughout the finished billet at 300 to 320 layers, where as the billets that began as 1/8" stock or less came out at .65-.68 carbon at 400 layers.

I also did the same experiments with a mix of 1080 and 15N20. The results of which were somewhat surprising to me..... the carbon content in billets as high as 700 layers remained within 3-5 points of what it started with....which is a big reason I advocate the use of a second high carbon alloy (particularly 15N20) in damascus billets.

My conclusion is that there is a lot more to it than just how many times it can be folded. Much depends on all the details.
On a side note, my personal opinion is that once you get past about 500 layers, layers start getting difficult to distinguish.
 
My eyes are getting so old and tired that stuff past 300 layers gets harder for me to discern.
 
Ain't it the truth Phil! I've been wearing safety glasses for about 5 years now that are "cheaters". (1.25 mags). I'm thinking I need to go see the eye Doc again....I tried a pair of 1.50 mags yesterday and I liked them! :eek:
 
I'm thinkingthe reason for a tamahaganae blade to be folded so much then is to work out impurities/add carbon with rice hulls

which would make folding non tamahagane steel past the point of having an even distribution of carbon of no performance value, just asthetics of the makers choice ?
 
In my experience, above 3000-5000 layers is too fine to matter. Of course it somewhat matters how thick the layers were to start with.
I find 1000 layers looks good on a Japanese blade, 3000 looks classic, and 5000 looks like tamahagane. Realize that tamahagane may be folded to more than a million layers, which sounds like a lot, but is only 30 folds in a single bar.

Stacy
 
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