On Topic: Wrought Iron

ddean

ddean

Joined
Mar 26, 2002
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Clearing the Confusion Over Wrought Iron
http://lametalsmiths.org/news/clearing_the_confusion_over_wrou.htm

"Rather than having the "snap-off" characteristic of modern steels, true wrought is like bread dough or candy taffy [Figure 1].
The reason behind the metal's unusual properties is the addition of iron silicate. This glasslike slag is interwoven in the iron and gives the metal its "dough-like" form [Figure 2]. In a single square inch there may be 250,000 or more of these little slag fibers. By their very nature, the fibers help the metal do a better job of absorbing stress."


Why -on- topic?

Because I'm reminded of something I read in the archive threads
about the kamis sprinking 'stone dust' onto the blades as
they were being forged.
If that stone contains quartz/silica,
then maybe forging it into the blade creates 'wrought steel'.
This would substantiate claims of special durability.
Maybe even a metal that gets 'sharper' with use;
perhaps from wear exposing this 'glassy slag',
or pulling it out of the metal creating voids on the edge
that act as micro-serrations.

Watcha think?

The link is a good & informative read in any case.
 
Originally posted by ddean
Clearing the Confusion Over Wrought Iron
Because I'm reminded of something I read in the archive threads
about the kamis sprinking 'stone dust' onto the blades as
they were being forged.

If that stone contains quartz/silica,
then maybe forging it into the blade creates 'wrought steel'.
This would substantiate claims of special durability.
Maybe even a metal that gets 'sharper' with use;
perhaps from wear exposing this 'glassy slag',
or pulling it out of the metal creating voids on the edge
that act as micro-serrations.

Watcha think?

The link is a good & informative read in any case.
Click to expand...

Now that's a thought!!!! :eek: :cool: :D And very well could be, but who's gonna volunteer a khuk to be cut up for testing?;)
 
"who's gonna volunteer a khuk to be cut up for testing?"

Hmmm, that's a toughie---since the most informative results would come from testing the khuk that stayed sharp the longest and was the toughest. One that broke wouldn't really provide supportive information.
 
Seems like a file shaving would work.

I'm guessing that it would just need to be examined
under an electron microscope to see the slag inclusions.
Most colleges should have these now.
Might make a good extra credit project for a student to do.
Back in '79 I took a college Electron Microscopy class.

A whole blade likely wouldn't fit in the vacuum chamber.
But I'm a little out-of-date;
we just did crystals, bug parts, & other common materials.

I wonder if the blades are still made this way.

Might need to compare an older blade too.
Maybe duck-duck would send in a Durba for evaluation.

If an electron microscope is not the way then (firkin?)
a quantitative analysis would need only a tiny file shaving.

Or easier still, (firkin?) dissolve a bit in acid and run it through
a flame spectrometer to get a silica content.

Firkin? How need do?
 
Dunno much about this stuff--next to nothing. It is a little different than making and analyzing small molecules. Homogenous solutions are little easier!!

That said, presumably wouldn't need much for flame spectroscopy, or neutron activation. But that only tells what elements are there. What seems to be imprtant is the morphology. There are a couple of metalurgists that post on the shop forum. Those are the guys to ask.

I'm pretty sure that there are some instruments that use scanned particle beams (don't recall if electrons or what) and analysis of the deflected radiation can provide information on the composition of very small structures--don't know if applicable in this case.

Haven't read your wrought iron links yet, but I plan to.

It's my current understanding that old-fashioned wrought iron isn't really made any more--people hoard old anchors, anchor chain, and pieces of bridges from the 1800's for this reason.
 
Originally posted by firkin
It's my current understanding that old-fashioned wrought iron isn't really made any more--people hoard old anchors, anchor chain, and pieces of bridges from the 1800's for this reason.
Click to expand...
Yeah. The link info says that, and describes how
the bloom or cast iron is forge folded to homogenize the metal.
What I haven't caught onto is how the iron silicate gets in.
Is it left from the original extraction of the iron?
(I'm guessing yes)
and the wroughting homogenizes this throughout the iron &
probably makes the inclusions smaller & fibrous.

Hmmmm. fibrous.

Pretty cool to think this may have been
the first technologic composite material.
Or at least one of the first.
(not counting alloys)
 
"Is it left from the original extraction of the iron?
(I'm guessing yes)
and the wroughting homogenizes this throughout the iron & probably makes the inclusions smaller & fibrous."

As I understand it, that is correct. I seems similar to descriptions I've seen of traditional Japanese steel-making--heat up a bunch or "iron sand" (sand (silica) thats mixed with iron oxides ?), with a bunch of charcoal powder to take up the oxygen to create a reducing environment, and then pick out the bloom and work it. Presumably the more it's worked at high temperature, the lower the slag content? Is making wrought iron similar except that carbon deosn't get mixed into the product to make steel?

Anyway it seems to be great stuff for making sandwich blades and furniature (kinfe and other). Sounds like there's enough around last a while, just have to locate it.
 
My 15" Bura AK acts, seem more logical. The darn thing just doesn't get sharpened because it has not needed it. I have used it a lot. The 18" Sirupati that I sent with Sarge the first time he went to the bad place was the same way. As long as I used it on green wood it just got as sharp as can be and stayed that way. I still don't know if this sounds right or not. But, that is the way they acted and the AK I still have and is as sharp or more so than my other blades.:) :)
 
Could this be what the original maker of the Ganga Ram Special was refering to. He said something about a magic blade that would get sharper with use. I hope I'm not the only one that read that.:)
 
"magic blade that would get sharper with use. I hope I'm not the only one that read that"

That's part of what I was recalling.
 
I've never read about the kamis sprinkling silica on the blades while forging, but I'd like to pose another possibility. Silica will melt at higher temps and coat the blade preventing it from scaling so bad. This will allow the kami to forge closer to final shape, and would reduce the amount of finish work required (especialy in shops that have no power equipment such as electric grinders). Silica in its molten form will form a flux that prevents oxides from forming and can thus also be used when forge welding multiple pieces of iron/steel together. Clean white sand was a very common flux amongst western smiths.

Slag and scale are something that you do not want forged into any cutting/chopping instrument. It would only weaken the edge, especially under impact. As far as overall toughness is concerned, any silica that was not molten that you might "beat" into the steel would tend to stay near the surface of the steel in the form of an inclusion. It would not alloy with the other elements as in modern steels (S5 is about 5%, 5160 about .25%), nor form fibrous silicon banding as seen in true wrought iron. Hope this is helpful, I'm sure that Art S could elaborate better than I. Adios, stevo
 
If someone comes up with a definite explanation of the -how- of:

" the addition of iron silicate. This glasslike slag is interwoven in the iron and gives the metal its "dough-like" form"

I'd really like to know.
 
Originally posted by ddean
If someone comes up with a definite explanation of the -how- of:

" the addition of iron silicate. This glasslike slag is interwoven in the iron and gives the metal its "dough-like" form"

I'd really like to know.
Click to expand...

Me too. And while we're taling about iron is wrought iron the same or the equivilant of malleable iron?
 
ddean, the iron silicates (and other components of the slag)are from mineral impurities in the raw iron ore that reacted with lime that was added to the original furnace charge (wow, that's a long sentence! :p ) The bloom that was formed out of this molten ore had a large quantitiy of slag and ipurities in it, and was full of voids. This bloom was taken and then hammered (rolled in later times) while very hot to weld shut the voids and drive out the bulk of the slag. The material would be drawn out (stretched by hammering) and folded back onto itself, welded, ad infinium. This would cause the formation of the silicate or slag stingers and planes (the fibrous structure seen in true wrought iron). A good visual of this is to watch the way multi colored taffy or hard candies are made via pulling and rolling.

Yvsa, malleable iron is a type of cast iron that will take on differant internal structures depending on how it is heat treated. Where as wrought iron is almost pure iron (98.5% +, almost no carbon), malleable is composed of 2-2.9% carbon, .9-1.9% silicon, and has a significant manganese content.

Wrought iron is not made in any quantity anymore due to it being expensive to manufacture. Again, hope that this helps out:)

edited to correct goofy spelling- sure I still left some of it mangled.
 
Wow, I actually had something to contribute for once :D I have only worked with true wrought iron once. A lady wanted some old andirons that had been in her family for about 100 years repaire ~ they had finally burned through. We didn't have any wrought iron to splice in so had to use mild steel. The stuff really moved easy under the hammer and forge welded nicely. If I ever start smithing again I would like to find some and use it in a damascus billet with some form of HC. Maybe someday:)
 
Wonder if you could do X-ray or neutron diffraction on a whole blade.

Possibly powder NMR on file shavings - wait a sec. Iron + big magnet. Probably not the best idea. :rolleyes:
 
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