Cast iron and wrought iron

[Frosty]

No, using cast iron as a high carbon "hard" layer will NOT do what you wish. Cast iron is brittle and NOT particularly hard, I can scratch a cast iron frying pan with a piece of mild steel.

The problem being that the carbon is taking up so much room in the metal it's the carbon that is making contact rather than the iron, especially in a thin section.

Japanese Katanas are and were never made by layering cast iron in the blade. What happens is the master selects the refined iron ore as it's broken out of the furnace. (Please forgive me I don't remember the proper names for the steel or equipment) As the bloom is broken into pieces the master selects and lays up the billet using observations taught to him/er by a few decades of experience. None of these pieces would be cast iron, some VERY high carbon steel but none so high C as to be considered cast iron.

However you can most certainly use cast iron as a carbon source to raise the C level in steel. This is an old trick I don't think the Japanese use, I was shown by a farrier last year and he uses it mainly to make calks harder so they don't wear as quickly.

First you need to know a few things about iron, steel and heat. The pertinent issue right now is the higher the carbon content the lower the melting temperature. So, what you do is make up some billet stock, say draw your wrought iron into strips say 1/18" x 2" x however long is handy to work with. Now, take a WI strip and bring it to near welding temperature and lightly draw a thin piece of cast iron across it's surface. Set this strip aside and repeat it on another. Repeat until all the strips for your billets have been coated on one face by the cast iron.

Stack your billet leaving the outside strips with untreated WI on the outside.

What this has done is lay in cast iron on the surface of welding temp iron, giving this face a much higher carbon content and lower melting temp but diluting the carbon so after bilet welding, folding, etc. it's no longer cast iron and brittle.

Oh yeah, just so you know, this isn't a beginner technique you have to have a feel for how much cast iron is enough and how much is too much. Learning how to pull it off is up to you. Good luck and have fun.

Frosty the Lucky.

[basher]

all that you are asking can be done .
If you get into smelting your own material then you will most probably end up with a pallet of bloomery products ranging from almost wrought iron with low or no carbon all the way up to cast iron with 2.5 to 4% carbon .
I have used a couple of methods to work cast iron bloomery product back into a billet to increase over all billet carbon content .
you can melt the Zuku ( japanese word for bloomery cast iron) with lower carbon fragments of bloom in a crucible , the resulting ingot can then be forged as wootz or flattened and added to a billet as a high carbon layer . I call this material Tamahagane-zuku-wootzu (with my tounge in my cheek).
alternatively you can braze the cast iron to lower carbon material and then fold it into a billet . can get messy though until the carbon diffuses a bit .
up until very recently (in the scheme of working iron and steel) this mix and match was pretty much the way blades were made and it is only in the last couple of centuries or so that we have really had the luxury of predictable homogenous steel ....
I say go for it , smelting and working bloomery material is a very worthwhile undertaking, it takes time but is very insightful to the material we call steel and how hard won it has been in past times.
for in depth info on all this go to:-
http://forums.dfoggknives.com/index.php?showforum=25

where there is an active community of people doing this stuff.
good luck and post you results ...the successes and failures.
All the best Owen

[BIGGUNDOCTOR]

What about all the crap in the wrought iron? True wrought iron is full of impurities. Seems to me that you will be working with two materials that are very unsuited for a blade. I get the concept, but I think that what you end up with will be very disappointing for a blade material.

The new knives with very high carbon contents, 3% range, are done with a lot of technology.

But hey, you said that you got time to burn, so get to it, and be careful.

[basher]

What about all the crap in the wrought iron? True wrought iron is full of impurities. Seems to me that you will be working with two materials that are very unsuited for a blade. I get the concept, but I think that what you end up with will be very disappointing for a blade material.

The new knives with very high carbon contents, 3% range, are done with a lot of technology.

But hey, you said that you got time to burn, so get to it, and be careful.

pretty much every blade made up untill the huntsman process in 1740 was made from a bloomery material ie full of crud which was worked untill it was suitable to turn into a blade . There are rare and notable exceptions .

[ThomasPowers]

Durn it why you have to go start this one while I'm offline over the weekend! I've smelted WI from ore---started about 15 years ago. I've done blister steel, I've *done* this sort of thing in experiments!

Now to try to remember all the points covered.

Cast iron is SOFT, unless it's white cast iron where the carbon is held in cementite; either way it's *brittle* grey cast iron comes equipped with millions of prior made cracks in the form of graphite lenses with pointy stress concentrators at the ends.

Grey cast iron can't be forged, your lucky if you can slump it a bit without it falling apart like cottage cheese.

Cast iron is a *liquid* at welding temps the billet *splashes* out huge cast iron drops that glow as they arc through the air until the carbon burns off and they burst into sparks as the iron burns. (I was using thin high grade cast iron from bathtub castings and mild steel.)

IIRC the iron plates submersed in cast iron is a method of cementation that was originally suggested as a possible method of making damascus and has since been disproven. Little evidence of it being used much for steel making has been dug up.

Crayoning on cast iron onto a blade edge to raise it's carbon content is described in the UN's book on blacksmithing techniques for Africa.

The ferrous silicates in wrought iron do NOT make the edge, fine grade WI may has 250000 per sq inch but they are still only a few percent of the total mass of the piece.

Piling---layering high and low carbon materials has been in use since Roman times. A bloomery can produce anything between very low carbon wrought iron through cast iron---recognizing what is what in a bloom is the hard part.

A typical pattern welded billet with thin layers will equalize carbon contents after about 4 times to welding heat.

The indirect method of making wrought iron (ore to cast iron to wrought iron) is about 700 years old now though the most effective methods are only aboyt 300 years old... (The Bessemer/Kelly process of course dates to the 1850's)

I'm sure I've missed a lot; but I have to get some stuff done before a meeting.

I commend to your attention:
"The Cementation of Iron and Steel"
"Steel Making Before Bessemer, vol 1 Blister Steel, vol 2 Crucible steel"
"The Celtic Sword"

[thingmaker3]

How long at what temp is needed to get that pesky graphite to dissolve?

[Frosty]

From videos I've seen of 3rd world smiths who use chewed charcoal and saliva for flux I'd just try using graphite for flux and test the resulting billet.

Frosty the Lucky.

[ThomasPowers]

If I recall correctly Patrick tried flux with powdered graphite in it.

Patrick; got your eyes on?

[Waiting]

Icykarma, did you end up trying this? Some pictures or an explanation of how it went would be nice... 

[Steve Sells]

The OP only logged in that one time way back then,  and left,  never to log back in again.   so I would not hold my breath waiting for any replay from him,  if I were you

[Robakyo]

This thread was genuinely fascinating and educational. I wonder if he succeeded. I've entertained similar thoughts about including cast iron in canned Damascus.

[Waiting]

Just wanted to check, I haven't had any luck keeping iron usefully sharp. I have seen some nice san mai laminates with iron cladding. Thanks for the replies, ill try not to drag up old posts in the future. Cheers. 

[Steve Sells]

nothing wrong with commenting on old posts, still good information,  Just pointing out the OP is long gone.

[JHCC]

Now I want to go to YouTube and see if he ever tried to make a sword out of plywood and glass.....

[AnBello]

The thing that impresses me the most is that this behaviour is usually "expected" to an extent from teenagers - boys in their 20s. But, according to his words, this was a well grown up man. Or maybe just an "old boy", but still, one would expect that age and experience helped him listen a bit more...

By all means, I'm not against trying things, but I think you should always have enough knowledge and experience in the "regular" way, before experimenting with something new. That way you have more chances of success, and a lot less chances of blowing yourself up.

[Steve Sells]

Glenn Conner told me he sees it as being a lot like baking a cake, While you can fiddle around little bit adjusting the components,  If we get too far off the basic recipe, you should not be surprised if you have no cake, only a mess.  Its best to follow establishes guidelines until after you gain a lot of experience baking cakes.

[DanielC]

We bake lots of cakes around my parts....

[Frosty]

This is a good example of not knowing how little you know. Occasionally we run across someone who's old enough s/he should know better but actually acts like a teenager. Not often but occasionally and not just here in the forum, they're everywhere, EVERYWHERE!

Frosty The Lucky.

[ThomasPowers]

Now I had some thin high grade cast iron---from a bathtub, that I removed the porcelain from and I had read some of the *old* speculations on how things like wootz was made and one was immersing wrought iron plates in molten cast iron as a means of carburizing the billet....so I tried welding up a cast iron wrought iron billet to see if I could duplicate the process.

1 Cast iron is a liquid at forge welding temps; besides dripping out of the billet; when I hit the billet I had large globs of molten cast iron that would travel through the air decarbing until they burst into a spray of "burning steel" sparks

2: It didn't work save for degradation of PPE

3. Now the UN blacksmithing manual(s) mentions using cast iron to "crayon onto" a piece of mild steel to provide a higher carbon edge for things like axes but the temps were far lower and the result far from "wootz"

Luckily we have new high grade research on how wootz was originally made (Verhoeven/Pendray !!!!!!!) so trying to prove in archaic guesses is not longer needed.