Who will custom cast either wrought iron or cast iron?

[Hillbillysmith]

A thought crossed my mind the other day and was wondering if there was anybody still around who can custom cast parts from either wrought or cast iron..... The idea behind this was I think it'd be cool to have your own style of anvil casted whatever size you want and then put a tool steel face on it.

-Hillbilly

[DSW]

Plenty of places out there that still cast iron. The question is if it's cost effective. I doubt going to the cost and hassle of casting your own anvil, then trying to get a tool steel top attached is worth the trouble. You'd be better off simply locating a company who would be willing to simply cast the shape you wanted out of tool steel like they do with the NIMBA anvils.

[njanvilman]

When FISHER stopped making their anvils in 1979, they tried to find an iron foundry that could continue their process and product.  No one could do it in a cost effective way.  As DSW said, going the cast steel route is the best way if one needs something that is totally custom.  Just be prepared to pay big $$ to have it done.  And then pay for proper heat treating.

[Steve Sells]

Forget using cast iron.  Use cast steel.

[ThomasPowers]

Once you melt wrought iron it stops being wrought iron and becomes cast steel---Huntsman figured that out in the 1700's and it was a major technological leap---followed by the discovery that it was *carbon* that turned iron into hardenable steel  late 1700's and then the Bessemer/Kelly process in the mid 1800's

[Hillbillysmith]

I was on the understanding that wrought iron has an extremely small amount of carbon, essentially pure iron besides the refining process to take out the impurities. Then, once you raise the carbon content and other alloying elements, you come into the diferent classes of steel (mild/medium/high carbon, low alloy, stainless, etc.) and once it reaches enough carbon that it can no longer be in solution and can only be casted, it's cast iron.... Then all three forms are capable of being casted and only wrought iron and steel can be forged.

Correct me if I'm wrong but this is what a multitude of text books and my own research online explain them as.

-Hillbilly

[Nick]

Wrought has a tiny, negligible amount of carbon in it, ~0.05% or so, it has significantly more impurities.  Wrought cannot be cast, if you can cast it it's no longer wrought.

[Hillbillysmith]

...And why can it not be casted? It can be melted. If one would melt it in a crucible and pour the liquified metal in a form, it would be a casting operation.

-Hillbilly

[Dodge]

I cant explain it in metallurgical terms but I believe its the carbon itself that allows iron/steel to be cast. Wrought iron won't cast BECAUSE of its low carbon content. Confirmations / oppositions?

[jacobd]

Just like wootz steel separates from it's contaminants when it reaches liquid stage, seems like wrought would do the same. So if I understand right, once it melts and separates it is no longer wrought iron. The silicates and slag inclusions in wrought would seperate from the iron and it would be the heavier iron on the bottom and the crud on top. No longer metalurgically wrought iron. I think that's right, or what the others are saying. Feel free to correct if wrong

[ThomasPowers]

"Modern" wrought irons tend to be quite low in carbon content; however medieval to ancient ones tend to have wildly variable carbon contents as the bloomery method of smelting iron can produce everything from cast iron (2%+ C) down to pretty much plain Fe admixed with the ferrous silicates.  One example of this is the Japanese tatara furnace, a type of bloomery furnace whose output is graded on carbon content and then further refined.

 

High carbon content drops the melting point of iron but does not preclude casting it at higher temps without it. Probably the biggest problem Western Europe had in casting steel was the lack of good refractories that could take the higher heats.

 

Cast iron is a composite material composed of iron and ferrous silicates; as Jacobd points out melting it separates the components:  Think of it like fiberglas---you can melt fiberglass if you get it hot enough but when you pour it out it's not fiberglass anymore!

 

May I commend to your attention  "Wrought Iron, It's Manufacture Characteristics and Applications"  Aston and Story; Also Steelmaking Before Bessemer" Vol I Blister Steel and Vol II Crucible Steel" Barraclough.

[Nobody Special]

Could be wrong, but was given to understand that aside from seperating from the silicates as it melts, carbon in the fuel tends both to lower the melting temp, and get absorbed in the process unless seperated from the material, by say melting in a sealed crucible.

 

One step further out on the limb, also understood that was why you should use charcoal for a bloom rather than coal. Lower temps, and more of a sintering process (is it really sintering? something like) as the slag melted off and the iron bits dropped to the bottom rather than a melt.

 

Was refractory in the west that bad? I thought wootz was made in clay crucibles originally? Grant you that's a tiny melt, relatively...Sigh...I need a bigger ferrous library.

[ThomasPowers]

OOPS that was supposed to be *Wrought* *Iron* is a composite material!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Carbon in the fuel only lowers the melting point if it is absorbed into the material being melted.

 

Having once *boiled* a clay pot in a forge fire the TYPE of clay has a big part to do with how good a refractory it is.

For a good overview on one cast steel crucible set up read Dr Feuerbach's thesis on Crucible steel in Central Asia

 

No the reason you smelted with charcoal as they had not figured out you had to *coke* the coal before using it in the smelter otherwise it puts too much sulfur in the iron/steel making it unusable for forged objects---hot short.  That is also why pretty much all steel produced using a blast furnace will contain Manganese to counteract residual sulfur.  (Abraham Darby of Coalbrookdale was the first to *commercially* smelt using coke and he had a bunch of fun getting usable iron from it!)

[DSW]

No the reason you smelted with charcoal as they had not figured out you had to *coke* the coal before using it in the smelter otherwise it puts too much sulfur in the iron/steel making it unusable for forged objects---hot short.  That is also why pretty much all steel produced using a blast furnace will contain Manganese to counteract residual sulfur.  (Abraham Darby of Coalbrookdale was the first to *commercially* smelt using coke and he had a bunch of fun getting usable iron from it!)

 

That's good to know. Because we are in Pennsylvania and not all that far from Bethlehem/Allentown area, I always get questions on "coke" when I do demos as they ask if it's the same stuff they used to make steel. I'll have to dig up more on this when I get some time.

[ThomasPowers]

Commercial Coke  is coal incompletely combusted to drive off a lot of the junk; just like the "breeze" we create in our forges.  However commercial coke is usually MUCH denser being engineered to withstand the tonnes of crushing force exerted on it in the bottom of a full blast furnace.  As such it's harder to light and tends to go out more easily; but it is a standard forge fuel in many places.  The lack of clouds of sulfur smoke make it a "nicer" fuel for urban use.  (Though nowadays it is oftern superceded by propane...)

[Nobody Special]

Well, still looking for the correct thesis.....but interesting reading so far.  http://www.vikingsword.com/vb/showthread.php?t=502 This was one of the bits I found where she goes on a bit about the process.

[ThomasPowers]

NS: will you be at Quad-State? I have a copy of it on disk...

[Nobody Special]

Not this year. I've got enough money to go to the end of the driveway...almost. Starting a new job, so not going anywhere for a bit.

 

I'm always interested in crucibles. Got away from casting for a few years, but played with clay ones somewhat.

 

They came a long ways, but they still break a scary amount of the time (and even with precautions, if they had only broke 20 percent whilst full of molten metal.......yikes!), too often to use for ordinary casting when there's "real" ones to be bought. 

 

But then again, may have been a lack of knowledge. Having a red clay bank on the property, I may have to try some again, or at least heat them without a load. Never tried rice husks as the consumable bit, but they did seem to work better with about a 10 percent (by volume) sawdust mix to the refractory........less breakage anyways.