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backshopknives

casting tool steel

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any time i cut or brake off o peice of tool steel or high carbon steel i keep it so that i can reform it. i want to melt my scraps down to form new more workable barse for knife making. i have looked into making tamahagene but i think it would cost more than i can aford. i have been looking into geting a crusible but im not sure how it would work. please help me out. thanks

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It is likely that it would cost far more to melt down scraps just to make a new bar or two than to just buy new material. This has been talked about many times on this site and it is generally agreed that it cant be done cheaply. The time and materials cost to do this would far over shadow buying brand new good steel

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Making your own steel -- even starting with scrap steel -- is far more expensive than buying it. Unless you want to make something exotic like wootz that can't be bought on the market, or you want the satisfaction of making a work of true sole authorship, I'm afraid you're barking up the wrong tree.

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another option is to weld the lumps together in a can and make a billet of scrap-mascus ;)

The only real reason to try and rework silly little bits like that rather than buying cheaper new known quality steel is because you can. That is a good reason in my opinion!

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remember that what you put into the crucible is not necessarily what you get out of the crucible! Keeping the steel chemistry as you want it is not a trivial thing. Also as poured will tend to have quite large grain that will need to be refined afterwards.

I'd think about making a can weld of all the scraps perhaps with shot blasting beeds poured in to take up some of the voids.

Or look into orishagane Japanese steel welded up from carbuerized bits

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And how well the "other damascus" was made---you can make a zero carbon damascus you know; it's not some miracle super steel.

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Thomas, Couldn't he just get a graphite crucible, fill it up with all the little bits of tool steel, some charcoal on top, put it in a melting furnace and make a metal similar to wootz ?

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Hey that made cast steel in central Asia as well as wootz. Wouldn't be wootz unless he had the correct level of carbon plus the right carbide formers.

Yes you can make cast steel; it will probably not be as good as the steel you started with but will probably be better than blister steel was...

(cf "Crucible Steel in Central Asia" Dr Feuerbach's doctoral thesis)

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remember that what you put into the crucible is not necessarily what you get out of the crucible! Keeping the steel chemistry as you want it is not a trivial thing.
And yet Huntsman seemed to do just that.

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Actually what Huntsman got out of the crucible was quite different than what went in and he LIKED it that way!

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Well he knew the problem trying to get a uniform clock spring was in the non-homogeneity of blister or shear steel springs based on wrought iron derived steels and melting the cut up spring in a crucible stuck in a glass furnace managed to remove the slag and homogenize the carbon content. If he didn't like what he got I assume he would have stopped and tried something else.

I'll see if anything is mentioned about his feelings on the subject in "Steelmaking before Bessemer, vol II Cast Steel"

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Huntsman succeeded, to be sure, but I wonder how long it took him to get decent control over the end product.

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Quite some time; however the real problem he had was in getting suitable refractories to melt the steel in if I remember the write up on his struggles right. I'll be perusing "A History of Western Technology" in the Dr's office today and may get time for "Steelmaking before Bessemer" tomorrow; but possibly on pain meds. Helps to have the sources in my personal library!

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Dr said "live with it till after the new year" So I may be grumpier than usual. Hist of Western Tech was a bit shy on Huntsman; may have to see if "Sources for the History of the Science of Steel" has any useful data.

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Huntsman succeeded, to be sure, but I wonder how long it took him to get decent control over the end product.

about five years from "discovery" to the move to the sheffield area to "full" production. Another five years before it was generally accepted and used more widely and by then others had stolen the process.
More or less.

As to getting out what you put in...it is not quite that simple, but in the case of Huntsman crucible steel he wanted to remove the waste (iron oxide and silicon slag) and melting did that. Over the years he had a repeatable process of several different grades of steel ingots and such....but to be sure there was still variation.

I have acquired a few old samples and will be looking for more...have the same for blister and shear steels....not enough to draw many conclusions other than the quality varied.
Words like homogeneous really do not tell the whole story when sections of ingots and bars are viewed under the microscope...perhaps a better term is slag free. Even carbon levels varied by 0.1 within a given ingot from top to bottom and interior to exterior..and alloy elements can be drastically different from one place in an ingot to another depending.


As to the original question BackShop:
It CAN be done, but the odds of getting a good ingot the first time out and then forging that ingot into bars is not great. Unless you have more success than I have over the past 20 years.
Better to simply forge-weld the bits and be done. If you kept track of what bit was what you can create some very interesting composites blades.

Ric

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Ric did you read that they are trying to find a home for Tylecote's sample library? The archeological Metallurgy mailing list had a post on it recently.

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No I had not Thomas....wonder how I throw my hat in the ring for that one....
Can you send me the mailing off list? I lost my subscription when I transferred email addresses.

Ric

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