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Thread: Blacksmith Fact or Fiction
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21st November 2007, 12:58 AM #1
Blacksmith Fact or Fiction
I was wondering if you wise metalworker could enlighten me. I have been by accident reading allot about blacksmithing and tool making. I came across an interesting claim. The claim is that a cutting tool beaten into shape by a blacksmith will have more carbon compressed into a smaller space then if the cutting tool formed by other means. The idea being that the carbon is what gives the tool its cutting edge and by smashing the steel you will have more of cutting carbon in one place.
This is why old tools are better then modern machined tools or so the advertising says.
Second Question can you blacksmith i.e. heat and shape only high carbon steels like O1 or can you heat and shape annealed steel like D2 into a tool like a chisel and the have it heat treated in a Vacuum Furnace later for tempering.
Cheers
Thumbsucker
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21st November 2007, 01:40 AM #2.
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First question I'll leave to someone like AndyMac.
Short answer is not without doing it all under a controlled atmosphere. D2 requires manufacture, shaping and heat treatment in a controlled atmosphere. If you stick it in a smithies furnace and beat it about on an anvil all in regular air it will lose some of its important alloying components (they burn or vaporise away) and the steel loses its characteristics.
In contrast, A2 or O1 do not require a controlled furnance to make or shape.
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21st November 2007, 06:42 AM #3
Having buggered about with making knives I have come to a conclusion that a forged blade will hold a much better edge than a ground one.
The texts do use terms like "packing" which might induce one to think that the carbon is compacted by the hammer blows. I think its more likely that the change induced by heat treatment induces the packing or re packing or carbon atoms from body centered cubic to a face cubic.
The edge holding ability of the tool would be derived from the toughness and flexibility that a forged unit seems to have and a mechanically shaped tool does not . Hopefully Andy Mac can also enlighten all of us as to why on that one.
Grahame
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21st November 2007, 08:01 AM #4
Have a look at how the samurai's make their swords.
http://www.pbs.org/wgbh/nova/samurai/sword.html
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21st November 2007, 10:06 AM #5
The term is packing, as Grahame says, but I think it has more to do with the grain of the steel itself, not necessarily the carbon component. The packing process from hammering tightens the grain and points it in the same direction, ie. if its a tapered end of a tool the grain conforms to that taper. To grind an edge instead, cuts across parallel grain....from what I understand (and I'm not a trained metalurgist or even a blacksmith).
I know nothing about o1 or D2 tool steels, only work with high carbon and spring steels.
Cheers,Andy Mac
Change is inevitable, growth is optional.
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21st November 2007, 01:20 PM #6
Andy and Grahame it is very interesting. I having a hard time imagining "grain" in metal. However I can imagine atoms being arranged like grain.
The question is it a quantifiable thing and does it increase the desirable attributes significantly like edge retention, and abrasions resistance? And how does and would it compare to a harder and stronger alloy's being ground.
To grind an edge instead, cuts across parallel grain.
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21st November 2007, 02:55 PM #7
My 2c worth.
ISTR a theory that blacksmithing:
- increased the surface carbon - carbon was picked up from the coke or other fuel in the hearth and got amalgamated into the surface of the article being worked on as it was beaten; and
- tended to align the molecular structure (grain) of the item so that it was parallel to the edge being created.
Cheers
Jeremy
If it were done when 'tis done, then 'twere well it were done quickly
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21st November 2007, 04:51 PM #8
G'day,
there's a book I have on scythes, and the old way of sharpening them was to peen them on a tiny anvil in a north/south direction (usually in the field) so that the molecules lined up the one way, making sharpening a lot easier.
dunno if its fact.
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21st November 2007, 05:47 PM #9
I've fiddled with quite a lot of old blades. Some are too soft. Some are too hard. Some are just right.....etc...
Just another statement thats trying to sell something.....uno, where only one reason is given to press a point......there'd be dozerns of fractors I'd say to blade quality.
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21st November 2007, 07:29 PM #10New Member
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Yes I have been told that.
Some things I would think about:
Is it
1. A gas forge
2. A coal forge
Because you can only increase the carbon content in a coal forge by "hammering" the carbon into the steel.
My understanding is the more carbon (to a degree) the better steel. I think O-1 has around .9 to 1% carbon D2 has around 1.5% both with other alloying elements. 1095 has .95 and 1055 has .5 % with no/negligible other elements. So you would be better off forging a knife with 1095 than 1055.
As apricotripper intimates "there'd be dozens of fractors I'd say to blade quality"
Stewart
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21st November 2007, 10:37 PM #11.
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"Better" is quite a subjective term, and one might well ask "better for what"? In general, increasing the carbon content means the steel can be made harder. See something like this. However, steel can be too hard - hard enough to shatter - this is not always good and can in fact be bad.
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21st November 2007, 11:31 PM #12
Basically, all the 'old is better than new' is pure marketing puff.
You can reproduce any of the old steels and old fabrication methods if you want to, but generally any problems you have with modern tools not holding an edge are because someone in production has cheaped out or not QA'd the material they ordered.
Here are some nice articles on steelmaking, for the curious!
http://en.wikipedia.org/wiki/Pattern_welding
Pattern welding - or laminated composites - basically doing the same thing as your tungsten carbide bit on a steel shaft - hard (but brittle) alloy supported by a softer (but tougher) steel.
http://en.wikipedia.org/wiki/Damascus_steel
A naturally occurring vanadium alloy steel from one mine, possibly in southern India. When the ore body ran out, so did the ability to make damascus steel.
A compounding reason is that the right ore is fairly high in phosphorus, which makes the metal 'hot short' - cracks easily at high temperatures - so the right forging techniques have to be used to overcome this.
http://en.wikipedia.org/wiki/Wootz_steel
Glass was used as a flux to remove impurities in the steel - instant improvement on how well the steel could hold an edge. The origins of damascus steel.
http://en.wikipedia.org/wiki/Katana
How everybody's favorite hacky-slashy was made, and why the blade was curved.
http://www.tms.org/pubs/journals/JOM...even-9809.html
Carbide banding on Damascus steel; Mohammed's Ladder pattern
http://home.att.net/~moltenmuse/Production.htm
Production of crucible steel and the damascus pattern.
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21st November 2007, 11:51 PM #13
It seems to me going by the views here that blacksmithing is more art then science. To much or to little of this or that then your tool is to soft or to brittle or really bloody good.
It seems to me that this is more myth then fact. I found the comment about orientating the scythe in one direction helped in sharpening. Which would raise the question about sharpening inside a CT machine because the CT machine aligns + and - poles in your body or something like that and it would do the same in the metal. Ahh but again that is crazy scientist stuff.
So I would say that if you had a modern high carbon steel like O1/O2 then you would prefer a gas forge because a coal forge will induce more carbon into the steel and alter the final product. Or so I think.
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22nd November 2007, 04:20 PM #14Senior Member
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When you talk of compressing steel (or the carbon in the steel or the iron in the steel) - it can't be done by hammer and anvil. All that does is reshape the steel and disrupt the grain boundaries. And even if the forging process does improve qualities of the steel, all of that is erased during heat treat (assuming a long enough soak to fully austenize the steel and too short a soak may (usually) result in an inferior tool). The heat treat of tools has much more to do with the quality of the tool than forming method. And the old tools that were inferiorly heat treated didn't last to be compared to modern tools only the best of the old tools are still around.
There are people who have successfully forged steels like D2 (and even stainless) but not many try because these steels tend to have very specific temperature requirements where they can be forged. The more alloying elements in the steel the more likely it is to be red hard or red short. Red hard means the steel is doesn't move very much under the hammer, red short means it falls apart at the grain boundaries when forged too hot. And if forged too cold, the steel may fracture.
ron
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22nd November 2007, 04:27 PM #15Senior Member
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Absolutly not. There are 3 types of fire (or zones withing the fire): reducing, neutral and oxidizing. A reducing fire can add carbon to the steel but this happens only after a long time and only on the surface. An oxidizing fire will tend to remove carbon from the steel but again on the surface. An oxidizing fire will also result in a lot more scale (iron oxide)
Ron
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