Back in my D&D days, unnatural beasties could oftentimes be hurt only by silver or cold-forged steel.
How, exactly, does one cold-forge steel? Don’t you have to melt the iron to get the carbon in?
Cold forging refers to working the steel stock after it’s been made, rather than the process of making the steel in the first place.
A cold forged sword and a hot forged sword could both start out the same, as a rod of steel at room temperature. The hot forged one would be heated before working in, and the cold would be left at room temperature.
Is there any particular benefit to doing this?
Steel isn’t made by forging. Steel is shaped by forging.
Iron already contains carbon. Gray cast iron, for example, contains up to 2% carbon a lot of which precipitates out as graphite flakes embedded in the iron when the casting cools. Steel is an alloy of iron and iron carbide with a lot of specialty steels having other alloys added to give different charcteristics.
Forging is the process of shaping metal by hammering. If you pound on a metal for awhile it “work hardens” and has to be heated to anneal it, otherwise it will crack. Stamping out sheet metal parts is a form of cold forging. If the part is complex, having sharp bends or deep channels the stamping (forging) has to be done in several passes with annealing between the operations.
Cold forging, I think, can’t be used for thick, heavy sections such as a crankshaft. To forge such shapes the metal is heated to high temperature.
I think the term is probably mumbo-jumbo that sounds good for a game.
I just looked this term up in Alexander Weygers’ “Complete Modern Blacksmith”. It isn’t in his glossary.
Forging steel, particularly for tools or weapons, requires the following steps:
1-Forging…Bringing the steel to a heat and hammering it to shape upon an anvil.
2-Anealing…Bringing the workpiece to a heat, and allowing it to cool slowly.
3-Hardening…Heating the workpiece to a cherry red heat, and colling it quickly by quenching.
4-Tempering…Bringing the (now hardened) workpiece to a straw yellow heat and allowing it to cool slowly.
Notes Re: Numbered processes listed above
1- Steel is what is known as a body centered matrix. More maliable metals, like lead for example, are face centered matrixes. Steel must be heated to it’s transformation temperature to behave like, or become, a face centered matrix.
To visualize this think of a die, such as one uses for dice games. It’s principal points are the corners on each of it’s six faces, or eight points. Think of the structure of the lead being like many dice stacked together. They can be moved about when struck because their faces slide past one another.
Steel has one other point that ties it together. Imagine another point in the center of the die. Imagine still that there is a structure that ties these points together simultaneous to that of the face. Almost like “ghost” dice were residing in our pile of dice, at a fourty five degree angle to the others. This ties the structure of steel and binds it. Heat loosens those bonds. The fire allows the steel to become maliable, and thus, forgeable.
When the tranformation temperature is reached, a magnet is not attracted to the steel. (<-------------My sex life. I must be Hot! 
)
2-After you’ve beaten all those little guys (the granular structure of the steel) to Hell and back they are stressed and filled with tension forces. Bringing them to a heat, and letting them cool slowly allows those stresses to work out.
3-Hardening makes the steel hard indeed. Like glass. It can hold an edge, but it’s too fragile.
4-Tempering is similar to annealing, but the steel is not heated enough to undo that which was done in the hardening process. This is why it’s done to a straw (yellow) heat.
Occasionally I sharpen a cabinet scraper by work hardening it. A hard tool, called a burnisher, is dragged along the edge of the scraper to roll a burr.
All of us know about this.
Want to break a piece of wire? What do you do?
You work it back and fourth, or “worry” it. By doing so, you work harden it. It becomes so hard that it is fragile, like glass.
Anyway, those are just some of my thoughts. I tried to find M. T. Richardson’s Blacksmithing book too, but it’s buried in clutter.
HTH
While we’re at it, what is Drop Forged mean?
IIRC, that’s where an automated hammer is used to pound the metal, rather than some big sweaty guy weilding it.
Cold Forging is most likely just gobblety gook made up for the game (though, now that I think about it, it could be a chemical treatment used to harden the metal, what those chemicals would be and the mechanism by which they’d operate, I’ve no idea). Though I’d wait for Doc_Nickel to show up before passing final judgement. (Doc’s had several years experience as a machinist, while I’m only a student machinist.)
[nitpick]
You obviously understand the difference between elemental iron and cast iron, so please don’t say things like “iron already contains carbon”.
[/nitpick]
steel contains saturated carbon up to about 1.2% giving the steel its characteristis of tenile-ity and malleability and able to be drawn cold and forged.
after this the carbon is in solution and not saturated but is free carbon (makes for easy machinning)
at that time it is called cast iron
you get low, medium, and high carbon steels.
you just get cast iron…and i think the limit is about 2%
mrcrow: “tenile-ity” = “ductility” maybe?
yeah that is some stupid word
i cant edit
so thanks
i refer to its tensile performance as in having a high curve for tensile strength…hookes law? could that be tensile-ity?
ductile
tensile
able to be cold drawn…?
ductility is the ability to be hammered?
i did metallurgy in 1958-1965 so i have forgotten a bit having spent all my life as a structural designer!!!
thanks for your appraisal.
For f… sake use a dictionary. Ductility = ability to be cold drawn. Malleability = ability to be hammered.
sorry can you clarify how you spell f…, is there a grave
as we used to say
the steel doesnt know what code its being designed to:D
I promised not to contravene the troll law.
i hope there is no law against me eating crow!
You’re right of course. I realized the possibility of confusion right after I hit the “Submit Reply” button. The bare word “iron” needs a modifier in order to sort out the various combinations of the elemental metal with other elements. Modifiers like cast, wrought and the like.
the carbon content of iron is over 1.2%
steel is the commodity which has the carbon contents from 0.25-1.2%
below 0.25% are the wrought irons
steel can be cast but is usually forged or rolled from cast billets
I haven’t really heard the term much, but it certainly has the obvious meaning: shaping a metal while cold. This work hardens the metal (if a steel).
Certainly this is done often when making armour. For example, when dishing out a knee or elbow cop you’ll almost always do it cold both to improve the strength of the steel as well as simply for simplicity. After you’ve done the preliminary shaping though, the metal normally needs to be annealed before the final working.
On the other hand, a helmet like a bascinet will usually be dished while hot, as it’s simply too deep a shape to be done cold.
similar treatment for wire and nails
cold drawn to put work hardening into the metal
leaves the product a bit susceptible to fatigue and lack of bend- ability
the grain flow i think is enhanced using cold forming treatments so strengthening a component and the accuraccy for rough components means no further machining is required
links pins and cotters etc.
I’m still in my D&D days(and hope to keep it that way), and I think you’re memory is is a bit faulty on this.
IIRC Ghouls, and various fairy folk are harmed by cold iron, which I’m assuming is the same as wrought iron.
I’m not an expert on chemistry or metallurgy, but I’d assume that the difference is important.