The definition of the metal may actually depend on the time period and metal used. Pig iron, white, silvery, gray, blazed, glazed, etc., is high carbon cast iron that was formed in the blast furnace into pig like casts. Wrought Iron is iron with silicate, an intrinsic flux, and little carbon, which can be found in old bridge structures. In England it is termed malleable iron and is universally, usually produced via a puddling process, in a pasty state just short of being fluid which is due to to a lower tempature and possesses a small bit of slag and isn’t really hardened upon quenching. A rabbler mechanically stirred iron silicate and iron oxide into cast iron to yield malleable or wrought iron. Some of the iron silicate was pressed out later as muck bars and subsequent merchant bars were made. Bascially the only thing that differentiates steel from wrought iron is that of being, or have been in a fluid state, free of slag and containing less than 2.2% of carbon and from a practical standpoint it required to have less than 1.5% of carbon which is where it differs from cast iron.
Wrought steel is wrought iron that can be hardened by quenching.
Cement steel was formed by the cementation process of carburizing wrought iron, and less frequently low carbon steel.
Early German Steel was produced in a bloomery very similar to a Catalan forge and was the result of refining pig iron to a very similar state of wrought iron.
Flux could be acidic or basic with basic flux being raw limestone or lime as well as magnesia, dolomite and possibly a few others. Sand was considered to be an acid flux and it with borax,
http://en.wikipedia.org/wiki/Borax , was used in welding to form a fused cinder. An acid open hearth process was rarely used vs. a basic open hearth process. So I would venture a guess that borax or lime was used as a flux and earlier silica may have been a default flux.
Kind Regards,
Raimey
rse
