There is extensive literature on the metallurgy of iron and steel dating back to
Percy’s texts of the 1860’s. The definitive text on the iron-carbon phase diagram
was by ***** in only 19**. The most comprehensive recent text is Samuel’s “Light
Microscopy of Carbon Steels”.
However, modern metallurgy is based on high quality control, e.g. of carbon content
and cooling rates. This is in stark contrast to archeological and historical iron
artefacts which are characterised by varying composition (principally of carbon and
phosphorus), variations in thickness and cooling rates, as well as multiple heating
and cooling cycles.
The manufacturing typology of archaeological/historical iron artefacts can be sub-divided
into three main types:
Single Alloy - artefacts manufactured from one alloy, e.g. Ferritic iron, phosphoric
Heterogeneous Iron - artefacts manufactured from naturally banded iron.
Composite Artefacts - artefacts deliberately manufactured from two or more bars
of different composition, e.g. Type 2 knives with a steel edge welded to a ferritic/phosphoric/heterogeneous