Production of Crucible Steel by Co-Fusion: Archaeometallurgical Evidence from the Ninth-Early Tenth Century at the Site of Merv, Turkmenistan

Various methods were used to produce steel in early Islamic times. According to early Islamic texts, three methods are described for indirect production of steel (fuladh). The methods are solid-state carburization of wrought iron, partial decarburization of cast iron or a high carbon steel, and co-fusion of cast iron with wrought iron. Evidence from a metallurgical workshop at Merv, dated to the ninth-early tenth century A.D., provides an illustration of the co-fusion method of steel production in crucibles. The primary investigations of the crucibles are presented. The crucible slag was found to contain droplets of cast iron and steel and the crucible fabric contains mullite.