Minerals and Metals in Ancient India v2.c45.s9.2

v2.c45.s9.2

Over centuries, it was found that the soft variety of wrought or pure iron could be carburised by contact with hot burning charcoal, and this produced some hardening of the samples at least on the surface. Evidently, austenite, ferrite and pearlite phases were formed in the carburised samples. There was a reference to hot forging in the *Kauṭilīya Arthaśāstra* (7.3.8-9).