History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c15.s2.48

c15.s2.48

Steel was produced in ancient India by a process resembling the modern *cementation* or *crucible* process Wrought iron prepared directly from magnetic iron ore, as already stated, formed the starting material. This was heated in closed crucibles with dry wood chips, stems and leaves of plants over charcoal fire maintained by blowing air with large bellows. The operation was completed in 4–5 hours' time, whereas the modern cementation process takes 6–7 days The steel first obtained was heated again in closed crucibles whereby the excess of carbon was burnt off. Sometimes water was poured on the hot metal, which was thus hardened on being quenched That this gives a correct account of the process in vogue in those early days can be assumed in all probability from the fact that steel was produced by this traditional method, though on a smaller scale, even in the 18th and in the beginning of the 19th century. The well-known conservatism of the Indian people must have served as a strong safeguard against any appreciable change of the original process. We thus find that the knowledge of the cementation process for making steel was acquired by the ancient Indian workers even before the beginning of the Christian era.