Minerals and Metals in Ancient India v1.c20.s3.t5.9

v1.c20.s3.t5.9

Jājamau (near Kanpur city) yielded 210 iron artefacts. Many of them were laminated structures. The cutting edge of an iron axe had a low carbon layer (0.2-0.24% carbon) sandwiched by two high carbon layers having carbon content as high as 0.6-0.65 per cent in some places. The low carbon layer had hardness HV 125 and the high carbon layer HV 267. The latter had a ‘tempered structure’ near the cutting edge having hardness HV 280. This suggests that the axe in the final stages was quenched, tempered and allowed to cool in air. It is not clear whether the axe had martensite in the cutting edges and whether the date of the axe could be 600 BC or later, since the site is dated 600 BC to AD 600.