Abstract
Investigations have been carried out to determine the effect of structure viz., martensite, bainites and ferrite-carbide aggregates on the tensile and tear properties as well as the nature of fracture in a 0.11%C-1.5%Mn-1.04%Cr-0.25%Mo-0.003%B steel. Both total elongation and uniform elongation vary almost linearly with tensile strength, the ratios of uniform elongation to total elongation being confined to 0.6-0.7. Replacing total elongation by uniform elongation to characterize the high strength-ductility combination is not found to be identical. The toughness (as measured by unit propagation energy) follows a trend almost similar to that of TS×El. Shear and/or microvoid coalescence are the operating modes of fracture and these, in turn, depend on the steel toughness and structure.
