Dependence of strength and strength-elongation balance on the volume fraction of cementite particles in ultrafine grained ferrite/cementite steels

An increase in the cementite volume fraction contributed to an increase in the athermal component of strength. Strain-hardening rate increased with carbon until 0.3 wt.%C and then caused little change with a further increase in carbon, which was reflected in the change of uniform elongation. The strength-elongation balance could be improved by using the proper cementite volume fraction.