The microstructure and mechanical properties under cool deformation conditions was investigated for three steels of approximately 0.03% carbon with different alloying additions of niobium and copper. Compression testing of the three steels was employed to study the influence of processing conditions (cool deformation) and chemical composition (niobium and copper) on the microstructure and mechanical properties. Overall, for the steel compositions examined, the addition of copper increased the strength. This can be explained by solid solution hardening effect of copper. The results show that there is very fine equiaxed ferrite that has formed, either by recrystallization or transformation induced by cool deformation