Effect of preliminary deformation on the hardening of commercial iron during natural aging

Abstract

1. The variation of the hardening effect during aging with the degree of deformation depends essentially on the type of deformation if the initial concentration of impurity atoms in the solid solution falls within the limits of 10−4 to 10−3%. With deformation by elongation the effect of hardening increases with the degree of deformation, while with deformation by rolling it varies in a complex manner. 2. A change in the initial concentration of impurity atoms within limits of 10−4 to 10−3% and the ferrite grain size has a quantitative influence on the hardening effect during aging in relation to the degree of deformation. This influence decreases with the transition to hardening associated with resistance to small plastic deformation. 3. With an initial concentration of impurity atoms of approximately 10−2% the variation of hardening during aging with the degree of preliminary deformation by elongation changes qualitatively — with increasing deformation the hardening effect first decreases and then increases.