It has been noted that during the cold working of a metal pa

Solution

Before work hardening, the lattice of the material exhibits a regular, nearly defect-free pattern (almost no dislocations). . As the material is work hardened it becomes increasingly saturated with new dislocations, and more dislocations are prevented from nucleating (a resistance to dislocation-formation develops). This resistance to dislocation-formation manifests itself as a resistance to plastic deformation.

Such deformation increases the concentration of dislocations which may subsequently form low-angle grain boundaries surrounding sub-grain .These strain fields generated by the accumulation of dslocations gradually provides hinderance to further strain hardening rate therby , decreasing the rate as well.