Work Hardening

Work hardening refers to the increase in strength and hardness of a metallic material through plastic deformation below its recrystallisation temperature. In stainless steel, for example, this effect occurs during cold rolling, deep drawing or bending. Mechanical stress causes an increase in the dislocation density in the crystal lattice, which inhibits the movement of dislocations and thus increases strength. However, work hardening is accompanied by a reduction in ductility, which makes the material more brittle. In practice, work hardening is used to specifically improve the mechanical properties of stainless steel components. Controlled cold forming can be used to achieve higher strengths without changing the chemical composition of the steel. One example of this is the cold drawing of flat steel, in which the tensile strength of the material is increased by work hardening. However, it is important to take work hardening into account when machining stainless steel, as it can affect machinability. Adapted machining strategies are therefore necessary to avoid undesirable effects.