This paper investigates processes leading to local bake hardening (BH) effects in multiphase steels.These steels are characterized by good ductility,continuous yielding,high strength and high BH effect.Bake hardening is the ability of a metal,to harden during an annealing after forming,for example during the paint baking process in the automobile industry,delivering a post-forming strength increase of the final component.Multiphase steels such as dual phase (DP) and complex phase (CP) steels have been investigated to examine the effect of thermo mechanical processing parameters on the local bake hardening ability of hot rolled DP and CP steels.For this purpose two methods of achieving local BH (local deformation and local heat treatment) have been investigated.The influence of a local deformation through bending on the work hardening,and bake hardening effects is examined.By locally limited laser treatment on cold-rolled material local BH can be reached through local heat treatment.Furthermore,the ageing stability of the gain in strength is examined.