Energy conservation, safety and environmental protection have now become themain themes of the automotive industry. High strength steels (HSS) and ultra highstrength steels (UHSS), especially the dual-phase (DP) steel with goodcrashworthiness and formability are increasingly applied. Cold reduced dual phasesteel sheet which can augment the automobile load capacity and reduce the total costis the first choice for automotive structural parts such as door beam, bumper and otherreinforcements. Laser welding, wi...