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To improve the form ability and surface appearance of HSS exposed panels new HSS grades based on ULC BH and IF-concepts have been developed. Both HDG/EG coated ULC BH and IF HSS have been studied by a number of laboratory and industrial stamping trials. The influence of steel grades, thickness on form ability, surface quality and dent resistance were subject of investigations. It was shown that improvements on die addendum enables the application of HSS (BH and non BH grades) with min. 220 MPa yield point to be used in all exposed panels up to very large panels of pick-ups (more than 2 m width) by excellent surface appearance and 60% higher dent ability.

One of the possibilities to fulfill the enhanced requirements on crash performance for new vehicles is the application of high strength steels (HSS) and even ultra high strength steels (UHSS). In order to achieve the strength, the strain rate sensitivity can be taken into account whereas the work hardening effect is difficult to be used. For UHSS with more than 500 MPa yield point the formability, spring back and weldability are important issues. In the present study the laser weldability of UHSS has been studied with positive results. Both Dual phase type and micro alloyed type LWBs showed high formability and good weldability and will satisfy the requirement of certain applications for body members. Stamping trials in the press shop under production conditions showed that the peak strain in certain parts can be reduced to avoid splits when LWBs were stamped. Simultaneously the spring back is reduced as well.