A new technique for the local heat treatment using lasers of high-strength steels has been found to soften the material in a limited area, increasing local formability.
With this process car makers would be able to reduce vehicle weight by using stronger steels with lower metal thicknesses without impairing the function of the parts. Car makers are looking to reduce weight because every kilogram saved reduces fuel consumption. A consortium made up of car makers, steel producers, a toolmaker, a laser manufacturer, and three research institutes has developed this new approach. With funding from the German Federal Ministry of Education and Research, they have created this technique for locally softening sheet metal using lasers.
The aim was to produce local, defined softening of high-strength steels. The newly developed technique now allows the material to be treated using the laser so that it can be deep-drawn much further at the modified points without cracks developing. Galvanised sheet metal can also be treated without impairing corrosion protection. In addition, the heat treatment can also be used on press-hardened components in order to improve joinability using spot welding.
At this year’s EuroBlech from 23-27 October in Hannover, the Fraunhofer Institute for Laser Technology ILT will be presenting parts treated this way.