Softening

Accurate heating - even softening across the surface - high process speed

The process

Softening is a process step for the transformation of steel components. At the softening process, the martensite formation hardened steel will be heated in predefined areas. Thereby, the steel microstructure is changed; depending on the temperature, the martensite is either annealed (softened) or transformed into a more flexible ferrite-pearlite via austenitization. For this heat treatment, lasers are the best tool because they guarantee a flexible and high-precision material treatment with little transition zone to the workpiece. Neither gas flames nor infrared radiators offer any comparable process quality.

The process advantages of the diode lasers

Compared to other laser types, Laserline's diode lasers have a bigger spot and homogeneous intensity distribution. Together, both make an even softening all over possible. Thanks to a technology that was developed together with Fraunhofer ILT using double-sided radiation, process speeds of more than 10 meters per minute can be realized in the future. 

Application examples

Deep drawing

By deep drawing, one of the most meaningful industrial cold deformation processes, a metal plate is brought into the required form with the help of a rigid forming press. Fixed in a blank holder, the plate is pressed with the help of a stamp into a die and then transformed into a car body construction or steel bathtub, for example. To avoid cracks or fractures in the workpiece during this pressing process – which is particularly threatening with high-strength steels - the plate is softened beforehand in the provided bending zones. For this, the relevant zones are heated and thereby changed in their metal structure. With Laserline's LDM and LDF diode lasers, this heating can be realized quite accurately and evenly, and with high process speed.

Creating crumple zones

In automobile construction, the targeted creation of crumple zones is one of the most important safety measures. Crumple zones are supposed to deform in case of an accident in such a way that the essential parts absorb the impact energy. To achieve this effect, the car body sheets are softened by heating in predefined zones. Here, with their precise and even heat input, Laserline’s LDM and LDF diode lasers can guarantee optimal results. The metal structure is softened at exactly those points where the crumple effect would be achieved; at all other car body areas, the required and likewise safety-relevant firmness remains. Finally, vehicle occupants can enjoy maximum protection.