New Laser Technique Reduces Processing Time for Heat-Treatable Steels

The Institute of Electrotechnology (ETP) and the Laser Zentrum Hannover (LZH) have developed a new, advanced process to weld and harden multiple pieces of heat-treatable steels in a single step.

Heat-treatable steels have good endurance strength and are highly tensile as a result of the heat treatment process. The steel is therefore primarily used for construction elements. Heat-treatable steels are usually welded by using a rigorous, multi-step process to makes it stress-resistant.

The ETP and the LZH’s process combines laser beam welding and inductive hardening of construction elements in a single step. During the process, the construction elements are heated at more than 900°C temperature, and the components are welded with laser and cooled.

Softening and cold cracks that usually occur in the welding seam are avoided during the conventional hot welding process, which instantly reduces the tension happening during the welding process.  To meet these limitations, a new processing head has been developed that incorporates an inductor, a shielding gas nozzle, a quench shower and a laser processing head. The processing head combines the heating, welding and cooling processes in a single step.

The processing head increases the depth of the welding by 25% compared to the elements that have not been pre-heated. After the welding and hardening process, the construction material’s surface can be hardened by using an inductor. The process simulation can also be utilized for accurate calculation of the process.