The very first application for laser welded blanks (LWBs) was to replace the overlap mash welding of cold-stamped sub-blanks. LWBs offered a major advantage: a smoother and direct transmission of energy between two sub-blanks in the event of an accident. Another major advantage of laser welding is the very narrow weld and heat-affected zone.
Typically, this laser welded zone becomes harder than the base metal due to metallurgical processes which occur as the weld cools.
This harder area severely limits the forming process and makes it difficult to achieve complex 3D shapes through stamping. The weld does not act as an obstacle, but flows into the deformation together with the base material.
ArcelorMittal developed specialized software to simulate forming processes. The software can also optimize the topology of the blank topology. This enables very complex parts to cold-stamped out of an LWB.
With the wide application of advanced high strength steel (AHSS) in car bodies, the use of LWBs is also increasing. By using AHSS with localized thickness changes, higher weight saving and improved crash management can be achieved at the same time.
As AHSS grades have very high strength, they are difficult to trim after stamping. Our Tailored Blanks division can deliver net-shaped blanks which require very little trimming.
Applications for cold stamped laser welded blanks
Welding cold stamped laser welded blanks