ThyssenKrupp Nirosta has developed a lightweight solution for auto manufacturers, reducing CO2 emissions using ThyssenKrupp Tailored Strips, which comprise strips of different thickness matched exactly to the stresses acting on the part. For the first time, this new technology is now being used in a stainless steel production part – a rear muffler made by automotive supplier Eberspächer for the new BMW 730d in the diesel version. It was developed by ThyssenKrupp Tailored Blanks in conjunction with ThyssenKrupp Nirosta and Eberspächer as innovation partners. Currently, stainless steel of uniform wall thickness is used in the construction of exhaust systems. The material thickness is selected to be able to handle the highest mechanical, temperature and corrosive stresses. ThyssenKrupp Tailored Strips now allow the thickness and properties of the materials used in exhaust systems to be matched exactly to various local requirements. The Tailored Strips allow in order to the demand wall thickness of between 0.7 and 1.2mm. On the rear muffler of the BMW 730d, for example, this leads to a weight saving of 700gms. Applying this process to other parts of the exhaust system can reduce the weight of a mid-size car by up to 3kg. The Tailored Strips are made by joining two or three coils of different grade, thickness or finish by laser welding. Another feature of this process is that the slit strips can be welded continuously to lengths of several hundred meters.
