Electrical steel strip for automotive drives precisely manufactured by Waelzholz

Johannes Zufacher offers insight into electrical steel strip production

In March 2019, Waelzholz participated in the 33rd Aachen Steel Colloquium by giving a talk on the manufacture of thin electrical steel strip for energy-efficient drive concepts. Organized this year by the IBF (Institute of Metal Forming of RWTH Aachen), the event in Aachen, Germany, focused on current issues and challenges related to metal forming technology. These were presented from the perspectives of materials technology, systems engineering, and the industries of application in a number of different lectures. The event offered attendees the opportunity to engage in in-depth technical discussions with the institutes and industry stakeholders.

As part of a series of lectures on “Low-loss electrical steel sheets for energy-efficient drives”, Johannes Zufacher from Waelzholz’s Electrical Steel Strip Materials Technology department spoke on the production of high-alloyed steel grade concepts for use in automotive drives. Due to their high speeds and the resulting high frequencies in the magnetic core, new drive concepts place particularly high demands on electrical steel strip. As a result, sophisticated manufacturing processes are needed to meet these requirements. On the basis of high-silicon alloying concepts, the magnetic and mechanical properties are adjusted through a combination of cold rolling and annealing processes. In this context, the individual process steps are carefully coordinated to each other. The goal is to always achieve the lowest possible core losses and high yield strengths in order to improve motor efficiency.   

“Optimizing the magnetic and mechanical properties is achieved through the interaction of the individual influencing parameters, taking into account the possibilities of large-scale industrial production,” said Mr. Zufacher, summarizing his presentation. In this context, it is still important that Waelzholz defines the material requirements together with the customer in order to manufacture the material in a process and application-optimized manner.