Mission: Precision.

How voestalpine sets new standards in thickness tolerances

voestalpine guarantees the narrowest thickness tolerances in hot-rolled steel strip. This provides quality and economic advantages. Daniel Roman Fritz of voestalpine Quality Control shares his insights of how this precision mission was accomplished.

Nonstop advantages

Automotive Notes: What are the advantages of the narrowest thickness tolerances in hot-rolled steel strip?

D. Fritz: Hot-rolled strip with the narrowest thickness tolerances in some cases can replace cold-rolled or medium-wide strip in the automotive sector. This provides substantial cost advantages. Modern processing tools have been designed for narrow thickness tolerances. The guaranteed thickness precision guarantees stable processes and the manufacture of high-precision components within the narrowest tolerances.

Guaranteed thickness tolerances across the entire with and length of the strip

Automotive Notes: Are narrowest thickness tolerances always required?

D. Fritz: This depends on the steel grade, the task at hand and the application of the strip. voestalpine offers three classes of thickness tolerance. Our chosen standard is the BASIC class, where voestalpine guarantees 50% of the thickness tolerances listed in DIN EN 10051:2010 for steel grades of classes A through D. 

In the ADVANCED class, we guarantee up to one fourth of the defined EN tolerances, depending on the nominal sheet thickness. In the ULTIMATE class, we even guarantee up to one sixth. This is down to an extremely small +/- 0.06 mm. voestalpine guarantees thickness tolerances across the entire width and length of the strip. That is pretty unique in the industry.

Commitment, expertise and self-learning production systems

Automotive Notes: How was this achieved?

D. Fritz: Quality and economy are decisive parameters in for the automotive industry. The demands on materials are increasing continually. Manufacturers like us are required to deliver the highest quality in every respect. Narrowest and guaranteed thickness tolerances are factors that we recognized to be of the highest importance years ago, and we have never stopped pursuing our objectives in this area. Our commitment and expertise have led us to successful achievement of our current leading position. 

Concrete measures include a special control system that is implemented during the skin-passing of strip surfaces. Using mechanical tools for high-precision measurement during strip throughout helps us regulate thickness.

The most essential factor is the software program that controls the hot-strip rolling mill. It has become a self-learning system that makes use of artificial intelligence. The measurement system collects a large amount of relevant data to be evaluated by the program. A large pool of comprehensive data has been collected in this way. Based on the data, the system automatically optimizes the parameters for the next coil throughput.

Automotive Notes: So human resources are no longer required?

D. Fritz: Not at all. Our human knowledge and experience are indispensable when we develop new grades, and this also applies to the further narrowing of thickness tolerances.

Automotive Notes: Is something in the pipeline already?

D. Fritz: I don't want to get into that here. But I enjoy speaking with customers about this. If they require even narrower tolerances than those guaranteed by the ULTIMATE class, they are welcome to contact me at any time.