Today, ever-stricter requirements are placed on tubular steels used, for example, in pipelines. They must withstand higher stresses and have smaller dimensions - while at the same time maintaining their toughness and remaining suitable for fabrication by welding. Here, the use of fine-grained steels offers a unique opportunity, which can be achieved metallurgically through microalloying and so-called thermomechanical rolling. Through a mechanism-oriented understanding of the complex interrelationships between precipitation formation and mechanical-thermal treatment, new strength classes become possible. 

In his dissertation, “Investigation of the Thermomechanical Rolling of Tubular Steel with Different Alloying Elements,” Michael Böcker, a former research scientist in materials engineering, used a model-based approach to investigate the development of particle formation and grain size across the entire process chain. He systematically determined suitable process windows for adjusting alloying elements and temperature-transformation control through targeted experiments and simulations.  

Close collaboration with the industrial partner ArcelorMittal in Bremen was a key factor in the success of the work’s practical implementation: Research based on actual production melts enabled the direct transfer of scientific results into industrial applications.