Successful experiments through industry collaboration

Rolling is the most common process for manufacturing of steel sheets and it is done in multiple stages from hot rolling to final cold rolling depending on the desired properties of the steel. Surface and near surface defects that are introduced in rolling can have significant effects on the material behaviour in subsequent manufacturing processes such as forming, bending, or punching.

Material testing for formability

Bend tests serve as a crucial tool for evaluating the local formability and ductility of various types of steel. The study of the formability of high-performance steels represents a significant advancement for the industry to develop steel with enhanced formability and reduced risk for crack initiation.

Experiments in collaboration with industry

SSAB has both industry-scale and research-grade advanced bend test machines, which are used to get comprehensive formability assessments based on globally approved international standards. The unique setup provides a direct comparison between real-world applications and advanced laboratory analysis, ensuring accurate and applicable results. SSAB has developed its own internal standard tool that uses cross-sectional moment-based bend analysis, which proved to be a more precise bend testing outcome.

The experiments at SSAB provided valuable insights into performing advanced bend tests and assessment methods based on different approved standards. These tests helped to evaluate the impact of manufacturing-induced surface defects on formability. The possibility of extracting samples from different hot rolling stages allowed the tracing of defect origins and their evolution. The correlation between surface and subsurface defects revealed previously unknown factors influencing bendability, highlighting the need for process optimization.

The collaboration between SSAB and LTU is crucial for bridging industrial expertise with advanced academic research, ensuring that the findings are directly useful to real-world manufacturing. Access to SSAB’s industrial-scale processes and testing facilities allows for comprehensive material evaluation that, combined with university research capabilities, provide in-depth analysis and optimization strategies. This partnership can enhance the understanding and development of strategies to optimize the manufacturing process to improve the formability of high-performance steel.