Process Chain Sensitivities in Green Steel Production: Tramp Element Impacts on Casting and Reheating

Surface defects are a critical indicator of semi-finished product quality, with the elements Cu and Sn exerting a significant influence through the phenomenon known as hot shortness. The present study quantifies the defect sensitivity caused by Cu and Sn for three different steel grades under continuous casting conditions using the In-situ Material Characterization by Bending (IMC-B) test. Building on this, purposefully pre-damaged samples were subjected to reheating under process-related conditions within a natural-gas combustion atmosphere. The objective is to investigate how surface defects from the casting process evolve depending on their initial depth and the selected final reheating temperature. Finally, metallographic analyses allow for a correlation between the initial defect depth and the surface morphology after reheating.