The main imperfections in heavy steel castings are related to hot tear formation during solidification. Depending on the steel grade, design and local solidification conditions, it is possible to predict regions with higher risk of hot tear formation during the casting process. However, steels containing boron show more complex crack and defect patterns compared to common steel casting alloys. The mechanisms behind the boron induced hot tearing is investigated in this work to understand the influence of boron enrichment during solidification and the influence on hot tearing. The experimental work includes the investigation of phase diagrams and the corresponding fractions of the solid and liquid phases depending on temperature using thermal analysis e.g. DSC and HT-LSCM. The hot tearing sensitivity and mechanical properties during solidification are obtained in the Submerged Split Chill Test, SSCT. Creep experiments for the determination of high-temperature material properties in the solid state are determined in the IMC-B 3-point bending test. Finally, a benchmark simulation of a real sized casting product is carried out and used to show the agreement between the numerical results and extensive non-destructive testing from industrial observations. The main goal is to improve the hot tear predictions based on the experimental work.

Moderated by: Hideyuki Yasuda