Hot Toughness of Continuously Cast Steel Slabs during Reheating

• Published in: Steel research international 2007-06, Vol.78 (6), p.482-491
• Main Authors: Yang, Bingye, Degischer, H. Peter, Xia, Guangmin, Presslinger, Hubert
• Format: Article
• Language: English
• Subjects: Concentration (composition); continuously cast carbon steel; crack sensitivity; fracture energy; Fracture mechanics; Fracture toughness; Heating; hot tensile properties; hot toughness; Reduction; reduction in area; Reheating; Slabs; Steels
• ISSN: 1611-3683; 1869-344X
• DOI: 10.1002/srin.200706235

Laboratory hot tensile tests on specimens taken from continuously cast steel slabs are executed by means of a Gleeble apparatus to investigate the ductility and hot toughness of steels during reheating of as cast conditions. The reduction in area at fracture and the fracture energy for 10 different heats with the carbon content in the range from 0.003 to 0.521 mass% and some variations in Nb, Cr and N are presented in the temperature range from room temperature up to 1025°C. Ductility minima regarding toughness are identified around 300°C and 650°C. Relationships of the reduction in area at fracture and of the specific fracture energy with the relevant elements of the steel composition are established. Equivalent carbon concentrations are defined which take the N concentration into account for the 300°C embrittlement and additionally the micro‐alloying element Nb for the 650°C ductility minimum. Limits for the reduction in area values and for the specific fracture energy are proposed to validate the crack sensitivity of as cast carbon steel slabs.