It is also demonstrated that the applied procedure could be useful in reducing the number of experiments required for developing compositions for other new steels.", Validation experiments showed that the predicted properties, i.e., hardness, hardenability and level of segregation, for the designed composition were realistic. The results showed that an addition of Nb decreases the austenite grain size during casting and after slab reheating prior to hot rolling. For further investigations and verification, the designed composition, i.e., in wt.% 0.40C, 0.20Si, 0.25Mn, 0.90Cr, 0.50Mo, was cast with two nominal levels of Nb: 0 and 0.012 wt.%. Important factors taken into account in the modeling and optimization were hardenability and as-quenched hardness, grain refinement and alloying cost. CALPHAD-based packages for the thermodynamics and kinetics of phase transformations and diffusion, namely Thermo-Calc, have been combined with an interdendritic segregation tool (IDS) to optimize the contents of chromium, molybdenum and niobium in a proposed medium-carbon low-manganese steel composition. In this work, this challenge is dealt with by combining metallurgical principles with computational thermodynamics and kinetics to design a novel steel composition suitable for thermomechanical processing and induction heat treatment to achieve a hardness level in excess of 600 HV with the potential for good fracture toughness. It is also demonstrated that the applied procedure could be useful in reducing the number of experiments required for developing compositions for other new steels.Ībstract = "The design of a new steel with specific properties is always challenging owing to the complex interactions of many variables.
CALPHAD-based packages for the thermodynamics and kinetics of phase transformations and diffusion, namely Thermo-Calc ® and JMatPro ®, have been combined with an interdendritic segregation tool (IDS) to optimize the contents of chromium, molybdenum and niobium in a proposed medium-carbon low-manganese steel composition.
The design of a new steel with specific properties is always challenging owing to the complex interactions of many variables.