The Role of Thermal Gradients and Heat Fluxes in the Development of Steel Microstructure

摘要

Under conditionsa of non-equilibrium cooling, many solid solution alloys such as low alloy steels solidify in a dendritic fashion. The heat fluxes vary between 4 MW/m~2 at low casting speed, up to 7MW/m~2 The cooling rates vary between 117℃/s at the surface to 38 ℃/s at the centre of the strip for low casting speed, and between 1215℃/s at the surface to 101℃/s at the centre of the strip for high casting speed. Surprisingly non-equilibrium cooling at cooling rates exceeding critical values of 140 K/s can produce gla structures in multi-component Fe base systems being assisted by comparable values of 8MW/m~2 for heat fluxes.