Effect of cleanness on undercooling of molten steel

The influence of cleanness on undercooling of molten steel was investigated by using ultra-high temperature DTA and vacuum glass encasement levitation melting for deoxidized pure iron and low carbon steel. At a cooling rate of 20 k/min the undercooling of pure iron and low carbon steel are 54.4 K and 34.2 K respectively. The under-cooling of pure iron decreases with the increase of oxide content and the arrangement of oxides in terms of influence on undercooling is MnO>SiO2>MgO>Al2O3. At a cooling rate about 2000 K/min the undercooling of low carbon steel remarkably increases after vacuum glass encasement levitation melting and a maximum undercooling of 328 K is shown for the steel treated for four times.