Carbon pick-up of interstitial free steel from low carbon content MgO-SiC refractories

摘要

The carbon pickup of interstitial free steel (IF steel) from resin bonded MgO-SiC refractories is studied via a medium frequency induction furnace. Samples of IF steel were heated in MgO-SiC crucibles with mould flux cover at 1600 deg C for 180 min. The carbon contents of IF steel samples taken from the molten steel every 30 min were examined and the refractories after heating were investigated by electron probe microanalysis (EPMA) with energy disperse spectroscopy (EDS) and X-ray diffraction (XRD). The carbon content of steel increased rapidly during the initial stage of heating, and then decreased because of the formation of a liquid layer on the refractory. The liquid layer separated the liquid steel from the bulk refractory and stopped pickup of carbon. At the same time, decarburization via oxygen through the liquid layer and flux started to reduce the carbon content of the liquid steel.