Abstract:In order to improve the service life of magnesia-chrome firebrick in the tuyere area of PS converter，the magnesia-chrome residual brick in the tuyere area of PS converter was used as the research object，and the erosion mechanism of matte，blister copper and slag on magnesia chrome brick was investigated by means of physical and chemical properties analysis，chemical composition analysis and scanning electron microscope. The following conclusions were drawn：the penetration of matte and blister copper mainly through pores，grain boundaries and microcracks caused the erosion of magnesium-chrome bricks. The structural porosity caused by SO2/SO3 atmosphere in the furnace and the cracks caused by thermal shock in production intensified the continuous penetration of matte and blister copper，which caused structural spalling and thermal spalling of magnesium-chrome bricks. This is the main cause of magnesium-chrome brick damage in tuyere area. After the slag penetrates into the magnesium-chrome brick，it reacts with the solid solution of periclase，resulting in the dissolution of periclase in the ferrosilicon slag，and the chromium concentrate in magnesium-chrome brick has good slag resistance. Therefore，on the one hand，the chemical composition，structure density and thermal shock resistance should be considered in the selection of refractory materials. On the other hand，in the actual production，the thermal shock effect caused by the drastic temperature fluctuations should be reduced by the balanced production，and the slag composition should be changed to weaken the reaction between slag and periclase in refractory brick.