The Properties of MgO-C Materials with Different Graphite Size Distributions

Monolithic stopper is one of the functional refractories. The security and continuity of the continuous casting maybe irrupted by the abnormal condition of monolithic stopper. MgO-C material composite monolithic stopper is often used to cast Ca-treated steel. But the thermal expansion of MgO-C materials is relatively large and there is a poor thermal matching between rod part and body part. To improve thermal shock resistance of MgO-C materials, the properties of MgO-C materials with different graphite size distributions are researched. The results show that 1000 mesh graphite addition will decrease thermal shock resistance, fracture energy and thermal expansion will increase. MgO-C materials with combined addition of 595 and 199 graphite present good thermal shock resistance. The trends of thermal shock resistance for MgO-C refractories by immerging molten steel methods agree with that of Rst.