Thermal shock resistance of magnesia–chrome refractories—experimental and criterial evaluation

Eleven commercially available magnesia–chrome refractories have been tested. Their basic properties have been determined along with bending strengths at 20,950 and 1400 °C, linear thermal expansion coefficients at 950 °C and 1400 °C, Young's modulus by the static method and the work of fracture at 950 °C. Young's modulus was determined within the temperature range 20–1000 °C, in the process of heating and cooling. The values of thermal shock resistance Rst and R4 were calculated and correlated to thermal shock resistance (TSR). It has been demonstrated that the Rst criterion is a useful tool to forecast TSR, no matter whether the value of the E modulus is determined by the static or dynamic method. The values of Young's modulus obtained by various methods at 20 °C and 950 °C have been compared. It has been proven that Young's modulus dependence on temperature is a specific feature of a given material.