.”Mechanical evaluation of Al2O3-MgO-C refractory bricks by stress-strain curves”

V. MUÑOZ; A. L. CAVALIERI; A.G. TOMBA MARTINEZ

Congreso; International Ceramic Congress CIMTEC 2010; 2010

The increasing demand for Al2O3-MgO-C refractory bricks in the steel-making industry is due to its high performance under the more and more severe operating conditions (higher temperatures and mechanical loads, thermal gradients and interaction with slag, gases and solid particles). However, the material damage is unavoidable, being imperative the knowledge of thermochemical and thermomechanical properties in order to improve the material design in view of increasing the lifetime and reducing both the costs and the environmental impact. In this work, the high temperature mechanical behavior of two commercial Al2O3-MgO-C bricks of steel-making use was evaluated by stress-strain curves. Uniaxial compression tests of cylindrical specimens were performed at a temperature range from RT to 1350°C in controlled atmosphere. The stress-strain curves were obtained using a servo-hydraulic machine with a high stiffness load frame (INSTRON) and an axial capacitive extensometer (± 0.6 mm) suitable for high temperature measurements. The tests were performed in displacement control (rate of 0.1 mm/min) up to the specimen failure. From these curves, mechanical parameters were determined: fracture strength and strain, and Young's modulus. After mechanical tests, several complementary techniques were used to analyze the main microstructural and compositional changes. The mechanical properties were analyzed in terms of both the refractory composition and microstructure and the changes occurred with temperature during the tests.