Different Methods of Young's Modulus Determination and Evaluation of Refractories at High Temperatures
TONNESEN T. 1, HENZE M. 2, HIRT G. 2, GONZALEZ-JULIAN J. 1
1 RWTH Aachen University, Institute of Mineral Engineering (GHI), Aachen, Germany; 2 RWTH Aachen University, Institute of Metal Forming (IBF), Aachen, Germany
Comprehensive knowledge about thermomechanical behavior is mandatory for an accurate prediction of occurring stresses to design load-optimized linings. Refractory linings are, in addition to loads due to corrosion and creep processes, particularly affected by thermomechanical stresses caused by the restricted thermal expansion of the lining. These stresses can occur within individual components as well as in bricks and can lead to plastic deformation, cracks, and material failure.
This study compares methods for determination of Young’s Modulus at different temperatures for the use in refractory modelling of lining systems. In three point bending tests the deflections of different refractory materials was examined during loading by means of digital image correlation (DIC) up to high temperatures. The achieved data allows to evaluate static Young’s Modulus values respectively. In parallel refractoriness under load (RUL) tests with higher loads up to 1.5 MPa have been carried. The measured data of change in temperature and length are then corrected by the thermal expansion and used to construct elastic lines for several temperatures, where the elastic slope is determined using the change in length and the respective load. Thus, Young’s modulus for several temperatures can be determined.
These obtained values for static Young’s modulus are then compared to values which have been determined the dynamic resonant frequency damping analysis (RFDA) measurements without load apply. Finally a validation for refractory linings using a finite element (FE) model by means of these data is discussed.