Quality evaluation of nitride bonded silicon carbide sidelining materials

A laboratory test method to determine the chemical/oxidation resistance of commercially available SiC-based sidelining materials was developed at SINTEF in 1996. Since then more than 260 samples from around 20 suppliers world-wide have been tested, and an overview of typical - and abnormal results will be given. The tests have demonstrated the importance of checking the quality of the SiC blocks throughout the entire cross section of the blocks. Large variations were found, depending on whether samples were taken near the surface or from the central parts of the blocks. The observed degradation will be discussed in terms of a proposed reaction mechanism, and related to material quality parameters and test conditions (bath acidity and gas atmosphere).