Abstract Starting with several different industrial silicon carbide tube and plate materials a series of corrosion tests was performed at temperatures between 1200 and 1400 °C in different atmospheres containing water vapour, hydrogen, sulphur dioxide, and hydrogen sulphide. The corrosion layers were characterized according to their structure, morphology and growth rate, but the main emphasis was given to measurements of the change of the silicon carbide bending strength after hot gas corrosion. Important results of this work are as follows: 1. (a) the fact that the corrosion behaviour of various silicon carbide materials under the same corrosion conditions differs over a wide range, 2. (b) the observed increase of strength of SiSiC tube material in hot water vapour in the presence of nitrogen, 3. (c) the decrease of strength in dry hydrogen - nitrogen atmospheres and 4. (d) the excellent resistance of silicon carbide materials against sulphurous atmospheres at temperatures near 1400 °C.