Abstract
Starting from silicon carbide tube and plate materials from industrial production, a series of corrosion tests was performed at temperatures between 1100 and 1400°C in different atmospheres containing water vapour, hydrogen, sulfur dioxide, hydrogen sulfide, and hydrogen chloride. Corrosion layers were characterized concerning their structure and morphology, but main emphasis was given to measurements on the change of the silicon carbide bending strength after gas corrosion. Important results of this work are
the very different corrosion behaviour of various silicon carbide materials under the same corrosion conditions depending on stoichiometry, structure, sintering aids, and distribution of free silicon phase,
the significant increase in the bending strength of SiCiC tube material with homogeneous silicon phase distribution after corrosion in hot water vapour in the presence of nitrogen,
the decrease in bending strength in dry hydrogen/nitrogen atmospheres,
the resistance of silicon carbide materials against sulfurous atmospheres at temperatures near 1400°C, and
the attack on SiSiC by HCl depending on the HCl concentration and the oxygen partial pressure.