method for korrosionsschutzbehandlung of items, graphite and treated by this method graphitgegenstaende

摘要

Graphite articles are coated with silicon carbide in a two-stage process; in the first stage the graphite is heated at below 1100 DEG C. in an atmosphere of hydrogen, hydrocarbon and silicon halide to form a deposit of silicon carbide in the pores of the graphite and in the second stage the graphite is heated at above 1200 DEG C. in an atmosphere of either hydrogen, hydrocarbon and silicon halide or of hydrogen and of a gaseous organic silicon compound to provide a thick uniform coating of silicon carbide on the graphite. The first stage is preferably carried out at about 1050 DEG C. and the second stage is preferably carried out at about 1400 DEG C. using toluene or methane as the hydrocarbon or using methyl trichlorosilane as the organic silicon compound.