FIELD: chemistry.
SUBSTANCE: invention relates to chemical and chemical-metallurgical industries. The surface of the article to be sealed which is made from coal-graphite material is coated with a slurry coating based on fine carbon filler with particle size from 1.5 to 63 mcm and a non-shrinking foam binder. The surface of the article and the slurry coating are saturated with pyrocarbon at partial pressure of supply-line gas containing not less than 98% methane of 7-20 mm Hg via stepwise raising of temperature from 850 to 990°C and contact time of the pyrolysis gas with the article of 3-10 s. The next temperature raise during saturation of the surface of the article and slurry coating with pyrocarbon is carried out each time content of hydrogen in the pyrolysis gas begins to fall. Deposition of the pyrocarbon coating is carried out at temperature 990-1050°C, partial pressure of the supply-line gas of 7-28 mm Hg and contact time of the pyrolysis gas with the article of 10-20 s. Temperature, partial pressure of the supply-line gas and contact time thereof with the article during deposition of the pyrocarbon coating are selected such that content of hydrogen does not exceed 38 vol. %.
EFFECT: invention reduces the duration of the process of sealing articles without reducing their degree of air-tightness.
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