| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of efficiently manufacturing a ceramic tubular formed body which is excellent in thermal shock resistance and corrosion resistance, preferably used for various kinds of heat treatment members including a protective tube for a thermocouple, an immersed protective tube for molten metal, and in particular, different in tube diameter and wall thickness. SOLUTION: In the manufacturing method of the ceramic tubular formed body in which the raw gas is introduced in a cylinder formed of a cylindrical graphite base member, a ceramic film is formed on an inner wall surface of the cylindrical graphite base member by the CVD reaction, and then, the graphite base member is removed, a plurality of cylindrical graphite base members are arranged in series in a reaction chamber of a CVD system via an elbow, the CVD reaction is set in a range of the reaction temperature of 1200-1700 deg.C, the raw gas concentration of 3-15 vol.%, the reaction pressure of 13-100 kPa, and the raw gas flow speed of 1-10 m/s, and the film forming speed is controlled in a range of 400-5000 μm/h. |
