PURPOSE: To produce the reaction tube for producing ethylene having prescribed carburization resistance by immersing the lower part of a cooled casting mold having a mold hole penetrating to the top and bottom into a specific molten metal, cooling and solidifying the molten metal intruded into the hole and continuously pulling up the solidified part, thereby forming a tubular body.
CONSTITUTION: The molten metal 6 of an Fe-Cr-Ni refractory alloy is formed and a pull up rod 2 is lowered to stick the molten metal 6 to a shaft 21 at the bottom end. The molten metal near the shaft 21 is cooled along the mold hole 11 by the cooling water in a water cooling jacket 13 enclosing a die hole wall 12, by which solidification 61 is generated. The solidified part 61 of the molten metal is pulled up as the tubular body 62 when the pull up rod 2 is risen. The molten metal which freshly comes into contact with the mold hole wall solidifies. The tubular body can be continuously cast by rising the pull up rod 2 at a specified speed. The tubular body is used in an as-cast state without machining the inside surface and the inside surface of the reaction tube exhibits the prescribed carburization resistance possessed by the above- mentioned heat resisting alloy.
SUGITANI JUNICHI
YOSHIMOTO TERUO
FURUTA MASAO
| JPS6333152A | 1988-02-12 | |||
| JPS5785652A | 1982-05-28 |
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