| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heating type heat treatment furnace for steel capable of preventing cracking and flaking of a furnace wall or the like around a heating burner, and capable of shortening build-up and recess time of the heat treatment furnace. <P>SOLUTION: The heat treatment furnace is provided with a furnace wall structure arranged with ceramic fiber 3 on at least a furnace wall inner side, and a burner 2 is installed in an insertion hole provided in a furnace wall. The burner port 4 composed of a silicon nitride based ceramics sintered body composed of 2.5-4.8 mass% of at least one phase from a Y<SB>2</SB>Si<SB>2</SB>O<SB>7</SB>phase, an Er<SB>2</SB>Si<SB>2</SB>O<SB>7</SB>phase, or a Yb<SB>2</SB>Si<SB>2</SB>O<SB>7</SB>phase, 2-6.5 mass% of an Si<SB>2</SB>N<SB>2</SB>O phase, 2-5 mass% of SiC based particles with an average grain diameter of 0.1-0.7 micrometers, and the rest β-Si<SB>3</SB>N<SB>4</SB>and unavoidable impurity, is adjacently arranged on a furnace inner side of the burner 2, and a tip of the burner port is projected from a furnace inner wall surface to the furnace inner side. <P>COPYRIGHT: (C)2008,JPO&INPIT |
