| 摘要 |
1,096,364. Furnace atmospheres. BABCOCK & WILCOX CO. Nov. 30, 1965 [Dec. 15, 1964], No. 50838/65. Heading F4B. Part of a tubular workpiece 20 to be heat treated is inserted into the chamber 16 of an induction furnace 10 defined by a water-cooled coil 11 with a liner 15, an end plug 17, and a front plate 21, the latter being formed with a manifold 25 with ports 25A through which a volatile boron compound, e.g. methyl borate, is introduced into the furnace. The manifold 25 is an unclosed loop to prevent excessive heating by the coil field. The temperature of the boron compound is maintained below the melting temperature of B 2 O 3 , and preferably below 750‹ F. A small quantity of this compound may be introduced through opening 17A in plug 17. The film of B 2 O 3 formed on tube 20 inhibits scale formation. |
