| 摘要 |
PURPOSE:To form a carbide layer uniformly on the surface of a material to be treated by forming a fluidized layer of powders of refractory, carbide forming element and ammonium halogenide having a specified flow rate in a fluidized layer type furnace and arranging the material to be treated in the furnace while heating the furnace. CONSTITUTION:The treating agent in which 60-350 mesh powder of 50-95wt% refractory powder such as Al2O3, SiO2, 50-5wt% carbide forming element such as V, Nb, Ta, Cr, 0.2-3wt% ammonium halogenide such as NH4Cl are mixed, is placed in the fluidized layer furnace 1 having air dispersing plate 3 at the under part, and the material 8 to be treated contg. >=0.1% C in steel, etc. is hung down therein. The furnace 1 is heated to 700-1,200 deg.C by a heater 6, inert gas such as Ar is supplied from a gas supplying tube 2, and the fluidized layer 7 of said treating agent is formed. In this way, gaseous Ar is supplied at >=50cm/ min flow rate per cross sectional unit area of said layer. The layer of said carbide of V, Nb, Ta, Cr, etc. is formed safely, and uniformly on the material 8. |
