| 摘要 |
The surface of a ferrous metal workpiece is heat treated by immersing the workpiece to be treated in the fluidized particulate bed of a fluidized bed furnace. The bed is fluidized by a gas atmosphere comprising ammonia gas, hydrocarbon gas, and optionally a non-reactive gas. The temperature of the fluidized bed is maintained at about 600 DEG F. to 1250 DEG F. The proportion of the ammonia gas in the gaseous atmosphere may be varied to alter the surface characteristics of the treated workpiece. The compound layer and the underlying diffusion zone exhibit increased thicknesses. Increased hardness and increased impact loading resistance of the treated surface are obtainable.
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