| 摘要 |
<p>1461083 Carbonitriding T BELL 3 Dec 1974 [8 Dec 1973] 56985/73 Heading C7U - Ferrous material is carbonitrided by heating in a furnace chamber containing ammonia and a carburizing gas, the amount of undissociated ammonia in the furnace being continuously monitored and adjusted if necessary, to the desired value. The monitoring may be by gas chromatography, dissociation pipette, or preferably by infrared ammonia gas analysis, and the adjustment is made by valves in the lines supplying the respective gases to the furnace. The temperature is 500-780‹C, and the surfaces treated may be of cast iron, sintered iron, low alloy steels, wrought and sintered plain carbon steels. The surfaces may previously be carburized or carbinitrided by a conventional process. The treated material may be quenched and tempered.</p> |
