Nitriding surface of ferrous metals - using electric signal to monitor gas in nitriding furnace continuously

摘要

The gas contains H2 and NH3, and the nitriding potential which is the ratio PNH3/PH2 1.5 is measured. Two gas analysers (a,b) measure the partial pressures (P) of the H2 (a) and the NH3 (b). Analyser (a) is connected to a function generator (FG) producing P1.5 for the H2. where as analyser (b) is connected to another FG which linearises PNH3. The two FG are connected to a divider circuit followed by an amplifier producing a control signal employed to adjust the nitriding gas. The nitriding potential can be continuously monitored and adjusted for optimum nitriding.