Nitriding Recipes/Programs

Nitriding Recipes can be broken down into three stages, Startup, Nitriding and Shutdown

In the Startup phase of the recipe, the furnace starts to heat up and is purged with Nitrogen.  As a general rule to assure safe operation of the furnace, the furnace should be purged with Nitrogen long enough to allow for 5 to 7 volume changes.  This ensures that it will be safe to add Ammonia and/or Dissociated Ammonia when required.  This purge time is determined by calculating the furnaces volume and dividing by the Nitrogen Flow.  The startup phase can also start adding ammonia once the desired purge time and temperature has been achieved.

 

In the Nitriding process stage of the recipe, the temperature and %Dissociation/Kn setpoints are set and the Soak times are set as well.  This phase will also enable the Trim enable feature for ammonia to allow for control of the furnace atmosphere to setpoint.

 

After the Nitriding process stage, the shutdown routine will run.  This typically involves, shutting off the Ammonia and Dissociated Ammonia, turning on Nitrogen and lowering the temperature setpoint to allow the furnace to cool.  This stage will also sound an alarm indicating the process is complete.