Furnace Muffle: How to Prevent Extreme Muffle Corrosion

Below are before and after photos of a sintering furnace muffle.  Alloy Engineering was contacted about this muffle, as discussed in part one of this blog.  After an on-site investigation and a lot of process Q&A with the customer, we offered our solutions. 

As mentioned in part one of this blog, our solution also included process recommendations.  We recommended that the customer not completely shut down the sintering furnace over weekends, but instead idle the furnace at a lower temperature.  This prevented build-up of the powder binder agent inside the muffle from corroding the muffle itself during the temperature swings.   We also recommended formal heat-up and cool-down procedures to lessen the mechanical stresses on the muffle, again furthering muffle life.  Lastly, we changed the muffle material of construction to an alloy better able to resist creep at higher temperatures. 

The end result is that the customer has now greatly exceeded their muffle life.  The Alloy Engineering muffle is still in service, and we don’t expect the customer will need a new muffle for at least a couple more years.