Technical Resources

RA330® Muffle Sintering Stage



A RA330® rectangular muffle was fabricated for the sintering stage of a powdered metal application. The muffle, specifically used for sintering iron, needed to handle temperatures in excess of 1093.33°C with excursions up to 1121°C. Operating 24 hours a day 7 days a week, the application used a gas fire furnace with an endothermic atmosphere inside the muffle.


Creep issues were the main cause of muffle failures in this furnace. Typically the top of the muffle would cave in on itself causing an obstruction for the powdered metal attempting to travel through the furnace. In the past muffles had been made from 75% Ni and 15% Cr alloy, which was a considerably more expensive alloy due to its high nickel content.

Muffle 2


The muffle was fabricated from 3/8-inch RA330® plates and welded together using RA330-04 electrodes.


Once fitted the RA330® muffle outlasted any of the previous muffles that had been used prior to its installation and lasted for an impressive 17 months with no atmosphere leaks or repairs having been made.  It lasted longer than any other muffle that was fitted in this furnace.

For more information on RA330® or to get a quote contact us today – a member of our team will be happy to advise you.

 Contact Us