One Minute Mentor: Gas nitriding equipment

Gas nitriding and nitrocarburizing can be processed in horizontal or vertical chamber furnaces with refractory insulation. However, to allow a quick change of the atmosphere and to avoid influences resulting from previous processes in the same furnace, retort furnaces are preferred.

To enable an acceptable production capacity, large vertical retort furnaces are used. The figure is a schematic sketch of a vertical retort furnace with a compensator for sealing against the atmosphere. Nowadays large horizontal retort furnaces are also used. Horizontal retort furnaces of different size and execution are preferred for nitrocarburizing processes. Similar to the vertical execution, a good circulation of the process gas is needed to get uniform results, which can be reached by the use of a muffle and a high circulation rate. Indirect cooling is performed with an external cooling fan, blowing cold air along the retort. Other designs allow direct cooling of the process gas with an external heat exchanger.

For more information, click on the link below (subscription required). Then scroll to Figure 23

R Schneider; R. Mesquita; H. Altena; T. Müller; P. Seemann, Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Leading die manufacturer adds Seco/Vacuum furnace to increase capacity

Seco/Vacuum, Meadville, Pa., has announced that a U.S.-based international manufacturer has placed an order for a Vector high-pressure gas quench furnace. The new furnace will increase the partner’s heat treat capability while improving part quality. The Vector will allow the partner to heat treat larger parts, at higher quantities per cycle than their existing furnace, all with improved quality control and reliability.

The partner’s equipment requires the use of large dies that require precise heat treating. Their current heat treatment setup includes a pair of vacuum furnaces, which have some limits compared to the Vector they are about to receive.

The new furnace, a bottom loading Vector vacuum furnace with 6 bar nitrogen gas quench, has a 60″ diameter, 72″ tall, and a 3-ton capacity working zone. It is equipped with convection heating which allows them to run their tempering cycle in the same furnace without having to move parts after hardening, a tremendous time and labor savings.

The furnace is also equipped with SECO/WARWICK’s FineCarb low-pressure carburizing system for future process developments. The Vector will increase production capacity to meet the rising market demand of today and tomorrow. The new furnace’s vertical configuration and rotary hearth were built specifically to accommodate more large dies, allowing the partner to meet the elevated demand with ease. SECO/VACUUM’s intuitive process controls ensure greater heating uniformity than their existing equipment in both convection mode and in vacuum mode.

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