The temperature you need to heat treat your material at will typically give you the answer: A FURNACE when you are above radiant heat (1300°F) and an OVEN with air recirculation when you are below.
To maintain the utmost accuracy and extend the life of your heating elements, you should replace the thermocouples at least once a year. The sensing tips on the thermocouples degrade over time and begin to lose accuracy causing the heating element to work harder, shortening element life.
You should always have an extra heating element on hand to avoid unexpected downtime as well as the expense of overnight delivery.
A protective atmosphere is used when exposure to air atmosphere may cause an undesirable chemical reaction with your parts. Note that if your parts are being cleaned or machined afterwards, the use of air atmosphere may be suitable. At Lucifer Furnaces we can provide you with a furnace using an inert protective atmosphere including nitrogen, argon or helium. Inert atmospheres can be used in a GT model furnace or an AM model furnace.
Both our GT and AM models are designed for use with inert protective atmospheres. GT Models are designed with a continuously welded furnace shell and gasketed door for operation with a positive flow of inert atmosphere. GT Models are best suited for constant operation to maintain a dry refractory environment in the work area to minimize oxidation on workloads. GT Models are a less expensive alternative compared to AM Models
AM Models are equipped with an alloy muffle (retort) which separates the refractory and heating elements from the workload and atmosphere to minimize scale and oxidation on most tool steels. The design of the AM Models achieves lower dew points, reduced atmosphere consumption and allow shorter purge times.
Stainless steel foil wrap will minimize decarburization and scale on most tool steels processed under normal air atmosphere.
NADCAP accreditation has to do with a company's compliance with certain specifications. There is no such thing as a NADCAP approved furnace or oven. Lucifer Furnaces can build your furnace or oven to comply with the requirements of AMS 2750D, a common furnace specification cited in NADCAP requirements for heat treating. It is your company or your process that becomes NADCAP accredited. If you are thinking about NADCAP accreditation, be sure to mention that when you are buying equipment.
With low watt density heating elements the heat is spread out over a greater surface area; the result being that low watt density heating elements burn out less frequently (they last longer) than higher watt density elements. Longer lasting elements reduce operating costs.