Termoprocesní technika

Protective Gas Boxes for Models N 7 - N 641

Box with protective gas connection N 11 with protective gas box

Winch stacker with hardening box and furnace

Working with Protective Gas Boxes for a Protective Gas Atmosphere

The hardening boxes for heat treatment under protective gas are equipped with a protective gas intlet and outlet. A box with protective gas is advisable for larger workpieces requiring defined heat treating. We would be pleased to carry out trials at our technical center. Up to furnace model N 61/H with downward door opening the gas ductway is laid through the upper section of the door collar, for larger furnaces with upward door opening the supply line is laid through the lower furnace collar. The box is pressurized with protective gases such as argon, nitrogen or forming gas 95/5 via the protective gas tube. A mixture of 95 % nitrogen and 5 % hydrogen produces optimal results. There are manual and automatic systems available for protective gas. See pages 15-16. for more information about protective gases which can be used as well as manual and automatic protective gas systems. After charging the box it is closed and preflushed outside the furnace. Afterwards the box is placed in the preheated furnace. The quantity of gas can be reduced to the process flush quantity. After the heat treatment the box is pulled out of the furnace, the charge taken from the box and placed in the quenching medium. In most steels, the brief exposure to ambient air while being pulled out normally has no effect on surface oxidation of workpieces. We recommend using binding wire (page 22) on the parts so that they can easily be grasped by tongs (page 22). There is a flexible type K thermocouple in the box for measuring the temperature; we recommend connecting it to a digital display device or to a temperature recorder (page 16). The box can also be cooled down on a cooling platform (page 20) while closed. Be sure that the protective gas flowrate is increased for this application.

  • Tmax 1100 °C
  • Protective gas box with lid, protective gas inlet and outlet through the furnace collar and seal profile. Gas connection including quick-release coupling with 3/8 inch hose connection
  • Lid sealed with ceramic fiber, ceramic insulating materials can alternatively be used
  • Starting with model N 81 the gas ductway runs through the lower furnace collar
  • Up to N 17/HR includes manipulating fork
  • Heat-resistant alloy 314 (AISI)/(DIN material no. 1.4841)
  • Charge thermocouple type K

Additional Equipment

  • Starting from N 31/H a charging trolley is recommended
  • Digital temperature display
  • Protective gas systems
Article no.FurnaceInner dimensions in mmExterior dimensions in mmPreflush/cooling rateProcess flush rate
631000382N 7, N 7/H1141647715020010215 - 205 - 8
631000383N 7/H1741949721023011015 - 20 5 - 8
631000384N 11, N 11/R17424410721028013215 - 20 5 - 8
631000385N 11/H, N 11/HR19429410723033013215 - 205 - 8
631000386N 17, N 17/R17439410721043013215 - 20 5 - 8
631000387N 17/H, N 17/HR19444410723048013215 - 205 - 8
631000398N 31, N 31/H29429414733033017220 - 25 10 - 15
631000388N 21, N 41, N 41/H19429414723033017220 - 25 10 - 15
631000389N 41, N 41/H24434417728038020020 - 25 10 - 15
631000390N 41, N 41/H29439419733043022220 - 25 10 - 15
631000391N 61, N 61/H27449419731053022220 - 2510 - 15
631000392N 8139449419743053022220 - 25 10 - 15
631000393N 16145655625049659635520 - 25 10 - 15
631000607N 32147285021258196033020 - 2510 - 15
631000608N 6417221050312860116045620 - 25 10 - 15
Larger boxes and custom dimensions available upon request
Article no. 601603960, 1 set of fiber insulation cord, 5 strips of 610 mm each