In general terms, annealing refers to the heating of a workpiece to a certain temperature, holding it at this temperature and then usually allowing it to cool down slowly.
All annealing processes, if carried out in an air atmosphere, lead to the scaling or decarburizing of the workpieces. This is particularly disturbingly evident with pre-processed parts or parts that are subsequently hardened. One avoids decarburization or scaling by avoiding contact between the steel and oxygen. This generally takes place by generating a special, oxygen-free complete atmosphere in the furnace or under vacuum conditions. One refers here to protective gas or vacuum annealing.

In our systems, in addition to nitrogen, argon, forming gases and other generally non-flammable gases it is also possible to generate a 100% hydrogen atmosphere as a protective gas (hydrogen annealing).
It is possible to differentiate between the following different forms of annealing:

  • Soft annealing
  • Stress-relief annealing
  • Normalising or normal annealing
  • Recrystallisation annealing
  • Coarse grain annealing