25.52 Heat treatment of metals

This class includes

• general activities for the heat treatment of metals
• thermomechanical heat treatment of metals (e.g. preheating, annealing, hardening, tempering, quenching, deep freezing of metal)
• thermochemical heat treatment of metals (e.g. carburising, carbonitriding, nitrocarburising, nitriding, oxidising, sulphidising, boriding)