... Usage:hardening,forging,welding,annealing and melting induction heating machinery for HF,MF ,SUPER AUDIO from Alibaba recommend manufacturer--ZHENGZHOU ... CO.,LTDAnnealing•Heating and slow cooling of a material for reducing hardness and brittleness. Typically, the material has ... induction.Tempering•Heating and slow cooling of a material for reducing hardness and brittleness. Typically, the material has ...