Induction Annealing and Tempering, both common induction heating applications, are similar methods of applying heat to a conductive metal in order to improve ductility, reduce the hardness of metals which have become too brittle, and relieve residual stress.
In contrast to hardening, the annealing process involves a relatively slow heating step followed by gradual cooling. Annealing is used when the material must be softened as much as possible; tempering softens the metal but not to the full extent possible.
Induction Annealing is a metal heat treatment in which a metal material is exposed to an elevated temperature for an extended time and then slowly cooled. Annealing heat treatment is largely characterized by induced micro-structural changes which are ultimately responsible for altering the material's mechanical properties. The ultimate goal of this process is to reduce the hardness of the metal and improve its ductility.
Induction Annealing specifically refers to the process of bringing the material to its softest possible point. Our induction tempering process softens the metal but not to the full extent possible. The degree of temper depends on the material, the maximum temperature reached and the length of the cool down time. Process or stress relief annealing is used to negate the effects of cold work; that is, to soften and increase the ductility of a previously strain-hardened metal. Internal stresses may develop as a result of plastic deformation processes such as machining or grinding, non-uniform cooling in a welding or casting process, or a phase transformation. Distortion and warping may occur if the internal stresses are not removed. Induction Annealing heat treatment will eliminate these stresses when the part is heated to the recommended temperature, held there long enough, and slowly cooled to room temperature.
Induction Annealing and tempering, both common induction heating applications, are similar methods of applying heat to a conductive metal in order to improve ductility, reduce the hardness of metals which have become too brittle, and relieve residual stress.