Induction Heat Treating

Induction Heat Treating

Heat treating metals can be accomplished in many different ways, each giving a unique quality and effect to the material. Specialized furnaces are used to achieve induction heat treatments and vacuum heat treatments. While vacuum heat treating heats the metal in the absence of oxygen, induction heat treatments use electricity over the traditional gas and flame methods. Some vacuum furnaces use induction for the heating of their metals. In contrast to more traditional heat treating methods, induction heat treating can quickly create higher intensity heat in selective locations. By using a coil carrying an alternating current, the treatment uses electromagnetic induction to heat the metal. As the currents move through the metal, heat is generated. The frequency at which the currents move is adjusted to size and material of the metal being worked with. Once the metals become liquid, the current frequencies can sometimes be used to stir the molten metal.

Induction heat treatment is most commonly used for hardening metals, softening certain parts, or joining metal parts together. Annealing is the slow cooling of metal that transforms small grains into larger grains and results in a soft, ductile metal. To join metals, a process called brazing is used in which melted metallic filler is used to bond two base pieces creating an extremely strong and often hermetic joint. In comparison with other heat treatment methods, induction heat treating is more energy efficient and environmentally friendly. Induction heat treating can also be more precise because of the ability to use electricity versus gas. This often allows the temperature to be heated more quickly, and a steady consistency to be more easily obtained. The coil also assists with the speed at which the metal is heated. Another advantage is induction heaters take up less floor space and require less start-up and shutdown time than regular furnaces used in other heat treating processes.