Induction Tempering and Stress Relieving

The transformation to martensite through heating and quenching of carbon steel wires creates a very hard and brittle structure of as-quenched martensite that is typically too brittle for commercial use. Reheating of the metal for tempering or stress relieving after hardening decreases or relaxes residual stresses and produces a ductile structure of tempered martensite. Time and temperature are two of the most critical parameters in tempering. Induction tempering differs from conventional way of furnace tempering (i.e., using gas-fired, infra-red or direct resistance furnaces) being a short-time/higher temperature process in comparison to longer-time/lower-temperature conventional tempering.