Time-temperature diagrams of induction hardening

Abstract

Our days are characterised by accelerated processes. In heat treatment technologies one of the most effective processes is induction hardening. Due to the induction hardening the time range of classic hardening-tempering processes can be decreased to tenth. However, the characterisation of this accelerated process is complicated with the common time-temperature diagrams, because of the simple fact, that there exists no maximal chamber temperature, only the given power of the induction coil can be given, which causes determined heat in the heat-treated base material. Based on heat-treatment diagrams, the forming microstructure can be characterised, and the mechanical behaviour can be predicted. In this paper the maximum temperature of a component with given geometry is examined during induction hardening, applying thermal camera and based on the experimental results and the determined heating and cooling times, time-temperature diagrams are drawn.