Improving productivity and energy efficiency in the heat treatment of steel castings
To ensure a successful austenitizing heat treatment, the steel casting industry has used conservative practices. The long process times result in inefficient use of time and energy. Past research has justified the application of shorter process times, but industry has been unable to implement their findings because of control limitations. The problem is identifying when the load has reached temperature. This paper discusses the disconnect between the recommended heat treatment process strategy and the control strategy and proposes an improved control strategy. The firing rate or output signal from the controller is introduced as a novel approach to identify indirectly when the load has finished soaking. This work has demonstrated potential savings of 30% in process time and gas consumption with each load.