Virtual numerical simulation of chemical-heat treatment process
Chemical heat treatment process causes distortion and sometimes cracking of treated part. To eliminate these undesired side effects the whole circle of heat treatment is simulated by FEM ( SYSWELD CODE, ESI GROUP), which makes possible a complete chemical, metallurgical, thermal and thermoplastic calculation. The goal of this simulation is to bring the whole cycle of chemical-heat treatment to optimum – to reach lowest level of residual stresses and distortion possible, requested depth and level of carbon content, requested material properties. Chemical – heat treatment numerical simulation consists of carburisation, nitridation, quenching (in water, air, oil or special medium), tempering follows. The whole calculation was held according to a pre-set thermal cycle which was at the same time being corrected according to calculated distribution of local temperatures, material structure and stress within the model in order to reach the lowest level of stress and distortion possible after heat treatment. The article describes the complete chemical-heat treatment as demonstration case.