Simulation of Environmental and Furnace Working Parameters Effect on Gas Carburizing Surface Treatment

In recent years an increase in simulation of metallurgical processes can be seen. This increase is mainly due to a decrease in the number of required experiments in order to control the process and therefore, decrease the spent time, energy and cost. One of these processes is the gas carburizing process. The percent of surface carbon content in parts manufactured by this process is the most important specification to facilitate manufacturing of standard parts. In order to determine the carbon content on the surface of steels in this surface heat treatment process, a lot of time and resources must be spent on conducting experiments.In the current study, the independent reactions in a carburizing furnace were first studied and then simultaneously modeled with the aid of MATLAB software. Afterwards, the equilibrium constant equations were solved with a computer and the equilibrium surface carbon content of the steel was calculated. As a final point, by inputting the amount of generated gases in the endothermic gas generator (air to fuel ratio), furnace temperature, furnace internal pressure, ambient temperature and humidity in the programmed software, the percent of surface carbon on the steel part is calculated and the effect of the mentioned parameters on the surface carbon content can also be studied. In addition, the results obtained from this simulation were confirmed by empirical results acquired from gas carburizing furnaces and a good relation between these two was found.