Modeling of an expert system for an electric muffle furnace for simple heat treatment processes

This article describes the modeling of an expert system for an electric muffle furnace for controlling the simple heat treatment processes like annealing and normalizing in case of plain carbon steels. The heat treatment process consists of three stages viz. heating, soaking and cooling. This paper deals with the heating stage i.e., it gives a method to design an expert system that sets up the required heating temperature for a given plain carbon steel. For this purpose, an expert system was created having a knowledge base containing information regarding carbon percentage, hardness and austenitizing temperature (temperature at which the iron, iron-based metal, or steel changes crystal structure from ferrite to austenite). The expert system was given two inputs viz. Carbon percentage and required Brinell Hardness Number on the basis of which temperature set point was set for the muffle furnace using fuzzy logic. The simulation of this expert system was done on MATLAB/ SIMULINK. The results obtained after simulation were compared with the standard results available in a standard design data book. The two results were found to be in good agreement with each other. It was found that the expert system decided the correct values of temperature set point for different types of annealing processes for plain carbon steels.