عنوان مقاله [English]
Design of experiments is one of the most powerful tools in improving manufacturing processes that are begun by determining a test and selecting process factors. One practical technique which used for modeling and problem solving is response surface methodology (RSM).In this study, Design of experiments has been used to survey the effect of three controllable input factors (i.e., Eq carbon, perdurability time and oxygen) on response variable (i.e., the Oxide scale consists of preheating furnace).Since all combinations of steel are effective in the oxidation, based on the definition American Society of Materials, carbon equivalent was used which actually contains carbon, manganese, chromium, silicon, molybdenum, vanadium, copper, and nickel This paper has been studied the effect of three input factors: carbon equivalent in percents, time in minutes and the ratio of oxygen/gas on quality of the product. The experiment was done by 23 factor plan and 5 center point, 6 pivotal points and 95% confidence level. After examination of the factors and the recognition of the effective factors, according to application of response surface methodology, the relationship between the related variables of the effective input factors and the response surface variable is determined using regression model. Finally, the optimum value of each variable in the regression models is obtained by goal programming method.