Mechanical characterization of quenched hardened chromoly steel using taguchi coupled WASPAS method

Abstract Heat treatment, in conjunction with quenching, is used to improve the mechanical characteristics of oil hardened steel. In order to get the greatest yield strength, hardness, and ultimate tensile strength, among other things, a variety of control parameters must be tweaked in order to achieve the optimum outcomes. One of the objectives of this study is to improve the process of improving the mechanical properties of AISI 4140 Chromoly steel by varying key parameters such as the quenchant used, the soaking time, and the heat treatment temperature. After using the Taguchi method for the purpose of experimental design, three output responses were produced, namely the yield strength, the hardness, and the ultimate tensile strength of the material. To determine the most optimum parameters for heat treatment and quenching, the Weighted Aggregated Sum Product Assessment method (WASPAS) was used. In this study, it was discovered that the hardness of the material is dependent on the heating temperature, with greater hardness being obtained at the highest possible heating temperature. A similar relationship exists between material strength and soaking time, with the greatest amount of soaking time leading to greater material strength. When comparing the mechanical properties of the three quenchants, new engine oil performed much better than coconut oil and old engine oil. It is clear that both the WASPAS method and the Taguchi-WASPAS method approach are very effective, as shown by the close agreement between the anticipated and experimental results. The ANOVA results revealed that among all of the factors considered for maximisation of mechanical characteristics in heat treated and quenched Chromoly steel specimens, temperature was the most significant and influencing factor, followed by soaking time as the second most significant parameter, and quenchant as the least significant variable. The relevance and effectiveness of both optimization approaches were also shown by a confirmatory test, which was conducted.