Optimization of Micro-Alloying Elements for Mechanical Properties in Normalized Cast Steel Using Taguchi Technique

Abstract

In this study, Taguchi method is used to find out the effect of micro alloying elements like vanadium, niobium and titanium on the hardness and tensile strength of the normalized cast steel. Based on this method, plan of experiments were made by using orthogonal arrays to acquire the data on hardness and tensile strength. The signal to noise ratio and analysis of variance (ANOVA) are used to investigate the effect of these micro alloying elements on these two mechanical properties of the micro alloyed normalized cast steel. The results indicated that in the micro alloyed normalized cast steel both these properties increases when compared to non-micro-alloyed normalized cast steel. The effect of niobium addition was found to be significantly higher to obtain higher hardness and tensile strength when compared to other micro alloying elements. The maximum hardness of 200HV and the maximum tensile strength of 780 N/mm 2 were obtained in 0.05%Nb addition micro alloyed normalized cast steel. Micro-alloyed with niobium normalized cast steel have the finest and uniform microstructure and fine pearlite colonies distributed uniformly in the ferrite. The optimum condition to obtain higher hardness and tensile strength were determined. The results were verified with experiments.

Effect of zirconium and niobium on the microstructure and mechanical properties of high-strength low-alloy cast steels

“…Figure 6 shows the EDS spectrum of the MACS 3 sample confirming the presence of ZrC precipitates in the ferritic matrix. The chemical composition obtained for ZrC in the MACS 3 sample is matching with the reported value in the literature [6]. Figure 7 shows the SEM micrograph of MACS 4, which exhibits the presence of NbC in the matrix of ferrite and pearlite.…”

“…The addition of the micro amount of alloying elements like titanium, vanadium, zirconium and niobium plays a key role in strengthening of these steel by precipitation hardening and grain boundary strengthening mechanisms [1][2][3][4][5]. The effect on microstructure and mechanical properties on MAS with combinations of V and Nb content has been studied extensively by many researchers [6][7][8][9]. The main purpose of adding microalloying elements in the steel is to modify the microstructure consisting of a fine fully ferritic grains instead of a ferrite-pearlite matrix [10][11][12][13].…”

improving the process of achieving required microstructure and mechanical properties of 38mnvs6 steel

“…Also, in the context of reduction of cost by production among others forgings made of micro-alloy steel, it is important the fact that when are produced under the right conditions, they do not require normalization. It results from micro additions introduced into steel, which allows creating a homogeneous and fine-grained structure, preventing the growth of recrystallized austenite grains [15]. However, if the need arises to the normalization of micro-alloy steel, which the aim is creating required microstructure and mechanical properties of steel, it anyway this process is less expensive than normalization of the alloy steel [16].…”

Archives of Foundry Engineering

“…A ferriticpearlitic microstructure with the predominant content of plastic ferrite is responsible for this combination of mechanical properties [1,2]. At the same time, these properties can be changed by increasing the Mn content to about 1.8% (solution strengthening) or by introducing micro-additives, such as V, Nb or Ti (structure refinement and strengthening with fine-dispersed particles of carbides and carbonitrides) [2][3][4][5][6][7][8][9].…”