Application of Response Surface Methodology in the Optimization of Thermal Diffusivity of Low Carbon Steel Weldment during Gas Tungsten Arc Welding

Authors: Ajato V, Achebo JI, Obahiagbon KO

DOI Info: N/A

ABSTRACT

The characteristics of thermal properties of materials during welding is important, thus the need to optimize them. One of such thermal properties investigated in this study is thermal diffusivity. The thermal diffusivity of low carbon steel weldment was optimized using statistically designed experiments under the following conditions: current (150-180 A), voltage (20-23 V), and gas flowrate (10-13 L/min). A second order statistical model was developed and validated to predict the thermal diffusivity while response surface methodology (RSM) was utilized for optimizing same. Analysis of variance (ANOVA) results showed that the model was statistically significant (p<0.05), did not show lack of fit and was able to predict thermal diffusivity with a high level of accuracy (R²=0.9546). Thermal diffusivity was significantly influenced by all three factors (p<0.05); although current had overall antagonistic effect while voltage and gas flowrate had a positive effect. Optimization results revealed that the optimum thermal diffusivity was 1.61×10^-5 (m²/s) while the optimum current, voltage and gas flowrate were 150.27 A, 23 V and 10 L/min respectively. Validation of the model indicated no significant difference between experimental observations and model prediction.

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