Abstract—Lightweight trend leads to new trend of welding in which optimizing tubes or pipes thicknesses due to its respective workloads. Thinner tube can be used in parts with low working loads and thicker tube for high working loads parts. In order to obtain a good weld, controlling the process parameters such as welding current and welding speed become very crucial as it significantly influences the mechanical properties. Thus, the purpose of this study is to investigate the process-properties relationship of welded mild steel tube of dissimilar thickness by using Metal Inert Gas (MIG) orbital welding. The effects of weld current and jig rotational speed to the tensile properties of welded mild steel tubes were studied. MIG welding was used to weld 26.70 mm diameter of mild steel tubes, which has dissimilar inner diameter of 2.87 mm and 3.90 mm, respectively. The mechanical properties were tested using Universal Tensile Machine (UTM) Instron 8802 model. Design of Experiment (DoE) was used to design the experiment as well as to analyze the data. It was found out that, tensile properties of welded tubes increase with increasing of welding current between 60 and 80 A. On the other hand, increasing in jig rotational speed between 40 and 50 rpm decreases the tensile properties of the welded tubes. Empirical mathematical model was generated and verified.
Index Terms—Mild steel, orbital welding, metal inert gas welding, tensile strength and empirical mathematical modeling.
N. I. S. Hussein and M. N. Ayof are with the Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka (UTeM), 76100 Durian Tunggal, Malacca, Malaysia (e-mail: izan@utem.edu.my, nizam@utem.edu.my).
S. Nordin was with the Faculty of Manufacturing Engineering, UTeM, Malacca, Malaysia (e-mail: safuranordin@gmail.com).
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Cite: N. I. S. Hussein, M. N. Ayof, and S. Nordin, "Tensile Strength of Orbital Welded Mild Steel Tubes with Dissimilar Thickness," International Journal of Materials, Mechanics and Manufacturing vol. 4, no. 1, pp. 56-59, 2016.
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