Observation of Microstructure and Mechanical Properties in Heat Affected Zone of As-Welded Carbon Steel by Using Plasma MIG Welding Process

Sarizam Mamat,Manabu Tanaka,Teo Pao Ter,Nur Azmina Sidek,Shinichi Tashiro,Toshifumi Yuji,Rose Alifah Ellyana Roslan,Nur Aina Aqilah Mohd Afandi

doi:10.3390/met12020315

Sarizam Mamat, Manabu Tanaka + Show 6 more

Open Access

https://doi.org/10.3390/met12020315

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Abstract

Plasma MIG welding is a hybrid welding process that combines two welding methods of conventional metal inert gas (MIG) welding with plasma arc welding. This study investigates the effect of plasma and plasma current values on the microstructure and microhardness properties of welded carbon steel plates. It was found that utilization of the plasma has resulted in a refined microstructure in the heat affected zones (HAZ), and a decrease in microhardness values as compared to conventional MIG welds. This potentially increases the ductility of the plasma MIG weldments. Furthermore, decreasing the plasma currents would result in the decrease of microhardness and grain sizes, thus further increasing the ductility of the welds.

Highlights

Gas metal arc welding (GMA), known as metal inert gas (MIG) welding, is a common method for joining various metals, such as carbon steel, aluminum and stainless steel
Further studied on microstructure characteristics of the welded steel by using laser—MIG hybrid welding found that the laser zone affects the microstructure grain size to be finer and narrower heat affected zone (HAZ) compared to the GMA arc zone due to the difference of temperature gradient [4]
It was seen that the plasma current influences the width of the HAZ

Summary

Introduction

Gas metal arc welding (GMA), known as metal inert gas (MIG) welding, is a common method for joining various metals, such as carbon steel, aluminum and stainless steel. It is a highly reliable and cost-effective technique, with high speeds and productivity [1]. The unstable arc of the MIG process causes low weld penetration and high spatter generation [2] To overcome this limitation, several hybrid methods have been developed to enhance the MIG process. The report showed that the hybridization increased the melting energy up to 23% compared to the individual welding process [3]. The above aforementioned hybridization of welding processes was developed individually and combined to contemplate the advantages of each process

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Conclusion