Studies on Effects of Welding Parameters on the Mechanical Properties of Welded Low-Carbon Steel

M. A. Bodude^1*, I. Momohjimoh²

¹Department of Metallurgical and Materials Engineering, University of Lagos, Lagos, Nigeria.
²Department of Metallurgical Engineering, Yaba College of Technology, Lagos, Nigeria.

DOI: 10.4236/jmmce.2015.33017                

Abstract

In this work, the effect of heat input on the mechanical properties of low-carbon steel was studied using two welding processes: Oxy-Acetylene Welding (OAW) and Shielded Metal Arc Welding (SMAW). Two different edge preparations on a specific size, 10-mm thick low-carbon steel, with the following welding parameters: dual welding voltage of 100 V and 220 V, various welding currents at 100, 120, and 150 Amperes and different mild steel electrode gauges of 10 and 12 were investigated. The tensile strength, hardness and impact strength of the welded joint were carried out and it was discovered that the tensile strength and hardness reduce with the increase in heat input into the weld. However, the impact strength of the weldment increases with the increase in heat input. Besides it was also discovered that V-grooved edge preparation has better mechanical properties as compared with straight edge preparation under the same conditions. Microstructural examinations conducted revealed that the cooling rate in different media has significant effect on the microstructure of the weldment. Pearlite and ferrite were observed in the microstructure, but the proportion of ferrite to pearlite varied under different conditions.

Keywords

Low Carbon Steel, Shielded Metal Arc Welding (SMAW), Oxy-Acetylene Welding (OAW), Heat Affected Zone (HAZ)

Conflicts of Interest

The authors declare no conflicts of interest.

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