Effect of Welding Parameters on Mechanical Properties of Low Carbon Steel API 5L Shielded Metal Arc Welds

摘要

The main objective of this research is to study the mechanical properties of welding results on API 5L low carbon steel through SMAW welding. The welding variable used consists of various types of welding electrodes and variations in the amount of current. The types of welding electrodes are E6010, E7016 and E7018 and the welding current given is 90A and 100A. Welding samples were cut and machined to standard configurations for tensile strength, impact, hardness tests and SEM for microstructure test. The results shows that there are significant effects of welding variables (type of electrodes and current given) the tensile strength, impact and hardness on the welding metal. The result shows that for all types of electrodes when the amount of current given increase then the mechanical properties such as tensile strength, impact and hardness decrease. The optimum tensile strength for welding metal is produced by the welding electrode E7016 at 90A with 617.155 MPa while the lowest value is 505.215 MPa for E6013 at 100A, the optimum of hardness is produced by E7018 at welding current of 90A with 194.40 VH while the lowest is 170.60 VH for E6013 at 100A and impact 1.915 J/mm~(2) by E 7018 at 90A while the lowest 0.728 J/mm~(2) for E6013 at 100A. Observation microstructure by SEM shows several phases namely Acicular Ferrite (AF), Grain Boundary Ferrite (GBF) and Bainite.