Investigation of The Effect of HAZ Width on Weld Metal Electrical Properties in Arc Welded Joints

Abstract

This study was carried out in order to fill the gap in the literature and to increase the usability of welded joints as electrical connectors. For this purpose, shielded electrode metal arc welding and gas metal arc welding methods, which are frequently used in the industry, were used. In addition to mechanical tests such as microstruc-ture, tensile and hardness of the joints made at different heat inputs, electrical con-ductivity tests were also performed and the results were evaluated together. According to the results obtained, electrical conductivity is lower in arc welding joint with shielded electrode, in other words, the weld metal has reduced conductivity. In the gas arc welding, the electrical conductivity five times more than in the electrode welding. In MAG welding, at the highest heat input 0.78 kJ/mm, 186.33 HV hardness was measured, while 191.33 HV hardness was measured at 0.60 kJ/mm, the lowest heat input. While 386.5 MPa tensile strength was obtained at 0.78 kJ/mm, 377 MPa tensile strength was measured at 0.60 kJ/mm heat input. In SMAW, 163 HV hardness was obtained at the highest heat input as 1.47 kJ/mm, while the tensile strength of the weld metal was measured as 343.5 MPa and the elec-trical resistance was measured as 21.5 Ohm. The electrical resistance was measured as 11.86 Ohm, with a 384 MPa tensile strength and a 174 HV hardness at the lowest heat input 1.17 kJ/mm. It was determined that as the weld metal hardness increased, the electrical conductivity decreased. The relation between the test findings and their interpretation are detailed in the study.