Effect of Process Parameters on the Shielded Metal Arc Welding of HY100 High Strength Low Alloy Steel

Abstract

This study investigated the effect of process parameters on the mechanical and microstructure properties of welded HY100 HSLA steel using shielded metal arc welding. The study revealed the influence of heat on a welded joint at constant voltage of 30 volts. It was observed that heat input of 1.22 kJ/mm produced high ultimate tensile strength of 300 MPa when E7018 electrode was used. When the heat input was 2.12 kJ/mm, the lowest ultimate tensile strength (UTS) of 265 MPa was observed, which show that high UTS is achieved at a lower heat input. In the case of yield strength of the welded joint, lower heat input of 1.22 kJ/mm produced the highest yield strength of 316 MPa using E7018 electrode. The lowest yield strength of 133 kJ/mm was achieved at heat input of 0.88kJ/mm using E6013 electrode. While higher hardness of 236.3 BHN was achieved at heat input of 1.22 kJ/mm using E6013 electrode thereby indicating that E6013 electrode induces better hardness at welded joint. The microstructure study revealed that the variations in the microstructure of the various welded zones occurred as a result of different heat inputs.