Effects on S690QL high strength steel and thermal conductivity

The hardness, corrosion resistance and thermal conductivity of Metal Inert Gas (MIG) welded S690QL at various parameters are investigated in this study. The structural steel S690QL is used in ship building, high rise building, bridges, off-shore structures etc where the hard impact and explosion are possible. The specimens of 50mm X 50mm X 5mm thick are extracted from long plate. The parameters considered to perform the MIG welding are Voltage (20V, 21V, 22V and 24V), current (100A, 105A, 110A and 115A), Welding speed (18 m/min, 19m/min, 20m/min and 21m/min). The Vickers hardness test results shows that the maximum reduction of 4.98% in hardness of the welded plate as compared to non-welded sample. The electro-chemical corrosion test is performed to study the corrosion resistance and it is observed that the maximum corrosion resistance is increased of 0.9% in corrosion resistance as compared to non-welded sample. The Thermal conductivity test is performed to study the thermal conductivity and is observed that the maximum thermal conductivity is decreased to 3.2% in thermal conductivity compared to non-welded sample .Finally the test results says that hardness and thermal conductivity decreases by 4.98% and 3.2% and corrosion resistance increase by 0.9% after welding.