Laser-Assisted Gas Metal Arc Welding of 25-mm-Thick HY-80 Plate Toughness properties were evaluated with dynamic tear and explosion bulge testing

ABSTRACT. Laser-assisted gas metal arc welding of HY-80 steel was investigated. The effect of welding parameters was studied and optimum welding conditions were identified. Welding using Lincoln LA-100 wire on 25-mm-thick HY-80 plate with a four-pass technique, a dou-ble 45-deg groove preparation, 9.5 mm deep with no root opening, a heat input of 1.6 kJ/mm and a 50 % Ar-50 % He gas shield produced a predominately martensitic weld metal microstructure. An acicular ferrite weld metal mi-crostructure could not be produced for any set of processing conditions investi-gated. This is believed to be a result of the high levels of dilution. The toughness of the laser-assisted gas metal arc welds was assessed with dynamic tear testing and explosion bulge testing. Toughness was found to be low but highly variable. Op-timum electrode chemistry would proba-bly allow the toughness to be improved