Mechanical Properties of Hyperbaric Gas Metal Arc Welds in x65 Pipeline Steel

In the present investigation, hyperbaric welding has been simulated by laboratory welding in a pressure chamber as part of the development programme for fully remote controlled GMA welding. The welding trials of x 65 pipeline steel were carried out at pressures of 12, 25 and 35 bar, using one metal cored tubular low-alloy steel and one solid Inconel 625 wire. All welds were characterized by macrographs, hardness measurements, and tensile and impact testing, in addition to metallurgical inspection through light microscopy and microprobe analysis. It is demonstrated that both welding wires can be used to provide high-quality welds under the prevailing conditions, satisfying current requirements set to hyperbaric welding.