Method of welding steel parts with at least one piece being a duplex steel ; Vessel including steel parts with at least one being a duplex steel

摘要

The process comprises moving a metal inert gas type welding head (51) comprising welding wire along edges (21.1, 31.1) of duplex stainless steel parts (21, 31) by a motor device, advancing an end part of the welding wire to the edges at a predetermined speed of 4.5 mm/s, advancing a terminal part (7) of the welding wire to the edges along a direction of advancement, which is perpendicular to the direction in which a recess is measured, and aligning welding cords by crushing of edges. The edges: define a set; and have dimension of greater than 6 m and chamfers. The process comprises moving a metal inert gas type welding head (51) comprising welding wire along edges (21.1, 31.1) of duplex stainless steel parts (21, 31) by a motor device, advancing an end part of the welding wire to the edges at a predetermined speed of 4.5 mm/s, advancing a terminal part (7) of the welding wire to the edges along a direction of advancement, which is perpendicular to the direction in which a recess is measured, and aligning welding cords by crushing of edges. The edges: define a set; have dimension of greater than 6 m and chamfers, which are flared towards an outer surface of the stainless steel parts; and are formed by circular ribs. The inclined chamfer forms an angle of -20[deg] with the direction of advancement. The end part is horizontal, and an upper edge is located above the end part and a lower edge is located below the terminal part. An inner end of the chamfer is located opposite to an inner end of the other chamfer. The motor device moves the welding head around an axis of revolution. An intensity of current forming electric arc is 175 A, and a voltage forming the electric arc is 25 V. The flow of an inert gas projected on the terminal part is 20-NL/min. An operator is boarded on the motor device to supervise the welding operations. An independent claim is included for a tank comprising welded duplex stainless steel parts.