Gas shield arc welding method and method for manufacturing steel pipe
AssigneeKabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
InventorTakashi Yashima
Life of this patent
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Abstract
A gas shield arc welding method that reduces the number of joints, which are the sites where defects occur more readily, and that enables automatic welding with a welding robot. A gas shield arc welding method in which a steel pipe Wo is welded by multi-pass welding with a steel frame erection adjusting tool attached to an erection piece on the steel pipe Wo to immobilize an open end section of the steel pipe. An initial single or several layers are welded to the open end section, after welding, the steel frame erection adjusting tool is removed; and remaining layers are welded with a welding robot such that two bead joints are formed at no more than two sites.
Claims12
A gas shield arc welding method for welding a steel pipe by multi-pass welding, comprising:
- attaching a steel frame erection adjusting tool to an erection piece provided on the steel pipe, such that a groove of the steel pipe is fixed;
- welding up the groove, by semiautomatic welding or manual welding, to an initial single layer or several layers;
- removing the steel frame erection adjusting tool after the welding up of the groove is finished;
- welding remaining layers by a single piece of a welding robot such that bead joints are formed at two sites or less, wherein the welding the remaining layers includes, at the bead joints, in a first layer of the remaining layers, setting a weld start point to any position, setting a weld end point to a position exceeding the weld start point, and setting an overlapping portion of a weld bead from the weld start point to the weld end point to 10 to 20 mm;
- and
- welding next and subsequent layers, including setting a circle, the circle having a radius of 0 to 5 mm and a weld end point of a previous layer as a center of the circle, as a weld start point of a next layer, setting a weld end point to a position exceeding the weld start point, and setting an overlapping portion of a weld bead from the weld start point to the weld end point to 10 to 20 mm.
A gas shield arc welding method for welding a steel pipe by multi-pass welding, comprising:
- attaching a steel frame erection adjusting tool to an erection piece provided on the steel pipe, such that a groove of the steel pipe is fixed;
- welding up the groove, by semiautomatic welding or manual welding, to an initial single layer or several layers;
- removing the steel frame erection adjusting tool after the welding up of the groove is finished;
- and
- welding remaining layers by at least one welding robot such that bead joints are formed at two sites or less,
- wherein the at least one robot includes a plurality of welding robots,
- wherein the remaining layers are welded by the plurality of welding robots,
- wherein the welding the remaining layers includes, at the bead joints, in a first layer of the remaining layers, for each of the plurality of welding robots, setting a weld start point to any position, setting a weld end point of one of the plurality of welding robots to a position exceeding a weld start point of an adjacent another one of the plurality of welding robots, and setting an overlapping portion of a weld bead from the weld start point to the weld end point to 10 to 20 mm, and
- wherein the method further comprises welding next and subsequent layers, for each of the plurality of welding robots, including setting a circle, the circle having a radius of 0 to 5 mm and a weld end point of a previous layer as a center of the circle, as a weld start point of a next layer, setting a weld end point of one of the plurality of welding robots to a position exceeding a weld start point of an adjacent another one of the plurality of welding robots, and setting an overlapping portion of a weld bead from the weld start point to the weld end point to 10 to 20 mm.
Dependencies are inferred from the claim text.