Shell circumferential-seam welding method using plasma welding

Abstract

The invention discloses a method for welding circular seams of a vessel by plasma welding. A laser head (18) for aiming at a weld bead is arranged on a plasma welder head, an upper large protective cover (19) is arranged on the front side of a welding seam, and a lower large protective cover (4) is arranged on the back side of the welding seam, wherein the upper large protective cover is arranged on a plasma welding torch at the front side of the weld bead, and the lower large protective cover is arranged on a tool capable of automatically aiming at the welding position in vessel cylinder; and the welding seam adopts a novel Y-shaped groove beveled edge to finish the welding for the circular welding seam of the vessel cylinder automatically and continuously. The method is applied to the welding the circular welding seam of the vessel cylinder made of zirconium, nickel, titanium, stainless steel and alloys, and composite plate materials, and has the remarkable advantages of good welding quality, high welding efficiency, and protective gas conservation, and the reduction of the labor intensity of operators.

Description

technical field [0001] The invention relates to a plasma welding method for welding the circular seam of a container cylinder, which is mainly used for welding the circular seam of the container cylinder and belongs to the field of metal container manufacturing. Background technique [0002] The plasma welding system uses the compressed arc between the electrode and the workpiece (transferred arc), the compressed arc between the electrode and the nozzle (non-transferred arc), or both arcs to heat the metal at the same time, so that the two metals are combined. [0003] Plasma welding is characterized by concentrated energy, high temperature, and fast welding speed; the arc is straight and stable, and can weld thinner and thinner workpieces; the change of arc length has little effect on the shape of the weld; the arc does not touch the workpiece, There is no risk of tungsten inclusion in the weld seam; the welding heat input is small and the welding quality is high. [0004]...

AI Technical Summary

Problems solved by technology

[0014] However, the traditional "Y" groove, because the height of the blunt edge is not easy to measure accurately during the processing process, will cause the height of the blunt edge to exceed the standard in some places. Even if the height of the blunt edge does not exceed the standard, the cylinder will produce longitudinal Movement, generally people think that the plasma arc is very narrow and has no width, but in fact the plasma arc has a certain width, so the material on the non-blunt edge groove will be melted during the welding process, resulting in an increase in welding thickness

Therefore, once the cylinder moves and the welding torch cannot follow the movement in time, the arc column will deviate from the weld bead, thereby increasing the welding thickness, causing defects such as incomplete penetration and pores, and even interrupting the welding process.

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