Automatic welding process of skewed tube fillet of boiler separator

Abstract

The invention relates to a submerged arc welding technology of an eccentric oblique crossing tube on a separator, which is characterized in that the technology of the invention includes the steps that one end of the separator is placed on a driven turning roll while the other end of the separator is clamped by a numerical control positioner; the processed eccentric oblique crossing tube and the separator are fixed at melting points; a welding device is moved to the welding part of the eccentric oblique crossing tube on the separator; a welding gun of the welding device is aligned with the position to be welded and the welding device is started so that the numerical control positioner rotates the separator; the synchronous displacement of the welding device coordinates with the synchronous interlinking of the welding gun of the welding device and the numerical control positioner, which leads to that the position to be welded of the eccentric oblique crossing tube is always at the horizontal position required by the submerged arc welding technology so as to realize the continuous automatic welding. The submerged arc welding technology of the invention has the advantages of significantly enhancing the productivity and welding quality, reducing the labor intensity and improving the working conditions.

Description

technical field [0001] The invention relates to an automatic welding process for angled pipe fillet welds of boiler separators, and belongs to the technical field of automatic welding process for eccentric oblique pipe fillet welds on separators of power station boilers. Background technique [0002] With the development of power plant units in the direction of large capacity and high parameters, power plant units have transitioned from subcritical units to supercritical and ultra-supercritical units. In supercritical and ultra-supercritical unit boilers, there is no drum in ordinary boilers, but replaced by steam-water separators. Therefore, the separator has become a very important component in today's power plant boiler products, and the welding quality of the steam-water separator has always been highly valued by manufacturers and users. At present, the circular seam of the separator can be automatically welded, and its welding quality can be reliably guaranteed. Weldi...

AI Technical Summary

Problems solved by technology

[0004] 1. The intersecting line between the eccentric oblique transfer pipe and the main pipe of the separator is an asymmetrical space saddle-shaped curve. During welding, since the welding position is continuously alternated and the slope is relatively large, the flux will And the molten pool is easy to lose, resulting in defects such as undercut during upslope welding and infusion during downslope welding. The weld formation is seriously deteriorated, which directly affects the welding quality, and thus becomes a difficult process problem in automatic submerged arc welding;

[0005] 2. Due to the dimensional tolerance of the workpiece itself, the processing and assembly errors of the pipe end, and the thermal deformation during the welding process, the trajectory of the welding torch calculated according to the mathematical model will not match the actual welding shape line during welding, so that Weld deviation occurs;

[0006] 3. The single V-shaped mount-type variable-angle groove has non-equal cross-sections of the welds in one week, that is, the cladding volumes of different parts of the welds in one week are not equal, which increases the difficulty of automatic welding bead

However, due to the characteristics of welding itself, such as strong electric field, strong magnetic field, irregular weld seam, poor repeatability and dimensional accuracy, the movement of the welding torch cannot be completely operated according to the mathematical model like the cutting torch, and must be in accordance with the actual welding position. Real-time correction; in addition, the automatic welding bead arrangement of multi-layer variable cross-section further increases the difficulty of control

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