A Welding Process of Fixed Guide Vane with No Welding Groove Structure at Water Edge

Abstract

The invention provides a fixed guide vane without welding groove structures at water inlet and outlet edges and an assembling and welding process. Welding grooves are not machined in the two ends of both the water inlet edge and the water outlet edge of the fixed guide vane; a U-shaped groove is machined in the middle area, except for the water inlet edge and the water outlet edge, of the fixed guide vane; and the middle groove section of the fixed guide vane is in gradually varied smooth transition with the planes of the two ends of the water inlet and outlet edges in the form of a turning tool circle R. When the fixed guide vane and a seat ring board are assembled, a welding shrinkage allowance is not additionally reserved; after the fixed guide vane and the seat ring board are assembled, the end part platform area of the fixed guide vane and the seat ring board are fixed through corner welding; during welding, a groove welding seam at the middle part of the fixed guide vane is welded first; after the welding is finished, welding grooves are gouged in platforms at the two ends of the fixed guide vane through carbon arc air gouging; and finally, welding seams at the end parts of both the water inlet edge and the water outlet edge of the fixed guide vane are welded. According to the fixed guide vane without the welding groove structures at the water inlet and outlet edges and the assembling and welding process, the dimensional tolerance of an opening of a seat ring after the welding can be accurately controlled, and the manufacturing quality of the seat ring product can beimproved.

Description

technical field [0001] The invention relates to a welding process for fixed guide vanes with no welding groove structure at the water inlet and outlet. Background technique [0002] The opening size tolerance of the seat ring of the pumped storage unit after welding is very strict. Generally, the half-opening tolerance is only ±2mm. Measures such as installing welding support bars and adjusting the welding sequence during the assembly and welding process cannot effectively control the opening size tolerance of the seat ring after welding. , It is often processed in the subsequent sequence by surfacing welding and relief grinding on the overcurrent surface of the seat ring and ring plate, which increases the workload of rework and the manufacturing cycle. [0003] The disadvantages of using traditional technology and welding methods are: [0004] 1) When assembling the fixed guide vane and the ring plate of the seat ring, it is necessary for the craftsman to provide the rese...

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Problems solved by technology

[0005] 2) Since the welds between the seat ring plate and the fixed guide vanes require root cleaning and penetration, and are also affected by the flatness of the seat ring plate itself and the difference in the assembly clearance between the seat ring plate and each fixed guide vane, the seat ring The welding shrinkage at each point of the opening circumference and the deviation of the opening size are relatively large

[0006] 3) When assembling the fixed guide vane and the seat ring plate, it is necessary to install welding support ribs to control the opening size of the seat ring and a large arc-shaped rib plate to prevent the guide vane from twisting and deforming between the inner and outer circles of the seat ring plate, which wastes welding and waste Material

[0007] 4) When assembling the fixed guide vane and the seat ring plate, due to the blunt edge contact between the guide vane and the seat ring plate plane, it is difficult to align the inner and outer circle tangent points with the marking line, and the assembly efficiency is low

[0008] From the above points, it can be seen that with the traditional fixed guide vane welding process, it is not only difficult to accurately give the reserved welding shrinkage, but also a large amount of support tie bars will be wasted in the manufacturing process, and the opening size of the seat ring is deviated after welding Therefore, it is necessary to develop a new fixed guide vane welding process that is easier to install and weld, and more conducive to precise control of the opening size tolerance after seat ring welding

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