A laser welding method for nuclear main pump shielding sleeve

Abstract

The invention discloses a laser wire-filling welding method for a nuclear main pump shield sleeve, and belongs to the field of nuclear power. A laser wire-filling welding system performs pulse laser wire-filling welding on the shield sleeve; a thin plate is precisely cut, wound and clamped on a special welding tool, wherein a connection gap is enabled to be 0 to 0.55 mm; a front-mounting wire feeding mode is selected to accurately adjust a welding wire feeding position, wherein a certain welding wire height and filament distance are kept; optimized welding process parameters are selected, to realize laser wire-filling welding for longitudinal joints of the nuclear main pump shield sleeve by controlling accurate and automatic continuous movement of a pulse laser welding head and a wire feeding nozzle. The laser wire-filling welding method can guarantee small welding deformation of the shield sleeve and high diameter size precision, and furthermore, crystalline grains in welding lines are obviously thinned, and the influence on the physical and mechanical properties of a material is low; in the welding process, by the adding of a welding wire, the accuracy requirement on thin plate cutting is reduced, and the welding line has certain sine and cosine heights; therefore, the strength of the welding line is enhanced, and the service life of the shield sleeve is prolonged.

Description

technical field [0001] The invention belongs to the field of nuclear power, and relates to a laser wire-filling welding method for a nuclear main pump shielding sleeve. Background technique [0002] At present, nuclear power, hydropower and thermal power constitute the three pillars of the world's energy and occupy an important position in the world's energy structure. Among the main equipment of the reactor coolant system of a nuclear power plant, the nuclear main pump is the only rotating part in the primary circuit system. Its reliability directly affects the safe operation of the nuclear reactor. It belongs to the nuclear safety first-level equipment and is called the "heart" of the nuclear power plant. . In order to completely isolate the stator winding and rotor of the nuclear main pump from the cooling medium of the primary circulation system, two shielding sleeves for the stator and the rotor are provided. Among them, the precision manufacturing of the shielding sl...

AI Technical Summary

Problems solved by technology

[0008] (1) The heat input of argon tungsten arc welding is larger, the weld size is wider, the heat-affected zone of the joint is larger, and the grain size of the joint is larger. Compared with the base metal, the performance of the joint is significantly reduced and the reliability is reduced

[0009] (2) Laser self-fluxing welding is affected by the diameter of the spot, and requires high precision in clamping the plate. Therefore, the requirements for cutting and grinding precision in the early stage of the weld are high, which increases the processing cost

[0010] (3) The gap tolerance of laser self-fluxing welding is poor, and the pre-processing accuracy and equipment accuracy of the weld seam can easily lead to poor weld formation and greatly reduce the mechanical properties of the welded joint

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