Automatic welding method for sealing welding with embedded ring

Abstract

The invention relates to the technical field of welding methods for groove butting sealing welding of nuclear reactor components, and discloses an automatic welding method for sealing welding with anembedded ring. The automatic welding method comprises the following steps that (1) welding grooves of two butting workpieces are machined, and each of the grooves is in a V shape, and provided with atruncated edge and a root gap; (2) the embedded ring is machined, tilt air flow channels are evenly distributed in the outer diameter of the embedded ring in the circumferential direction, the sectionof the embedded ring is in a V shape, and the included angle of the V shape is 56 degrees + / - 0.5 degree; (3) the two butting workpieces and the embedded ring are contained in a welding machine, positioning is conducted on the grooves of the butting workpieces, and the embedded ring is embedded into the grooves and centering is conducted; (4) the positioned grooves and the embedded ring are subjected to multipass welding through a pulse tungsten electriode argon arc welding method; and (5) after each pass welding is completed, welding passes are cleaned. By adopting the automatic welding method, the stability and the reliability of a sealed weld joint are improved greatly, and good guarantees are provided for the designable service life of an existing machine unit in our country.

Description

technical field [0001] The invention relates to the technical field of a groove butt butt seal welding method for nuclear reactor components, in particular to an automatic sealing welding method with an embedded ring. Background technique [0002] The existing groove butt welding mainly includes manual argon arc welding and automatic argon arc welding, and the filling materials include welding wire and embedded ring. Defects such as incomplete fusion at the root, incomplete penetration, and poor surface formation are common. [0003] In nuclear power plant projects, the quality requirements of butt welding are very high. If defects occur, leakage or failure will occur during the movement of the nuclear power plant. lead to serious safety accidents. [0004] The sealing seam of the control rod driving mechanism is welded by the sealing shell assembly and the stroke sleeve assembly. After the two assemblies are screwed together, they are sealed by the sealing seam. The part...

AI Technical Summary

Problems solved by technology

However, the back of the sealing weld of the control rod drive mechanism is an annular cavity. It is very difficult to add gas protection on the back under the premise that the specific shell cannot be damaged.

If the method of filling the groove gap with argon gas for a period of time to fill the entire sealing shell assembly and then inserting the embedded ring for welding will not only waste most of the inert gas, but also the protection state of the back of the weld cannot be guaranteed

Ordinary manual argon arc welding is a waste of inert gas, low in efficiency, and difficult to guarantee the shape

The current automatic welding process for fitting embedded rings often has problems such as incomplete fusion, incomplete penetration, undercut, poor weld surface shape, incomplete penetration at the arc, serious oxidation on the front and back sides, and stress concentration caused by excessive reinforcement on the back side. series of questions

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