Bismuth-free stainless steel flux cored wire gas shielded welding technology for connecting pipes

Abstract

The invention discloses a bismuth-free stainless steel flux cored wire gas shielded welding technology for connecting pipes. According to the technology, a welding manipulator is transformed, a connecting plate provided with a T-shaped groove is fixed at one end of a cross beam of the welding manipulator, a transition frame provided with a slide rail is clamped through the T-shaped groove, a mechanical arm swing mechanism is installed on the slide rail, a cross arm beam is mounted at the bottom of the mechanical arm swing mechanism, an extension arm is fixed at the bottom of the cross arm beam, the bottom of the extension arm is connected with a fastener, a welding torch locking block is installed on the fastener, and a welding torch is placed in the welding torch locking block. By means of the welding device, parameters such as welding currents, voltages, welding wire extension and weld bead lifting capacity are matched, the bismuth-free stainless steel flux cored wire gas shielded welding technology capable of performing stable welding is developed and applicable to circumferential bismuth-free stainless steel flux cored wire gas shielded build up welding and butt welding of regular connecting pipes, the welding process is stable, formed welding seams are attractive in appearance, and the productivity is improved by 6-7 times than that of A-GTAW.

Description

technical field [0001] The invention relates to a circumferential welding process for a connecting pipe, in particular to gas-shielded welding of the inner surface, outer surface, end face, rounded corner, inner ring seam, outer ring seam, etc. of a regular shaped pipe in the ring direction without bismuth-free stainless steel flux cored welding wire. Background technique [0002] The lower head of the AP1000 steam generator is equipped with an inlet connection, an outlet connection, a manhole and a PRHR connection, and the size of the connection is from Φ 内 296~Φ 内 836.7 varies. The inner surface of these connecting pipes and the rounded corners where the inner surface of the connecting pipe intersects with the arc surface of the head require surfacing welding of austenitic stainless steel to meet the corrosion resistance requirements during the operation of the equipment. [0003] For the welding of the surfacing layer on the inner surface of such pipes, the same industr...

AI Technical Summary

Problems solved by technology

[0005] However, the AP1000 steam generator design document stipulates that the stainless steel flux-cored wire used is Bi%≤0.002, and there are special restrictions on the flux composition of the flux-cored wire

Due to the limitation of the composition of the flux-cored wire, it is difficult to guarantee the manufacturability of this welding material during welding

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