Flux-cored welding wire for overlaying welding and application thereof

Abstract

Aiming at the disadvantages and market demands of the prior art, the invention discloses a flux-cored welding wire for overlaying welding, which consists of a low-carbon steel strip and a flux core; the weight percentage composition of the flux core comprises: 1 to 3 percent of Mo, 2 to 6 percent of B, 1 to 4 percent of Si, 1 to 4 percent of Mn, 0.5 to 4 percent of C, 3 to 7 percent of Nb, 10 to 40 percent of Cr, 1 to 4 percent of Re and the balance of Fe. The filling amount of the flux core is 30 percent of the total weight of the flux-cored welding wire. The flux-cored welding wire for overlaying welding can be used for the overlaying welding of a wearproof belt of a drill rod of an oil field. Compared with the prior art, the flux-cored welding wire has excellent welding manufacturability, small splashing, good compatibility and good repeated overlaying weldability; and as the wearing resistance and antifriction performance of the wearproof belt of the welded drill rod are improved, the hardness of the wearproof belt reaches HRC 59-61.

Description

technical field [0001] The invention relates to a flux-cored welding wire for surfacing welding and its application, in particular to a flux-cored welding wire used for surfacing welding of drill pipes in oil fields. Background technique [0002] During the drilling process, the wear of the drill string and casing has always been a problem that affects the production and development of the oilfield. The wear of the drill string can reduce the service life of the drill string, and seriously cause the failure of the drill string, resulting in serious economic losses and waste of resources; Pipe wear will reduce the anti-collapse and internal pressure strength of the casing string in the slightest, affecting the quality and safety of subsequent drilling, completion, and production operations; scrapped. Therefore, the existing technology uses oilfield drill pipe hardbanding technology to protect the drill string and casing string, but the drill pipe hardbanding used in the mark...

AI Technical Summary

Problems solved by technology

[0003] 1) Tungsten carbide wear-resistant belt: high hardness, good wear resistance, but poor anti-friction performance, which will cause serious wear to the casing, and is brittle, easy to fall off, affecting drilling operations;

[0004] 2) Imported drill pipe wear-resistant belt: Some have better anti-friction performance, but poor wear-resistant performance. It was found in the oil field that a well has not been drilled, but the wear-resistant belt has been polished. Subsequent drilling, It is that the drill pipe joint and the casing or the formation are worn, and the wear is very serious. Some of the latest products have improved wear resistance and anti-friction performance, but the price is very expensive and unacceptable to users;

[0005] 3) Other wear-resistant belt products used in the market or the wear-resistant performance and anti-friction performance are difficult to obtain a reasonable balance, or the welding process performance is not ideal, or the compatibility with other types of wear-resistant belt is poor, and the application is limited, etc.