Flux-cored wire for build up welding and preparation method of flux-cored wire

Abstract

The invention discloses a flux-cored wire for build up welding and a preparation method of the flux-cored wire. The flux-cored wire for build up welding comprises a low-carbon steel belt and a flux core. The filling content of the flux core accounts for 30% of the total weight of the flux-cored wire. Powder of the flux core comprises, by weight percent, 1%-3% of Zr, 2%-6% of B, 1%-4% of Si, 1%-4% of Mn, 0.5%-4% of C, 3%-7% of Nb, 10%-40% of Cr, 1%-4% of Re and the balance Fe. The flux-cored wire for build up welding is prepared through pelleting, powder preparing, powder mixing, low-carbon steel belt clearing, roll forming and wire drawing forming. The flux-cored wire is good in welding manufacturability, small in splashing and good in compatibility and repeated build up welding performance. The wear resistance and friction reduction performance of a drill rod wear-resisting belt obtained through build up welding of the flux-cored wire are improved, the hardness of the wear-resisting belt is HRC59-61, and the flux-cored wire can be used for build up welding of the drill rod wear-resisting belt in an oil field.

Description

technical field [0001] The invention relates to the field of wear-resistant banding of oilfield drill pipes, in particular to a flux-cored welding wire used for surfacing welding of oilfield drill pipes with wear-resistant bands and a preparation method thereof. Background technique [0002] During the drilling process, the wear of the drill string and casing always affects the production and development of oilfields. The wear of the drill string will reduce the service life of the drill string in the slightest, and cause the failure of the drill string in the worst case, resulting in serious economic losses and waste of resources; the wear of the casing will reduce the anti-collapse and internal pressure strength of the casing string in the slightest, affecting The quality and safety of the subsequent drilling, well completion and mining operations will cause deformation, leakage, collapse of the casing string, and sometimes cause the entire well to be scrapped. Therefore,...

AI Technical Summary

Problems solved by technology

[0003] 1) Tungsten carbide wear-resistant belt: high hardness, good wear resistance, but poor friction reduction, 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 bands: some have good friction reduction properties, but poor wear resistance. Often a well has not been drilled, but the wear-resistant bands have been polished. Subsequent drilling is done with bare drill pipe joints and casing or Stratum wear, wear is very serious, and some latest products have improved wear resistance and friction reduction, but the price is very expensive, which is difficult for users to accept;

[0005] 3) For other wear-resistant belt products on the market, it is difficult to achieve a reasonable balance between wear resistance and friction reduction, or the welding process is not ideal, or the compatibility with other types of wear-resistant belts is poor, and the application is limited. Restrictions, etc.