Fe-Nb-Mo-Cr-Mn-B iron-based surfacing flux-cored wire for wear-resistant strip of drill rod joint

Abstract

The invention relates to an Fe-Nb-Mo-Cr-Mn-B iron-based surfacing flux-cored wire for a wear-resistant strip of a drill rod joint, and belongs to the technical field of welding materials. A carbon steel strip is adopted to coat flux core powder, filling rate of the flux-cored wire is 20-26%, and alloying elements of the flux-cored wire powder include, by mass, 0.6-1.2% C, 0.8-1.2% of B, 2-9% of Cr, 10-19% of Nb, 4-10% of Mo, 4-10% of Mn, 3-8% of Si, 1-4% of Ti and the balance Fe. Grain structures generated by a coating, carbide and boride after wire surfacing are closely arrayed into a hard metallographic phase to be dispersed in martensite, the size of an NbC hard phase is quite small and is about 1-2 micrometers. No crack exists after welding, average Rockwell hardness is more than 60HRC, and the flux-cored wire has reasonable wear resistance and crack resistance matching performance; surfacing manufacturability is good, weld joints are beautiful in formation, the wear-resistant strip is smooth, the flux-cored wire is few in splash, free of peeling, high in cohesiveness, reusable for surfacing and excellent in compatibility.

Description

technical field [0001] The invention belongs to the field of material processing and welding, and in particular relates to a wear-resistant band flux-cored welding wire for surfacing welding drill pipe joints. Background technique [0002] Overlaying metal wear-resistant bands on oil drill pipe joints is one of the effective measures to reduce the wear of drill pipes and casings. With the development of drilling technology, the extension of drilling time, the increase of the lateral force of the drill pipe on the casing and other factors, the wear problem of the casing and drill pipe has become more and more serious, and the torsional resistance of the drill pipe has been reduced. The bending strength and the anti-collapse and internal pressure strength of the casing string will cause the casing string to collapse, deform and leak, and even cause the entire well to be scrapped, thereby greatly increasing the drilling cost. Metal overlay welding on the oil drill pipe joint W...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of lack of crack resistance of most of the current surfacing welding materials, high wear rate of the casing, poor adhesion, and peeling of the substrate. When repeated welding, the old wear-resistant belt needs to be removed, and it cannot be directly welded on it to provide a low-cost Fe‐Nb‐Mo‐Cr‐Mn‐B iron-based wear-resistant surfacing flux-cored wire

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