Friction Welding Method of Welded Heavy Drill Pipe

Abstract

The invention relates to a friction welding method of a welded heavy drill pipe. The process steps of the method are as follows: when the welding outer diameter is 5.13in, the welding inner diameter is 3.0in and the welding area is 13.57in2, the welding parameters are: inertia: 11036.5lb .ft2, rotating speed: 920±20r / min, upsetting pressure: 1400±40psi, holding time: 35±1s, theoretical displacement: 0.625±0.1in. When welding with this welding parameter, the actual displacement is 0.616in; or: when the welding outer diameter is 3.88in, the welding inner diameter is 2.06in, and the welding area is 8.45in2, the welding parameters are: inertia: 4600lb.ft2, speed: 1100±20r / min, upsetting pressure: 1300±40psi, holding time: 35±1s, theoretical displacement: 0.625±0.1in. When welding with this welding parameter, the actual displacement is 0.630in. In the present invention, since the friction welding adopts low inertia, high rotating speed, and low upsetting pressure, the two materials of the pipe body and the joint are well welded, and after the weld seam undergoes quenching and tempering heat treatment, there is no cracking in the bending sample clockwise or counterclockwise.

Description

technical field [0001] The invention relates to a friction welding method, in particular to a friction welding method of a welded heavy drill pipe. Background technique [0002] Petroleum drill pipe is the main tool for oil field drilling. The structure includes the pipe body and the joints at both ends of the pipe body. The pipe body and the joint are connected by inertia friction welding. The chemical composition (mass percentage %) of the pipe body and the joint is shown in Table 1: [0003] C Si mn P S Ni Cr Mo Cu Al Tube 0.24-0.30 0.20-0.35 1.05-1.2 ≤0.015 ≤0.008 ≤0.25 0.8-1.0 0.15-0.2 ≤0.2 0.005-0.04 connector 0.35-0.38 0.15-0.35 0.85-1.00 ≤0.015 ≤0.008 ≤0.25 0.90-1.20 0.28-0.33 ≤0.2 [0004] At present, the inertial and direct drive friction welding machine of the American Manufacturing Technology Company—400BX inertial friction welding machine is generally used. Taking the 5-inch G105 drill pipe as an examp...

AI Technical Summary

Problems solved by technology

According to the metallographic inspection report of the weld, it can be seen that the two materials of the pipe body and the joint are basically not fused in the weld area, which makes the weld and heat-affected zone have low strength and poor impact toughness, which seriously affects the weld. Mechanical properties, its use safety, poor reliability

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