石油钻铤(如图1)是细长厚壁管件,长达9300mm,长径比>50,因此在加工制造中难免产生壁厚差(管体同一截面上最大壁厚与最小壁厚之差)。但若壁厚差过大(有关资料规定的钻铤壁厚差应控制在±10mm以内),在钻井时,由于钻铤的重心偏离钻柱轴心,将会产生较大的离心力,导致井斜,影响钻井质量。在制造过程中如何控制并减少壁厚差是制造工艺上的主要难题。一、国内外工艺概况分析 1.日本日本某公司钻铤生产采用的工艺为:轧制的成形棒材→热处理(校直、回火)→深孔对钻→车螺纹等,采用深孔双向对钻设备。由于从两端同时打孔,减小 Oil drill collar (Figure 1) is a long, slender pipe with a length of 9300mm and an aspect ratio> 50, so it is inevitable that the pipe will have poor wall thickness (the difference between the maximum wall thickness and the minimum wall thickness in the same section of the pipe body) ). However, if the wall thickness difference is too large (the relevant data stipulates that the difference of the wall thickness of the drill collar should be within ± 10mm), a large centrifugal force will be generated during the drilling because the center of gravity of the drill collar deviates from the axis of the drill string. Oblique, affecting the drilling quality. How to control and reduce the thickness difference in the manufacturing process is the main manufacturing process. First, an overview of domestic and international process 1. Japan Japan, a company drill collar production process used are: rolled bar forming → heat treatment (straightening, tempering) → deep hole drilling → car thread, using deep hole two-way Drilling equipment. As the punch from both ends at the same time, reduce