管坯宽度数学模型

The Mathematical Model of the Pipe Base Width

依据高频直缝焊管生产原理，通过分析焊管外径、管壁厚度与管坯宽度三者之间的内在联系，将管坯宽度分为构成焊管实体的基本尺寸Ｂ１和加工余量ΣΔＢ两个部分。指出ΣΔＢ对焊管质量举足轻重，继而运用数理统计方法对已被实践证明能满足生产出合格焊管要求的ΣΔＢ进行相关分析，从中导出关于加工余量ΔＢ１＊与管壁厚度ｔ以及加工余量ΔＢ２＊与焊管外径Ｄ的相关直线方程，在此基础上建立了管坯宽度数学模型Ｂ＝（Ｄ－ｔ）π＋０．４３８ｔ＋０．０３５Ｄ＋２．０７。本模型优点是：拚弃了以往诸多公式的一个共同弊端——参数选择的主观随意性；对统一管坯计算口径、规范焊管工艺、推动行业技术进步有重要意义；模型对厚、薄壁管或公、英制管均适用。

According to the productive principle of the longitudinally high frequency welded pipe, after analysing the internal relationship among the external diameter of the welded pipe, the thickness of pipe wall and the width of the pipe base, the width of the pipe base is divided into two parts: the basic dimension ( B 1), which constitutes the welded pipe and finishing allowance Σ ΔB .The Σ ΔB is essential to welding quality. Using mathematical statistics, the Σ ΔB which is satisfactory to produce the qualified welded pipe is analysed. The linear equations which show the relationship between the finishing allowance ( ΔB 1 *) and the thickness of the pipe wall (t) and between the finishing allowance ( ΔB 2 *) and external diameter of welded pipe (D) are derived. On the basis of these, the mathematical model of the pipe base width B=(D-t )π+0.438 t+0.035D +2.07 is established. The advantages of this model are that the common drawbacks of former formulas, subjective posibility of option when the parameters are selected, are abandoned. This model has a wider significance to the uniformity of calculating pipe base diameter, the standardization of welded pipe techniques and the development of professional technology, and this model is suitable to either the thick wall pipe or thin wall pipe and either the metric system or English system.