1.前言在热轧无缝钢管生产中,为得到具有一定尺寸精度和真圆度的成品管需进行定径。如尚若较大的减少外径,通常采用单架减径率和总减径率皆较定径大得多的减径生产技术。在减径过程中按相邻机架间管段是否承受张力,又分为无张力减径和张力减径两种。定径和无张力减径过程中要求保持金属秒流量相等,即维持前一架出口速度和后一 1. Introduction In hot-rolled seamless steel pipe production, in order to obtain a certain size precision and roundness of the finished pipe to be sizing. If still larger to reduce the outer diameter, usually using single-frame reduction rate and total reduction rate are much larger than the diameter reduction production technology. In the process of reducing the pipe between the adjacent rack is under tension, and is divided into tension-less and tension-reducing two. Sizing and tension reduction process required to maintain equal flow of metal second, that is, to maintain the previous exit speed and the latter