对管材无模镦粗变形时壁厚变化进行了实验研究。分析了管材无模镦粗时壁厚变化的影响因素及影响规律。对于薄壁管材无模镦粗时，镦粗后壁厚相对变化与管材外径、内径的相对变化以及（１＋Ｒｓ）１／２相等；对于厚壁管材无模镦粗时，壁厚相对变化与镦粗后管材外径、内径的相对变化以及（１＋Ｒｓ）１／２成正比。 The experiment of wall thickness variation during tubeless upsetting was conducted. The influencing factors and influencing rules of wall thickness variation during tubeless upsetting are analyzed. For the thin-walled tube without die upsetting, the relative change of the wall thickness after upsetting is equal to the relative change of the outer diameter and the inner diameter of the pipe, and (1 + Rs) 1/2; for the thick-wall pipe without die upsetting, Upset pipe diameter, the relative change in diameter and (1 + Rs) 1/2 is proportional to.