本文阐述了140机组所轧钢管直道内折产生的原因及形成过程。由于顶头“挂蜡”和磨损严重,使管壁产生了直道内折。同时分析了顶头磨损和“挂蜡”的各种因素,并且论述了消除办法。控制轧制温度和管壁压缩量,确保润滑质量和顶头制造质量是消除直道内折的主要措施。 This paper elaborates the causes and forming process of the straight inflexion of the rolled steel pipe in 140 units. Due to the head “hanging wax” and serious wear and tear, so that the wall had a direct straight-fold. At the same time, the various factors of head wear and “waxing” were analyzed, and the elimination method was discussed. Control of rolling temperature and wall compression, to ensure the quality of lubrication and head manufacturing quality is the main measure to eliminate straight in-fold.