Investigation of the factors affecting the defect formation on the inner pipe surface during plug-rolling

Abstract

A typical challenge associated with pipe-rolling machinery comprising an automatic mill or a tandem mill is the occurrence of defects on the inner pipe surface, such as roll marks (depressions). The presence of such defects prevents the application of high-quality insulation coating to the inner pipe surface. A significant number of studies have been devoted to solving the issue of roll mark occurrence, however, the proposed solutions do not fully account for the specifics of pipe production using individual machinery units. Therefore, solving the problem requires either adapting the existing methods to a specific unit, or searching for new, more universal methods. The article provides a summary of the available information concerning the problem of roll mark formation on the inner pipe surface, and describes studies conducted by the authors in an attempt to refine the defect occurrence mechanisms using computer simulation. Based on the computer models and combined statistical analysis of the pipe quality, the factors contributing to the occurrence of defects have been identified.