Roll forming of electric resistance welded pipes with high ductility

点击翻译按钮获取中文摘要

Recently electric resistance welded pipes made of high strength steel are increasingly needed to decrease weight of cars and to develop deep wells of gas and oil. On the other hand, springback and work-hardening are emphasized in high strength steels, which yield the manufacturing of the pipes much more difficult than conventional steels. In this study, the influence of roll type, roll diameter and sheet strength on the roll forming of the pipes was examined in detail. The following two kinds of rolls were used: The one (Type A) was the roll stand that pinched the sheet entirely in circumferential direction by top and bottom rolls, and the other one (Type B) was the roll stand that pinched the sheet only in the edge. From the experimental and numerical investigations, a basic deformation mechanism of roll forming of the pipe could be clarified, and moreover, it was found that Type B roll gave better formability in terms of work-hardening that arose during the roll forming process.