The Effect Manufacturing Processes on Residual Stress and Yield Stress of ERW Pipes

Abstract

ERW(Electoric Resistance Welded) pipes are manufactured from a steel coil with various cold-forming works - mainly uncoiling, leveling, forming and sizing. Since the steel is given great plastic deformation in these processes. it is necessary to consider multi dimensional stress state. The manufacturing processes give much effect on the mechanical characteristics of the steel, as a result, ERW pipes get the material initial imperfections such as residual stress and change of yield stress. In this report, these initial imperfections are estimated by qualitative and quantitative analysis.