JCO공정에 의한 고망간강 파이프 굽힘강도 해석

Abstract

With development of non-OECD countries, worldwide oil and gas consumption has gradually increased. Hence, not only the prices of energy have raised but also depth of subsea well has been further and deeper than before. Because of that, pipelines which have higher performance and larger diameter were needed to convey producted oil and gas from the well to the land. Corrosion resistance is one of the critical requirements for subsea pipelines since it takes tremendous expenses for replacement or maintenance of old pipelines. Therefore, high-manganese steel can be a proper material which has high corrosion resistance and reasonable price. Also, for manufacturing the large diameter pipelines, JCO process is mostly considered because of its economic feasibility. This process can produce large diameter pipelines in lower prices comparing with seamless pipes. However, cold forming which trigger residual stresses after process is main procedure so it is important understanding the effects of forming process on the structure. In this research, a tensile test was performed since it is essential obtaining mechanical properties for nonlinear analysis. Then, finite element analysis of JCO forming process for OD533 pipe was also performed based on the data from the tensile test. The residual stress after forming was imported to cylindrical tube for evaluating the effects of forming process. Though considerable residual stress remained from forming but there was a negligible effect on the ultimate strength of the pipe.