公开(公告)号：US20170304953A1

公开(公告)日：2017-10-26

申请号：US15649469

申请日：2017-07-13

申请人： NIPPON STEEL & SUMITOMO METAL CORPORATION

发明人： Yukinobu NAGATA ,  Eiji TSURU ,  Yasuhiro SHINOHARA

IPC分类号： B23K31/02 ,  F16L13/02 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/12 ,  C22C38/00 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  F16L13/04 ,  C22C38/14 ,  B23K101/10

CPC分类号： B23K31/02 ,  B23K2101/10 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  F16L13/02 ,  F16L13/04 ,  Y10T428/12

摘要： A pipeline is a pipeline having plural weld zones in which ends of plural steel pipes are joined by welding, the plural steel pipes are produced from plural charges of molten steel having one or more steel compositions; yield point elongation is not present on a stress-strain curve obtained when stress is applied in a longitudinal direction of each of the steel pipes; a thickness of each of the steel pipes t (mm) and an average pipe outside-diameter D (mm) satisfy t/D×100≦6; and in the plurality of the weld zones, ΔYS which is a yield strength difference between one steel pipe and the other steel pipe that are welded to each other (MPa), and YR representing a yield ratio that is a ratio of the yield strength to tensile strength of a pipe having a low yield strength out of the one steel pipe and the other steel pipe, satisfy ΔYS≦−1.75×YR+230.