For line pipe to which a strain-based design is applied, control of mechanical properties such as yield to tensile strength (Y/T) ratio, yield strength (YS) and flow stress at a low strain is required. These mechanical properties generally change during thermal coating treatment. A high strength UOE line pipe that is less susceptible to strain aging has recently been developed. In UOE pipes, mechanical properties change along the circumferential direction. However, the strength distribution has received little attention. Furthermore, the extent to which the change in strength along the circumferential direction affects the strain limits in strain-based design application is unclear. In this paper, firstly, the pipe forming strain variation and mechanical properties distribution along the circumferential direction of the X80 UOE line pipe suitable to the application of strain-based design are presented. Secondly, change in the properties distribution after thermal coating application is examined. Finally, the effect of strength distribution on the strain limits in strain-based design is discussed.

This content is only available via PDF.
You do not currently have access to this content.