Determination of Mechanical Properties of High Strength Linepipe

Commercial scale trials of X100 for Artic gas transmission pipelines have been conducted at IPSCO. Different alloying systems and thermo-mechanical controlled processes have been employed to make X100 coils. The coils were made into spirally welded pipes at IPSCO Spiral Mill in Regina, Canada. These pipes were tested in different conditions, namely as-welded, after hydro-testing, and after thermal coating. Therefore, the effects of as-supplied material and pipe-making processes on the final mechanical properties of pipe were evaluated. It was found that the tensile specimen size and sampling location had a noticeable effect on the testing results. The difference was also observed between the flattened strap specimen and round bar. The influence of the anisotropy of the as-supplied coils and the thermal coating on the final pipe properties will also be presented.