The pipelines are one of most important section of the fuel and energy complex of Russia. About 75% of them are presented by gas pipelines of large diameter (1020–1420 mm) for the operating pressure up to 7.4 MPa. CNIIchermet after I.P. Bardin put a big contribution into creation of pipe steels and mastering of technologies for their production at steel-works of Russia. The Institute in cooperation with leading steels-works developed an array of pipe steel, which are successfully used at construction of modern gas and oil pipelines. Tendencies of requirements increasing to characteristics of steels for large diameter pipes for pipelines considered, creation stages of grade range of steels and technology of rolled products production analyzed. Main technological requirements for achieving mechanical properties high level determined. It was shown, that K60–K65 strength class steels meet requirements to northern pipelines for a pressure up to 11.8 MPa, to thick walled underwater pipelines for a pressure of 25.0 MPa and to pipes for seismic arears. Steel-works and pipe-manufacturing plant of Russia provide the production of longitudinal-welded pipes with wall thickness up to 40–60 mm with anticorrosion external coating and smooth internal coating.
Features of the expansion process in the technology of production of large diameter pipes for main oil and gas pipelines
