Noname

Results of tests over samples made of steel X60 (in accordance with API) on a gas main (Ø1420 x 20) and 09Г2С on a trunking oil pipeline (Ø1020 x 10) are examined. Magnitudes of the accumulated plastic strain depending on a range of stress and amounts of stress cycles are determined at the extension. Results of microstructure analyzises at various stages of stressing, variations of macro-and microhardness, internal stresses, coercive force, corrosive activity, and also data of microrentgenoscopy are presented.