Effect of long-term operation on steels of main gas pipeline: Structural and mechanical degradation

Based on the results of experimental studies of 17MnSi steel the regularities of the in-service degradation influence into its deformation and strength properties were established with the use of full strain diagrams. The important role of the hydrogen absorption that takes place under operation and its negative influence onto the mechanical properties of 17MnSi steel are shown. The latter is manifested through the microdefect growth in the gas pipeline material wall (in the form of dispersed damages) and reduction of its resistance to the brittle fracture.