CRITICAL FACTORS OF CORROSION-FATIGUE DEGRADATION OF 17G1S STEEL OF MAIN GAS PIPES UNDER CONDITIONS OF INCOMPLETE LOAD OF THE GTS
DOI:
https://doi.org/10.34185/1991-7848.itmm.2026.01.010Keywords:
17G1S pipe steel, corrosion fatigue fracture, low-frequency loading, cyclic crack resistance, structural degradation, incomplete loading of the GTS, asymmetry coefficientAbstract
The results of the study of the influence of non-stationary modes of incomplete loading of main gas pipelines on the critical indicators of cyclic crack resistance of 17G1S steel, which has been in operation for over 35 years, are presented and a comparison is made with the steel in the initial state. It was experimentally established that structural degradation ("working aging") and the specifics of the load (change in the asymmetry coefficient R, frequency f of the load cycle and increase in the dynamic component) cause a significant decrease in the crack resistance thresholds. A powerful synergistic effect between low-frequency cycles and an aggressive operating environment has been revealed, which leads to an almost threefold acceleration of corrosion-fatigue destruction of steel compared to the design modes. The results of the work can be used to refine the methods for predicting the residual resource of pipelines under conditions of changed technological operating modes.
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