بررسی مکانیزم و علل تخریب محل نشتی خط لوله مدفون خروجی ایستگاه تقلیل فشار گاز

Pressure reduction stations serve as gas distribution centers for industries and households. Leakage in these stations’ pipelines poses explosion hazards and can disrupt gas supply to downstream areas. Highlighting the importance of this issue, this study examines observed leakage on a 6-inch underground pipeline at the outlet of a pressure reduction station connected to the Isfahan Gas Company. After cutting out the damaged section and conducting a visual inspection of the sample, we performed metallographic tests, chemical analysis, hardness testing, and tensile tests. The results of these tests, along with a review of the pipeline’s history, indicated that two corrosion mechanisms—crevice corrosion and stress corrosion cracking (SCC)—contributed to the failure of the sample. Notably, the SCC mechanism led to the formation of cracks and subsequent leakage in the pipeline. The presence of tensile stress in the pipeline, combined with a corrosive environment, created the conditions necessary for SCC to occur, resulting in the initiation and growth of cracks that caused the leakage.