Corrosion Behavior of X80 Pipeline Steel in Typical Soil Simulation Solutions of West-east Gas Pipeline II

The stress corrosion behaviors of submerged arc welding X80 pipe, widely used in the West-East Gas Project II, are studied in five typical soil simulation solutions: (1) made from brown desert soil collected from Hami of Xinjiang Province, (2) meadow solonchak collected from Yumen of Gansu Province, (3) cinnamon soil collected from Yichuan of Henan Province, (4) yellow-brown soil collected from Wuhan of Hubei Province, and (5) red oil collected from Zhangshu of Jiangxi Province, respectively). The results showed a certain degree of stress corrosion susceptibility of X80 pipeline steel studied in those soil simulation solutions, but they were not serious. The stress corrosion susceptibility of the X80 pipeline steel gradually decreases from Yumen (meadow solonchak) soil, Yichuan (cinnamon) soil, Wuhan (yellow-brown) soil, Hami (brown desert) soil and Zhangshu (red) soil. Serious pitting occurred on the specimen in red soil simulation solution. The corrosion behavior of X80 pipeline steel in the other four kinds of simulation solutions was governed by general corrosion, although there were a few pitting occurrences on local positions.