Stress corrosion cracking behavior of buried oil and gas pipeline steel under the coexistence of magnetic field and sulfate-reducing bacteria

Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence.

Temporal and spatial variation in the environmental impacts of China’s resource extraction at the provincial scale

Introduction:Over the past two decades,China has experienced rapid economic development,which has not only led to a rapid increase in the use of raw materials but has also created environmental problems.This research analyzes the environmental impacts of resource extraction in China at the provincial level,and fully considers the environmental impact of various resources extraction.In addition,it is the first time to quantitatively study the spatial pattern and evolution characteristics of the environmental impacts of China’s resource extraction from multiple perspectives by means of spatial visualization.Outcomes:The results showed that the center of gravity of abiotic depletion potential(ADP)moved northwest,respiratory inorganics(RI)moved southwest and global warming potential(GWP)moved west.The results of the standard deviation ellipse showed that RI and GWP varied over time and space,while ADP showed a discrete trend.In addition,the distribution of the four in the northeast-southwest direction became more prominent.Conclusion:To mitigate the environmental impacts of resource extraction,we recommend that regional governments implement measures to control environmental impacts in the provinces within the distributed ellipse and design targeted policies based on actual conditions.