A preliminary investigation of the effects of environmentally assisted cracking on natural gas transmission pipelines

摘要

Concepts for the development of a model to predict natural gas transmissionpipeline lifetime in a corrosive environment are constructed. Primarily, the effects ofenvironmentally assisted cracking (EAC) are explored. Tensile test specimens from asample of API 5L X-52 pipeline were tested in a simulated groundwater solution andsubsequently analyzed. The results suggested that the simulated environment ultimatelyreduced the ductility of the test specimens; however, no evidence of ??classical?? stresscorrosion crack morphology was discovered. However, corrosion pits up to 0.75 mm(0.03 in) were revealed during metallographic analysis. A Marin factor analogy and anenergy method concept are suggested and explored. Ultimately, the test data set was toosmall for the results to be of any directly applicable significance.