Experimental and Numerical Investigation of Gas-Solid Erosion in Common Natural Gas Pipeline Steels

Solid impurities in natural gas pipelines cause severe erosion damage to pipelines. To predict and prevent erosion accidents in pipeline steels during gas transportation, this study conducted gas-solid erosion experiments on X80, X65, and X42 pipeline steels using an ASTM G76-compliant air jet experimental apparatus. The erosion patterns under varying impact angles and velocities were systematically compared, and erosion mechanisms were further analyzed through SEM and three-dimensional profilometry. The erosion rates of X80, X65, and X42 pipeline steels followed consistent trends: rates decreased with increasing impact angles and increased with impact velocity. The macroscopic erosion morphology transitioned from elliptical to circular as impact angles increased, while material removal mechanisms gradually shifted from ploughing to compaction and cracking, with impact velocity having no effect on macroscopic morphology. Material differences significantly influenced erosion depth and removal mechanism efficiency: under identical conditions, erosion depth and wear volume followed X80, X65, X42, X80 exhibited the shortest and narrowest ploughing grooves, along with the shallowest compaction-induced crater depths and fewest cracks. The erosion behavior of X80, X65, and X42 aligns with the general principles of typical ductile materials, with X80 demonstrating the best erosion resistance among the three steels. Erosion rate equations for X80, X65, and X42 pipeline steels were established, and nozzle-erosion chamber CFD erosion models were developed to validate the equations. The relative errors remained within acceptable tolerance limits, providing critical support for gas-solid erosion simulations of pipeline steels in complex flow fields using CFD.