Construction of erosion mechanism maps for pipeline steels

Oil and gas industry spends millions of dollars every year dealing with problems caused by erosion. Erosion is a complex phenomenon and in order to recommend ways to mitigate its effect, it is essential to have a full understanding of the tribo-mechanisms involved. In the present study, erosion tests were conducted on AISI 1018, AISI 1080, API X42, API X70 and API X100 steels using aluminum oxide as erodent. Particle velocities and attack angles employed were as follows: 36, 47, 63 and 81 m s−1 at 30°, 45°, 60° and 90°, respectively. Erosion rate decreases with increasing impact angle and increases with increasing particle velocity. Several mechanisms are found to be responsible for the behavior of these steels under the experimental conditions employed in this work. Heavy plastic deformation and fracture, ploughing, delamination and different forms of metal cutting are identified as operative mechanisms during erosion. Empirical erosion mechanism maps are constructed showing the variation in erosion regimes, as a function of impact angle and normalized velocity.