No abstract

The objective of this study is examining the level of degradation caused by the welding process, the influence of defects by third parties and the speed of loading on the integrity of the pipeline. The use of Charpy instrumented pendulium coupled with the the volumetric method analysis allowed us to calculate the dynamic fracture toughness of the API 5L X52 pipeline steel in presence of a real defect characterized by its notch radius but also, to show the need for a second parameter to overcome the problem of fracture toughness transferability.

In the present work, an experimental study of the influence of tribological parameters upon the mechanical wear behavior of unalloyed and high-alloy steels is proposed, in order to monitor the residual stress evolution as a function of the friction coefficient. For both types of steel, the tests are carried out on specimens polished mechanically or chemically. The dry friction tests were performed on a ball-on-plate testing machine in order to determine the cyclical friction coefficient and the residual stresses developed during the slip of the tempered steel wiper on the specimen. Using the data analysis technique, the correspondence factorial analysis method describes more quickly a large data source by exploiting sophisticated descriptive statistics. The data will are then subjected to a factorial treatment using the metric of Chi-squared (2c) to preserve the probabilistic nature of the problem. This method is considered to be very useful and very precise for determining the residual stress under the cyclical loading caused by dry mechanical friction.