Correlação entre as temperaturas de transição dúctil-frágil de corpos de prova convencionais e miniaturizados no ensaio de impacto Charpy dos aços API 5L X65, L80 e P110

Abstract

The Charpy impact test is used to evaluate the impact fracture resistance of the material and its transition temperature from a ductile-to-brittle fracture behavior. In some situations, the manufacturing of conventional specimens is not possible since the material may have a complex geometry or the component, in which the analysis is desired, is on operation. In order to avoid stopping an equipment on operation or analyze complex geometry components, miniaturized specimens may be manufactured. This work aimed to correlate the results of Charpy impact test between conventional and miniaturized specimens, manufactured in accordance with ISO 148 and ISO 14556, for three steels used in the oil and gas industry. The main focus of this study was on the correlation of ductile-to-brittle transition temperatures of the materials. The starting point of this study was a review of the results from previous authors. Subsequently, the specimens were manufactured, identified and measured using international standards as guidelines. Finally, assay and transition temperature calculation procedures were established. Concluding the work, it was possible to observe that there was a drop in transition temperatures between conventional and miniaturized specimens. Moreover, that this variation depends essentially on the type of material tested.