Avaliação das propriedades mecânicas de uma junta soldada de uma tubulação de aço API 5L-X60 utilizada em exploração de petróleo.

Abstract

The effects of the microstructural variation, specimens dimensions and granulometry on the values of toughness of a High Strength Low Alloy (HSLA) pipeline steel API 5L-X60 welded joint used to petroleum exploration were investigated. In a first analysis, Charpy impact tests in specimens machined of different places of the welded joint were made on both as-welded and stressrelieved conditions at 873K (600°C). In the second analysis, Charpy impact tests and CTOD at maximum load ( 8 m a x ) in different specimens dimensions and machined of different places of the weld metal were made. The results showed significative variations in the values of impact resistance and fracture toughness, evidencing the importance of notch machined position in the Heat Affected Zone interest region, of contribution of the weld metal recrystallized grains and of the stress/strain state on the crack tip, on the estimation of the mechanical properties of welded joints produced by multipass technique.