The aim of this research was to investigate the influence of metallurgy on the corrosion behaviour of separate weld zone (WZ) and parent plate (PP) regions of X65 pipeline steel in a solution of deionised water saturated with CO2, at two different temperatures (55 °C and 80 °C) and at initial pH~4.0. In addition, a non-electrochemical immersion experiment was also performed at 80 °C in CO2, on ...

fault tree analysis (fta) as a probabilistic risk assessment (pra) method is used to identify basic causes leading to an undesired event, to represent logical relation of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. to conduct a quantitative fta, one needs a fault tree along with failure data of the basic events (bes). someti...

This paper discusses two common problems, “weld tenting” and low coating thickness over the external weld, and their causes in traditional three layer polyolefin pipeline coatings. To tackle these problems, a new approach to applying multilayer polyolefin coating to pipes is introduced. The new system consists of side-extruding high density polyethylene over a graded structure polyethylene (GSP...

Large welded structures, including ships and offshore structures, are normally in operation under cyclic fatigue loadings. These structures include many geometric as well as material discontinuities due to weld joints, and the fatigue strength at these hot spots is of critical importance for the structural performance. In the past, various Non-Destructive Evaluation (NDE) techniques have been d...

Underwater wet welding is one of the most common repair measures for corroded offshore steel structures. Few studies have been carried out systematically concerned with mechanical properties of such welds, thus current design provisions rely heavily on limited experimental data on welds made underwater and design properties for corresponding welds made in air. This paper presents a series of ex...

With fossil fuels being phased out and growing global interest in a hydrogen economy, there is demand for re-purposing existing pipelines transportation of gas. However, embrittlement (HE) can limit pipeline steel’s performance. In this study, the effect on mechanical properties an X60 base metal (polygonal ferrite/pearlite) its girth weld (acicular was measured with novel slow strain rate tens...

Pipe girth welds are prone to incomplete fusion problems in the automatic welding process of long-distance pipelines, which is often related temperature inhomogeneity weld bead. The narrow gap and micro-swing technique was applied pipeline construction improve quality. manuscript provides a detailed investigation with combination experiments numerical simulation. A swing strategy proposed accor...