The complexity of corrosion mechanisms in harsh offshore environments poses safety and integrity challenges to oil gas operations. Exploring the unstable interactions complex required an advanced probabilistic model. current study presents development a approach for consequence-based assessment subsea pipelines exposed mechanisms. Bayesian Probabilistic Network (BPN) is applied structurally lea...

A method for finding the microstructural parameters of low-carbon steel using its metallographic images is proposed. It allows to determine the following parameters: the ratio of perlite to ferrite phases, the parameters of grains of crystallites and their mutual arrangement; the degree of granularity of the pearlite phases. The method is aimed at predicting the strength characteristics of stee...

In this paper, the effects of dispersed 3~10 nm NbC precipitates on hydrogen diffusion in X80 pipeline steel were investigated by means of high resolution transmission electron microscopy (HRTEM), electrochemical hydrogen permeation, and thermal desorption spectroscopy (TDS). The relationship between hydrogen diffusion and temperature was determined for Nb-free X80 and 0.055 wt% Nb X80 steel. T...

ommunication from within the steel pipeline by inspecting or sensing tools or robots is usually performed via a cable. As the length of the tether restricts the communication distance and as the cable may encumber the tool’s movement, we explore the feasibility of acoustic communication from within the liquid-filled pipe to an external sink through the steel pipe walls. The paper derives the so...

Although the probability of defect detection using magnetic flux leakage (MFL) inspection is sufficient for most applications for which it is used; inspection of ferromagnetic pipeline, wire rope, etc., accurate defect characterisation is problematic. The use of pulsed excitation in conjunction with MFL provides an opportunity for the extraction of depth information from the MFL signal using an...

The ductile fracture arrest may present supplementary requirement for selection of base material for most demanding steel welded structures. The most representative one with such requirement are gas pipelines. Therefore to ensure that the pipeline materials has adequate toughness to arrest a ductile fracture, the pipe material must be designed and tested in accordance with the specific procedur...

A former radioactive waste disposal site is surveyed with two non-intrusive geophysical techniques, including magnetic gradiometry and electromagnetic induction. Data were gathered over the site by towing the geophysical equipment mounted to a non-electrically conductive and non-magnetic fibre-glass cart. Magnetic gradiometry, which detects the location of ferromagnetic material, including iron...

The Charpy energy of the sample after heat–treatment was significantly higher than the as–welded sample when the V–notches were located 1 or 3 mm away from FL. However, when the V–notch was located on FL, the improvement in toughness from the heat treatment was not so obvious with no enhancement noted for the test temperature of −40 ◦C. Under this condition, the facets of the fracture surface a...