https://cyberleninka.org/article/n/1004079.pdf

Pipe Failure Analysis and Impact of Dynamic Hydraulic Conditions in Water Supply Networks

Around the world, there are thousands of metal structures completely or partially buried in the soil. The main concern in their design is corrosion. Corrosion is a mechanism that degrades materials and causes structural failures in infrastructures, which can lead to severe effects on the environment and have direct impact on the population health. In addition, corrosion is extremely complex in the underground environment due to the variability of the local conditions. The problem is that there are many methods to its evaluation but none have been clearly established. In order to ensure the useful life of such structures, engineers usually consider an excess thickness that increases the economic cost of manufacturing and does not satisfy the principles of efficiency in the use of resources. In this paper, an extended revision of the existing methods to evaluate corrosion is carried out to optimize the design of buried steel structures according to their service life. Thus, they are classified into two categories depending on the information they provide: qualitative and quantitative methods. As a result, it is concluded that the most exhaustive methodologies for estimating soil corrosion are quantitative methods fed by non-electrochemical data based on experimental studies that measure the mass loss of structures.

Methods to Evaluate Corrosion in Buried Steel Structures: A Review

Effect of electrochemical charging on the hydrogen embrittlement susceptibility of alloy 718

The soil environment of an emergency section of a main gas pipeline is characterized as “near-neutral” (pH < 8) with middle or, in some cases, even high (more than 0.3 mm/year) corrosion activity and can be modeled by the NS4 solution. Long-term operation (23 years) decreases mainly the static crack resistance of X60 and X70 steels, whereas hydrogenation under the potential of cathodic protection sharply increases their susceptibility to stress corrosion fracture under both static and cyclic loading. The X70 steel is more sensitive to the negative influence of operation and hydrogenation as compared with X60 steel. We have evaluated the residual lifetime of the section of the “Urengoi–Pomary–Uzhgorod” main gas pipeline with regard for hydrogenation of the pipeline wall.

Evaluation of the residual lifetime of a section of a main gas pipeline after long-term operation

This paper undertakes a critical review of the literature concerning mechanisms and impacts of soil-related geohazards to UK infrastructure. The country is predicted to have drier, hotter summers and wetter, warmer winters that in turn will increase the magnitude and frequency of many soil-related geohazards – predominantly due to changes in soil moisture. Probabilistic assessment will be required given the inherent uncertainty in assessing chronic soil hazards. The aim of this paper is to recommend a national framework methodology to aid the management of future risks posed by soil geohazards to UK infrastructure. The framework will help to prioritise ground investigations in high-risk areas, help to design suitable mitigation measures and encapsulate expert knowledge to interpret risk.

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Soil impacts on UK infrastructure: current and future climate

On the basis of the well-known theoretical concepts and some experimentally substantiated hypotheses, we propose a physicochemical model and establish mathematical relations for the description of the stress-corrosion fracture of pipe materials of underground oil-and-gas pipelines with regard for the intensification of this process by diffusion-moving hydrogen. We also quantitatively estimate the effect of hydrogenation on the rate of soil corrosion and residual service life of the pipes of oil-and-gas pipelines.

Effect of hydrogenation of the walls of oil-and-gas pipelines on their soil corrosion and service life

We propose an engineering approach to the analysis of the strength and durability of structural elements of power-generating equipment with regard for the influence of hydrogen-containing media, high pressures, and elevated temperatures. We study the stress-strain state of a boiler drum made of 22K steel, under the operating conditions with regard for the hydrogenation of its wall and the actual geometry of the drum. We compute the parameter of accumulated damage to the drum metal for different operating conditions. It is shown that hydrogen accelerates the accumulation of defects and reduces the operating time of the metal by 20–30% in the case of a scheduled shutdown of the boiler and by 30–40% in the case of its emergency shutdown.

Determination of the Durability of Elements of Power-Generating Equipment with Regard for the Influence of Working Media

We propose an algorithm and programs for the solution of the three-dimensional problem of hydrogen diffusion. Some numerical solutions of this problem and the problem of heat conduction in the three dimensional statement are verified by analyzing test problems whose analytic solutions are known. The dependence of the relative error on the density of elements of the grid and time intervals is constructed by using the finite-element method.

Influence of the Parameters of Discretization on the Accuracy of Numerical Solution of the Three-Dimensional Problem of Hydrogen Diffusion

We consider a problem of cracking of metals (formation of blisters) in the oil-and-gas equipment. The causes of initiation of the nuclei of hydrogen blisters are investigated and, on this basis, a mathematical model of their growth is developed with regard for the electrolytic hydrogenation of the metal surface, hydrogen diffusion into the metal, and its accumulation in the internal microdefects. We also present an example of analysis of the kinetics of growth of circular blisters in low-carbon and low-alloy steels under the action of hydrogen penetrating into the metal in the process of corrosion in wet hydrogen-sulfide media.

O. V. Hembara

Papers

Evaluation of the residual lifetime of a section of a main gas pipeline after long-term operation

Effect of hydrogenation of the walls of oil-and-gas pipelines on their soil corrosion and service life

Determination of the Durability of Elements of Power-Generating Equipment with Regard for the Influence of Working Media

Influence of the Parameters of Discretization on the Accuracy of Numerical Solution of the Three-Dimensional Problem of Hydrogen Diffusion

Numerical analysis of the kinetics of propagation of hydrogen blisters in the oil-and-gas equipment