The Problem of Assessing the Reliability and Residual Resource of Long-Term Operating Welded Joints in Steam Pipelines of Thermal Power Plants
Year: 2025
Type: article
Abstract: Assessing the reliability of welded joints of steam pipelines made of heat-resistant pearlitic steels that are operated for a long time (over 270 thousand hours) under creep and fatigue conditions, has become an extremely relevant issue. The purpose of this research is to determine the avenues for the development of regulatory provisions regarding the reliability of welded joints of steam pipelines that are operated for a long time under creep and fatigue conditions. To achieve the goal, appropriate methods of research and analysis were used to study the structural-&-phase state and determine the chemical composition and physical-&-mechanical properties of the metal of welded joints, as well as the level of their damageability. It was established that the damageability of the metal of welded joints depends primarily on its structural-&-phase state. With an increase in the operating time of welded joints, a ferrite-carbide mixture is gradually formed in their initial structure, and accordingly, and the amount of it as its component is increased. The presence of such a mixture contributes to the damageability of welded joints. which follows creep and fatigue mechanisms. The feasibility of detecting a ferrite-carbide mixture in the structure of welded joints by using already improved techniques and developing new quality control methods has been substantiated. To obtain appropriate results, we propose improving the quality control methods for welded joints of steam pipelines that operate for a long time under creep and fatigue conditions. We substantiated that when developing new and improving standard methods for quality control of metal of welded joints that operate for a long time under creep and fatigue conditions, it is necessary to consider their structural and phase state, which will increase the reliability of the operation of welded joints. Improving the technologies already available as well as developing new methods and techniques for quality control of metal of steam pipelines and their welded joints, will allow us to improve the assessment of their structural and phase state and the presence of damages. Considering the results obtained in relation to new regulatory provisions will allow us to improve the assessment of the reliability of aging steam pipelines and their welded joints, as well as to determine their residual resource.
Authors: Vitaly Dmitrik, Xinlei Chen, Oleksandr Usatyi, Ihor Kasianenko
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4411280345