СТРУКТУРНО-ФАЗОВІ ОСОБЛИВОСТІ ПОШКОДЖУВАНОСТІ ЗВАРНИХ З’ЄДНАНЬ ПАРОПРОВОДІВ ТЕС З ТЕПЛОСТІЙКИХ СТАЛЕЙ (Огляд).

The paper considers the peculiarities of damage to welded joints of steam pipelines that have been operated for a long time (more than 280 thousand hours) under creep and fatigue conditions. It is established that the damage caused by creep and fatigue depends to a large extent on the structural and phase state of the metal of welded joints, which changes considerably during their long-term operation. With longer service life of welded joints, a ferrite-carbide mixture forms in their structure as one of the components. The presence of such a mixture contributes to acceleration of damage of welded joints. The dependence of formation of the ferritecarbide mixture on the initial structure of welded joints was established, and recommendations were given for producing an initial structure with improved quality characteristics, which is advisable for increasing their reliability and service life. [ABSTRACT FROM AUTHOR]