DEGRADATION OF THE PROPERTIES AND STRUCTURE OF WELDED JOINTS OF PIPELINES IN WWER-440 REACTORS IN THE PROCESS OF HEAT AND HEAT-STRAIN AGING UNDER CONDITIONS OF LONG-TERM OPERATION

摘要

We study the behavior of the properties and structure of the metal of welded joints of pipelines of WWER-440 reactors in the process of heat and heat-strain aging under the conditions of long-term operation (for more than 100,000 h). In the case of cyclic loading in the region of the weld, we establish the dependence of the dynamics of structural changes in the metal on the initial level of elastoplastic strains in the zone of thermal influence.