Analysis of the Events of Failures of Pipelines Made of Austenitic Steel in Nuclear Power Generating Industry

摘要

On the basis of the experience of long-term operation of nuclear power plants with RBMK (high-power channel reactors) and water-cooled water-moderated reactors, we analyze the events of failures of pipelines made of Kh18N10T steel. It is shown that the main mechanism of failures of welded joints in pipelines made of this type of steel is intercrystalline corrosion cracking. As the causes of the appearance of defects of this sort, one can mention the joint action of high levels of stresses, significant amounts of oxygen in the heat carrier, and sensitization of steel in the heat-affected zone of welded joints in pipelines. We propose compensating measures aimed at decreasing the negative effect of interciystalline corrosion cracking in the process of operation.