Aging of materials of the equipment of nuclear power plants after designed service life

Degradation of structural steel properties under the prolonged influence of operating temperatures

“…1 gives the general trends of changes in the steel and its weld standard properties (welding performed by automatic welding under a layer of flux at 350°C in a limited time-20000 hbasis). Russian [7][8][9][10][11] and foreign specialists continued further studies in that direction. For example, in Hun gary for the fourth power unit of the Paks NPP (VVER 440/V 213 reactor), a thermal set of reference specimens [12] was tested after 4 years of operation (p = 12.2 MPa, T = 295°C).…”

“…In making an estimation of the ser vice life, it is necessary to determine degradation of mechanical properties and take into account that for years these materials are subjected to constant and variable loadings and high temperatures and also cor rosion and radiation. In Russia, these studies are car ried out within 10-15 years [6][7][8][9][10][11][12]. Their results are generalized in this review for the following groups of materials: heat resistant steels; carbon steels such as 22K and 20; high alloyed austenite stainless steels such as 08Cr18Ni10Ti.…”