Peculiarities of the brittlement of welded joints of bodies of WWR-type reactors

摘要

The reversible tempering brittlement is the main reason of accelerated brittlement of welded joints of the bodies in the initial periods of their service, caused by increased concentration of diffusive impurities, especially phosphorus.Segregation of impurities on the grain boundaries depends both on the temperature-time operation conditions of the body and density of radiation defects of crystal lattice. Increased content of nickel intensifies segregation. The saturation of the metalwith diffusion hydrogen, causing static fatigue, has noticeable influence on degradation of the properties of welded joints.