History of Science and Engineering Annotation << Back Quality of Steel 15KH2NMFA Moden Fabrication and 70–80 Years Fabrication Chernobaeva А.А. Kuleshova E.A. Mal'zev D.A. Medvedev K.I. Krasikov Е.А. Papina V.B. Titova T.I. Shul'gan N.A. Korbatova E.V. Batov Yu.M. Upgrading of metallurgical production last years at «ОМZ Special Steels») decrease the contents of such impurities as phosphorus, sulfur in forging for VVER Reactor pressure vessels (RPV) from steel 15Kh2NMFAA not less than in 2 times. The comparative analysis of impurity contents, strength properties and transition temperature in initial state of forging for VVER RPV from steel 15Kh2NMFAA modern fabrication and 70–80 years fabrication has been done in this work. The study of nonmetallic inclusions in ductile parts of broken Charpy specimens fracture surface from steel 15Kh2NMFAA modern fabrication and 70–80 years fabrication has been performed. It was shown that density of nonmetallic inclusions in steel of modern fabrication significant lower then in forgings of 70–80 years fabrication. The Charpy curve upper shelf depends on chemical composition, most of all from sulfur content. Lower content of sulfur in steel 15Kh2NMFAA modern fabrication comparing with steel 15Kh2NMFAA of 70–80 years fabrication reduce the nonmetallic inclusions density and increase the Charpy curve upper self. Decrease the sulfur content increase the specific energy of formation of ductile part of fracture surface and reduce transition temperature steel 15Kh2NMFAA in initial state. Keywords: impurity; durability characteristic; non-metallic constituent; upper shelf. Contacts: E-mail: anna.chernobaeva@gmail.com Pp. 106-118.