Influence of the Functional Layer on the Operating Characteristics of Zr – 1% Nb Alloy at a Temperature of 380°С

• Published in: Materials science (New York, N.Y.) Vol. 57; no. 2; pp. 234 - 239
• Main Authors: Trush, V. S., Fedirko, V. М., Voyevodin, V. М., Lukyanenko, A. G., Stoev, P. І., Panov, V. А.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2021; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Fuels; Heat treatment; Materials Science; Niobium; Operating temperature; Solid Mechanics; Structural Materials; Tubes; Zirconium alloys; Zirconium base alloys; subsurface layer; thermochemical treatment; oxygen-nitrogen-containing media; zirconium alloy; mechanical properties
• ISSN: 1068-820X; 1573-885X
• DOI: 10.1007/s11003-021-00537-y

We study the influence of thermal treatment of fuel cladding tubes in various gas media on the short-term and long-term strengths at an operating temperature (380°C). The thermochemical treatment in nitrogen-containing media increases the short-term strength of annular specimens by ~ 30 MPa in the tests carried out in air at 380°C. At the same time, treatment in oxygen-containing media somewhat (by ~ 15 MPa) decreases this parameter. The highest long-term strength on a base of 100 h is exhibited by annular specimens after thermochemical treatment in nitrogen. The thermochemical treatment in oxygen-containing media guarantees a long-term strength of the tubes on the same level as after the standard heat treatment of fuel cladding tubes made of Zr – 1% Nb zirconium alloy. We reveal the character of fracture of the annular specimens of Zr – 1% Nb zirconium alloy depending on the medium and the mode of thermal treatment.