Optimization of the Medium of Thermal Treatment of GFE-1 Hafnium Alloy

• Published in: Materials science (New York, N.Y.) Vol. 53; no. 2; pp. 194 - 199
• Main Authors: Trush, V. S., Fedirko, V. M., Luk’yanenko, O. H., Kovtun, K. V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2017; Springer; Springer Nature B.V
• Subjects: Alloys; Atmospheric pressure; Bending fatigue; Characterization and Evaluation of Materials; Chemistry and Materials Science; Diffusion layers; Fatigue (Materials); Fatigue life; Hafnium; Hafnium base alloys; Hardening; Heat treatment; Materials Science; Nuclear energy; Oxygen; Plastic deformation; Solid Mechanics; Solution strengthening; Specialty metals industry; Structural Materials; oxygen-containing gas medium; subsurface layer; fractography; thermochemical treatment; hafnium alloy; fatigue life
• ISSN: 1068-820X; 1573-885X
• DOI: 10.1007/s11003-017-0062-2

We optimize the conditions of thermochemical treatment of the plates (~ 1 mm) made of GFE-1 hafnium alloy after plastic deformation from the viewpoint of the influence of interstitial elements (oxygen) on the solid-solution hardening of the subsurface layers and the fatigue durability of the hafnium specimens subjected to symmetric pure bending. It is shown that the thermochemical treatment ( T = 850°C, τ = 2 h) performed in the oxygen-containing gaseous atmosphere at P = 1.33·10 −2 Pa leads to the formation of a diffusion-hardened subsurface layer on the GFE-1 hafnium specimens, which increases their fatigue life (for the strain amplitude ± ε a = 0.6%) as compared with the other levels of pressure of the same medium. The fracture of the specimens of GFE-1 hafnium alloy subjected to the thermochemical treatment in oxygen-containing rarefied gas atmospheres under various pressures is investigated.