Journal Published Online: 01 May 1989
Volume 17, Issue 3

Influence of Heat Treatment on Structure and Oxidation Behavior of Zr-2.5Nb



This paper presents the influence of different heat treatments on the microstructure and isothermal oxidation behavior of Zr-2.5Nb in oxygen. The quenched structure consisted of martensitic α′. Upon tempering the quenched alloy at 500°C for up to 100 h, βNb precipitated in the matrix, at twin and α′ needle boundaries. At higher tempering temperatures and after longer periods, Nb-rich βZr also precipitated. Specimens slowly cooled from the β-phase showed the least resistance to oxidation. The oxidation behavior also varied with the tempering time and temperature. The increased oxidation rate of specimens tempered at 500°C for 1000 h or at 600°C, as compared to those tempered at 500°C for shorter times, has been attributed to formation of Nb containing oxides on the coalesced Nb-rich precipitates and to cracking.

Author Information

Ramanathan, LV
University of Manchester, São Paulo, England
Costa, I
University of Manchester, São Paulo, England
Monteiro, WA
University of Manchester, São Paulo, England
Pages: 9
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Stock #: JTE11108J
ISSN: 0090-3973
DOI: 10.1520/JTE11108J