BARC/PUB/2015/0777

 
 

Influence of loading rate and hydrogen content on fracture toughness of Zr-2.5Nb pressure tube material

 
     
 
Author(s)

Bind, A. K.; Singh, R. N.; Khandelwal, H. K.; Sunil, S.; Avinash, G.; Chakravartty, J. K.; Stahle, P.
(MMD)

Source

Journal of Nuclear Materials, 2015. Vol. 465: pp. 177-188

ABSTRACT

For the safety assessment of PHWR, it is required to study the flaw tolerance capacity of the pressure  tubes as a function of the loading rate. In this work, the effect of loading rate and hydrogen content on the fracture behaviour of a Zr-2.5Nb alloy pressure tube was investigated between 25 and 300 oC. For the as received material, the pulling rate only had an effect on fracture toughness at 25 oC whereas for hydrided material the pulling rate affected fracture toughness in the transition regime. For all pulling rates, hydrided materials showed typical S curve behavior with an increase in lower shelf, upper shelf and transition temperature with pulling rate. The number of axial splits on fracture surfaces increased with an increase in the pulling rate and a decrease in temperature and fracture toughness was found to decrease with an increase in the number of axial splits. The reduction in fracture toughness is attributed to a localised deformation between axial splits.

 
 
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