Effect of heat treatment on the mechanical properties of HT9 fuel cladding tube for Sodium-cooled Fast Reactor (SFR)

Abstract

Ferritic-martensitic cladding tube (12Cr1MoWV, HT9) was manufactured by KAERI as a part of developing fuel cladding for the Sodium-cooled Fast Reactor (SFR). After making steel ingot, followed by the multiple processes of tube reduction and the subsequent heat treatments, a seamless HT9 tubes having 7.4mm outer diameter, 0.56mm thickness and 3,000mm length could be manufactured. The objective of this report is to evaluate the effect of heat treatment on the mechanical properties of the HT9 tubes for the purpose of optimizing its performance. Cladding was normalized and tempered with the various temperature set and axial tensile test was carried out to find out the optimized heat treatment range.