The applicability of the strain-hardening rule to creep deformation of Zircaloy fuel cladding tube under dry storage condition

Variable stress and temperature creep tests were carried out at temperatures between 626 and 693 K for the Zircaloy-4 tubular specimens in the hoop stress regime 55 to 125 MPa to examine the applicability of the strain hardening rule to creep deformation of Zircaloy-4 fuel cladding tube. Results were compared with those of the constant temperature/stress tests, indicating that the strain hardening rule but not the time hardening rule can be applicable for predicting creep deformation of fuel cladding tube at temperatures tested. It is also suggested that although Zircaloy-4 fuel cladding tube tends to deform under multiaxial condition, it can satisfy the requirements for the strain hardening rule at temperatures of interest during dry storage condition.