Creep Curve Modeling of Hastelloy-X Alloy by Using the Nonlinear Regression Method in the Kachanov-Rabotnov Creep Model

Abstract:

To design HTGR components for up to 1000oC, their creep curves are necessary during a design process. In this study, the full creep curves were modeled by the nonlinear least square fitting method using the Kachanov-Rabotnov (K-R) creep model. A series of creep data was obtained experimentally under various stress levels for Hastelloy-X at 950oC, and the data was used to model the creep curves. The K-R model gave a poor description of modeling creep curves, but the modified K-R one, which has another variable, K in the K-R model, was in better agreement than the K-R one. It was found that the λ parameter in the K-R model was constant regardless of the stress variations. The λ value was about 3.9 for the K-R model and about 5.8 for the modified one.

• Periodical: Key Engineering Materials (Volumes 345-346)
• Pages: 589-592
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.345-346.589
• Online since: August 2007
• Authors: Woo Gon Kim, Song Nan Yin, Woo Seog Ryu, Yong Wan Kim, Won Yi
• Keywords: Creep, Creep Curve, Hastelloy X, High Temperature Gas Cooled Reactor (HTGR), Kachanov-Rabotnov(K-R), Nonlinear Least-Squares Method

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