High-temperature creep life prediction of 9%Cr steel based on creep cavitation modelling

ABSTRACT

In present work, the creep rupture life of 9% Cr heat-resistant steel (P91) was evaluated based on the creep cavitation modelling. At 873 K, a series of creep rupture tests were carried out under the stresses of 140–190 MPa to achieve several sets of ruptured specimens . The constrained and unconstrained models of cavity growth were introduced to investigate the creep behaviour of P91 steel. The obtained results showed that the rupture mechanism of these specimens was mainly attributed to the ductile rupture under the present creep conditions. Besides, reasonable extrapolations were calculated to predict the creep rupture life of P91 steel by combining different constitutive equations with the cavity growth model. It suggested that the model predictions with constraints were better than those with unconstrained conditions. In particular, the Sinh equation based constrained cavity model shows greater potential in predicting the long-term creep life of P91 steel.

KEYWORDS:

• Heat-resistant steel
• high temperature creep
• cavity behaviour
• life prediction

Nomenclature

Table

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data are being used as part of an ongoing study.

Additional information

Funding

The authors would like to acknowledge the assistance from the National Natural Science Foundations of China (Grant No. 61901373) and Natural Science Foundation of Shaanxi Provincial Department of Education (Program No. 21JK0939).