Creep lifetime prediction of virgin and service-exposed Super304H austenitic stainless steel boiler tubes based on hierarchical multiscale analysis and creep cavitation model

ABSTRACT

Creep deformation of Super304H austenitic stainless steel boiler tubes in thermal power plants is evaluated using crystal elasto-viscoplastic finite element analysis (CEV-FEA). The material properties of Super304H at elevated temperatures are obtained from experiments and computations at different scales as follows: anisotropic elastic constants of Super304H at elevated temperatures (500–700°C) are obtained from molecular dynamics simulations; microstructures of virgin and service-exposed Super304H boiler tubes are observed using scanning electron microscopy; and macroscopic stress–strain and creep strain curves at 650°C are measured from tensile and miniature creep tests, respectively. Stress concentration evolution at a triple junction of grains featuring various combinations of crystallographic orientations in polycrystalline Super304H is evaluated using CEV-FEA during creep deformation. The remaining creep lifetime of polycrystalline Super304H austenitic stainless steel boiler tubes is estimated from the creep cavitation model, where the stress concentration at the triple junction is used as a representative stress driving creep cavitation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Crystal elasto-viscoplasticity
• finite element analysis
• Super304H
• creep lifetime
• creep cavitation

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science and ICT) [Grant Number NRF-2017R1A2B4012081] and the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea [Grant Number 20161110100090].