Time-dependent deformation behaviours of two stainless steels at elevated temperature: Correlation between slow strain rate and creep testing

Abstract

Austenitic stainless steels, such as Sanicro 25 and Sanicro 28, exhibit excellent mechanical properties at elevated temperatures. This study investigates their time-dependent deformation behaviours through two distinct testing methods: slow strain rate tensile (SSRT) and creep testing at 650 °C. Microstructural analysis revealed that Sanicro 25 has a finer grain structure and superior high-temperature resistance compared to Sanicro 28. The deformation and fac­ture mechanics have been evaluated. A novel strain energy rate approach was developed to correlate SSRT and creep test data, providing insights into the materials’ high-temperature performance. This study offers a new perspective for evaluating and optimizing stainless steels for demanding applications.

Keywords

• Austenitic stainless steels
• high-temperature deformation
• slow strain rate tensile (SSRT)
• creep
• fracture analysis
• strain energy rate