Work

Thermo-Mechanical Fatigue in AISI 347 Austenitic Stainless Steel: Phase Transformation Kinetics at Elevated Temperatures

Year: 2025

Type: article

Abstract: Thermo-mechanical fatigue remains one of the more difficult phenomena to analyze due to the interplay between temperature, mechanical properties, and microstructural features of the material. For austenitic stainless steel, thermo-mechanical fatigue plays a particularly critical role—temperature changes the affinity of γ austenite to transform into α′ martensite under overcritical deformation. This paper presents the results of an in situ study of γ→α′ deformation-induced transformation kinetics at elevated temperatures in AISI 347. Fatigue tests were conducted in the temperature range of 20 to 320 °C. A uniaxial magnetic balance was used to directly measure the change in ferromagnetic volume fraction of the fatigue specimens as the fatigue load was applied. From this data, an empirical mathematical model was found. This model describes the kinetics of γ→α′ transformation as an exponential function of temperature, where the rate of phase transformation decreases with temperature, asymptotically approaching zero but never actually reaching it.

Source: Applied Sciences

DOI: 10.3390/app151810095

Authors: Viktor Lyamkin, Sascha Power, Christian Boller, Peter Starke

Institutions: University of Applied Sciences Kaiserslautern, Saarland University

Language: English

Topic: Fatigue and fracture mechanics

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,896

Funders: Universität des Saarlandes, Bundesministerium für Umwelt, Naturschutz, nukleare Sicherheit und Verbraucherschutz