Microstructure and mechanical properties of TP347HFG austenitic stainless steel after long-term service

• Published in: The International journal of pressure vessels and piping Vol. 188; p. 104160
• Main Authors: Golański, G., Zieliński, A., Sroka, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2020
• Subjects: Mechanical properties; Microstructure; TP347HFG austenitic Stainless steel; TP347HFG austenitic Stainless steel; Mechanical properties; Microstructure
• ISSN: 0308-0161; 1879-3541
• DOI: 10.1016/j.ijpvp.2020.104160

The paper presents the results of research on the microstructure and mechanical properties of TP347HFG steel after long-term service. The test samples for research were taken from the coil of a boiler superheater serviced for 105 000 h at a steam pressure of 12.5 MPa at the temperature of 540 °C. The tests have shown that the process of long-term service of the steel mostly contributed to the processes of precipitation of secondary particles: M23C6 and MX, and the matrix recovery. The changes in the microstructure of the steel had a fairly minor influence on the strength and creep properties. The extent of degradation of the steel microstructure and mechanical properties was relatively minor, which resulted from its low temperature of service.
•Austenitic creep-resistant TP347HFG steel after long-term service has been investigated .•Changes in the microstructure after long-term service havebeen examined .•Precipitation of the secondary carbides NbC and M23C6 was observed after service.•Decrease in plastic properties and impact energy was observed.