EVOLUTION OF LAVES PHASE PARTICLES IN A 9 %CR-3 %CO-3 %W MARTENSITIC STEEL DURING CREEP AT 650 °C

1 FEDOSEEVA Alexandra
Co-authors:
1 DUDOVA Nadezhda 1 KAIBYSHEV Rustam
Institution:
1 Belgorod State University, Belgorod, Russian Federation, fedoseeva@bsu.edu.ru
Conference:
27th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 23rd - 25th 2018
Proceedings:
Proceedings 27th International Conference on Metallurgy and Materials
Pages:
681-687
ISBN:
978-80-87294-84-0
ISSN:
2694-9296
Published:
24th October 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
15 views / 4 downloads
Abstract

9 % Cr martensitic steels are perspective candidates for elements of boilers, steam pipes and tubes for novel fossil fuel power plants which are able to work at ultra-supercritical parameters of steam (T = 600 - 620 °C, P = 25 - 30 MPa). Crept structure and creep properties of 0.1С-9Сr-3Co-3W-VNbBN steel after creep tests at 650 °C under a stress of 100 – 220 MPa with a step of 20 MPa were studied. During first 5.000 h, Laves phase particles are essentially stable their sizes remain unchanged, while after 5.000 h the extensive coarsening of these precipitates starts to occur. The coarsening of the Laves phase particles was also calculated using the Prisma software. The results of the calculations are corroborated by experimental observations. There are three features of microstructural evolution of the Laves phase particles during creep in the steel studied. First, volume fraction of Laves phase increases with time. Second, there is well-defined peak in the size distribution of Laves phase. Third, interfacial energy of Laves phase changes with transition from short-term creep to long-term creep.

Keywords: Creep-resistant steel, tempered lath martensite, Ostwald ripening, Laves phase particles
Scroll to Top