Study on microstructure and mechanical properties of P92 steel after high-temperature long-term aging at 650°C

• Published in: High temperature materials and processes Vol. 39; no. 1; pp. 545 - 555
• Main Authors: Duan, Peng, Liu, Zongde, Li, Bin, Li, Jiayao, Tao, Xiangqian
• Format: Journal Article
• Language: English
• Published: Berlin De Gruyter 20-10-2020; Walter de Gruyter GmbH
• Subjects: Aging; Aging (metallurgy); Elongation; Heat resistant steels; High strength steels; High temperature; Laves phase; long-term aging; Mechanical properties; Microstructure; Optical microscopes; P92 steel; Ultimate tensile strength
• ISSN: 0334-6455; 2191-0324
• DOI: 10.1515/htmp-2020-0087

A series of long-term high-temperature aging tests of ASME A335-P92 steel from 1,000 to 29,000 h at 650°C were carried out. The microstructure evolution of as-received and aging specimens at different stages was investigated using optical microscope observations, scanning electron microscope examinations, and TEM investigations. The static mechanical strength properties (yield strength/ultimate tensile strength) at room and 600°C test temperatures and the plastic performance (elongation/reduction in area) were also analyzed. The experimental results show that the Laves phase can be precipitated rapidly in the early aging period. After a certain aging period, the continuous precipitation of M
and the relatively high coarsening rate of Laves resulted in a rapid decrease of room and high-temperature mechanical properties in the early aging period. However afterwards for the long aging time, a slow decline in tendency of mechanical properties was presented.