Oxidation and fatigue crack propagation in the range of low stress intensity factor in relation to the microstructure in P122 Cr–Mo steel

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2009-01, Vol.499 (1), p.262-266
• Main Authors: Bae, S.Y., Kang, H.G., Yun, H.S., Kim, C.W., Lee, D.B., Lim, B.S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Corrosion; Corrosion mechanisms; Exact sciences and technology; Fatigue; Fractures; HAZ (heat-affected zone); High temperature; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; P122; Weldment
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.04.076

Fatigue strength and life of weldment at high temperatures are important for the materials in power plants. The fatigue crack growth rate is accelerated by oxidation. Similarly, the high-temperature fatigue life is influenced by oxidation. The base metal, the weld metal and the heat-affected zone (HAZ) of the P122 (Cr–Mo steel) weldment were oxidized between 600 °C and 700 °C for up to 500 h in air, and their oxidation behavior was examined. The oxidation resistance increased in the order of HAZ, base metal and weld metal. The scales were mainly Fe 2O 3. Fatigue tests were performed to measure the fatigue crack growth rate in the range of low stress intensity factor, and the results are discussed from the viewpoint of different microstructures and oxidation.