Evaluation of creep crack growth properties of Gr. 92 steel weldment

Issue title: International Conference on Fracture and Strength 2010 – From Physical to Holistic, Part 2

Article type: Research Article

Authors: Tabuchi, M.^; | Yokobori Jr., A.T. | Sugiura, R. | Yatomi, M. | Kobayashi, K.

Affiliations: National Institute for Materials Science, Tsukuba, Japan | Department of Nano Mechanics, Tohoku University, Sendai, Japan | IHI Corporation, Yokohama, Japan | Department of Urban Environmental Systems, Chiba University, Chiba, Japan

Note: [] Address for correspondence: M. Tabuchi, 1-2-1 Sengen, Tsukuba, 305-0047 Japan. Tel.: +81 29 859 2220; Fax: +81 29 859 2201; E-mail: [email protected].

Abstract: High Cr ferritic heat resistant steels are used for boiler components in ultra-super critical thermal power plants. In weld components of these steels, Type-IV creep damages formed in the fine-grained heat-affected zone (HAZ), causing their creep strength to decrease at high temperatures. To assist the standardization of the testing method for creep crack growth in weld components, we conducted round robin tests using ASME Grade 92 steel as part of the VAMAS TWA31 collaboration. The CCG tests were carried out using the CT specimen and the circumferentially notched round bar specimen for both the base metal and weld joint of Gr. 92 steel. The effects of specimen configuration, temperature, load and stress triaxiality conditions on the crack initiation and growth properties were investigated.

Keywords: Gr. 92 steel, weld joint, Type-IV failure, creep crack growth, FEM

DOI: 10.3233/SFC-2011-0132

Journal: Strength, Fracture and Complexity, vol. 7, no. 2, pp. 137-146, 2011