On the Creep Fracture Toughness of 2¼Cr1Mo Steel
To assess the failure risk of high temperature structures, it is essential to obtain the creep fracture toughness of materials. In the present paper, Creep crack growth (CCG) tests for 2¼Cr1Mo steel have been carried out by utilizing the side grooved compact tension (CT) specimen and direct current (DC) electrical potential technique. The material parameter of creep fracture toughness, c mat K , were obtained from analysis of 11 CCG tests at temperatures of 500 and 565oC. It has been found that for 2¼Cr1Mo steel c mat K decreases with increasing time and increases with elevating temperature. For this reason, the value of c mat K at lower temperature or longer service time can be used to extract a conservative result in the high temperature defect assessment where the accurate value of c mat K is unavailable. It is also validated from this test that the proposed formula by Ainsworth et al can be adopted in practice.
Young-Jin Kim, Dong-Ho Bae and Yun-Jae Kim
F. Z. Xuan et al., "On the Creep Fracture Toughness of 2¼Cr1Mo Steel ", Key Engineering Materials, Vols. 297-300, pp. 1464-1469, 2005