基于微裂纹扩展的疲劳蠕变寿命预测方法.pdf

44 10 Vol.44 No.10 2008 10 1167—1170  ACTA METALLURGICA SINICA Oct. 2008 pp.1167–1170 ∗ 1,2)  1) 1) 1,2) 2) 1) , 230031 2) , 230027 , , . . Tomkins , C∗ Æ. 1.25Cr0.5Mo 540 , . Æ , , , O346.2, TG142.33 A 0412−1961(2008)10−1167−04 PREDICTION METHOD OF FATIGUE CREEP LIFE BASED ON MICROCRACK PROPAGATION DONG Jie 1,2), CHEN Xuedong 1), FAN Zhichao 1), JIANG Huifeng 1,2), LU Shouxiang 2) 1) National Technology Research Center on Pressure Vessel and Pipeline Safety Engineering, Hefei 230031 2) Department of Safety Science and Engineering, University of Science and Technology of China, Hefei 230027 Correspondent: DONG Jie, Tel: (0551)5335485, E-mail: Jiedong@mail.ustc.edu.cn Supported by National Key Technologies RD Program of China (No.2006BAK02B02–02) and Nat- ural Science Foundation of Anhui Province (No.070415223) Manuscript received 2008–01–15, in revised form 2008–06–13 ABSTRACT On the basis of the concept of equivalent crack, theories of crack growth and the point of failure induced by microcrack propagation, a new fatigue creep life prediction model was presented. The influences of time–independent fatigue, time–dependent static creep and cyclic creep were considered in the model to investigate microcrack growth. Tomkins microcrack growth model was applied to describe time–independent fatigue crack propagation, and C ∗ was set as the control parameter for time–dependent creep crack propagation. The fatigue creep life with stress controlled at 540 for the 1.25Cr0.5Mo steel was predicted by the model. The predicted results are correlated well with the experimental ones. KEY WORDS microcrack