Fatigue Behavior of K447A Superalloy under Low Cycle Fatigue and Creep-Fatigue Interaction Conditions

Abstract:

Strain-controlled low cycle fatigue (LCF) and creep-fatigue interaction (CFI) tests of K447A are conducted at 760oC in order to investigate the effects of different dwell times and strain ratios on the fatigue behavior and life. For the cases of stain ratio R_ε=-1 with balanced hold time, the tensile and compressive mean stresses will generate. For the case of stain ratio R_ε=-1 with compressive holding 60s, the tensile mean stress will produce. For the case of stain ratio R_ε=-1 with tensile holding 60s, the compressive mean stress will produce. For the cases of stain ratio R_ε=0.1 and R_ε=-1with no hold time, the tensile mean stress will produce. The cyclic damage accumulation (CDA) method and modified CDA method were employed to predict the fatigue life for K447A, respectively. The fatigue life predicted by CDA method is within the scatter band of 18.2X. The fatigue life predicted by the modified CDA method agrees very well with the experimental life and the predicted life is well within the scatter band of 3.1X, which means that the modified CDA method is able to consider the influences of dwell time and strain ratio on the fatigue life of K447A.

• Periodical: Applied Mechanics and Materials (Volume 750)
• Pages: 121-126
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.750.121
• Online since: April 2015
• Authors: Hui Chen Yu*, Cheng Li Dong, Ying Li
• Keywords: Creep-Fatigue Interaction, Cyclic Damage Accumulation, Dwell Time, Low Cycle Fatigue, Superalloy

References

[1] S.K. Bhaumik, T.A. Bhaskaran, Failure of turbine rotor blisk of an aircraft engine, Eng. Fail. Anal., 9(2002)287-301.

DOI: 10.1016/s1350-6307(01)00017-6

[2] A.L. Li, X. Tang, L.M. Cao, Q.D. Gai, Creep-fatigue life assessment of cruciform weldments using the linear matching method, J. Aeronaut. Mater., 32(2012)13-19.

[3] Y. Gorash, H.F. Chen, Creep-fatigue life assessment of cruciform weldments using the linear matching method, Int. J. Pres. Ves. Pip., 104(2013)1-13.

DOI: 10.1016/j.ijpvp.2012.12.003

[4] R. Lagneberg, R. Atterno, The effect of combined low-cycle fatigue and creep on the life of austenitic stainless steels, Metal. Mater. Trans., 7(1971)1821-1827.

DOI: 10.1007/bf02913411

[5] G.R. Halford, M.H. Hirschberg, S.S. Manson, Temperature effects on the strain range partitioning approach for creep fatigue analysis, ASTM STP(1973).

DOI: 10.1520/stp38877s

[6] S. P, Zhu, H.Z. Huang, L.P. He, Y. Liu, Z.L. Wang, A generalized energy-based fatigue–creep damage parameter for life prediction of turbine disk alloys, Eng. Fract. Mech., 90(2012)89-100.

DOI: 10.1016/j.engfracmech.2012.04.021

[7] G.X. Cheng, A. Plumtree, A fatigue damage accumulation model based on continuum damage mechanics and ductility exhaustion, Int. J. Fatigue., 20(1998)495-501.

DOI: 10.1016/s0142-1123(98)00018-8

[8] J.P. Jing, G. Meng, Y. Sun, S.B. Xia. An effective continuum damage mechanics model for creep-fatigue life assessment of a steam turbine rotor, Int. J. Pres. Ves. Pip., 80 (2003)389-396.

DOI: 10.1016/s0308-0161(03)00070-x

[9] R.S. Nelson, G.W. Levan, P.R. Harvey, Creep fatigue life prediction for engine hot section materials (isotropic), NASA-CR-189221, Final Report(1993).

[10] J.L. Liu, X.G. Yang, D.Q. Shi, Fatigue life prediction model for Nickel-based directionally solidified superalloy considered complex loading and orientation, Gas. Turbo. Exp. Res., 4(2013) 495-501.