Finite element analysis of uniaxial and multiaxial state of stress on creep rupture behaviour of 2.25Cr–1Mo steel

Abstract Effect of multiaxial state of stress on creep rupture behaviour of 2.25Cr–1Mo steel has been investigated. Multiaxial state of stress during creep test has been introduced by incorporating two different circumferential U-notches in the uniaxial creep specimen. Creep tests on both plain and notched specimens were carried out at 873 K over a stress range of 90–210 MPa. The creep rupture life of the material was found to increase in presence of the notch with the consequent decrease in creep rupture ductility. The increase in rupture life was found to be more for relatively sharper notch. Finite element analysis coupled with continuum damage mechanics was carried out to understand the creep damage evolution during uniaxial and multiaxial creep exposures. The predicted uniaxial creep deformation and rupture life of the material were in good agreement with the experimental results. The creep rupture life of the notched specimen has been predicted and was found to be controlled predominantly by von-Mises stress. The creep damage in this steel under multiaxial state of stress was predominantly in the form of microstructural degradation with some evidences of intergranular creep cavitation especially at lower stresses.

[1]  M. D. Mathew,et al.  Finite element analysis of type IV cracking in 2.25Cr–1Mo steel weldment based on micro-mechanistic approach , 2011 .

[2]  D. R. Hayhurst,et al.  Skeletal point stresses in circumferentially notched tension bars undergoing tertiary creep modelled with physically based constitutive equations , 1993, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[3]  David R Hayhurst,et al.  Creep stress redistribution in notched bars , 1977 .

[4]  G. Eggeler,et al.  Creep rupture of circular notched p91-specimens influence of heat treatment and notch geometry , 1992 .

[5]  David R Hayhurst,et al.  Constitutive equations for creep rupture , 1977 .

[6]  Kamran Nikbin,et al.  Finite element analysis of notched bar skeletal point stresses and dimension changes due to creep , 2004 .

[7]  Thomas H. Hyde,et al.  Benchmarks for finite element analysis of creep continuum damage mechanics , 2002 .

[8]  G. Eggeler,et al.  The principal facet stress as a parameter for predicting creep rupture under multiaxial stresses , 1989 .

[9]  C. R. Calladine,et al.  Time-scales for redistribution of stress in creep of structures , 1969, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[10]  W. Nix.  Mechanisms and controlling factors in creep fracture , 1988 .

[11]  T. Noda,et al.  The role of microstructural instability on creep behavior of a martensitic 9Cr-2W steel , 1992 .

[12]  F. Leckie,et al.  The effect of creep constitutive and damage relationships upon the rupture time of a solid circular torsion bar , 1973 .

[13]  David R Hayhurst,et al.  Failure in notched tension bars due to high-temperature creep: Interaction between nucleation controlled cavity growth and continuum cavity growth , 2008 .

[14]  David R Hayhurst,et al.  Continuum damage mechanics analyses of type IV creep failure in ferritic steel crossweld specimens , 1999 .

[15]  David R Hayhurst,et al.  Development of continuum damage in the creep rupture of notched bars , 1984, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[16]  G. Eggeler,et al.  A numerical study of parameters controlling stress redistribution in circular notched specimens during creep , 1993 .

[17]  Percy Williams Bridgman,et al.  Studies in large plastic flow and fracture , 1964 .

[18]  T. B. Gibbons,et al.  Tertiary creep in nickel-base superalloys: analysis of experimental data and theoretical synthesis , 1987 .

[19]  Kamran Nikbin,et al.  A Code of Practice for conducting notched bar creep tests and for interpreting the data , 2004 .

[20]  F. A. Leckie,et al.  Creep problems in structural members , 1969 .

[21]  Thomas H. Hyde,et al.  Prediction of creep failure in aeroengine materials under multi-axial stress states , 1996 .

[22]  E. Ellison,et al.  Influence of constraint on creep stress distribution in notched bars , 1984 .

[23]  R. T. Fenner,et al.  Steady-State stress distributions in circumferentially notched bars subjected to creep , 1982 .

[24]  F. Leckie,et al.  Creep rupture of notched bars , 1978, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[25]  Thomas H. Hyde,et al.  Failure prediction for multi-material creep test specimens using a steady-state creep rupture stress , 2000 .

[26]  David R Hayhurst,et al.  Creep rupture under multi-axial states of stress , 1972 .