A Critical Analysis of the Conventionally Employed Creep Lifing Methods

The deformation of structural alloys presents problems for power plants and aerospace applications due to the demand for elevated temperatures for higher efficiencies and reductions in greenhouse gas emissions. The materials used in such applications experience harsh environments which may lead to deformation and failure of critical components. To avoid such catastrophic failures and also increase efficiency, future designs must utilise novel/improved alloy systems with enhanced temperature capability. In recognising this issue, a detailed understanding of creep is essential for the success of these designs by ensuring components do not experience excessive deformation which may ultimately lead to failure. To achieve this, a variety of parametric methods have been developed to quantify creep and creep fracture in high temperature applications. This study reviews a number of well-known traditionally employed creep lifing methods with some more recent approaches also included. The first section of this paper focuses on predicting the long-term creep rupture properties which is an area of interest for the power generation sector. The second section looks at pre-defined strains and the re-production of full creep curves based on available data which is pertinent to the aerospace industry where components are replaced before failure.

[1]  M. Evans.  Method for improving parametric creep rupture life of 2.25Cr-1Mo steel using artificial neural networks , 1999 .

[2]  P. J. Scharning,et al.  A new methodology for analysis of creep and creep fracture data for 9–12% chromium steels , 2008 .

[3]  C. Leyens,et al.  Titanium and titanium alloys : fundamentals and applications , 2005 .

[4]  P. J. Scharning,et al.  The θ projection method applied to small strain creep of commercial aluminium alloy , 2001 .

[5]  B. Wilshire,et al.  Creep and creep fracture of polycrystalline copper , 2007 .

[6]  P. J. Scharning,et al.  Prediction of long term creep data for forged 1Cr–1Mo–0·25V steel , 2008 .

[7]  Mark Whittaker,et al.  Creep and creep fracture of 2.25Cr–1.6W steels (Grade 23) , 2010 .

[8]  S. Manson,et al.  Stress-Rupture Properties of Inconel 700 and Correlation on the Basis of Several Time-Temperature Parameters , 1956 .

[9]  I. Mamuzic,et al.  Correlation of Creep-Rupture Data for Complex Alloys at Elevated Temperatures , 2007 .

[10]  R. P. Carreker.  Plastic Flow of Platinum Wires , 1950 .

[11]  Mark Whittaker,et al.  Advanced Procedures for Long-Term Creep Data Prediction for 2.25 Chromium Steels , 2012, Metallurgical and Materials Transactions A.

[12]  M. Whittaker,et al.  Creep fracture of the centrifugally-cast superaustenitic steels, HK40 and HP40 , 2013 .

[13]  Steve Brown,et al.  Creep strain and creep life prediction for the cast nickel-based superalloy IN-100 , 1986 .

[14]  E. C. Larke,et al.  Paper 50: A Critical Examination of Some Methods of Analysing and Extrapolating Stress-Rupture Data , 1963 .

[15]  Mark Whittaker,et al.  The role of grain boundaries in creep strain accumulation , 2009 .

[16]  D. L. Marriott,et al.  Design for creep , 1972 .

[17]  B J Cane,et al.  Creep life assessment methods , 1994 .

[18]  C. R. Ensign,et al.  Interpolation and extrapolation of creep rupture data by the minimum commitment method. I - Focal-point convergence , 1978 .

[19]  M. Evans.  Sensitivity of the theta projection technique to the functional form of the theta interpolation/extrapolation function , 2002 .

[20]  S. Williams,et al.  Advances in the Wilshire extrapolation technique—Full creep curve representation for the aerospace alloy Titanium 834 , 2012 .

[21]  R. Evans.  The θ projection method and low creep ductility materials , 2000 .

[22]  Stuart Holdsworth,et al.  The European Creep Collaborative Committee (ECCC) Approach to Creep Data Assessment , 2008 .

[23]  Mark Evans,et al.  Long-term creep data prediction for type 316H stainless steel , 2012 .

[24]  S. S. Manson,et al.  A linear time-temperature relation for extrapolation of creep and stress-rupture data , 1953 .

[25]  J. E. Dorn,et al.  CORRELATIONS OF RUPTURE DATA FOR METALS AT ELEVATED TEMPERATURES , 1953 .

[26]  M. Bache,et al.  25 Year Perspective Recent developments in analysis of high temperature creep and creep fracture behaviour , 2010 .

[27]  R. W. Evans,et al.  Design of a creep resistant nickel base superalloy for power plant applications: Part 3 - Experimental results , 2003 .

[28]  S. K. Ray,et al.  Larson–Miller correlation for the effect of thermal ageing on the yield strength of a cold worked 15Cr–15Ni–Ti modified austenitic stainless steel , 2006 .