Law of Crack Growth Life for P92 Steel Under the Conditions of Creep-Fatigue Multiplication and Projection of the Threshold Temperature of Creep Crack Growth Based on This Law

2009 ◽  
Author(s):  
A. T. Yokobori ◽  
R. Sugiura ◽  
S. Kimoto ◽  
D. Yoshino ◽  
T. Matsuzaki
Keyword(s):  
Crack Growth ◽  
Creep Crack Growth ◽  
Transition Function ◽  
Holding Time ◽  
Time Dependent ◽  
Threshold Temperature ◽  
P92 Steel ◽  
Operational Costs ◽  
Creep Fatigue ◽  
Heat Resistant Steels

W-added 9Cr ferritic heat-resistant steels, ASME grade P92, are used under the high temperature creep-fatigue condition. Concerning the maintenance of the operational safety and minimizing operational costs, it is necessary to construct a law of predicting the crack growth life by clarifying the dominant factors of the crack growth life under the condition of creep-fatigue multiplication (the effect of stress holding time on the time-dependent fracture). In this study, crack growth tests under the conditions of creep-fatigue multiplication were conducted with various conditions of stress holding time, applied stress and temperatures. As a result, a unified law of predicting the crack growth life under the conditions of creep-fatigue multiplication was derived based on the concept of Q* with the transition function of crack growth life from fatigue to creep.

Creep crack growth laws in heat-resistant steels

1991 ◽  
Vol 40 (6) ◽  
pp. 1147-1163 ◽  
Author(s):  
V.A. Vainshtok ◽  
M.V. Baumshtein ◽  
I.A. Makovetskaya ◽  
I.V. Kramarenko
Keyword(s):  
Crack Growth ◽  
Creep Crack Growth ◽  
Creep Crack ◽  
Heat Resistant ◽  
Growth Laws ◽  
Heat Resistant Steels

Characteristic of Crack Growth Life for W Added 9Cr Ferritic Heat Resistant Steel Under the Conditions of High Temperature Creep-Fatigue Multiplication Based on Non-Equilibrium Science

2007 ◽  
Author(s):  
A. T. Yokobori ◽  
R. Sugiura ◽  
D. Yoshino ◽  
M. Tabuchi ◽  
Y. Hasegawa
Keyword(s):  
Crack Growth ◽  
Resistant Steel ◽  
Boiler Tube ◽  
Tube Material ◽  
P92 Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Creep Fatigue ◽  
Cycle Dependent ◽  
Non Equilibrium

The W added 9Cr ferritic heat resistant steel ASME grade P92, developed as a boiler tube material, is used under the conditions of creep-fatigue multiplication. In this paper, using P92 steel, crack growth tests under the conditions of creep-fatigue multiplication were conducted and the effects of cycle-dependent and time-dependent mechanisms on the crack growth life tf were investigated. Furthermore, on the basis of the concept of non-equilibrium science, the multiple effects of creep and fatigue on the crack growth life tf were clarified.

Prediction of creep crack growth behavior in ASME P92 steel welded joint

2012 ◽  
Vol 61 ◽  
pp. 185-193 ◽  
Author(s):  
Lei Zhao ◽  
Hongyang Jing ◽  
Yongdian Han ◽  
Junjie Xiu ◽  
Lianyong Xu
Keyword(s):  
Crack Growth ◽  
Welded Joint ◽  
Creep Crack Growth ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
P92 Steel ◽  
Creep Crack

Assessment of Creep and Creep-Fatigue Crack Growth Following the R5 Procedures

2003 ◽  
Author(s):  
R. A. Ainsworth ◽  
P. J. Budden ◽  
D. W. Dean ◽  
M. J. H. Fox ◽  
M. P. O’Donnell ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
High Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Creep Crack Growth ◽  
Single Procedure ◽  
Technical Developments ◽  
Creep Fatigue ◽  
Creep Fatigue Crack ◽  
Assessment Procedures

Parts of the R5 high temperature assessment procedures address creep and creep-fatigue crack growth. The procedures were developed some years ago as separate approaches for creep crack growth (R5 Volume 4) and creep-fatigue crack growth (R5 Volume 5). A major revision to these procedures has recently been completed. This unifies the separate approaches into a single procedure for creep-fatigue crack growth (R5 Volume 4/5). The revision restructures the procedure for easier application and includes a number of technical developments, including criteria for deciding when creep-fatigue interactions are important. This paper describes in outline the new R5 creep-fatigue crack growth procedure.

Effects of Stress Ratio and Hold-Time on Fatigue Crack Growth in Alloy 718

1979 ◽  
Vol 101 (3) ◽  
pp. 224-230 ◽  
Author(s):  
P. Shahinian ◽  
K. Sadananda
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stress Ratio ◽  
Hold Time ◽  
Creep Crack Growth ◽  
Time Dependent ◽  
J Integral ◽  
Alloy 718 ◽  
Test Conditions

Crack growth rate da/dN in Alloy 718 at 650°C, compared on the conventional ΔK basis, increased with increase in R (Kmin/Kmax) and also generally with inclusion of hold time at Kmax and Kmin. An exception, however, was that a 1-min hold at a Kmin just below the threshold K for creep crack growth caused retardation of crack growth. Correlation of da/dN for various R levels was better with Kmax than with other parameters such as Kmin, ΔK, and Δ J-integral. Fatigue crack growth in the alloy was found to be time dependent and Kmax controlled under these test conditions and consequently the best overall correlation was given by da/dt with Kmax. An unusual observation was that the addition of hold time to the loading cycle at near zero Kmin (R = 0.05) caused an increase in da/dN, as the result of an environmental interaction.

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