Cavitation damage and creep crack growth

1981 ◽  
Vol 12 (2) ◽  
pp. 173-181 ◽  
Author(s):  
R. Pilkington ◽  
D. A. Miller ◽  
D. Worswick
Keyword(s):  
Crack Growth ◽  
Creep Crack Growth ◽  
Cavitation Damage ◽  
Creep Crack

The Linkage Between Microscopic Cavitation Damage and Macroscopic Crack Growth

2000 ◽  
Vol 122 (3) ◽  
pp. 279-282 ◽  
Author(s):  
P. R. Onck ◽  
B.-N. Nguyen ◽  
E. van der Giessen
Keyword(s):  
Crack Growth ◽  
Power Law ◽  
Scale Up ◽  
Creep Crack Growth ◽  
Stress Fields ◽  
Process Window ◽  
Macroscopic Scale ◽  
Cavitation Damage ◽  
Creep Crack ◽  
Random Nucleation

This paper is concerned with a recent microstructural approach to model creep crack growth. The model spans three different length scales, from the scale of individual cavities, through the grain scale up to the macroscopic scale of cracks in components and test specimens. In order to study the initial stages of creep crack growth, we consider a near-tip process window in which a large number of grains are represented discretely. This window is surrounded by a standard continuum. Macroscopic specimen dimensions and loading configuration are communicated to this near-tip region by applying boundary conditions in accordance with the asymptotic stress fields for power-law creeping materials. The paper presents some novel results of this type of modeling obtained using remote higher-order crack-tip fields. Specific attention is focused on the effect of random nucleation and grain deformation on nonsymmetric crack growth from either initially sharp or blunt cracks. [S0094-4289(00)00703-9]

Creep crack growth and cavitation damage in a 12% CrMoV steel

1989 ◽  
Vol 37 (10) ◽  
pp. 2733-2741 ◽  
Author(s):  
C. Wiesner ◽  
J.C. Earthman ◽  
G. Eggeler ◽  
B. Ilschner
Keyword(s):  
Crack Growth ◽  
Creep Crack Growth ◽  
Cavitation Damage ◽  
Creep Crack

Creep Crack Growth and Cavitation Damage

1981 ◽  
pp. 525-541 ◽  
Author(s):  
R. Pilkington ◽  
D. A. Miller ◽  
D. Worswick
Keyword(s):  
Crack Growth ◽  
Creep Crack Growth ◽  
Cavitation Damage ◽  
Creep Crack

Estimation of Creep Crack Growth Properties Using Circumferential Notched Round Bar Specimen for 12CrWCoB Rotor Steel

2005 ◽  
Vol 297-300 ◽  
pp. 397-402
Author(s):  
Je Chang Ha ◽  
Joon Hyun Lee ◽  
Masaaki Tabuchi ◽  
A.Toshimitsu Yokobori Jr.
Keyword(s):  
Crack Growth ◽  
Axial Stress ◽  
Creep Crack Growth ◽  
Turbine Rotor ◽  
Rotor Steel ◽  
Creep Ductility ◽  
Crack Growth Behaviour ◽  
Creep Crack ◽  
Round Bar ◽  
Growth Properties

Most heat resisting materials in structural components are used under multi-axial stress conditions and under such conditions ductile materials often exhibit brittle manner and low creep ductility at elevated temperature. Creep crack initiation and growth properties are also affected by multi-axial stress and it is important to evaluate these effects when laboratory data are applied to structural components. Creep crack growth tests using circumferential notched round bar specimens are a simple method to investigate multi-axial stress effects without using complicated test facilities. Creep crack growth tests have been performed using a 12CrWCoB turbine rotor steel. In order to investigate the effects of multi-axial stress on creep crack growth properties, the tests were conducted for various notch depths at 650°C. The circumferential notched round bar specimen showed brittle crack growth behaviour under multi-axial stress conditions. Creep crack growth rate was characterized in terms of the C* parameter. A 12CrWCoB turbine rotor steel has been tested using circumferential notched round bar specimens with different multi-axiality. Circumferential notched round bar specimens show increased brittle creep crack growth behaviour due to the multi-axial stress condition. Creep crack growth properties could be predicted by allowing for the decrease of creep ductility under multi-axial conditions.

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