Fatigue Life Evaluation of Pipe Welds in Power Plant Using Advanced Nondestructive Methods

2007 ◽  
Vol 26-28 ◽  
pp. 1251-1254
Author(s):  
Sang Guk Lee ◽  
Keun Bong Yoo ◽  
Sung Keun Park ◽  
Duck Gun Park
Keyword(s):  
Fatigue Life ◽  
Power Plant ◽  
Fatigue Damage ◽  
Pipeline Steel ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Life Evaluation ◽  
Fatigue Life Evaluation

The objective of this study is to estimate the feasibility of advanced nondestructive method(X-ray diffraction, AE(acoustic emission) and BN(barkhausen noise)measurement application for fatigue life evaluation of the high-temperature pipeline steel such as main steam pipe etc. in power plant. In this study, various nondestructive tests using various types of specimen simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages such as 1/4, 1/2 and 3/4 of fatigue life, respectively. As a result of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio. And also, AE and BN signal due to fatigue damage has linear relationship with fatigue life ratio algebraically. From this relationship, it was suggested that direct expectation of the life consumption rate was feasible.

Assessment of Fatigue Life for High-Temperature Pipeline Welds Using X-Ray Diffraction Technique

2007 ◽  
Vol 353-358 ◽  
pp. 130-133
Author(s):  
Keun Bong Yoo ◽  
Jae Hoon Kim
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Diffraction Method ◽  
Life Assessment ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray

The objective of this study is to examine the feasibility of the X-ray diffraction method for the fatigue life assessment of high-temperature steel pipes used for main steam pipelines, re-heater pipelines and headers etc. in power plants. In this study, X-ray diffraction tests were performed on the specimens simulated for low cycle fatigue damage, in order to estimate fatigue properties at the various stages of fatigue life. As a result of X-ray diffraction tests, it was confirmed that the full width at the half maximum (FWHM) decreased with an increase in the fatigue life ratio, and that the FWHM and the residual stress due to fatigue damage were algebraically linearly related to the fatigue life ratio. From this relationship, a direct assessment of the remaining fatigue life was feasible.

Investigation of Residual Stresses in a Sleeve Coldworked Lug Specimen by Neutron and X-ray Diffraction

1994 ◽  
Vol 38 ◽  
pp. 455-461
Author(s):  
R. Lin ◽  
B. Jaensson ◽  
T. M. Holden ◽  
R. B. Rogge ◽  
J. H. Root
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Aircraft Industry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initiation And Propagation ◽  
Structural Parts ◽  
Compressive Residual Stresses

Sleeve coldworking (SCW) is a mechanical process used in the aircraft industry to strengthen fastener holes of structural parts. By cold-expanding the holes, compressive residual stresses and a high dislocation density are introduced around the holes, the effect of which is to counteract the initiation and propagation of fatigue cracks and thus increase the fatigue life of the parts. The knowledge of residual stress due to SCW is therefore crucial for assessing the fatigue properties of a treated part. In this study, residual stresses were investigated, by employing neutron and X-ray diffraction methods, in a lug specimen that was sleeve coldworked and fatigued. The specimen had been used for testing the influence of the SCW process on fatigue life and crack propagation behaviour under constant amplitude or variable amplitude cyclic loading.

Characterization of low cycle fatigue damage in 9Cr–1Mo ferritic steel using X-ray diffraction technique

1999 ◽  
Vol 76 (5) ◽  
pp. 275-281 ◽  
Author(s):  
Sanjay Rai ◽  
B.K Choudhary ◽  
T Jayakumar ◽  
K.Bhanu Sankara Rao ◽  
Baldev Raj
Keyword(s):  
Fatigue Damage ◽  
Ferritic Steel ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Influence of Ultrasonic Surface Rolling Process and Shot Peening on Fretting Fatigue Performance of Ti-6Al-4V

2021 ◽  
Author(s):  
Ning Wang ◽  
Jin long Zhu ◽  
Bai Liu ◽  
Xiancheng Zhang ◽  
Jiamin Zhang ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Shot Peening ◽  
Surface Hardness ◽  
Rolling Process ◽  
Fretting Fatigue ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Strengthening ◽  
Stress Layer

Abstract The shot-peening (SP) and ultrasonic surface rolling process (USRP) were performed on Ti–6Al-4V plate specimens. The surface hardness and residual stresses of the material were tested by vickers indenter and X-ray diffraction residual stress analyzer. The effects of different surface strengthening on its fretting fatigue properties were verified by fretting fatigue experiments. It is shown (i) that the fretting fatigue life of Ti–6Al-4V effectively improved after USRP and SP and（ii）that the surface integrity of specimens after USRP is the best, which has deeper residual compressive stress layer and more refined grain. The fretting fatigue fracture surface and wear morphology of the samples were studied and analyzed by means of microscopic observation, and the mechanism of improving fretting fatigue life by surface strengthening process was further explained

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