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

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.

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.

Quantification of cyclic twinning-detwinning behavior during low-cycle fatigue of pure magnesium using high energy X-ray diffraction

2019 ◽  
Vol 125 ◽  
pp. 314-323 ◽  
Author(s):  
Aeriel D. Murphy-Leonard ◽  
Darren C. Pagan ◽  
Armand Beaudoin ◽  
Matthew P. Miller ◽  
John E. Allison
Keyword(s):  
Low Cycle Fatigue ◽  
High Energy ◽  
Pure Magnesium ◽  
Cycle Fatigue ◽  
X Ray Diffraction ◽  
X Ray

Characterization of Low-cycle Fatigue Damage in Inconel 718 by Laser Light Scanning

1997 ◽  
Vol 12 (8) ◽  
pp. 2048-2056 ◽  
Author(s):  
K. J. C. Chou ◽  
J.C. Earthman
Keyword(s):  
Fatigue Damage ◽  
Inconel 718 ◽  
Laser Light ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Microcrack Density ◽  
Gauge Section ◽  
Number Of Cycles ◽  
Defect Frequency

A technique for in situ laser light scanning (LLS) was developed to monitor surface damage on nickel-base superalloy specimens under low-cycle fatigue conditions. This technique characterizes the surface state with a parameter called the defect frequency which minimizes memory requirements and data processing time since it does not involve image processing. As a result, the present technique is capable of scanning speeds that are substantially greater than those achieved with image processing methods. Cylindrical Inconel 718 specimens were tested using an automated servo-hydraulic machine at ambient temperature under fully reversed strain control conditions for constant strain amplitudes ranging from 0.3% to 1%. The fatigue damage was monitored by scanning a laser beam along the gauge section of the specimens during periodic interruptions of the cyclic loading. Acetate replicas of the gauge section surface were also made on some of the specimens to characterize the damage using SEM and image analysis techniques. Comparisons of the results demonstrate the capabilities of the present light-scanning technique for characterizing fatigue damage on the surface of the Inconel 718 specimens. In particular, a rapid rise in the mean defect frequency is shown to correspond to an initial increase in microcrack density that saturates at approximately 20% of the fatigue life. This transient behavior is followed by a plateau in defect frequency which corresponds to crack propagation and interlinkage until failure occurs. The number of cycles to microcrack density saturation as indicated by the defect frequency is found to be linearly related to the number of cycles to failure. Accordingly, the present system provides a characterization of microcrack damage that may be used to predict the low-cycle fatigue life of Inconel 718 specimens long before failure occurs.

Characterization of High Temperature (873 K) Low Cycle Fatigue Damage in Modified 9Cr–1Mo Steel Using Magnetic Barkhausen Emission Technique

2016 ◽  
Vol 69 (2) ◽  
pp. 315-318
Author(s):  
G. V. K. Kishore ◽  
K. Mariappan ◽  
Anish Kumar ◽  
Vani Shankar ◽  
R. Sandhya ◽  
...  
Keyword(s):  
High Temperature ◽  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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