scholarly journals Examination of Transgranular Crack on SC0234

2021 ◽  
Author(s):  
Brian Berger ◽  
Rene Chavarria ◽  
Stanley Pierce
Keyword(s):  
Transgranular Crack

Mechanical Factors Affecting Stress Corrosion Crack Growth Rates in Buried Pipelines

2000 ◽  
Author(s):  
S. B. Lambert ◽  
J. A. Beavers ◽  
B. Delanty ◽  
R. Sutherby ◽  
A. Plumtree
Keyword(s):  
Crack Growth ◽  
Growth Rates ◽  
Electrical Potential ◽  
Potential Drop ◽  
Maximum Load ◽  
Load Test ◽  
Factors Affecting ◽  
Transgranular Crack ◽  
Groundwater Environment ◽  
Crack Growth Rates

Over the past several years, investigations have been carried out into the rate of crack growth in pipeline steels in simulated, near-neutral pH, groundwater environment (NS4 solution). Pre-cracked specimens were subject to constant amplitude loading under various frequencies, maximum loads and R-ratios (minimum/maximum load). Test times varied from about 20 to 400 days. Transgranular crack features, similar to those found in service, have been observed. The extent of crack growth was monitored using either electrical potential drop or detailed metallographic examinations at two laboratories. The resulting crack growth rates from both labs are consistent with a superposition model based on a summation of fatigue (Paris Law) and static (SCC) crack growth rates. Differences between the results at the two laboratories are discussed.

A Comparison of Hydrogen and Mercury Embrittlement in Monel at Room Temperature

1986 ◽  
Vol 108 (1) ◽  
pp. 31-36 ◽  
Author(s):  
L. B. Traylor ◽  
C. E. Price
Keyword(s):  
Crack Initiation ◽  
Strain Rate ◽  
Room Temperature ◽  
Tensile Tests ◽  
Cohesive Strength ◽  
Slow Strain Rate ◽  
Transgranular Crack ◽  
Monel 400

Slow strain rate tensile tests were performed on annealed and cold drawn Monel 400 and Monel R405 at room temperature in air, mercury, and electrolyte hydrogen. Hydrogen and mercury caused embrittlement with the fractures having the same specific features. Crack initiation was largely intergranular but an increasing proportion of transgranular cracking occurred subsequently, especially in the presence of hydrogen and for Monel R405. It is believed that the decreased cohesive strength and enhanced shear models of embrittlement apply to the intergranular and transgranular crack modes respectively.

In situ observations of transgranular crack propagation in high-manganese steel

2015 ◽  
Vol 100 ◽  
pp. 32-35 ◽  
Author(s):  
Sung-Il Baik ◽  
Tae-Young Ahn ◽  
Woong-Pyo Hong ◽  
Yeon-Seung Jung ◽  
Young-Kook Lee ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Manganese Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
Transgranular Crack ◽  
In Situ Observations

Validation of the K and J Parameters in a Compact Tension Specimen Containing Intergranular and Straight Crack Paths

2010 ◽  
Author(s):  
A. N. Mehmanparast ◽  
C. M. Davies ◽  
K. M. Nikbin
Keyword(s):  
Finite Element ◽  
Grain Boundary ◽  
Crack Growth ◽  
Crack Tip ◽  
Compact Tension ◽  
Growth Direction ◽  
Compact Tension Specimen ◽  
Contour Integral ◽  
Transgranular Crack ◽  
Crack Profile

Methods have been examined to evaluate the fracture mechanics parameters J and K in finite element (FE) analyses on a compact tension, C(T), geometry using a mesh appropriate for the evaluation of both intergranular and transgranular microstructural damage processes. Realistic grain and grain boundary microstructures were modelled using ABAQUS. Both straight and deviating crack profiles were considered, representing transgranular and intergranular crack growth processes, respectively. Elastic and elastic-plastic finite element analyses were performed on a C(T) specimen model with a standard straight and deviating crack profile to derive and compare the stress intensity factor, K, and J parameter values under plane stress and plane strain conditions. Considerations as to the validity of the J domain integral calculations that ABAQUS computes are discussed. It has been found that the values of K and J obtained from FE simulations are consistent with theoretical solutions and the stress distribution ahead of the crack tip is very close to that of expected from analytical studies for the case of a straight fronted transgranular crack. Reasonable values of K and J parameters could also be achieved from the FE contour integral values of a deviating crack when the contours selected were adequately far from the crack tip. However, significant differences were found between the analytical and FE contour integral values of a deviating crack when the crack growth direction was considered to continue at the angle defined by its grain boundary. The values of J obtained by from the load line displacement measurements were uninfluenced by the crack profile and in good agreement with other analytical solutions.

Study of Pore Modality of Irradiated UO2 Fuel Assembly

2017 ◽  
Vol 727 ◽  
pp. 693-697
Author(s):  
Yan Hua Peng ◽  
Fei Wang ◽  
Wei Zhu ◽  
Yan Jiang ◽  
Hong Kui Tang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Fuel Assembly ◽  
High Performance ◽  
Local Area ◽  
Transgranular Crack ◽  
Fuel Pellets ◽  
Micro Cracks ◽  
Fission Gas ◽  
Main Factors ◽  
Irradiated Fuel

UO2 fuel pellets may be swelling and recrystallization during irradiation. Density, dimension and distribution of pores are main factors to induce irradiation swelling, especially the size distribution of pellet pores plays an important role. 4×4-4 fuel assembly was a high performance fuel assembly which was self-designed and manufactured, the average burn-up of the fuel assembly was 42GWd/tU.For studying the effect of irradiation on pore modality, the specimens of irradiated UO2 fuel pellets were taken from 4×4-4 fuel assembly after dismantling, microscopic structure and distribution of pores for UO2 fuel assembly by scanning electron microscopy were studied in this paper. The results showed that there were many cracks in fuel pellets, most micro-cracks were transgranular crack. The release rate of fission gas with burn up were augmentation, which was consistent with the porosity of diversity burp up fuel rod. Pores were distributed non-uniformly in irradiated fuel pellets, gathered at local area and more obvious connectivity of pores. The size of pores after the irradiation was between 0.2~1.2 μm, and mostly distributed at 0.3μm ~0.6 μm; The pores at grain boundary of two adjacent grains was less, the pores at grain boundary were distributed by the way of triangle or quadrilateral. The size of pores was increased than pre-irradiation, but ratio of pores and density of pores were decreased obviously, the phenomenon of irradiation densification was occurred in fuel pellets after irradiated. Recrystallization and Rim structure effect were not found.

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