A Combined Experiment and Modeling Analysis of ASTM G85 WB Accelerated Corrosion Testing of Galvanically Coupled Sensitized AA5456-H116 and CDA 706 Cupronickel

CORROSION ◽  
10.5006/3852 ◽  
2021 ◽  
Author(s):  
Lindsey Blohm ◽  
Chao Liu ◽  
Robert Kelly
Keyword(s):  
Water Layer ◽  
High Water ◽  
Product Formation ◽  
Localized Corrosion ◽  
Accelerated Corrosion ◽  
Galvanic Couple ◽  
Modeling Analysis ◽  
Accelerated Corrosion Testing ◽  
Water Layers ◽  
Best Fit

AA5456-H116 undergoes accelerated localized corrosion when in a galvanic couple with cupronickel alloy C70600 during ASTM G85 Appendix 2 Wet Bottom (G85 WB) testing. Surface and subsurface damage of AA5456-H116 was investigated and quantified. These results were compared to Finite Element Modeling results investigating relative humidity (RH) and water layer (WL) thickness. The best fit between experimental results and the modeling results was found when modeling assumed that a 3,000 µm water layer was formed during the spray portion of the G85 cycle with thinner water layers present during the decreasing RH portion of the cycle, which led IGC attack that was focused in the proximity of the CDA/AA5456-H116 interface. The high-water layer thickness is likely the result of the corrosion product formation that traps additional electrolyte than would be present on a clean surface.

scholarly journals Residual Stresses in Ultrasonically Peened Fillet Welded Joints

2014 ◽  
Vol 996 ◽  
pp. 755-760 ◽  
Author(s):  
Bilal Ahmad ◽  
Michael E. Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Fatigue Cracks ◽  
Steel Plates ◽  
Contour Method ◽  
Mechanical Method ◽  
Accelerated Corrosion ◽  
Accelerated Corrosion Testing ◽  
Measured Residual Stress

Fatigue cracks mostly initiate at areas subjected to high tensile residual stress and stress concentration. Ultrasonic peening is a mechanical method to increase fatigue life by imparting compressive residual stress. In this study residual stresses are characterized in fillet welded ship structural steel plates with longitudinal attachments. As-welded, ultrasonically peened, and specimens peened then subjected to accelerated corrosion testing were measured. Residual stress characterization was performed by the contour method and neutron diffraction.

scholarly journals Variations in the Temporal and Spatial Distribution of Microalgae in Aquatic Environments Associated with an Artificial Weir

2020 ◽  
Vol 12 (16) ◽  
pp. 6442
Author(s):  
Suk Min Yun ◽  
Sang Deuk Lee ◽  
Pyo Yun Cho ◽  
Seung Won Nam ◽  
Dae Ryul Kwon ◽  
...  
Keyword(s):  
Significant Variation ◽  
Lower Layer ◽  
Aquatic Organisms ◽  
Water Layer ◽  
Aquatic Environments ◽  
Temporal And Spatial Distribution ◽  
Water Layers ◽  
High Turbidity ◽  
Temporal And Spatial ◽  
Microalgal Community

The construction of weirs causes changes in the aquatic environment and affects several aquatic organisms. To understand the ecosystem in the Sangju Weir, Gyeongsangbuk-do Province, variations in the spatiotemporal distribution and composition of microalgae communities were analyzed. Microalgae were collected fortnightly from April to November 2018 from six sites in the Nakdonggang River. There was significant variation in environmental factors, microalgal community structure, and flora. Microalgae communities were dominated by diatoms (e.g., Fragilariacrotonensis, Ulnariaacus, and Aulacoseiraambigua), green algae (e.g., genera Eudorina and Desmodesmus), cyanobacteria (e.g., genera Anabaena and Microcystis). Multidimensional scaling indicated that species composition and diversity were generally similar among sites but varied between the bottom and the surface and middle water layers. Vertical migration of microalgae was difficult to investigate because of the thermocline in the study area and high turbidity in the lower layer. The distribution of microalgae was little affected by the construction of the weir, but the formation of thermocline changed microalgae communities in the water layer.

A two-dimensional hydrogen-bonded water layer in the structure of a cobalt(III) cubane complex

2014 ◽  
Vol 70 (2) ◽  
pp. 198-201 ◽  
Author(s):  
Ji Qi ◽  
Xiang-Sheng Zhai ◽  
Hong-Lin Zhu ◽  
Jian-Li Lin
Keyword(s):  
Water Clusters ◽  
Three Dimensional ◽  
Water Layer ◽  
Water Molecules ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
Solvent Water ◽  
Water Layers ◽  
Hydrogen Bonded

A tetranuclear CoIIIoxide complex with cubane topology, tetrakis(2,2′-bipyridine-κ2N,N′)di-μ2-carbonato-κ4O:O′-tetra-μ3-oxido-tetracobalt(III) pentadecahydrate, [Co4(CO3)2O4(C10H8N2)4]·15H2O, with an unbounded hydrogen-bonded water layer, has been synthesized by reaction of CoCO3and 2,2′-bipyridine. The solvent water molecules form a hydrogen-bonded net with tetrameric and pentameric water clusters as subunits. The Co4O4cubane-like cores are sandwiched between the water layers, which are further stacked into a three-dimensional metallo-supramolecular network.

Weak quadratic interactions of two-dimensional waves

1971 ◽  
Vol 50 (1) ◽  
pp. 107-132 ◽  
Author(s):  
Young Yuel Kim ◽  
Thomas J. Hanratty
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Wave Train ◽  
Water Layer ◽  
Rate Of Change ◽  
Two Dimensional ◽  
Low Frequencies ◽  
Resonant Interactions ◽  
Water Layers ◽  
Phase Angles

This paper reports on weak quadratic interactions which can occur with two-dimensional waves on shallow water layers and in the capillary-gravity range on deep water layers. It supplies experimental support of theoretical predictions for resonant interactions, but, perhaps of more significance, it explores in detail interactions which occur under conditions near resonance.Waves of approximately sinusoidal form are introduced on the surface of water in a long rectangular tank. For deep water a rapid distortion in the sinusoidal wave and sometimes additional crests are observed because of energy exchange among the first, second and third harmonics at frequencies where both surface tension and gravity are important (7·5–13 c/s). An even greater exchange of energy can be observed on shallow water layers at low frequencies. For example, a wave train with seven secondary crests can be observed when the wave maker is operated at 3·04 c/s in a water layer of 0·65 cm.Measured amplitudes and phase angles of the Fourier components of the wave train are described by a system of equations using only quadratic interactions among participating harmonics. The exchange of energy among Fourier components under certain conditions is explained in terms of the rate of change of relative phase angles of the different harmonics.

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