Analysis of the Excavated Archaeological Iron Using Xray-CT

2003 ◽  
Author(s):  
Hideki Yoshikawa ◽  
Kenichi Ueno ◽  
Takashi Honda ◽  
Shingo Yamaguchi ◽  
Mikazu Yui
Keyword(s):  
Cast Iron ◽  
Corrosion Behavior ◽  
Main Body ◽  
Natural Analogue ◽  
Corrosion Depth ◽  
X Ray ◽  
Reducing Conditions ◽  
Archaeological Iron ◽  
Corrosion Data

In order to evaluate the long-term corrosion behavior of carbon steel, we investigated the rust of archaeological iron buried in soil. It is difficult to obtain experimental data of the long-term corrosion in the laboratory. However, it is possible to obtain corrosion data over several hundred years by using archaeological iron and to develop a reliable model for the long-term corrosion behavior by using such natural analogue data. Since these archaeological samples are very rare and important, we can not get agreement to destroy it for analysis. The rust of the sample has been analyzed no-destructively and quantitatively using high-power X-ray computed tomography. The X-ray strength was developed in the two-demensional image. We observed a rust layer distinct from the inner iron metal as a main body by using X-ray map element concentration. A mass-balance quantity of rust calculation was performed from the amount of corroded layer. A sample of axe which was excavated in the Izumo-Taisha-ruin (Shimane prefecture) was analyzed by using the method. The region in Izumo is famous as the production area of the iron from ancient times in Japan. The axe is traditional Japanese type, made of iron, and probably used for a foundation ceremony of the building. The sample has been buried under the column of the shrine and enveloped by clay. It is assumed that the axe remained under reducing conditions until its discovery in 2001 for about 750 years. We have also investigated the corrosion of the gas pipe buried in the soil in several decades as natural analogue study. By the comparison of these data with the corrosion data of water pipe (cast iron) buried in clay soil at most for 100 year, the results of this study do not exceed the extrapolated pitting corrosion depth based on the corrosion depth of the cast iron pipe.

Geochemical Behaviour of Uranium in Sedimentary Formations: Insights From a Natural Analogue Study

2009 ◽  
Author(s):  
Ulrich Noseck ◽  
Vaclava Havlova ◽  
Juhani Suksi ◽  
Thomas Brasser ◽  
Radek Cervinka
Keyword(s):  
Current Knowledge ◽  
Natural Analogue ◽  
Near Surface ◽  
Co2 Partial Pressure ◽  
Long Term Stability ◽  
Reducing Conditions ◽  
Phosphate Mineral ◽  
Sedimentary System ◽  
The Impact

Groundwater data from the natural analogue site Ruprechtov have been evaluated with special emphasis on the uranium behaviour in the so-called uranium-rich clay/lignite horizon. In this horizon in-situ Eh-values in the range of −160 to −280 mV seem to be determined by the SO42−/HS− couple. Under these conditions U(IV) is expected to be the preferential redox state in solution. However, on-site measurements in groundwater from the clay/lignite horizon show only a fraction of about 20% occurring in the reduced state U(IV). Thermodynamic calculations reveal that the high CO2 partial pressure in the clay/lignite horizon can stabilise hexavalent uranium, which explains the occurrence of U(VI). The calculations also indicate that the low uranium concentrations in the range between 0.2 and 2.1μg/l are controlled by amorphous UO2 and/or the U(IV) phosphate mineral ningyoite. This confirms the findings from previous work that the uranium (IV) mineral phases are long-term stable under the reducing conditions in the clay/lignite horizon without any signatures for uranium mobilisation. It supports the current knowledge of the geological development of the site and is also another important indication for the long-term stability of the sedimentary system itself, namely of the reducing geochemical conditions in the near-surface (30m to 60 m deep) clay/lignite horizon. Further work with respect to the impact of changes in redox conditions on the uranium speciation is on the way.

Atmospheric Corrosion Behavior of Salvaged Marine Cast Iron Artifacts

2013 ◽  
Vol 690-693 ◽  
pp. 97-100
Author(s):  
Wei Zhen Ouyang
Keyword(s):  
Cast Iron ◽  
Corrosion Behavior ◽  
Atmospheric Corrosion ◽  
Solid Material ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Spherical Shells ◽  
X Ray ◽  
Iron Artifacts ◽  
Active Corrosion

The atmospheric corrosion behavior of cast iron after six months immersion was studies by means of optical stereomicroscope and X-ray diffraction techniques. The results showed that active corrosion occurred on the rusted specimen covered with many thin spherical shells of solid material. The XRD analysis indicated the formation of β-FeOOH tends to increase with increasing exposure.

Evaluation of Corrosion Behavior of Different Grades of Cast Iron Insodium Chloride Solutions

2020 ◽  
Vol 835 ◽  
pp. 223-228
Author(s):  
Adel Nofal ◽  
Amal S.I. Ahmed ◽  
Wafaa A. Ghanem ◽  
W.A. Hussein ◽  
Nanis K. Mohamed
Keyword(s):  
Cast Iron ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Ductile Cast Iron ◽  
X Ray ◽  
Grey Cast ◽  
Nickel Addition ◽  
Eis Measurements ◽  
Circuit Technique

In this work, the corrosion behavior of different grades of cast iron in 3.5% and 5% of NaClsolution was evaluated. The samples used in this work are; Grey cast iron (GI), ductile cast iron(DI), austempered ductile cast iron (ADI), intercritically austempered cast iron (IADI) and Ni-Resist cast iron. The study was carried out using the Open- Circuit technique (OPC),Potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS)measurements and complemented by Scanning electron microscopy (SEM) and Energydispersive X-ray analysis (EDAX). The results obtained showed that the austempering heattreatment and nickel addition improves the corrosion resistance of cast iron. The order ofcorrosion resistance in NaCl solution is as follows: Ni-Resist > ADI > IADI > DI > GI.

Dissolution of used Candu Fuel at Various Temperatures and Redox Conditions

1985 ◽  
Vol 50 ◽  
Author(s):  
S. Stroes-Gascoyne ◽  
L. H. Johnson ◽  
P. A. Beeley ◽  
D. M. Sellinger
Keyword(s):  
Potential Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Saturated Water ◽  
Reducing Conditions ◽  
Release Studies ◽  
Show Evidence ◽  
Radionuclide Release

AbstractSamples of used UO2 fuel exposed to air-saturated water at 25°C for eight years have been examined using electron microscopy and X-ray diffraction techniques. The results, in conjunction with solution analysis uata, show evidence for a UO3.2H2O precipitate on the fuel surface, and confirm the importance of grain-boundary leaching in controlling Cs-137 release. Studies of useo-fuel dissolution under both oxidizing and reducing conditions at 150°C show significantly lower radionuclide release to solution for reducing conditions, illustrating the potential importance of reoox chemistry in determining the long-term stability of used fuel after disposal.

Analysis in Atmospheric Corrosion Behavior of Bainite Steel Exposed in Offshore Platform Based on the Artificial Neural Network

2011 ◽  
Vol 291-294 ◽  
pp. 1212-1216 ◽  
Author(s):  
Ming Zhang ◽  
Jian Fei Yu ◽  
Shan Wu Yang ◽  
Xin Lai He
Keyword(s):  
Neural Network ◽  
Corrosion Behavior ◽  
Atmospheric Corrosion ◽  
Back Propagation ◽  
Offshore Platform ◽  
Weathering Steel ◽  
Corrosion Depth ◽  
Bainite Steel ◽  
Bp Neural Network Model ◽  
Corrosion Data

Back propagation (BP) neural network model was established, using the corrosion data of five kinds of recently developed bainite weathering steel and the commercial weathering steel 09CuPCrNi exposed in the offshore platform in Wanning. The influences of elements P, Cu, C and Cr on the corrosion behavior of weathering steel were studied according to the model. The experimental results indicate that the corrosion depth of bainite weathering steel corroded for 1 year could decline owing to the increasing contents of P, Cu and Cr in steel while C has little effect on the variation of the corrosion depth.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

Long-term variations in individual particle types in the aerosol of Phoenix, Arizona, as determined using automated electron microprobe analysis and multivariate statistical techniques

1993 ◽  
Vol 51 ◽  
pp. 742-743
Author(s):  
Karen A. Katrinak ◽  
James R. Anderson ◽  
Peter R. Buseck
Keyword(s):  
Electron Microprobe ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
Motor Vehicles ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
X Ray ◽  
Mineral Particles ◽  
Anthropogenic Air Pollutants

Aerosol samples were collected in Phoenix, Arizona on eleven dates between July 1989 and April 1990. Elemental compositions were determined for approximately 1000 particles per sample using an electron microprobe with an energy-dispersive x-ray spectrometer. Fine-fraction samples (particle cut size of 1 to 2 μm) were analyzed for each date; coarse-fraction samples were also analyzed for four of the dates.The data were reduced using multivariate statistical methods. Cluster analysis was first used to define 35 particle types. 81% of all fine-fraction particles and 84% of the coarse-fraction particles were assigned to these types, which include mineral, metal-rich, sulfur-rich, and salt categories. "Zero-count" particles, consisting entirely of elements lighter than Na, constitute an additional category and dominate the fine fraction, reflecting the importance of anthropogenic air pollutants such as those emitted by motor vehicles. Si- and Ca-rich mineral particles dominate the coarse fraction and are also numerous in the fine fraction.

Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

2002 ◽  
Vol 713 ◽  
Author(s):  
Roman V. Bogdanov ◽  
Yuri F. Batrakov ◽  
Elena V. Puchkova ◽  
Andrey S. Sergeev ◽  
Boris E. Burakov
Keyword(s):  
Chemical Shifts ◽  
Pyrochlore Structure ◽  
Type Structure ◽  
Waste Form ◽  
X Ray ◽  
Ceramic Waste ◽  
Natural Minerals ◽  
The Us ◽  
Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

Effect of Zn Content on Structure, Roughness and Corrosion Behavior of Zn-Ni Alloys

2019 ◽  
Vol 17 (17) ◽  
pp. 17-22
Author(s):  
Hayette Faid
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Stripping Voltammetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys ◽  
Sulfate Bath ◽  
Zn Content ◽  
Polarization Test ◽  
Δ Phase

AbstractIn this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

Sign in / Sign up

Export Citation Format

Share Document