μRaman Analysis of the Rust Layer on Rusted Cast Iron Artifacts

2014 ◽  
Vol 887-888 ◽  
pp. 262-265
Author(s):  
Wei Zhen Ouyang

The components of corrosion products on rusted cast iron artifacts in a wet/dry atmospheric environment have been studied by micro-Raman spectroscopy. The observations show that microstructures of outer and inner interfaces are different; indicating that active corrosion occurred on the rusted specimen covered with many cracks and pores. The μRaman spectra of outer and inner layer results prove to be composed of three main iron oxyhydroxides. In addition, Fe3O4 only exists in the inner layer.

2021 ◽  
Vol 11 (18) ◽  
pp. 8668
Author(s):  
Jinbo Li ◽  
Ziying Zhu ◽  
Hongwei Chen ◽  
Shaojie Li ◽  
Hongyan Wu ◽  
...  

Corrosion behavior of 60Si2Mn-A and 60Si2Mn-B in simulated industrial atmospheric environment was investigated by alternate immersion corrosion test and electrochemical method. The phase, morphology, characteristics of corrosion products, and the distribution of Cr, Cu, and Ni in the corrosion products of experimental steel were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results show that the phase of rust layer is Fe3O4 and γ-FeOOH in the early stage and then changes to α-FeOOH and γ-FeOOH in the later stage; the size of the rust layer with corrosion resistance of 60Si2Mn is less than 60Si2Mn; the Cr element accumulates in the rust layer of the experimental steel in the early stage of corrosion resistance; and Cu, Ni, and Cr in the corrosion resistance 60Si2Mn are concentrated in the rust layer near the substrate In the later stage of corrosion. As the corrosion cycle is prolonged, the corrosion potential and the resistance of the rust layer of the experimental steel increases, and the corrosion current decreases; in the same corrosion cycle, the corrosion potential and corrosion resistance of 60Si2Mn-B are greater than 60Si2Mn, and the corrosion current is less than 60Si2Mn.


2013 ◽  
Vol 690-693 ◽  
pp. 97-100
Author(s):  
Wei Zhen Ouyang

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.


ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 234
Author(s):  
Tilde De Caro ◽  
Emma Angelini ◽  
Leila Es Sebar

<p>In this paper, a study of the corrosion products formed on archaeological bronze artefacts excavated in Tharros (Sardinia, Italy) is presented. The investigation was carried out by means of the combination of different analytical techniques, including optical microscopy, micro-Raman spectroscopy (µ-RS), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray diffraction. The artefacts under study are three bronze coins from the Phoenician–Punic period that are deeply corroded due to the chloride-rich soil of the Tharros excavation site. µ-Raman spectroscopy was chosen to investigate the corroded surfaces of the artefacts because it is a non-destructive technique, it has high spatial resolution, and it makes it possible to discriminate between polymorphs and correlate colour and chemical composition. Through µ-RS, it was possible to identify different mineralogical phases and different polymorphs, such as cuprite (Cu<sub>2</sub>O), copper trihydroxychloride [Cu<sub>2</sub>Cl(OH)<sub>3</sub>] polymorphs, hydroxy lead chloride laurionite [PbCl(OH)] and calcium carbonate polymorph aragonite. The experimental findings highlight that micro-Raman spectroscopy can be used to provide further knowledge regarding the environmental factors that may cause the degradation of archaeological bronzes in soil.</p>


1998 ◽  
Author(s):  
I. De Wolf ◽  
G. Groeseneken ◽  
H.E. Maes ◽  
M. Bolt ◽  
K. Barla ◽  
...  

Abstract It is shown, using micro-Raman spectroscopy, that Shallow Trench Isolation introduces high stresses in the active area of silicon devices when wet oxidation steps are used. These stresses result in defect formation in the active area, leading to high diode leakage currents. The stress levels are highest near the outer edges of line structures and at square structures. They also increase with decreasing active area dimensions.


2021 ◽  
Vol 37 ◽  
pp. 102910
Author(s):  
Jhih-Huei Liu ◽  
Weiying Ke ◽  
Ming-chorng Hwang ◽  
Kuang Yu Chen

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