| 1. |
- Alipour, Yousef, et al.
(författare)
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Corrosion of furnace wall materials in waste-wood fired power plant
- 2015
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 50:5, s. 355-363
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Tidskriftsartikel (refereegranskat)abstract
- Corrosion tests were performed with four different materials exposed at the furnace wall in a power boiler burning recycled wood, with the aim of evaluating coatings to reduce the corrosion. The nickel base Alloy 625 and the iron-chromium-aluminium alloy Kanthal APMT had the lowest corrosion rates followed by the stainless steel 310S. The low alloy steel 16Mo3, from which the walls are constructed, had the highest rate. Different corrosion mechanisms were found to occur according to the alloy type. Thermodynamic modelling showed that chlorine gas exists at extremely low levels under the prevailing conditions and the hydrated form is thermodynamically favoured.
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| 2. |
- Deflorian, F., et al.
(författare)
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Stress corrosion cracking (SCC) failure in marine areas of fixed guards for climbing
- 2015
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 50:6, s. 462-466
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Tidskriftsartikel (refereegranskat)abstract
- This work studies the particular mechanism of environmental stress corrosion cracking (SCC) that has been described to interest stainless steel products, like climbing anchors, installed in sea areas. The failure analysis of several broken anchors was carried out. The samples were collected in different parts of the world, always from climbing structures close to the sea. The analysis confirmed the stress corrosion mechanism of degradation, giving also important information about the specific environments causing the metal fracture. These results are in agreement with a few previous works about this subject and are in the frame of the larger topic of SCC of austenitic stainless steel at room temperature. Moreover, some corrosion tests were carried out on stainless steel samples simulating the operation conditions, after contamination with electrolytes at different concentration. The tests are performed in order to better understand the degradation mechanism and to evaluate the influence of some environmental parameters over the susceptibility to SCC. With these experimental data, a possible interpretation model has been proposed together with some reasonable solutions for the material selection process, considering the problem's characteristics and the multiple alternatives available nowadays for climbing materials.
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| 3. |
- Halldin Stenlid, Joakim, et al.
(författare)
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Computational Analysis of the Early Stage of Cuprous Oxide Sulphidation : A Top-Down Process
- 2017
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 52:S1, s. 50-53
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Tidskriftsartikel (refereegranskat)abstract
- The initial steps of Cu2O sulphidation to Cu2S have been studied using plane-wave density functional theory at the PBE-D3+U level of sophistication. Surface adsorption and dissociation of H2S and H2O, as well as the replacement reaction of lattice oxygen with sulphur, have been investigated for the most stable (111) and (100) surface facets under oxygen-lean conditions. We find that the (100) surface is more susceptible to sulphidation than the (111) surface, promoting both H2S adsorption, dissociation and the continued oxygen–sulphur replacement. The results presented in this proceeding bridge previous results from high-vacuum experiments on ideal surface to more realistic corrosion conditions and set the grounds for future mechanistic studies. Potential implications on the long-term final disposal of spent nuclear fuel are discussed.
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| 4. |
- Johansson, Adam Johannes, et al.
(författare)
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Insights from post-test examination of three packages from the MiniCan test series of copper-cast iron canisters for geological disposal of spent nuclear fuel : impact of the presence and density of bentonite clay
- 2017
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 52, s. 54-60
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Tidskriftsartikel (refereegranskat)abstract
- MiniCan is a field test designed to highlight certain aspects of corrosion in a KBS-3 type repository for spent nuclear fuel. Five experimental packages containing miniature copper-cast iron canisters were installed in the Äspö Hard Rock Laboratory in 2006. Three packages have been retrieved, MiniCan 3 in 2011 and MiniCan 4 and 5 in 2015. The packages were examined regarding surface chemistry, microbiology and corrosion of copper and iron. The main difference in design between the retrieved packages was the presence and density of bentonite clay. Black deposits of sulphides were visually noted during dismantling of both MiniCan 3 (low density clay) and MiniCan 5 (no clay), but not in MiniCan 4 (high density clay). Extensive corrosion of cast iron specimens was observed in all three packages, with local attacks corresponding to the loss of hundreds of µm/y. Sulphate reducing bacteria (SRB) were found to be present in ground water, in bentonite clay and on surfaces of various specimens of iron and copper, and it is suggested that the SRB activity had a pronounced influence on the corrosion observed. Copper surfaces display a roughness at the µm level and the integrated corrosion rate of copper mass-loss specimens was generally low. This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems. © 2017 The Author(s).
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| 5. |
- Liu, G.Q., et al.
(författare)
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Naphthenic acid corrosion characteristic and corrosion product film resistance of carbon steel and Cr5Mo low alloy steel in secondary vacuum gas oil
- 2016
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 51:6, s. 445-454
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Tidskriftsartikel (refereegranskat)abstract
- Although naphthenic acid corrosion (NAC) has been studied for many years, the mechanism of NAC is not fully understood. The objective of this paper is to study high-temperature NAC in secondary vacuum gas oil of an industrial crude oil vacuum distillation tower. A high-temperature autoclave was applied to conduct high-temperature corrosion test to investigate NAC behaviour of carbon steel and Cr5Mo low alloy steel at different sulphur contents and total acid numbers (TAN). The result shows that the corrosion rate of carbon steel and low alloy steel is high at low TAN and high TAN while it keeps at a low value at medium TAN. Corrosion product film on Cr5Mo low alloy steel surface is denser and more compact than that of carbon steel at high TAN. The chromium present in Cr5Mo low alloy steel plays an important role in NAC resistance by the formation of Cr7S8 film in the inner layer of the scale. Corrosion rates of the two steels in secondary vacuum gas oil are high at low TAN and high TAN, but low at medium TAN which are strange and different from previous experimental results conducted in non-industrial oil solution. A tentative explanation for this new phenomenon is also put forward.
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| 6. |
- Necib, S., et al.
(författare)
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Assessment of the resistance to environmentally assisted cracking (EAC) of C-steel casing and overpack in the COx claystone
- 2017
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Ingår i: Corrosion Engineering, Science and Technology. - : Taylor and Francis Ltd.. - 1478-422X .- 1743-2782. ; 52, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- The French national radioactive waste management agency (Andra) is in charge of studying the disposal of high level wastes (HLW) in deep geological repositories. The reference concept for HLW disposal cells consisted of a multi-barrier system: horizontal boreholes drilled in the Callovo Oxfordian (COx) claystone, cased with carbon steel (C-steel) and containing C-steel overpacks with the nuclear waste packages. Mechanical strength is required for the metallic structures to ensure safety. This study presents the work performed on C-steel to assess in situ mechanical loading, long-term mechanical behaviour based on modelling and environmentally assisted cracking (EAC) susceptibility. The results from in situ experiments have demonstrated anisotropy of the mechanical loading of the casing. Long-term calculations revealed local plastic strain after a few years to a few decades, which highlighted the need to assess the potential risk of EAC. Eventually, the results on EAC assessment in the COx claystone confirmed that the microstructure of the casing and overpack plays a key role on the mechanical resistance. This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.
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| 7. |
- von Fieandt, Linus, et al.
(författare)
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Corrosion properties of CVD grown Ti(C,N) coatings in 3.5 wt-% NaCl environment
- 2018
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Ingår i: Corrosion Engineering, Science and Technology. - 1478-422X .- 1743-2782. ; 53:4, s. 316-320
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Tidskriftsartikel (refereegranskat)abstract
- The corrosion behaviour of Titanium carbonitride (Ti(C,N)) films grown by chemical vapour deposition was analysed in artificial sea water environment. From potentiodynamic polarisation curves, two passivation zones were detected, which originated from an initial oxidation of TiC and TiN to TiO2 followed by growth of the TiO2 layer upon increased polarisation. X-ray photoelectron spectroscopy analyses verified the mechanism by detecting a gradual decrease in Ti(C,N) peaks accompanied by a gradual increase of oxidised Ti (e.g. TiO2). It was likewise found that carbon in TiC mainly decomposes into carbonate species while the nitrogen in TiN remains elemental and likely escapes as nitrogen gas. Accordingly, Ti(C,N) behaves like a superposition of TiC and TiN with their individual oxidation behaviour, resulting in a highly corrosion resistant material.
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| 8. |
- Örnek, Cem
(författare)
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Additive manufacturing–a general corrosion perspective
- 2018
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Ingår i: Corrosion Engineering, Science and Technology. - : Taylor and Francis Ltd.. - 1478-422X .- 1743-2782. ; 53:7, s. 531-535
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Tidskriftsartikel (refereegranskat)abstract
- Metallic additive manufacturing will replace some materials produced by conventional fabrication methods in the nearest future. However, corrosion will remain an important aspect needed to be prevented. The corrosion behaviour of additively manufactured alloys has been sparsely studied and very little work has been published so far. In this article, a general discussion about materials produced by additive manufacturing will be provided.
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| 9. |
- Örnek, Cem, et al.
(författare)
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On the Volta potential measured by SKPFM - fundamental and practical pects with relevance to corrosion science
- 2019
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Ingår i: Corrosion Engineering, Science and Technology. - : Taylor & Francis. - 1478-422X .- 1743-2782. ; 54:3, s. 185-198
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Forskningsöversikt (refereegranskat)abstract
- The Volta potential is an electron-sensitive parameter and describes the ermodynamic propensity of a metal to take part in electrochemical actions. It has found widespread acceptance among corrosion searchers due to its connection to the corrosion potential and its sy measurability in local scale, being often used to study localised rrosion phenomena and micro-galvanic activities. The principle object this paper is to provide a comprehensive, fundamental insight into e meaning of the Volta potential and to define a polarity convention measured potentials by the scanning Kelvin probe force microscopy KPFM) in order to assess local nobilities in microstructures. nditions to relate the Volta potential with the mixed-potential theory e discussed and a possible connection to corrosion phenomena plained. The limitations of the Volta potential as well as the SKPFM chnique are also aimed to be explained, with some practical formation to maximise the output of high quality data.
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