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1

X-ray computer tomography study of degradation of the zirvaloy-2 tubes oxidized at high temperatures

Trybuś B., Olive J. M., Lenoir N., Zieliński A.

Advances in Materials Science

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2019

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Vol. 19, nr 2(60)

54--71

EN

The investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube surfaces, below and over crystalline transformation temperature of zirconium oxides. The commercial tubes were oxidized at 1273 K and 1373 K in calm air for 30 min and then examined with a technique novel for such purpose, namely a high-resolution X-ray computer tomography. The light microscopy was used to examine the cross-surfaces. The obtained results show that the form and intensity of oxide damage is significant and it is in a complicated way related to oxidation temperature and on whether external or internal tube surface is studied. The found oxide layer damage forms include surface cracks, the detachment of oxide layers, the appearance of voids, and nodular corrosion. The oxidation effects and damage appearance are discussed taking into account the processes such as formation of oxides, their phase transformation, stress-enhanced formation and propagation of cracks, diffusion of vacancies, formation of nitrides, diffusion of hydrogen into interface oxide-metal, incubation of cracks on second phase precipitates are taken into account to explain the observed phenomena.

2

Hydrogen degradation of pre-oxidized zirconium alloys

Szoka A., Gajowiec G., Zieliński A., Serbiński W., Olive J. M., Ossowska A.

Advances in Materials Science

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2017

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Vol. 17, nr 1(51)

5--21

EN

The presence of the oxide layers on Zr alloys may retard or enhance the hydrogen entry and material degradation, depending on the layer features. This research has been aimed to determine the effects of pre-oxidation of the Zircaloy-2 alloy at a different temperature on hydrogen degradation. The specimens were oxidised in laboratory air at 350°C, 700°C, and 900°C. After, some samples were tensed at 10-5 strain rate and simultaneously charged with hydrogen under constant direct voltage in 1 N sulfuric acid at room temperature. Other specimens were charged without any tension, then annealed at 400°C for 4 h and finally tensed at above strain rate. The SEM examinations were performed on the cross-sections and fracture faces of specimens. The obtained results demonstrate the effects of the oxide layer on the cathodic current and hydrogen entry, mechanical properties and the appearance of hydrides and fracture behaviour.

3

Laser surface treatment of aluminium-silicon alloy at gryogenic conditions

Serbiński W., Olive J.M., Rudnicki J.

Advances in Materials Science

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2003

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Vol. 3, nr 1(3)

51--59

EN

The main reason for laser remelting of the components made of cast aluminium alloys is to obtain high hardness, corrosion and wear resistance at the surface for larger lifetime as a resalt of the rapid solidification. The final microstructure, phase composition and properties of aluminium alloys depend on the laser process parameters and obviously on the nature of the equilibrium system. The effect of laser surface remelting at cryogenic conditions on the microstructure, microhardness, wear and corrosion characteristics of the AISi13MglCuNi alloy are presented. The beneficial effect of laser treatment on the microstructure, microhardness, wear and corrosion behaviour of the cast aluminium alloy used for piston fabrication were observed.

4

Relation between corrosion rate, and hydrogen intake and diffusion in the 26H2MF structural alloy steel.

Świeczko B., Domżalicki P., Serbiński W., Skalski I., Zieliński A., Ćwiek J., Olive J.M., Michalak P., Desjardins D.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

920-923

EN

The corrosion rate of the 26H2MF steel was estimated by electrochemical potentiodynamic and impedance techniques in sulphuric acid of different concentration and in heavy fuel. The highest corrosion rate was noted in concentrated acid, lower in diluted acid and very small - in heavy fuel. The simulation of hydrogen ingress and diffusion in the steel showed that hydrogen content in material exposed to acid solutions was sufficient to cause the hydrogen degradation.

PL

Oszacowano szybkość korozji stali 26H2MF techniką potencjodynamiczną i impedancyjną w roztworach kwasu siarkowego o różnym stężeniu i w paliwie ciężkim. Najwyższą szybkość korozji zmierzono w bardziej stężonym kwasie, mniejszą w bardziej rozcieńczonym, zaś w paliwie ciężkim była ona bardzo mała. Symulacja wnikania i transportu wodoru wykazała, że zawartość wodoru w materiale będącym w kontakcie z kwasem była wystarczająca do spowodowania niszczenia wodorowego.

5

Corrosion characteristics of laser surface remelted Al-Si alloy.

Serbiński W., Olive J.M., Frayret J.P.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

812-815

EN

The effects of laser surface remelting at cryogenic conditions on the local chemical compositions, microstructure and corrosion characteristics of AlSi13Mg1CuNi alloy have been presented. The beneficial effect of laser treatment on the corrosion behaviour of the cast aluminium alloy in 0.01 M H2SO4 solution was observed.

PL

Przedstawiono wpływ laserowego przetapiania w warunkach kriogenicznych na lokalny skład chemiczny, mikrostrukturę i charakterystyki korozyjne stopu AlSi13Mg1CuNi. Uzyskano pozytywny wpływ obróbki laserowej na zachowanie korozyjne odlewniczego stopu aluminium w roztworze 0.01 M H2SO4.

6

Evaluation of hydrogen production and concentration at the corrosion fatigue crack tip of 316L stainless steel

Ćwiek J., Olive J. M.

Marine Technology Transactions. Technika Morska

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1999

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Vol. 10

81-92

EN

Corrosion fatigue tests were performed on 316L stainless steel in boiling MgCl2 solution at 117°C. By using in-situ video microscopy the volume of gaseous hydrogen produced per cycle inside a natural crack was measured as a function of crack depth. It was estimated that a quantity of adsorbed and absorbed hydrogen is lower than gaseous hydrogen by an order of magnitude. Based on some electrochemical considerations a volume of an alloy dissolved at a crack tip per cycle has been proposed.

PL

Wykonano badania zmęczeniowo-korozyjne stali kwasoodpornej gatunku 316L we wrzącym roztworze chlorku magnezowego w temperaturze 117°C. Przy użyciu układu optyczego do obserwacji in-situ z kamerą video wymaczono ilość wodoru wydzielającego się wewnątrz naturalnego pęknięcia, w funkcji głębokości pęknięcia. Oceniono, że ilość wodoru adsorbowanego i rozpuszczonego jest o rząd wielkości mniejsza od ilości wodoru cząsteczkowego, który wydziela się z pęknięcia. N a podstawie zależności elektrochemicznych wyznaczono minimalną ilość stopu rozpuszczanego przy czole pęknięcia, w funkcji głębokości pęknięcia.