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Wpływ polaryzacji elektrochemicznej na pękanie korozyjne stopu układu Al-Mg

Kyzioł L.

Autobusy : technika, eksploatacja, systemy transportowe

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2016

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R. 17, nr 6

960--963

PL

Badano wpływ polaryzacji elektrochemicznej na odporność korozyjno-naprężeniową stopu AlMg2 Mn0,47Fe0,5. Próbki umieszczono w 3,5 % roztworze wodnym NaCl poddając obciążeniu przy stałej szybkości odkształcenia w warunkach polaryzacji anodowej i katodowej. Podatność na pękanie badanego stopu określono na podstawie obniżenia właściwości mechanicznych i przez pomiar energii zniszczenia. Stwierdzono, że wpływ wodoru oraz proces anodowego roztwarzania odgrywają zasadniczą rolę w naprężeniowo-korozyjnym niszczeniu stopów aluminium.

EN

Resistance to stress corrosion AlMg2 Mn0,47Fe0,5 alloy was studied by electrochemical polarization. Samples were placed in a 3.5% aqueous solution of NaCl and samples were subjected to a load at a constant strain rate conditions anodic and cathodic polarization. The susceptibility to cracking of samples was determined by the decrease in mechanical properties and destruction energy. Hydrogen and anodic dissolution are the main cause of the destruction of aluminum alloys in a process stress-corrosion.

2

The effects of boron impurity atoms on nickel ∑ 5 (012) grain boundary by first principles calculations

Kart H. H., Cagin T.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 30, nr 2

177-181

EN

Purpose: Impurity atoms in the grain boundary can be responsible for embrittlement or they can strengthen a material. In this work, we have modeled the effect of B impurity on ∑ 5 (012) symmetrical tilt grain boundary in Ni by using first principle quantum-mechanical calculations. The grains can either be pushed apart or pulled together depending on the size of the impurity and nature of the local relaxations. Design/methodology/approach: The calculations were carried out by using the Vienna ab-initio simulation package VASP with the projector augmented wave (PAW) potentials within generalized gradient approximation (GGA). K-space sampling is performed using a 2x2x1 Monkhorst Pack scheme for Brillouin-zone integration in all model systems. The Methfessel-Paxton smearing method with 0.1 eV smearing width is used for the determination of partial occupancies for each wave function. Findings: It is found that the extension of the nickel grain boundary is due to the repulsion of the segregated and neighboring B atoms. Moreover, the effects of tensile strength loaded uniaxially along the (012) direction are analyzed when the impurity atoms of B are substituted into the ∑ 5 (012) symmetrical tilt grain boundary in Ni. Our calculations are compatible with the other first principle calculations. Research limitations/implications: Cohesive energy calculations indicate that interstitial sites are preferred to substitutional sites and that B leads to cohesive enhancement. Originality/value: The effects of boron impurity atoms on nickel ∑ 5 (012) grain boundary by first principles calculations were evaluated.

3

Analiza pękania korozyjnego rur ze stali żaroodpornej ferrytycznej

Kalinowska-Ozgowicz E., Krukiewicz W.

Ochrona przed Korozją

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2005

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nr 6

238-243

PL

W pracy przedstawiono wyniki badań korozji rur rekuperatora ze stali ferrytycznej chromowej gatunku H25T eksploatowanej w środowisku spalin gazu ziemnego o temperaturze 850¸1100C°. Badania struktury i własności mechanicznych stali ujawniły, że atmosfera spalin gazu ziemnego i ich wysoka temperatura stanowią dogodne warunki dla przebiegu złożonych procesów korozji wodorowej i naprężeniowej badanych rur. Stwierdzono, że istotnymi czynnikami niszczenia korozyjnego rur są: procesy pełzania, wydzielanie faz międzymetalicznych oraz absorpcja wodoru.

EN

The paper presents the results of investigations on the corrosion of recuperator tubes made of ferritic chromium type H25T steel, used in a medium of natural gas combustion products with a temperature of 850¸1100°C. Investigations concerning the structure and mechanical properties of the steel have shown that the atmosphere of combustion gases and the high temperature provide suitable conditions for the complex processes of hydrogen corrosion and stress corrosion of the tested tubes. Creeping, the precipitation of intermetallic phase and the absorption of hydrogen have been found to be key factors in the corrosion of these tubes.

4

Stress corrosion cracking of Titanium alloy weldment

Tubielewicz K., Melechow R.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2002

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z. 58 [193]

315-320

EN

A study of susceptibility to stress corrosion cracking (SCC) of welded joints of the Ti-6AI-1,5V-6Zr alloy in sea water was made. Ways of increasing the SCC resistant properties of weldments were found. A mechanism of corrosion crack initiating has been described. The relationship between local elemental composition of weldments and SCC susceptibility is shown.

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Posouzení odolnosti tepelně ovlivněné oceli 02Cr24Ni22Mo7CuN proti koroznímu praskání metodou det

Blahetová M., Lasek S., Číhal V.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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1999

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z. 59

79-82

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Influence of internal stresses on corrosion crack of single-phase brasses in ammonia atmosphere.

Kucharska B., Nitkiewicz Z., Stachura S.

Inżynieria Materiałowa

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1998

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R. XIX, nr 3

548-551

EN

The effect of internal stresses on corrosion crack of single-phase brasses in ammonia atmosphere is presented. The pipes made of CuZn28Sn1 and CuZn20Al2 brasses were investigated. The stress simulating the remainders after the drawing process and mechanical damages in the form of indentation were introduced. It was found that the tin brass is more sensitive to corrosion cracking than the other. It was also stated that the amount of cracking on the degree of deformation dependence is different for each grade of brass. In the aluminium brass the cracks are shorter. The corrosion cracks lead of the brittle fracture.