Wyniki wyszukiwania - BazTech

1

Badania eksperymentalne efektu redukcji przewodności cieplnej w autoklawizowanym piaskowym betonie komórkowym (ABK 500)

Zapotoczna-Sytek G., Zmywaczyk J., Koniorczyk P., Lubińska K., Górska B.

Cement Wapno Beton

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2009

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R. 14/76, nr 6

301-307

PL

W pracy przedstawiono wyniki wstępnych badań efektu redukcji przewodności cieplnej w przypadku próbek autoklawizowanego betonu komórkowego (ABK). Próbki ABK miały grubość od 5 do 40 mm, a zawartość wilgoci wynosiła 8%. Pomiary przewodności cieplnej wykonano w zakresie temperatur od 0°C do 160°C, przy czym w zakresie od 0°C do 70°C próbki były kopertowane w przeźroczystej cienkiej folii, natomiast w zakresie temperatur o 80°C do 160°C próbki nie były kopertowane. Pomiary wykazały znaczny wpływ efektu redukcji przewodności cieplnej i w przypadku próbek o większej grubości ich przewodnictwo cieplne może być nawet trzykrotnie większe. Zawartość wilgoci ma wpływ na efekt redukcji przewodności cieplnej w przypadku próbek grubszych od 30 mm, natomiast w przypadku próbek o grubości od około 2 mm do 30 mm jest pomijalnie mały.

EN

The results of preliminary studies of "thickness effect curve" in the samples of autoclaved aereted concrete (AAC) are presented. The samples of AAC had the thickness from 5 to 40 mm and their moisture was equal 8%. Thermal conductivity was measured at the temperature range from 0°C to 160°C, but at 0°C to 70°C the samples were enveloped in thin transparent foil while at 80°C to 160°C they were not enveloped. The measurements showed the significant "thickness effect curve" and the thermal conductivity of thicker samples can be even three times greater. The content of moisture has an influence on "thickness effect curve" for the samples thicker than 30 mm, but in the case of the samples from about 5 to 30 mm thick, this effect was negligible.

2

Stress corrosion cracking of the clad structural steel after its high temperature hydrogen degradation

Lubińska K., Tsyrulnyk O., Herdil M., Nykyforchyn H., Kurzydłowski K. J.

Advances in Materials Science

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2007

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Vol. 7, nr 1(11)

27-32

EN

It is known that long term service of installations in energy and refinery industry in conditions of simultaneous action of loading and corrosion-hydrogen environments causes degradation of structural steels. This process of degradation is the most intensive on grain boundaries. Therefore structures with clad metal, namely, refinery shell, should be especially sensitive to degradation process. Three types of clad metal "low alloy steel/stainless steel" were studied: 15HM/304L, 516GR60/410S and 5l6GR70/N201. In-service degradation was modeled by thermocycling of specimens in the range of 25-550 st.C in hy-drogen atmosphere with fast rate of cooling. It allows to fix at law temperature such amount hydrogen in metal which is in equilibrium at high temperature and this is the reason of the intensive hydrogen degradation. Metal was tested after 30 and 100 thermocycles. Sensitiveness to hydrogen degradation was evaluated by slow strain rate tension of specimens during moderate cathodic polarisation. Same peculiarities of hydrogen cracking of clad metal were established and it was revealed that thermocycling in hydrogen atmosphere increases sensitivity of clad metals to hydrogen degradation. The degradation level depends on the type of clad metal and number of thermocycling.

3

Hydrogen damage in power industry

Sozańska M., Michalska J., Lubińska K.

Advances in Materials Science

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2007

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Vol. 7, nr 2(12)

69-75

EN

Hydrogen damage is the generic name given to a large number of metal degradation processes due to interaction with hydrogen. Especially in rower industry, several major components such as steam generator tubes, boilers, steam/water pipe lines, water box of condensers and the other auxiliary components often fail catastrophically due to hydrogen embrittlement. This article consists of a classification of hydrogen damage, brief description of the various processes and their mechanisms, and some guidelines for the control of hydrogen damage in rower plants. Furthermore, same histories of failures of steel components due to hydrogen embrittlement, which are reported in literature, are presented.

4

Effect of hydrogen on adhesion of stainless steel to structural steel in explobond clad plates

Lubińska K., Szummer A., Szpila K., Kurzydłowski K.J.

Advances in Materials Science

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2007

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Vol. 7, nr 1(11)

147-152

EN

Clad plates are usually made of carbon or law alloy steel plates with a thinner layer of stainless steels which offer resistance to different corrosive environments containing hydrogen, in diverse industries like chemical, offshore, petrochemical, petro-leum refineries, nuclear, etc. It is well known that hydrogen deteriorates structure and properties of stainless steels and law alloy steels as well. In the case of clad steels, hydrogen may induce underclad cracking. In this work the results are presented of the study of the influence of hydrogen on adhesion of austenitic stainless steel to the law alloy steel in explobond clad plates. Specimens were destructively tested in band shear test. Light and scanning electron microscopy were used for examination of the shear fracture surface. It was shown that hydrogen significantly lowers a shear strength of bonding between austenitic stainless steel flyer and parent law alloy steel.