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Pack Aluminizing of Copper

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Journal of Materials Science & Technology 1997年第2期13卷 127-132页

作者： M.E.Abd El-Azim H.M.Soliman (Metallurgy Dept., atomic energy authority Cairo, Egypt) Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Aluminizing of Cu by a pack cementation process was performed to improve its surface *** effect of variation of pack aluminizing temperature from 800 to 900℃ and aluminizing time from 1 to 6 h on the microstructure and the thickness of the aluminide coating of Cu was investigated. Pack aluminizing of Cu significantly improved the microhardness and the oxidation resistance. The microhardness was increased about seven times and the oxidation resistance,after 96 h exposure in air at 900℃, was extremely increased ten times by aluminizing Cu at 900℃ for 3 h.

关键词： VHN Pack Aluminizing of Copper

Performance of the Aluminide Coating of SomeLow Alloy Steels

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Journal of Materials Science & Technology 1997年第6期13卷 462-466页

作者： H.M.Soliman and M.E.Abd E1-Azim(Metallurgy Dept., atomic energy authority, Cairo, Egypt ) Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Two low alloy steels 0.5Cr-0.5Mo-0.25V and H85 were pack-aluminized at 900°for 4 h by using Fe-Al powder mixture containing 48% Fe, 20.6% Al- 29.4% Al2O3 and 2% NH4Cl by weight. The microhardness and oxidation resistance at 900℃ of the aluminide coatings were studied. It was found that pack-aluminizing improves the microhardness of the 0.5Cro.5Mo-0.25V steel while it reduces the microhardness of the H85 steel. Pack aluminizing highly improves the oxidation resistance after 20h exposure at 900℃ in air for the investigated steels.

关键词： Cr Performance of the Aluminide Coating of SomeLow Alloy Steels

Characterization of Failure Mechanisms of Duplex and Graded Thermal Barrier Coatings Exposed to Thermal Shock Test

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Journal of Materials Science & Technology 1996年第1期12卷 35-40页

作者： A.F.Waheed and H.M.Soliman(Dept. of Metallurgy, Nuclear Research Center, atomic energy authority, Cairo, Egypt) Dept. of Metallurgy Nuclear Research Center Atomic Energy Authority Cairo Egypt

The beginning of failure of a (ZrO2-7%Y2O3)/(Ni-22%Co-17%Cr-12.5%Al-0.6%Y) duplex andgraded coating systems on lnconel 617 and IN738LC in burner rig tests has been *** test conditions are 40 s heating up to 75O℃ substrate temperature followed by 80 s aircooling. Failure is considered at the appearance of the first bright spot during heating *** due to thermal expansion mismatch strains on cooling are the probable cause of life-limiting in this conditions of testing.

关键词： Co Miller Characterization of Failure Mechanisms of Duplex and Graded Thermal Barrier Coatings Exposed to Thermal Shock Test

Effect of Molybdate Ions on the Corrosion Behaviour of Ti Alloys

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Journal of Materials Science & Technology 2000年第1期16卷 45-49页

作者： Magda.M.A.Gad, Kamal.E.Mohamed and Abdelwahab A.El-Sayed (Metallurgy Dept., Materials Division, atomic energy authority, Cairo, Egypt) Metallurgy Dept. Materials Division Atomic Energy Authority Cairo Egypt

Titanium alloys are extensively used in power, chemical and petroleum industries as constructional materials for vessels and heat transfer tubes. Moreover they are candidate materials for nuclear waste disposal. These alloys have superior resistance to localized forms of corrosion compared to stainless steels and Ni-base alloys. However, this resistance is not as remarkable in crevice corrosion conditions in some aggressive media. Electrochemical corrosion tests were conducted on two ASTM Ti grades namely, Ti-2 and Ti-12 in extremely low pH acidic environment. Results indicated that Ti-2 has less resistance to both general and crevice corrosion attack than Ti-12. Both alloys possess better resistance to general corrosion than to crevice corrosion. Also, results showed that the molybdate addition improves remarkably the resistance of Ti-2 to both types of attack. The increase of molybdate ions concentration from 0.03 mol/L to 0.15 mol/L made Ti-2 to be as resistant as, or somewhat higher than, Ti-12. The elecrochemical findings were further supplemented by optical examination of the corroded surface.

关键词： Ti Mo Effect of Molybdate Ions on the Corrosion Behaviour of Ti Alloys

Cadmium status in Egypt

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Journal of Environmental Sciences 2001年第3期13卷 351-360页

作者： M. F. Abdel Sabour (Soil & Water Pollution Unit, Nuclear Research Center, atomic energy authority, Cairo, Egypt 13759. Soil & Water Pollution Unit Nuclear Research Center Atomic Energy Authority Cairo Egypt 13759. mamdouhsabour@***

It is inferred from these studies that releases of Cd are still increasing and it is recommended that measures must be taken to reduce emissions of cadmium. Any cadmium discharged into the Egyptian environment may move from one compartment to another at varying rates, resulting in an accumulation in compartments such as soils and biota. Such accumulation can be expected to increase with continued emissions, and attention should be given to all sources of cadmium, natural as well as anthropogenic especially in the industrial cities in Egypt. Cadmium present in sewage, as well as industrial effluent (also, other liquid and solid wastes) and sewage sludge will increase levels in soils and is expected to contribute to dietary levels and body burdens. The current information indicates that such effects may have to be evaluated over long periods of time, possibly as long as 50-100 years.

关键词： cadmium accumulation dietary intake

Effect of Hydrogen Charging on the Tensile and Constant Load Properties of an Austenitic Stainless Steel Weldment

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Journal of Materials Science & Technology 2001年第4期17卷 444-448页

作者： A.M.Nasreldin, M.M.A.Gad, I.T.Hassan, M.M.Ghoneim and A.A.El-sayed Metallurgy Dept., Nuclear Research Centre, atomic energy authority P.O.13759, Cairo, Egypt Atom energy Author Dept Met Nucl Res Ctr Cairo Egypt

The effect of cathodic hydrogen charging on the tensile and constant load properties was deter- mined for an austenitic stainless steel weldment comprising a 304L steel in the solution treated condition as a base metal and a 308L filler steel as a weld metal. Part of the 304L solution treated steel was separately given additional sensitization treatment to simulate the microstructure that would develop in the heat affected zone. Tests were performed at room temperature on notched round bar specimens. Hydrogen charging resulted in a pronounced embrittlement of the tested materials. This was manifested mainly as a considerable loss in the ductility of tensile specimens and a decrease in the time to failure and threshold stress of constant load specimens. The 308L weld metal exhibited the highest, and the 304L solution treated steel the lowest, resistance to hydrogen embrittlement. Hydrogen embrittlement was associated with the formation of strain induced martensite as well as a transition from brittle to ductile fracture morphology onwards the centre of the specimens.

关键词： Effect of Hydrogen Charging on the Tensile and Constant Load Properties of an Austenitic Stainless Steel Weldment 308

Effect of diluents on the extraction of praseodymium and samarium by Cyanex 923 from acidic nitrate medium

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Journal of Rare Earths 2010年第2期28卷 215-220页

作者： YA El-Nadi Hot Laboratories Centre Atomic Energy Authority(Egypt)

The solvent extraction of Pr(Ⅲ) and Sm(Ⅲ) with trialkyl phosphine oxide(Cyanex 923) in chloroform,carbon tetrachloride,n-octane,cyclohexane,1,2-dichloroethane,benzene,toluene,xylene and nitrobenzene from acidic nitrate medium was *** the basis of slope analysis data,the composition of the extracted species was determined as(M(NO3)3?2CY923),CY923 refers to Cyanex *** values of the equilibrium constants and the separation factors were *** effect of the diluents on the metal extracti...

关键词： extraction diluents praseodymium samarium Cyanex 923 rare earths

Oxidation Resistance of the Aluminide Coating Formed on Carbon Steels

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Journal of Materials Science & Technology 1997年第5期13卷 383-388页

作者： Soliman, H.M. Ohamed, K.E. Abd El-Azim, M.E. Hammad, F.H. Metallurgy Dept. Atomic Energy Authority Cairo Egypt

Low and medium carbon steels were aluminized by the pack aluminizing technique using halideactivated pure-Al and Fe-Al packs. The effect of mixture composition, aluminizing temperatureand time and C content of the steel substrate on the structure and thickness of the aluminidelayer, and on the oxidation resistance was investigated. The optimum oxidation resistance canbe achieved with a low carbon steel substrate when the intermetallic phases Fe3Al and FeAlform the surface of the aluminide layer. In this case, the Al concentration at the surface of thealuminide coating is at least ≥15 wt pct. Formation of high Al concentration phases (FeAl3 andFe2Al5) during aluminizing should be avoided as they tend to embrittle the aluminide layer andreduce its oxidation resistance.

关键词： OO Figure Oxidation Resistance of the Aluminide Coating Formed on Carbon Steels

Effect of Aging on the Toughness of Austenitic and Duplex Stainless Steel Weldments

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Journal of Materials Science & Technology 2010年第9期26卷 810-816页

作者： Omyma Hassan Ibrahim Ibrahim Soliman Ibrahim Tarek Ahmed Fouad Khalifa Metallurgy Dept. Nuclear Research CentreAtomic Energy Authority(Egypt) Nuclear Safety Centre Atomic Energy Authority(Egypt) Shoubra Faculty of Engineering Benha University

In the present study,the effect of aging heat treatment at 650,750,and 850？C on the impact toughness of 316L austenitic stainless steel,2205 duplex stainless steel and their weldments has been *** process was conducted using the TIG（tungsten inert gas） welding *** impact testing,at room temperature,was employed to determine the effect of aging treatment on the impact properties of investigated *** treatment resulted in degradation in the impact toughness as demonstrated by the reduction in the impact fracture energy and deformation parameters（strain hardening capacity,fracture deffection,and crack initiation and propagation energy）.The degree of embrittlement was more noticeable in duplex stainless steel parent and weld-metal than in 316L stainless steel and became greater with the increase of aging *** degradation in impact toughness was discussed in relation to the observed precipitation of the intermetallic sigma phase in the microstructure of the stainless steel weldments and the corresponding fracture surface morphology.

关键词： Austenitic and duplex stainless steels Aging Instrumented impact Toughness