An evaluation of a chromium-base alloy for high-temperature service

Northwood, J. E.; Shaw, Murray; Smith, Robert S.

doi:10.1016/0022-5088(68)90112-4

Cited by 7 publications

(2 citation statements)

References 3 publications

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“…The samples that were drained for the longest period of time (which were also the treatments flooded for the shortest duration) had mobile Ni and Cr concentrations that were at a level lower than those observed prior to inundation (Figure 2), indicating that the influence of flooding on Ni and Cr mobility in this floodplain soil is transient. Nickel and Cr are both used as alloys (Northwood et al 1968; Restall 1984; Wallinder et al 2006). Therefore the Ni and Cr in these soils may have originated from the same source but the precise origin remains uncertain.…”

Section: Resultsmentioning

confidence: 99%

“…There has been extensive mineral extraction of gravels in the Blackwater Valley, particularly in the vicinity of Yateley and Eversley Cross—in part, the reason that there are dozens of historic landfill sites within the Loddon catchment (Environment Agency 2015). Other potential point sources of historic pollution to the River Loddon include a former paper mill at Arborfield; 2 factories—Thornycroft and Wallace & Stevens—that opened in the late 1800s and made engines, vehicles, and agricultural equipment in Basingstoke; and the former National Gas Turbine Establishment at Pyestock, near Farnborough, where primary research into jet engines—such as the development and use of Al‐, Ni‐, and Cr‐containing alloy coatings for the protection of gas turbines—took place during the 20th century (Northwood et al 1968; Restall 1984). It is likely, in the past, that all these industries discharged effluent into the river upstream of our sampling location.…”

Section: Methodsmentioning

confidence: 99%

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The Effect of Flooding and Drainage Duration on the Release of Trace Elements from Floodplain Soils

Kelly

Hamilton

Watts

et al. 2020

Enviro Toxic and Chemistry

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Floodplains downstream of urban catchments are sinks for potentially toxic trace elements. An intensification of the hydrological cycle and changing land use will result in floodplains becoming inundated for longer durations in the future. We collected intact soil cores from a floodplain meadow downstream of an urban catchment and subjected them to an inundation/drainage cycle in the laboratory to investigate the effect of flood duration on trace element concentrations in the soil porewater. The porewater concentrations of Ni, Cr, and Zn increased, whereas Cu and Pb decreased with flood duration. All the Cr present in porewaters was identified as Cr(III). Copper concentrations increased after drainage but Pb mobility remained suppressed. Both pH and dissolved organic carbon (DOC) increased with flood duration but were lower in treatments that were drained for the longest duration (which were also the treatments flooded for the shortest duration). The porewater concentrations of Cr and Ni decreased after drainage to levels below those observed before inundation, mirroring the DOC concentrations. We concluded that the duration of floodplain inundation does have an influence on the environmental fate of trace elements but that flooding does not influence all trace elements in the same way. The implications of an intensification of the hydrological cycle over the coming decades are that floodplains may become a source of some trace elements to aquatic and terrestrial ecosystems.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

The Effect of Flooding and Drainage Duration on the Release of Trace Elements from Floodplain Soils

Kelly

Hamilton

Watts

et al. 2020

Enviro Toxic and Chemistry

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Present and future heat-resistant alloys

Nazarov¹,

Maslenkov²

1970

Met Sci Heat Treat

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Recent Developments in Chromium and Chromium Alloys

Klopp

1969

JOM

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Recent developments in chromium pertinent to its potential use in advanced jet engines are reviewed. Although chromium has a strength-to-density advantage over nickel, its inherent brittleness and further embrittlement by nitrogen during high-temperature exposure are serious limitations to its use. Twelve chromium alloys are currently under development, the strongest showing a potential 150' F (83 K) service temperature advantage over nickel-base superalloys. However, a better balance between solution strengthening and precipitate strengthening must be achieved in order to improve the low temperature ductility of these alloys. Improved coatings for protection against nitrogen embrittlement must be developed. Lewis Research Center S U M~R YChromium-base alIoys, which have been under study now for slightly more than two decades, are attractive as potential competitors for nickel alloys for high temperature applications in advanced jet engines. Although chromium has a strength-to-density advantage over nickel, it is normally brittle at room temperature and is further embrittled by nitrogen during high temperature air exposure.The high temperature strength of chromium can be increased threefold to fourfold by solution strengthening with elements such as tantalum, columbium, tungsten, molybdenum, and rhenium. Solution strengthening, however, involves a significant increase in the ductile-brittle transition temperature. Similar or larger improvements in the strength of chromium can be achieved by precipitate strengthening with borides, carbides, and nitrides of the Groups IVa and Va elements. These precipitates do not embrittle chromium to the same extent as do solution strengthening additions and may even be ductilizing. Coarsening rate estimates suggest that carbides at least should retain sufficiently fine sizes as to be strengthening for times of 1000 hours o r longer at 2000' to 2200' F (1366 to 1478 K).Nitrogen is particularly deleterious to the ductility of chromium because of its high solubility at elevated temperatures and the nature of the CrZN precipitate. Nitrogen embrittlement of chromium during high temperature exposure can be reduced by rare earth alloying, but the effectiveness of these additions is reduced on further alloying for high temperature strength. rently under development. These include five from the United States, three from Australia, and four from the Soviet Union. The strongest of these alloys offer up to a 1 5 0 ' F (83 K) temperature advantage over nickel alloys but the impact ductile-brittle transition temperatures are high.surface alloying techniques to reduce nitrogen embrittlement and emphasis on dispersion strengthening to achieve a better balance between high temperature strength and low temperature ductility.

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An evaluation of a chromium-base alloy for high-temperature service

Cited by 7 publications

References 3 publications

The Effect of Flooding and Drainage Duration on the Release of Trace Elements from Floodplain Soils

The Effect of Flooding and Drainage Duration on the Release of Trace Elements from Floodplain Soils

Present and future heat-resistant alloys

Recent Developments in Chromium and Chromium Alloys

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