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V
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Chemical symbol for Vanadium. |
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Vacuum Annealing
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Annealing carried out at sub-atmospheric pressure. |
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Vacuum Arc Remelting
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A process used for producing advanced steels to the most demanding
and critical specifications, particularly in such areas as aerospace
applications. The steel is first produced to a very close analysis
and the resulting ingot is slowly remelted in a Vacuum Arc Remelting
furnace for up to 14 hours. Such steels are, by necessity, expensive
to manufacture. |
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Vacuum Degassing
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A ladle of molten metal is placed within a chamber which is then
evacuated. This reduces the gas content, particularly hydrogen, as
well as reducing non- metallic inclusions. Modern secondary steel
making processes using Vacuum Arc Degassing units that include
automated stirring and control of temperature and chemical analysis,
ensure a consistent and high quality product. |
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Vacuum Deposition
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Condensation of thin metal coatings on the cool surface of work in a
vacuum. |
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Vacuum Furnace
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A furnace using low atmospheric pressures instead of a protective
gas atmosphere like most heat-treating furnaces. Vacuum furnaces are
categorized at hot wall or cold wall, depending on the location of
the heating and insulating components. |
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Vanadium
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Steels containing vanadium have a much finer grain structure than
steels of similar composition without vanadium. It raises the
temperature at which grain coarsening sets in and increases
hardenability where it is in solution in the austenite prior to
quenching. It also lessens softening on tempering and confers
secondary hardness on high speed steels. Vanadium is used in
nitriding, heat resisting, tool and spring steels in conjunction
with other alloying elements. |
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Vapor Plating
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Deposition of a metal or compound on a heated surface by reduction
or decomposition of a volatile compound at a temperature below the
melting points of the deposit and the base material. The reduction
is usually accomplished by a gaseous reducing agent such as
hydrogen. The decomposition process may involve thermal dissociation
or reaction with the base material. Occasionally used to designate
deposition on cold surfaces by vacuum evaporation. |
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Vickers Hardness Test
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A method of determining the hardness of steel whereby a diamond
pyramid is pressed into the polished surface of the specimen and the
diagonals of the impression are measured with a microscope fitted
with a micrometer eye piece. The rate of application and duration
are automatically controlled and the load can be varied. |
