METAL PROPERTIES, CHAR, USES, AND CODES - OD1643 - LESSON 1/TASK 1
aircraft parts, as a pyrotechnic for railroad signals and military
purposes, and to make magnesium castings used for engine housings,
blowers, hose pieces, and aircraft landing wheels.
(b) Capabilities.
Magnesium can be forged, cast welded, and
machined.
(c) Limitations.
Magnesium in fine chip form will ignite at
low temperatures (800 to 1,200 Fahrenheit).
The flame can be
smothered with suitable materials such as carbon dioxide (CO2), foam,
and/or sand.
(7) Manganese. The chemical symbol for manganese is Mn, and the
chief ore of manganese is black manganese dioxide.
(a) Uses. Manganese is mainly used as an alloying agent in the
manufacture of steel to increase its tensile strength.
It is also
added during the steel-making process to remove sulfur as a slag.
Austenitic manganese steels are used for railroad trackwork, power
shovel buckets, and rock crushers.
Medium-carbon manganese steels
are used in the manufacture of car axles and gears.
(b) Capabilities.
Manganese can be welded, machined, and cold-
worked.
(c) Limitations. Austenitic manganese steels are best machined
with cemented carbide, cobalt, and high-speed cutters.
(8) Molybdenum. The chemical symbol for molybdenum is Mo, and its
chief ores are molybdenite and wulfenite. Pure molybdenum has a high
tensile strength and is very resistant to heat.
(a) Uses. Molybdenum is principally used as an alloying agent
in steel to increase its strength, hardenability, and resistance to
heat.
Heating elements, switches, contacts, thermocouples, welding
electrodes, and cathode-ray tubes are made of molybdenum.
(b) Capabilities.
Molybdenum can be swaged, rolled, drawn, or
machined.
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