and frequently used for decorative trim and equipment
subjected to high pressures and temperatures.
Martensitic Chromium. These steels are mag-
netic and are readily hardened by heat treatment. They
contain 12% to 18% chromium, 0.15% to 1.2% carbon,
and up to 2.5% nickel. This group is used where high
strength, corrosion resistance, and ductility are required.
ALLOY STEELS. Steels that derive their prop-
erties primarily from the presence of some alloying
element other than carbon are called ALLOYS or AL-
LOY STEELS. Note, however, that alloy steels always
contain traces of other elements. Among the more com-
mon alloying elements are nickel, chromium, vana-
dium, silicon, and tungsten. One or more of these
elements may be added to the steel during the manufac-
turing process to produce the desired characteristics.
Alloy steels may be produced in structural sections,
sheets, plates, and bars for use in the as-rolled condi-
tion. Better physical properties are obtained with these
steels than are possible with hot-rolled carbon steels.
These alloys are used in structures where the strength of
material is especially important. Bridge members, rail-
road cars, dump bodies, dozer blades, and crane booms
are made from alloy steel. Some of the common alloy
steels are briefly described in the paragraphs below.
Nickel Steels. These steels contain from 3.5%
nickel to 5% nickel. The nickel increases the strength
and toughness of these steels. Nickel steel containing
more than 5% nickel has an increased resistance to
corrosion and scale. Nickel steel is used in the manufac-
ture of aircraft parts, such as propellers and airframe
Chromium Steels. These steels have chromium
added to improve hardening ability, wear resistance, and
strength. These steels contain between 0.20% to 0.75%
chromium and 0.45% carbon or more. Some of these
steels are so highly resistant to wear that they are used
for the races and balls in antifriction bearings. Chro-
mium steels are highly resistant to corrosion and to
Chrome Vanadium Steel. This steel has the
maximum amount of strength with the least amount of
weight. Steels of this type contain from 0.15% to 0.25%
vanadium, 0.6% to 1.5% chromium, and 0.1% to 0.6%
carbon. Common uses are for crankshafts, gears, axles,
and other items that require high strength. This steel is
also used in the manufacture of high-quality hand tools,
such as wrenches and sockets.
Tungsten Steel. This is a special alloy that has the
property of red hardness. This is the ability to continue
to cut after it becomes red-hot. A good grade of this steel
contains from 13% to 19% tungsten, 1% to 2% vana-
dium, 3% to 5% chromium, and 0.6% to 0.8% carbon.
Because this alloy is expensive to produce, its use is
largely restricted to the manufacture of drills, lathe tools,
milling cutters, and similar cutting tools.
Molybdenum. This is often used as an alloying
agent for steel in combination with chromium and
nickel. The molybdenum adds toughness to the steel. It
can be used in place of tungsten to make the cheaper
grades of high-speed steel and in carbon molybdenum
Manganese Steels. The amount of manganese
used depends upon the properties desired in the finished
product. Small amounts of manganese produce strong,
free-machining steels. Larger amounts (between 2%
and 10%) produce a somewhat brittle steel, while still
larger amounts (11% to 14%) produce a steel that is
tough and very resistant to wear after proper heat treat-
Nonferrous metals contain either no iron or only
insignificant amounts used as an alloy. Some of the more
common nonferrous metals Steelworkers work with are
as follows: copper, brass, bronze, copper-nickel alloys,
lead, zinc, tin, aluminum, and Duralumin.
NOTE: These metals are nonmagnetic.
This metal and its alloys have many desirable prop-
erties. Among the commercial metals, it is one of the
most popular. Copper is ductile, malleable, hard, tough,
strong, wear resistant, machinable, weldable, and cor-
rosion resistant. It also has high-tensile strength, fatigue
strength, and thermal and electrical conductivity. Cop-
per is one of the easier metals to work with but be careful
because it easily becomes work-hardened; however, this
condition can be remedied by heating it to a cherry red
and then letting it cool. This process, called annealing,
restores it to a softened condition. Annealing and sof-
tening are the only heat-treating procedures that apply
to copper. Seams in copper are joined by riveting, silver
brazing, bronze brazing, soft soldering, gas welding, or
electrical arc welding. Copper is frequently used to give
a protective coating to sheets and rods and to make ball
floats, containers, and soldering coppers.