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Steelworker Volume 01 - Building manual for how to work with steel | Next
Mechanical Properties |
CHAPTER 1
PROPERTIES AND USES OF METAL
In the seabees, Steelworkers are the resident
experts on the properties and uses of metal. We lay
airfields, erect towers and storage tanks, assemble
pontoon causeways, and construct buildings. We use
our expertise to repair metal items, resurface worn
machinery parts, and fabricate all types of metal
objects. To accomplish these tasks proficiently, one
must possess a sound working knowledge of various
metals and their properties. As we learn their different
properties and characteristics, we can then select the
right type of metal and use the proper method to
complete the job. Steelworkers primarily work with
iron and steel; however, we also must become familiar
with the nonferrous metals coming into use more and
more each day. As Steelworkers, we must be able to
identify various metals and to associate their
individual properties with their proper application or
use.
The primary objective of this chapter is to present
a detailed explanation of some of the properties of
different metals and to provide instruction on using
simple tests in establishing their identity.
METAL PROPERTIES
There is no simple definition of metal; however,
any chemical element having “metallic properties” is
classed as a metal. “Metallic properties” are defined
as luster, good thermal and electrical conductivity, and
the capability of being permanently shaped or
deformed at room temperature. Chemical elements
lacking these properties are classed as nonmetals. A
few elements, known as metalloids, sometimes behave
like a metal and at other times like a nonmetal. Some
examples of metalloids are as follows: carbon,
phosphorus, silicon, and sulfur.
Although Steelworkers seldom work with pure
metals, we must be knowledgeable of their properties
because the alloys we work with are combinations of
pure metals. Some of the pure metals discussed in this
chapter are the base metals in these alloys. This is true
of iron, aluminum, and magnesium. Other metals
discussed are the alloying elements present in small
quantities but important in their effect. Among these are
chromium, molybdenum, titanium, and manganese.
An “alloy” is defined as a substance having metallic
properties that is composed of two or more elements.
The elements used as alloying substances are usually
metals or metalloids. The properties of an alloy differ
from the properties of the pure metals or metalloids that
make up the alloy and this difference is what creates the
usefulness of alloys. By combining metals and metal-
loids, manufacturers can develop alloys that have the
particular properties required for a given use.
Table 1-1 is a list of various elements and their
symbols that compose metallic materials.
Table 1-1.—Symbols of Base Metals and Alloying Elements
1-1
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