Page 4 - Structural Steel Designers Handbook AISC, AASHTO, AISI, ASTM, and ASCE-07 Design Standards

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PROPERTIES OF STRUCTURAL STEELS AND EFFECTS OF STEELMAKING AND FABRICATION

1.2 CHAPTER ONE

FIGURE 1.1 Typical stress-strain curves for structural steels. (Curves have been
modified to reflect minimum specified properties.)

A36 steel has been the principal carbon steel for bridges, buildings, and many other structural
uses. This steel provides a minimum yield point of 36 ksi in all structural shapes and in plates up to
8 in thick. In structural steel framing for building construction, A36 steel has been largely replaced
by the higher-strength A992 steel (Art. 1.1.2).
A529 is a carbon-manganese steel for general structural purposes, available in shapes and plates
of a limited size range. It can be furnished with a specified minimum yield point of either 50 ksi
(Grade 50) or 55 ksi (Grade 55).
A573, another carbon steel listed in Table 1.1, is available in three strength grades for plate appli-
cations in which improved notch toughness is important.

1.1.2 High-Strength Low-Alloy Steels

Those steels which have specified minimum yield points greater than 40 ksi and achieve that strength
in the hot-rolled condition, rather than by heat treatment, are known as HSLA steels. Because these
steels offer increased strength at moderate increases in price over carbon steels, they are economical
for a variety of applications.
A242 steel is a weathering steel, used where resistance to atmospheric corrosion is of primary
importance. Steels meeting this specification usually provide a resistance to atmospheric corrosion
at least four times that of structural carbon steel. However, when required, steels can be selected to
provide a resistance to atmospheric corrosion of five to eight times that of structural carbon steels.
3
A specified minimum yield point of 50 ksi can be furnished in plates up to / 4 in thick and the
lighter structural shapes. It is available with a lower yield point in thicker sections, as indicated in
Table 1.1.
A588 is the primary weathering steel for structural work. It provides a 50-ksi yield point in plates
up to 4 in thick and in all structural sections; it is available with a lower yield point in thicker plates.
Several grades are included in the specification to permit use of various compositions developed by

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