Page 74 - Mechanical Behavior of Materials

Section 3.3 Irons and Steels 73

Table 3.4 Some Typical Irons and Steels

Principal Alloying Elements, Typical % by Weight
Description Identification UNS No. C Cr Mn Mo Ni Si V Other
Ductile ASTM A395 F32800 3.5 — — — — 2 — —
cast iron
Low-carbon AISI 1020 G10200 0.2 — 0.45 — — 0.2 — —
steel
Medium-carbon AISI 1045 G10450 0.45 — 0.75 — — 0.2 — —
steel
High-carbon AISI 1095 G10950 0.95 — 0.4 — — 0.2 — —
steel
Low-alloy AISI 4340 G43400 0.40 0.80.7 0.25 1.80.2 — —
steel
HSLA steel ASTM A588-A K11430 0.15 0.51.1 — — 0.20.05 0.3 Cu
Martensitic AISI 403 S40300 0.15 12 1.0 — 0.60.5 — —
stainless steel
Austenitic AISI 310 S31000 0.25 25 2.0 — 20 1.5 — —
stainless steel
Precipitation 17-4 PH S17400 0.07 17 1.0 — 4 1.0 — 4 Cu
hardening 0.3 (Nb + Ta)
stainless steel
Tungsten AISI T1 T12001 0.75 3.80.25 — 0.20.31.1 18 W
high-speed
tool steel
18 Ni ASTM A538-C K93120 0.01 — — 5 18 — — 9 Co, 0.7 Ti
maraging steel

added for quenching and tempering to be effective, a major increase in strength is possible.
Additional alloying and special processing can be combined with quenching and tempering and/or
precipitation hardening to achieve even higher strengths.

3.3.1 Naming Systems for Irons and Steels
A number of different organizations have developed naming systems and specifications for various
irons and steels that give the required alloy composition and sometimes required mechanical
properties. These include the American Iron and Steel Institute (AISI), the Society of Automotive
Engineers (SAE International), and the American Society for Testing and Materials (ASTM
International). In addition, SAE and ASTM have cooperated to develop a new Unified Numbering
System (UNS) that gives designations not only for irons and steels, but also for all other metal
alloys. See the Metals Handbook: Desk Edition (Davis, 1998) for an introduction to various naming