List the four classifications of steels. (b) For each, briefly describe the properties and typical applications.

Low Carbon Steels 

 Properties:  nonresponsive to heat treatments;  relatively soft and weak;  machinable and weldable. 

 Typical applications:  automobile bodies, structural shapes, pipelines, buildings, bridges, and tin cans. 

  Medium Carbon Steels 

 Properties:  heat treatable, relatively large combinations of mechanical characteristics. 

 Typical applications:  railway wheels and tracks, gears, crankshafts, and machine parts. 

  High Carbon Steels 

 Properties:  hard, strong, and relatively brittle. 

 Typical applications:  chisels, hammers, knives, and hacksaw blades. 

  High Alloy Steels (Stainless and Tool) 

 Properties:  hard and wear resistant;  resistant to corrosion in a large variety of environments. 

 Typical applications:  cutting tools, drills, cutlery, food processing, and surgical tools. 

a) Cite three reasons why ferrous alloys are used so extensively. (b) Cite three characteristics of ferrous alloys that limit their utilization. 

(a)  Ferrous alloys are used extensively because: 

  (1)  Iron ores exist in abundant quantities. 

  (2)  Economical extraction, refining, and fabrication techniques are available. 

  (3)  The alloys may be tailored to have a wide range of properties. 

 (b)  Disadvantages of ferrous alloys are: 

  (1)  They are susceptible to corrosion. 

  (2)  They have a relatively high density. 

  (3)  They have relatively low electrical conductivities.