Metals and Alloys

Introduction

• Today we will examine cast irons and steels.
• Metals are divided into two groups: ferrous and non-ferrous.

Ferrous Metals

• Steels and Cast Irons
  • They are ferrous metals.
  • The iron element is located in Group B.
  • Other group elements gain or lose electrons, making their use difficult.

Historical Use of Metal

• Metal usage is seen in many areas, such as historical weapons and coins.

Metal Structure

• Metals are usually elements that donate electrons and have shiny colors.
• Group B elements are the most used elements.

Alloys

• An alloy refers to a physical mixture of two or more metals.
• Examples:
  • Solder: A mixture of lead and tin.
  • Brass: A mixture of copper and zinc.
  • Bronze: A mixture of copper and tin.

Crystal Structure

• In alloys, elements with similar atomic radii occupy the same positions.
• Irregular alloys and intermetallic compounds behave differently.

Iron Production

• Ore, limestone, and coke are used for iron production.
• Process:
  1. Mixing iron ore with coke and limestone.
  2. Limestone cleans the non-metallic parts.
  3. Coke provides heat and removes oxygen to reveal iron.

End Product

• Pig Iron: Contains 0.95% pure iron.
• Cast Iron: Contains more than 2% carbon.

Furnace Operations

• A typical blast furnace design:
  • Slag area at the top, metal area at the bottom.
  • Slag collects at the top because it is lighter, while metal gathers at the bottom.

Properties of Steels

• Carbon Ratio:
  • Steel: Up to 2% carbon.
  • Cast Iron: More than 2% carbon.
• Carbon is a significant element affecting the structure.
• Advantages of steels:
  • High strength, rigidity, and toughness.
  • Capability to deform (up to 25%).

Mechanical Properties

• Steels provide high strength and ductility.
• Suitability for different forming methods (welding, casting, rolling, etc.).

Conclusion

• By focusing on ferrous metals, we examined the production processes and properties of steel and cast iron.