Metals are grouped under two board groups; what are they?
Ferrous metals & Non-ferrous metals
Name 4 Ferrous Metals
- Pig iron
- Cast iron
- Wrought iron
- Steel
Name 4 Non-Ferrous Metals
- Copper
- Tin
- Nickel
- Zinc
What is the difference between ferrous metals and non-ferrous metals?
Ferrous metals contain iron, where non-ferrous metals don’t.
Name the 3 stages that are involved in the manufacture of pig iron.
- Dressing
- Calcinating and roasting
- Smelting
What are the properties of pig iron?
- It cannot be magnetized.
- It does not rust
- Bending is not possible
- It is hard and brittle
- Melts easily
-Riveting or Welding is not possible
What is the process of manufacturing Cast iron?
1: Cast iron is manufactured by remelting pig iron with coke and limestone.
2: The impurities in the pig iron are removed by this process, and comparatively pure iron is obtained in the molten stage from the bottom of the furnace.
3: The slag is removed at regular intervals from the top of the cast iron.
4: The molten cast iron is led into the molds called cast iron castings
Name 5 properties of Cast iron.
- It has high compressive strength.
- It has a fairly low melting point.
- It is hard and brittle but not ductile.
- It has a fairly good corrosion resistance.
- It cannot be magnetized.
What is Steel?
Steel is a very ductile alloy consisting of iron and carbon.
Name two uses for mild steel.
Mild steel is used to manufacture of:
- tin plate
- sheet metal
- tubes
- tools
Name two uses for hard steel.
Hard steel is used in the manufacture of:
- cutlery
- axes
- springs
- heavy tools
What are 3 examples of Alloy steel?
- Silicon steel
- Nickel steel
- Stainless steel
- Tungsten steel
Name 4 properties obtained through the addition of alloying elements to steel.
- To improve tensile strength
- To improve machinability
- To improve hardness and toughness
- To improve the elastic properties of steel
- Improves corrosion and fatigue resistance
Name 5 non-ferrous metals.
- Tin
- Copper
- Lead
- Zinc
- Nickel
Name 2 important principle classes of copper alloys.
- Brass
- Bronze
Name the principal elements that are alloyed with pure aluminum to improve its tensile strength and hardness.
- Copper
- Silicon
- Manganese
- Zinc
- Nickel
- Magnesium
