Materials:Introduction Of Metals

Question 1

How is steel produced?

Answer 1

Steels are produced from iron ore which is heated in a blast furnace in the presence of coke.
-At 1800 degrees, the metallic iron has about 95% iron and other impurities.
-The molten iron is then refined into steel

Question 2

What is EAF?

Answer 2

Electric arc furnaces use scrap metals as raw materials and it is more energy efficient than a blast furnace. It is used for high strength stainless steels

Question 3

What is coke?

Answer 3

Coke is a coal based fuel that is used as fuel for blast furnace and acts as a reducing agent

Question 4

What makes blast furnace slag?

Answer 4

Adding a fluxing agent like limestone breaks into CaO and binds to the impurities

Question 5

How are impurities removed?

Answer 5

By adding a fluxing agent like limestone which breaks into CaO and binds to the molten slag

Question 6

What is the EAF process?

Answer 6

-Charging-scrap metal is loaded together with burnt lime to remove impurities
-The basket is held above the furnace and the charge is emptied
-Melting-after this, the electrodes are lowered and large current passes through the electrodes which go to the bottom as the metal melts
-Oxygen is injected while lime forms slag with the impurities
-Slagging-oxidation must be complete and impurities removed before tapping the metal

Question 7

What are crystals?

Answer 7

Crystals are solids in which atoms are arranged in regular, repeating 3D patterns

Question 8

What is a BCC and FCC?

Answer 8

BCC= body centred cube
FCC= face centred cube

Question 9

What is crystal structure?

Answer 9

Refers to the way the fundamental building blocks are arranged in a material

Question 10

What is a crystalline material?

Answer 10

Solids in which atoms are arranged in regular patterns, long range order

Question 11

What is an amorphous material?

Answer 11

One which atoms are irregularly arranged, short range order

Question 12

What is a unit cell?

Answer 12

The smallest pattern that repeats itself

Question 13

What is the radius ratio?

Answer 13

The ratio of an atom that can fit in the space to the radius of the overall atom

Question 14

R ratio

Answer 14

R ration = R fit/R tot

Question 15

What does filling the space do?

Answer 15

We reduce the total empty space in the element and the properties of the element we are adding with contribute to the properties of the metal

Question 16

Rule for BCC and FCC?

Answer 16

N = N inside + N face/2 + N corner/8

Question 17

Rule for HCP?

Answer 17

N= N inside + N face/2 + N corner/6

Question 18

What is the packing factor?

Answer 18

The total atoms in a cell x atomic volume/ volume of a unit cell

Question 19

Number of atoms at different temperatures

Answer 19

At room temp, BCC, 2 atoms
Above 910 deg, FCC, 4 atoms