1. What is shown in the photo?
IRON and STEEL
What is shown in the photo?

2. Atomium in Brussels
This building is a giant model of body-centered cubic crystalline lattice of iron – the main metal for human civilization
(enlarged 165,000,000,000 times)

3. Crystalline structure of iron: unit cell
Body-centered cubic crystalline lattice (BCC)

4. Relationships between basic components

5. Photomicrograph of iron: ferrite
Commercially pure iron: less than wt% C

6. Photomicrograph of low-carbon steel: ferrite and pearlite
Steel used for various structural shapes and sheets: 0.15 wt% C

7. Photomicrograph of medium-carbon steel: ferrite and pearlite
Steel used for various machine parts: 0.4 wt% C

8. Photomicrograph of high-carbon steel: pearlite
Steel used for springs: 0.8 wt% C

9. Photomicrograph of high-carbon steel: pearlite and cementite
Tool steel: 1.2 wt% C

10. Photomicrograph of high-carbon steel: spheroid pearlite
cementite
ferrite
Tool steel having a spheroid microstructure 1000x

11. Photomicrograph of grey cast iron: pearlite and graphite
cementite
Pearlitic grey cast iron: approximately 4.0 wt% C

12. Photomicrograph of cast irons
nodular
malleable
gray
white
All cast irons contains between 3.0 and 4.5 wt% C