2. Strain around solute atoms

3. Strain around small 2nd phase precipitates

6. 2 different distributions of Phases

7. 2 different distributions of precipitates

8. Strain around small 2nd phase precipitates

9. Fe-C phase diagram

12. Allotropy
Some elements exhibit more than one crystal structures. This phenomenon is called Allotropy
e.g., IRON exists in:
upto 912°C BCC (body centered cubic)
912°C °C FCC (face centered cubic)
1394°C – melting BCC

13. Two crystallographic form of Carbon

14. Allotropes of Uranium
alpha (orthorhombic) Uranium Stable up to 667.7°C
beta (tetragonal) Uranium Stable ° °C
gamma (body-centered cubic) Uranium Stable 774.8°C - melting point This is the most malleable and ductile state.

16. Microstructure of Steel

17. Different carbon contents

18. Eutectoid microstructure

19. Influence of Cooling Rate

20. Effect of cooling rate

21. Annealing 1. Heat to austenite region 2
Annealing 1. Heat to austenite region 2. Soak for a suitable time depending upon size of component 3. Cool to room temperature in furnace
Normalizing 1. Heat to austenite region 2. Soak for a suitable time depending upon size of component 3. Cool to room temperature in air
Hardening
1. Heat to austenite region 2. Soak for a suitable time depending upon size of component 3. Cool to room temperature by quenching into oil or water

22. Mechanical Properties of Steels mainly depend upon:
1. Carbon Content (+ other Alloying elements) 2. Cooling rate

23. Martensite

25. Microstructure of high-speed tool steel