1. What is the difference between the cooling rate and hardenability? How the sample sizes affect the cooling rate and hardenability?
2. Martensite can also be obtained through water quenching of alloy steels, why oil quenching is normally used in industries?
3. You will have both 1045 plain carbon steel and 4340H alloy steel samples with size 20 mm in diameter and 10 mm thick, can you obtain 100% martensite at the centre of the sample? Why?
4. In the same steel, which microstructure is harder? Ferrite, coarse pearlite, fine pearlite, bainite or martensite?