Sir, Never have I ever attended a lecture like this teaches the very basic concept "Which is the difference between different heat treatments of Plain carbon Steel".... Simply awesome sir. Thanks for this lecture
Sir, please add me to your fan followers list. Never had I ever enjoyed learning material science as I did after visiting your lecture series. Your explanation is really covering every nuance, like why >2% carbon is called cast iron (because melting point decreases & hence it is beneficial to use in casting). Sir, maybe I would run out of words to admire your explanation. Just to let you know, (without any intention to offend anybody), I started your lecture series after going through IIT Roorkee & IIT Bombay lectures on Phase diagrams. Your lectures & your explanation is just beyond comparison. Thank you for your efforts!
Sir, Does pure ferrites have carbon in them? They are purely ferrous compounds right? So they should not have carbon in them, but in the phase diagram we show that even pure ferrite and Austenite have carbon in them. Why is that so?
Ferrite and austenite are used in two senses: for pure iron as well as solid solution of iron with other elements. Thus pure monatomic BCC Fe is ferrite. But if small amount of C is added, which go into the octahedral voids, we get an interstitial solid solution with BCC crystal structure. This is also called ferrite.
You are right. I have made a mistake here. As per Dieter, Mechanical Metallurgy, the useful range for C scale is from 20 to 70. So 20 can be considered as minimum value on this scale. So what i should say that the hardness is less than RC 20. Perhaps, it should be measured on B scale.
