Microstructure of a Hypoeutectoid Steel

CORRECTION: In the phase diagram shown from 00:38, please note that the two-phase region marked as α+Fe3C is γ+Fe3Cand the two-phase region marked as γ+Fe3C is α+Fe3C.
Thanks to the user Emanuel George for pointing out this mistake!
Microstructure of a Hypoeutectoid Steel
Proeutectoid ferrite
Pearlite

[@introductiontomaterialsscience]

CORRECTION: In the phase diagram shown from 00.38 s, please note that the two-phase region marked as γ+Fe3C is α+Fe3C and the two-phase region marked as γ+Fe3C is α+Fe3C. Thanks to the user Emanuel George for pointing out this mistake!

[@bhaskarmahanthi6868]

nice lectures sir . tnq so much i listen your lectures and i am going write my end sem exams with positve vibes

[@fablihazarin6769]

Thank you so much , professor! These videos are really very useful.

[@emanuelgeorge2679]

You should correct the lower region that is alpha + Fe3c not gama + fe3c

[@introductiontomaterialsscience]

Thanks for pointing this out.

[@dasappan6038]

Malayali poli thanne.. Bro ippo entha chayana joli ayoo😅😅😅

[@brightonnyasha8764]

thanks prof. you made this chapter simple. one love ✍👷👷

[@vikneshviknesh281]

I didn’t see comments before.i was too confused that ,y it was gamma + Fe3C ...after go through the comments,now I clear in concept.🙂.thank u..and thank u so much for ur good lecture sir..

[@rajeshprasadlectures]

Sorry for the confusion!

[@kapilsaraswat3034]

great knowledge....great teacher.....great explanation...thank you sir...

[@nyquist_control]

amazing. 10x clearer than my 'professor'.

[@al-hasanmansuri1678]

sir would please make a video on monotectic transformation and layer type system

[@GilangRamadhan-jr9jo]

thanks,its so usefull

[@aryansinghparihar6932]

@Rajesh Prasad Sir, if we take Fe-C alloy at 0.02 wt% C composition in the Gamma + Alpha region and start cooling then on reaching eutectoid horizontal we will have no Gamma phase left (from lever rule) then on further cooling Eutectoid reaction will take place?

[@introductiontomaterialsscience]

As no gamma is left, there will no eutectoid reaction.

[@aryansinghparihar6932]

@@introductiontomaterialsscience Okay Sir Got it. Thank You🙏🙏

[@cricketlover123.4]

please sir give the explanation of peritectic system and peritectoid system

[@abhiseknayak6063]

Sir if we see at the equilibrium line (910°-0.8 line) what will be the microstructure ?

[@rajeshprasadlectures]

If you are exactly at the equilibrium line then it should be fully austenite.

[@yashsharma6112]

After 1 year also this error is same please correct it

[@scottcrawshaw4297]

If a hypo or hyper eutectoid steel is heat treated and then allowed to cool to room temperature, will the micro structure return to the same shape when cooled?

[@introductiontomaterialsscience]

It will depend upon the tempearture to which you heat and also the subsequent cooling rate. For example, suppose the hypoeutectoid steel you are starting with has a proeutectoid ferrite and pearlite. If you heat it to the austenite region to form austenite and then quench you will form martensite. But if you cool the austenite slowly, you will get ferrite and pearlite back.

[@harshavardhanlakhinana5280]

I have followed the nptel lectures for almost all my semesters in collage but these are the only videos which have more than 50K views. Does anyone know why?

[@shivasmart967]

tq sir

[@random.stranger07]

0:50 sir composition wronlgly mentioned

[@introductiontomaterialsscience]

Please specify.

[@shreyashavaldar2076]

@@introductiontomaterialsscience there should be austinite at the left sir, but i have written ferrite?

[@introductiontomaterialsscience]

@@shreyashavaldar2076 Yes, there is a mistake. Correction has been pointed out in the description.

[@shreyashavaldar2076]

@@introductiontomaterialsscience thanks, for replay sir, I got it

[@ManishKumar-qh8qr]

This 147 lecture of material science is enough for gate or this is a very much . Please recommend . I have less time.

[@debarchanbasu768]

Only for Physical metallurgy.

[@rajeshprasad101]

I was not thinking of GATE exam when delivering this set of lectures. they serve as an introduction to material science. For GATE you will certainly need more stuff.

[@debarchanbasu768]

Dr. @Rajesh Prasad actually sir, apart from a problem-solving perspective, I believe your lectures are pretty sufficient for Physical metallurgy part in GATE as well! I tallied them with the syllabus too.

[@ahmedreshi5697]

Sir the horizontal you have drawn, isnt it the eutectic horizontal instead of the eutectic horizontal, if you look at the original full graph.

[@introductiontomaterialsscience]

There is no liquid phase involved in this case. So it is not a eutecTIC horizontal but a eutecTOID horizontal.

[@geminiblue6677]

Can anyone explain why a proeutectoid cementite forms as a network rather than as a separate grain unlike proeutectoid ferrite ? Is it because there is insufficient cementite ?

[@firstlegend5105]

Yes, but it's the same case as the proeutectoid ferrite. If there is sufficient ferrite, it will also form a network, it depends on the composition and cooling rate of steel

[@formula2763]

It's very informative video.. Just a minor mistaje at lower end of temp 725 degree cel.. Please correct this to alpha + fe3c

[@introductiontomaterialsscience]

Thanks. Others have also noted this earlier. I have put a correction note in the video description.

[@BC-yr6eg]

👍👍👍👍

[@Engr_Muhammad_Ahmed]

Sir please correct your point in start where you have to deliver your lecture, that how α exist at above the critical line (above 727 degree Celsius) with α+ Fe3C and, how gamma phase exist at below 727 degree Celsius?? If I'm not wrong it's your mistake and should be correct it..

[@rajeshprasad101]

Thanks for pointing it out. It is my mistake.

[@narsinghsvn5750]

replace alpha with gamma