9.1 | MSE104 Non-equilibrium cooling of steels

Segment 1 of Lecture 9. Non-equilibrium cooling of steels. Martensite, tempering, steels TTT curves, effect of alloying.
Course webpage with notes: dyedavid.com/mse104
Lecturer: Dr David Dye.
Licence: Creative Commons
Department of Materials, Imperial College, London, UK

[@victorfanarcara6663]

Thank you Professor Dye. You save people from all around the world.

[@henryrroland]

And keeps helping in 2021

[@sethaandewiel923]

You sir saved a few students from some very confusing lectures.

[@upesade2825]

I am from India and your lectures help me a lot ..Thank You Sir.

[@prajnadattameher6210]

Definitely had FUN.Thank You indeed.

[@sumballaboi]

also cheers for the sheffield shout out :P

[@waltzski]

My job is heat treating tempered martinsite, and David really spells out the differences in the recipes. But wait, theres more.

[@virendrakawade1235]

Your lectures are great sir. It will be great if you upload lectures on heat treatment

[@sumballaboi]

thank you so much

[@norvinmallari7258]

but how about if we quench it rapidly and stop at temperature 600 celcius, we can still get the pearlite right? or theres difference between rapid cooling and slow cooling

[@LaszloVondracsek]

The diagrams TTT (Temperature, Transformation, Time) are very important and at the same time very difficult. A distinction must be made between isothermal and continuous cooling (TTTI, TTTC.). Although it seems the same, something else is obtained.

[@fatihozzturk]

i've already knowed that but very lovely video

[@BirukGedifWorku]

Is martensitic transformation can occur in TTT case?

[@eddie2096]

Does it always have 1% of primary ferrite? How do you get that number?

[@christoffdt]

Great video! Understood nothing after my lecture but this has helped immensely. At 20:55 though, wouldn't number 3 form 50% Bainite and 50% Martensite?

[@TehMaxLightning]

+kanaka_katan Yeah I'm confused about that too. In addition I don't understand where the ferrite came from for path 1. If someone can explain that would be swell.

[@mahdimerabtene9800]

why does the ferrite form in the grain boundaries??

[@numair23]

+Mahdi Merabtene It's easier for nucleation to occur in grain boundaries due to inclusions and dislocations giving rise to higher interfacial energy

[@aldiansyahwahfi]

hey, are you that guy who teaches mathematics for machine learning at coursera? it's weird to find you here lol