Wow, that's awesome! I've only seen that inside my head.

This is what I have been looking for, thanks for the clear visualization!!

Beautiful !

@bhadeshia123

Жыл бұрын

Thank you! Cheers!

Amazing!!

@bhadeshia123

Жыл бұрын

Thank you. There is more information available on www.phase-trans.msm.cam.ac.uk/2002/martensite.html

the experiment demonstrates the athermal nature ( indepandent of time) , and the transformation happens very fast (nearly sonic)

The sample was not etched, but metallographically polished and then heated in a vacuum to produce austenite, followed by cooling to achieve phase transformation, detected by the displacements.

Wow,, I can't believe that phase transition is so fast..!

Awesome!

Appreciate for open the noteworthy experimental result!. I have one question professor. The specimen used in this experiment was pre-etched or only mechanically polished?

Very interesting and many thanks

is the time given in seconds??

Much better than my simulation. XD

Thank you great video Sir In some foundries high Mangnese steel is water quenched just immediately after solidification in mold. Not like traditional method of separate water quenching heat treatment. from where do i get more information about in mold water quenching. Please help

@bhadeshia123

6 ай бұрын

I think you already have asked this question once and got a response.

Are there preferred sites for martensite to nucleate, or is it completely random ?

@bhadeshia123

4 жыл бұрын

Heterogeneous nucleation on defects such as dislocations and boundaries.

What if there was cementite nanowires present? You know like the ones in damascus steel.

Is it correct to say that martensite is a constituent of ferrite and cementite?

@bhadeshia123

10 ай бұрын

No. Please download my book (free) from www.phase-trans.msm.cam.ac.uk/2023/Theory_Transformations_Steel.pdf

Temp is in Fahrenheits? Because Martenzite start temp is abou 200 degrees ofCelsius.

@bhadeshia123

7 ай бұрын

Celsius

Hi Prof.Bhadeshia In Oleg D.Sherby's paper "Revisiting the Structure of Martensite in Iron-Carbon Steels", it mentioned that phase transformation during quenching was observed around 725C for 0.88wt%C steel. Measured by in-situ XRD. Would you like to share any comments on that? Thanks

@blahbleh5671

5 жыл бұрын

no

@Cooltaha

7 ай бұрын

@@blahbleh5671 virus

Love it

Ok, according my material science handout, based on the c wt％, this is the lath one, right?

@bhadeshia123

2 жыл бұрын

I don't know, need three-dimensional information.

Can someone try to explain why it's turning into martensite and not pearlite? Isn't a cooling rate of ~2,4C/sec (if the numbers are correct) much too slow?!

@bhadeshia123

8 жыл бұрын

Because the other solutes in the alloy give it sufficient hardenability.

hello is this steel?

@bhadeshia123

3 жыл бұрын

Yes it is.

could u explain what happen ?? :((

@bhadeshia123

9 ай бұрын

The disciplined movement of atoms causes the shape deformation. For more information, download the free book from the link below, and study the chapter on martensite: www.phase-trans.msm.cam.ac.uk/2023/Theory_Transformations_Steel.pdf

Great video ! What are the units on time ? Wanted to see if the speed of sound pops out when we can calculate the rate of propagation of the lath across the grain. Thanks !

@bhadeshia123

3 жыл бұрын

It is real time in seconds. Bear in mind that the major growth direction may not lie in the plane of observation. But you could calculate the apparent maximum growth rate.

@rakeshkamath2588

3 жыл бұрын

@@bhadeshia123 From a back-of-the-envelope calculation, the apparent growth rate from the front turns out to be around 500 microns/s. (Using the front which moves from top to bottom from video times 0:04 to 0:05), whereas the velocity of sound in steel is around 4500 m/s. I very much agree with your comment on the plane of observation not bearing the major growth direction. Do you have any thoughts on why we are observing a high discrepancy between the apparent growth rate and speed of sound (10^7 times) ?

@bhadeshia123

3 жыл бұрын

@@rakeshkamath2588 Thank you.

Hi, is there any publication available where the video was published first?

@bhadeshia123

3 жыл бұрын

Trends in Welding Research, Oku, Asakura, Inoue and Koseki, published by ASM, pages 272-276 (2009), editors S. A. David, T. DebRoy, T. Koseki and H. B. Smart

This video needs a suitable epic music

@bhadeshia123

3 жыл бұрын

You can download an Android app of the acoustic emissions due to displacive transformation: www.phase-trans.msm.cam.ac.uk/2011/Android/CB.html

Its like ice cracking upon cooling

@bhadeshia123

3 жыл бұрын

Your analogy is correct if you consider that both cracking and the shape deformation accompanying martensite are deformations. But i the former case there is no transformation and in the latter case there is no fracture.

Is this kelvin, centigrade, or fahrenheit? Ms is generally under 230c and M50 around 170c.

@bhadeshia123

7 жыл бұрын

No, M_S depends on composition. The units are centigrade.

@TheDuckofDoom.

7 жыл бұрын

This the highest M_s for a steel that I have seen. I did not notice the low carbon content in the description. Most of my TTT knowledge is centered on high carbon steels, simply because quenching has fewer practical uses on low carbon steels.

@bhadeshia123

7 жыл бұрын

Read a little more: www.msm.cam.ac.uk/phase-trans/2002/martensite.html

@MrMustacheio

6 жыл бұрын

I work on a steel that has an Ms of 420°C and a carbon content of 0.08 wt%

Wer is auch wegen dem Wasmuth hier?

@bhadeshia123

2 жыл бұрын

No sense.

@aureliolinhares5739

6 ай бұрын

he is speaking in German@@bhadeshia123