Steels: martensitic transformation, part 1. Lecture 1 of 12

[@jianhaochen9527]

A great teacher! Many thanks, Sir!

[@bhadeshia123]

You are welcome.

[@manishrao2707]

Very Informative...!!!!

[@bhadeshia123]

Thank you

[@chenhu8187]

Thank you professor Bhadeshia, this video and the book Steel helps a lot. However, I still have one question and hope you can help me. For my understanding, one one hand the shape deformation requires a invairant-plane; on the other hand, the book says the coherent interfaces cannot be found in MT. So are the invariant plane equal to the coherent interfaces? If so, can we state that the needed "invariant plane" also does not exist, but is just accommodated by slip or twinning? Thanks!

[@bhadeshia123]

I think that is a good way of describing the transformation. The plane is only invariant on a macroscopic scale.

[@chenhu8187]

@@bhadeshia123 Thank you sir! BTW, why does high-C martensite tend to accommodate by twinning while low-C matensite by slip? Can we say these twinned martensite is not stable thermaldynamically?

[@purnimakumari4832]

Sir, which model is used for multiphase structures (RA+F+B+Ms) in TRIP STEEL

[@bhadeshia123]

See Lecture 4 in the series Steels:2020, or Page 425 of Steels: microstructure and properties, 4th edition.

[@Kianarevision]

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