AndrewFinAustralia
Materials
- May 1, 2015
- 37
Hi All,
Former materials Engineer (Hons) now teaching at a high school - yes, we teach ferrous metallurgy to 17 year olds in NSW if they want to study engineering.
I was always taught that increasing the amount of carbon in martensite increased hardness through increased lattice distortion and volume increase.
I went looking for details of the austenite-martensite volume expansion for course notes - conflicting information that I could not make sense of without a trip to the local (60km away) university.
See attached images.
ASM handbooks (thanks google books) gives the volume increase ferrite-martensite is maximum at zero percent carbon (4.53%) as well as minimum at zero
Is anybody able to explain? - I'll back intuition and suggest increased % carbon = increased volume expansion due to deformation of lattice but am (now) completely confused on this point. Doesn't make sense to me as I know the formulae in the handbook pass strict peer review
Former materials Engineer (Hons) now teaching at a high school - yes, we teach ferrous metallurgy to 17 year olds in NSW if they want to study engineering.
I was always taught that increasing the amount of carbon in martensite increased hardness through increased lattice distortion and volume increase.
I went looking for details of the austenite-martensite volume expansion for course notes - conflicting information that I could not make sense of without a trip to the local (60km away) university.
See attached images.
ASM handbooks (thanks google books) gives the volume increase ferrite-martensite is maximum at zero percent carbon (4.53%) as well as minimum at zero
Is anybody able to explain? - I'll back intuition and suggest increased % carbon = increased volume expansion due to deformation of lattice but am (now) completely confused on this point. Doesn't make sense to me as I know the formulae in the handbook pass strict peer review