Interlamellar Spacing in Pearlite

[RPI_Quantum]

I was wondering if somone could explain the dependence of iterlamellar spacing in pearlite on undercooling to me. I understand that a higher undercooling results in finer lamella, but beyond that I cannot put it all together.

Any help is appreciated, thanks!

 

[Astronuc]

The more rapid the cooling and the lower temperature produces more nucleation sites at which the lamella initially precipitate. This is observed in many alloy systems in which there are second phases, which are chemically different from the main alloy solution.

Further precipitation occurs at the lamella sites.