The below micro structure of Spindle which failed during rolling process hot rolled plates , this is having 0.39%carbon, can anyone please explain the micro structure.
The microstructure consists of ferrite (mostly acicular ferrite and a small fraction of polygonal ferrite, light contrast) and pearlite (lamellar structure of ferrite and cementite, dark contrast). Acicular ferrite forms at a large volume fraction when the cooling rate is very fast. The temperature dropped rapidly between the rolls, which may have caused the failure during hot rolling.