Electron-microscopic study of the structure of coarse lamellar pearlite in a cold-worked plain carbon steel

The evolution of the structure of coarse lamellar pearlite in a plain carbon steel upon cold plastic deformation was studied by electron microscopy using the g - b analysis. It was found that a subgrain structure is formed in the ferrite component of the coarse lamellar pearlite already at the early stages of plastic deformation (epsilon similar to 10%). Deformation from one ferrite lamella into another is passed by intersection of cementite lamella on the ((1) over bar 03)(cem) parallel to ((1) over bar 01)(f) planes, which are parallel to the planes of planar defects. It is shown that, as the degree C of deformation increases to epsilon greater than or equal to 40%, the cementite lamellae are dissolved in pearlite with the carbon segregation near planar defects in cementite and dislocation subgrain boundaries in ferrite. It was established that the disc solution of cementite lamellae is accompanied by the precipitation of fine carbide particles in the ferrite lamellae.