Question - What Is Carbide?
Answer -
The epsilon carbide is transition carbide of between Fe2C and Fe3C composition, with hexagonal close packing microstructure, which forms over a range of 250400 ºC temperature during lowerbainite transformation. This transformation happens during tempering heat treatment of quenched steels, or during slow cooling in that temperature range.
It is fine dispersed carbide in a ferrite needlelike matrix. Lower bainite has lower tensile strength (about 510%), but usually same hardness as martensite structures, but with a higher toughness.