TEM INVESTIGATION ON MICROSTRUCTURES OF EUTECTOID CEMENTITE IN HIGH CARBON LOW ALLOY STEELS
高碳低合金钢中共析渗碳体微观结构的TEM研究

The eutectoid cementite in several rail steels has been studied by means of TEM.It was found that the eutectoid cementite lamellae arc not of homogeneous structure but contain some ferrite sub-lamellae with different widths and same orientation. The continuity of the eutectoid cementite lamellae was reduced when the ferrite sub-lamellae were incorporated. The planar indices of the ferrite sub-lamellae are found usually close to {211}F.Some contrast fringes observed at the cementite/ferrite interface were analyzed and compared with the sub-lamellae in the eutectoid cementite. The formation mechanism of ferrite sub-lamellae in eutectoid cementite was also discussed.