低碳钢中晶内形核铁素体三维形貌的唯象研究

Optical microscope and scanning electron microscope were used to study metallographic microstructures of intragranular ferrite in a low carbon steel. The three-dimensional morphology of ferrites was reconstructed based on observed two-dimensional observations on the computer. The inclusions of MnS enhance the nucleation of intra-granular ferrites evidently. The three-dimensional morphology of acicular ferrites was prolate plate. A number of ferrites connected to each other in space, and some of them associated with inclusions. Three possibilities are considered for the nucleation of ferrites: sympathetic nucleation on previous ferrite, nucleation of the ferrite directly on the inclusions’ interface and heterogeneous nucleation at the junction of a pre-existing ferrite crystal and inclusion.