X.L. Xu
,
L. Wang
,
Z. W. Yu and Z.K. Hei(Institute of Metal and Technology
,
Dalian Maritime University
,
Dalian 116024
,
China)
金属学报(英文版)
The cross-sectional microstructure of an ion-nitrided layer on a No.45 steel was studied by transmission electron microscopy (TEM). The results show that the columnar crystals constitute the compound layer. Most of them have the microstructure of alternating ε-Fe2-3N and γ-Fe4N and others are single ε-Fe2-3N phase. There are abnormal strip ferrites between the columnar crystals. The transition layer mainly consists of spherical γ-Fe4N and cementite (Fe3C) particles in the pearlite are dissolved in this layer. In diffusion layer, besides the equilibrium phase γ-Fe4N, there are α -Fe16N2 and the satellite spots around main spots of α-Fe16N2 demonstrate its modulation structure. A metastable ordered cluster zone of the nitropen atoms was found in the division layer.
关键词:
ion nitriding
,
null
,
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