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本文用金相显微镜、X射线衍射仪、电子探针及精密天平研究了离于硫氮碳共渗化合物层的形成动力学、组织结构以及硫、氮、碳分布。试验表明,离子硫氮碳共渗试样表面上形成疏松多孔状的硫化铁(FeS),其厚度和增重量与处理时间的平方根成正比关系。次表面化合物层主要由γ′-Fe_4N和ε-Fe_(2～3)(N,C)组成。45钢540℃×6h离子硫氮碳共渗时,次表面层化合物组成从外到内是按照γ′_多+ε_少→γ′_少+ε_多→γ_多+ε_少→γ′_少+ε_多顺序分布。在离子硫氮碳共渗层中,硫主要集中在表面疏松层中和次表面化合物层与表面疏松层之间的界面处;氮的最大浓度出现在次表面化合物层最外侧上;碳浓度峰值,短时共渗,在次表面外侧上,而延长共渗时间,其峰值朝内移动,并出现两个峰值。
In this paper, the formation kinetics, microstructures, sulfur, nitrogen and carbon distributions from the nitrocarburising compound layer were studied by means of metallographic microscope, X-ray diffraction, electron probe and precision balance. The results show that the loose and porous iron sulfide (FeS) formed on the surface of the ion-sulfurized nitrocarburizing specimen is proportional to the square root of the treatment time. The subsurface compound layer mainly consists of γ’-Fe 4 N and ε-Fe 2 (N 3 C). 45 steel 540 ℃ × 6h ion sulfur carbonitriding, subsurface layer compound composition from outside to inside in accordance with γ’_ more + ε_ less → γ’_ less + ε_ more → γ_ more + ε_ less → γ’_ less + ε_ multi-order distribution. In the ion-sulphided carbonitriding layer, sulfur mainly concentrates in the surface loose layer and the interface between the subsurface compound layer and the surface loose layer; the maximum nitrogen concentration appears on the outermost side of the subsurface compound layer; and the peak of carbon concentration , Short-term infiltration, on the outer surface of the subsurface, while prolonging the permeation time, the peak moves inward, and two peaks.