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(Fe,M)B和(Fe,M)_2B(M指Cr或Ni)是铁合金渗硼层的两个主要组成相。本文给出了这两个相的硬度变化以及与合金中Cr、Ni、C含量的关系。已经发现,尽管这些合金硼化物的硬度都低于纯硼化铁的硬度,但合金中的铬既提高整个渗硼层的硬度,也提高硼化物相的硬度。碳不溶于硼化物相中,而富集在渗层与基体的界面上,然而,由于碳改变了硼原子的扩散机理,故它将间接地提高渗硼层的硬度。合金中的镍总是稍微降低硼化物相的硬度,特别是对于含镍量最高的(Fe,Ni)_2B相。
(Fe, M) B and (Fe, M) _2B (M refers to Cr or Ni) are the two major constituents of the iron alloy boronizing layer. This paper gives the hardness changes of these two phases and the relationship between the contents of Cr, Ni and C in the alloy. It has been found that although the hardness of these alloy borides is lower than that of pure boriding iron, the chromium in the alloy both increases the hardness of the entire boriding layer and also increases the hardness of the boride phase. Carbon does not dissolve in the boride phase and is enriched in the interface between the diffusion layer and the substrate. However, carbon indirectly increases the hardness of the boronizing layer because carbon changes the diffusion mechanism of boron atoms. Nickel in the alloy always slightly decreases the hardness of the boride phase, especially for the (Fe, Ni) _2B phase with the highest nickel content.