CrMoCu合金铸铁低温离子渗硫层微观结构及形成机理

Microstructure and formation mechanism of the low temperature plasma sulphurized layer of CrMoCu alloy cast iron

采用低温离子渗硫工艺,在CrMoCu合金铸铁表面渗硫,利用SEM、TEM、EDS及XRD等分析技术,对渗硫层表面和截面的微观结构进行系统分析,进一步探讨渗硫层的形成机理。结果表明,渗硫层表面由200～300 nm均匀的硫化物小颗粒组成,并含有α-Fe、Fe1-xS及FeS相,渗硫层的硫含量由表及里逐渐减少。通过TEM电子衍射花样分析,发现渗硫层存在FeS非晶相,并分析了其产生的原因。

The sulphurized layer was prepared on the surface of CrMoCu alloy cast iron by plasma sulphurization.Surface analysis methods such as SEM,TEM,electron diffraction pattern,EDS and XRD were employed.The microstructure of the sulphurized layer was systematically investigated and the formation mechanism of the sulphurized layer was discussed.The results show that the sulphurized surface makes up of 200~300 nm even sulphide granules,which contain the phases of α-Fe、Fe1-xS and FeS.The sulphur content of sulphurized layer gradually decreases from surface to inner.By the Electron diffraction pattern of TEM,FeS noncrystal phases was found in the sulphurized layer and the reason of formation was analyzed.