奥氏体不锈钢纳米化/渗硫层的摩擦学性能

Tribological Properties of Nanocrystallization/Sulphurized Layers of Austenitic Stainless Steel

针对1Cr18Ni9Ti奥氏体不锈钢硬度低、耐磨性差和低温离子渗硫层薄等问题,采用超音速微粒轰击技术先对1Cr18Ni9Ti不锈钢进行表面纳米化预处理,再对预处理前后的试样同炉进行低温离子渗硫处理制备了渗硫试样。通过X射线衍射仪(XRD)和扫描电子显微镜(SEM)对渗硫层的形貌、物相结构进行了表征;通过显微硬度计和粗糙度仪对渗硫层的硬度、粗糙度进行了分析;在润滑油条件下采用摩擦磨损试验机,考察了直接渗硫层和纳米化/渗硫层的耐磨性。结果表明:与直接渗硫样品相比,纳米化/渗硫层试样的Fe S相的含量明显增多,Fe S2相的含量明显减少,渗硫层厚度提高了2倍,摩擦系数下降了0.19,耐磨性提高了1.78倍。这归因于纳米晶表面层具有较高的硬度和化学活性。

For the defects of 1CrlSNi9Ti anstenitic stainless steel such as low hardness, poor wear resistance, thin low temperature sulphide layer, a compound technology of supersonic bombarding of fine particles and low temperature ion sulfur percolation was adopted to prepare sulfur- permeated sample： nano-crystallization pretreatment was first conducted on the surface of 1Crl8Ni9Ti austenitic stainless steel and followed by the sulfur percolation in the same furnace. The morphology and phase structure of the snlphurized layers were characterized by X-ray diffractometer and scanning electron microscope. The mechanical properties of snlfur-permeable layer were analyzed by the methods of indentation and needle-tracing. Under the lubricating oil condition, the friction- abrasion testing machine was used to investigate the abrasive resistance of supersonic particle bombardment and the sulphide iayer. Resuhs showed that compared with the sample by the direct sulfuration, the content of FeS phase of the sample by this compound technology significantly increased while the content of FeS2 significantly reduced. The thickness of the percolation layer increased by two times, and the friction factor decreased by 0.19 as well as the wear resistance increased by 1.78 times. All these characteristics attributed to the high hardness and chemical activity of the nanoerystalline surface layer.