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研究了20钢在不同渗硼温度和不同渗硼时间下对渗硼层组织和性能的影响。用金相显微镜和扫描电镜观察了渗硼层的形貌,测定了渗硼层的厚度;用维氏硬度计测定了渗硼层的硬度;用纳米压痕仪测定了渗硼层不同深度的硬度;评定了渗硼层与基体的结合力;采用X射线衍射仪分析了渗硼层的物相组成;在不同溶液中进行了渗硼层耐蚀性试验。结果表明:渗硼层厚度均匀,呈齿状结构,与基体结合牢固,渗硼层主要由Fe_2B组成。在860℃下保温不同时间,渗硼层的厚度随时间的增长而增大;在不同温度下保温5h时,渗硼层的厚度随温度的升高而逐渐增大。渗硼层表层硬度稍低,然后升高达到最大值,在渗层与过渡区的交界处急剧下降。除HNO_3外,渗硼处理后的试样在HCl、H_2SO_4、NaCl和NaOH溶液中的耐蚀性均比未渗硼的试样好。
The effect of 20 steel on the microstructure and properties of boronizing layer at different boronizing temperature and different boronizing time was studied. The morphology of the boronizing layer was observed with a metallographic microscope and a scanning electron microscope. The thickness of the boronizing layer was measured. The hardness of the boronizing layer was measured with a Vickers hardness tester. The depth of the boronizing layer with different depths Hardness; the bonding strength of the boronizing layer and the substrate was evaluated; the phase composition of the boronizing layer was analyzed by X-ray diffraction; and the corrosion resistance of the boronizing layer was tested in different solutions. The results show that the boronizing layer is uniform in thickness and dentate in shape, and is firmly bonded to the substrate. The boronizing layer mainly consists of Fe_2B. At 860 ℃ for different time, the thickness of the boronizing layer increases with time. When the temperature is 5h, the thickness of boronizing layer increases with the increase of temperature. Boronizing layer surface hardness slightly lower, and then increased to reach the maximum, at the junction of the infiltration layer and the transition zone decreased sharply. In addition to HNO_3, the corrosion resistance of the samples after boronizing treatment in HCl, H_2SO_4, NaCl and NaOH solutions were better than those of boron-free samples.