论文部分内容阅读
灰口铸铁由于其成本低廉、减振和切削加工性能良好获得应用。这些突出优点源自游离态石墨的存在和液态金属的良好流动性,后者有利于制作形状复杂的薄壁铸件。适合的渗层能改善灰口铸铁的耐磨性,从而扩大其应用范围。高硬度的碳化铌可以达到这一目的。本文研究用的灰口铸铁试样成分为3.47%C-2.39%Si-0.55%Mn-0.15%Ni-0.65%Cu-Fe(余量),采用Fe-Ni合金、NH_4Cl和Al_2O_3的粉末混合物进行热反应扩散渗铌,温度900℃,时间2 h。碳化铌渗层的硬度可达2 000 HV,微黏着磨损和微磨粒磨损试验证明,固体渗铌处理可显著提高灰口铸铁的耐磨性。
Gray cast iron is used due to its low cost, good damping and machinability. These outstanding advantages result from the presence of free graphite and the good fluidity of the liquid metal, which facilitates the fabrication of thin-walled castings with complex shapes. The suitable layering improves the wear resistance of gray cast iron and expands its range of applications. High hardness of niobium carbide can achieve this goal. The gray cast iron sample used in this study is 3.47% C-2.39% Si-0.55% Mn-0.15% Ni-0.65% Cu-Fe with the powder mixture of Fe-Ni alloy, NH 4 Cl and Al 2 O 3 Thermal reaction diffusion niobium infiltration, temperature 900 ℃, time 2 h. The hardness of niobium carbide layer can reach 2 000 HV. The micro-adhesive wear and micro-abrasive wear test prove that the solid niobium treatment can significantly improve the wear resistance of gray cast iron.