论文部分内容阅读
用加入0,0.3%,0.8%(质量分数)稀土钕(Nd)的盐浴分别对H13试样进行TD处理,使试样表面形成碳化钒(VC)渗层。通过比较加与不加稀土Nd所获得渗层,研究Nd对TD处理的影响。采用扫描电镜(SEM)、X射线衍射仪(XRD)和维氏显微硬度计对渗层的组织、物相和硬度进行测试分析。结果表明:加入Nd可以避免对H13钢处理时产生合金元素富集,合金元素聚集导致材料表面附近一区域组织粗大,影响材料性能。Nd可以提高渗层以及渗层和基体间过渡区的硬度,过渡区硬度的提高可以对高硬度层起到更好的支撑作用,利于增加渗层与基体的结合强度;Nd的浓度并非越高越好,本文中用含0.8%Nd的盐浴处理后的试样效果最好,渗层硬度可达2400~2500 HV。
The H13 specimens were treated with TD by salt bath containing 0, 0.3% and 0.8% (mass fraction) of rare earth neodymium (Nd), respectively, to form a vanadium carbide (VC) layer on the specimen surface. The effect of Nd on TD was studied by comparing the layers with and without Nd addition. The microstructure, phase and hardness of the layer were tested by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Vickers microhardness tester. The results show that adding Nd can avoid the enrichment of alloying elements during the treatment of H13 steel. Aggregation of alloying elements results in the coarsening of the coarse structure in a region near the surface of the material, which affects the material properties. Nd can improve the hardness of the diffusion layer and the transition zone between the infiltration layer and the matrix, and the improvement of the hardness of the transition zone can play a better supporting role in the high hardness layer, which helps to increase the bonding strength of the infiltration layer and the matrix; the Nd concentration is not higher The better, in this paper, with the 0.8% Nd salt bath treated samples the best results, the hardness of the infiltration layer 2400 ~ 2500 HV.