论文部分内容阅读
通过化学热力计算和对实验的观察,对于碳化硼渗硼反应机制和渗硼工艺的改革提出一些看法。在渗硼反应中存在着生成硼原子和氧化消耗硼原子的矛盾。为了增加硼原子的净积累率,渗硼环境应该是强还原性的。在液体渗硼时,反应放出的一氧化碳等气体易于附着在工件表面上,从而降低渗硼速度,如果能加快气体的排出,则可以大大加快渗硼速度。KBF_4在粉末渗硼中催渗的主要原因在于BF_3和B_4C反应放出BF_2,而BF_2再进一步和Fe反应渗硼。由于KF粘性大,限制了KBF4的加入量。增加KBF_4比例时,如果不是使它和渗剂均匀混合,而是集中使用,就有可能大大提高KBF_4的催渗效果。
Through the chemical thermodynamic calculation and the observation of the experiment, some opinions on the boronizing reaction mechanism of boron carbide and the reforming of boronizing process are put forward. In the boronization reaction there is a contradiction between the generation of boron atoms and the oxidation of boron atoms. In order to increase the net boron atom accumulation rate, the boronizing environment should be strongly reducible. When the liquid is boronized, the gases such as carbon monoxide released by the reaction tend to adhere to the surface of the workpiece, thereby reducing the boronizing rate. If the gas is expelled, the boronizing speed can be greatly accelerated. The main reason of KBF_4 seepage in powder boronizing is that BF_3 and B_4C emit BF_2, while BF_2 further reacts with Fe. Due to the large viscosity of KF, the addition of KBF4 is limited. KBF_4 ratio increase, if it is not evenly mixed with the penetration agent, but to focus on, it is possible to greatly enhance the effect of KBF_4 permeability.