【摘要】 本文采用固体渗硼方法,对多种钢材渗硼层进行孔洞形态特征的观察和孔洞内成分元素的测定,探讨了孔洞的成因并提出了孔洞形成的一些看法。结果表明:孔洞是含有Si、S及微量渗剂分解元素的多面体缺陷,并是先天性微裂源。孔洞沿晶界滑移或解理导致孔洞的联结和显微裂纹的扩展。作者认为:孔洞的形成是渗硼初期表层过饱和品格空位聚集成核,并因渗硼气氛沿硼化物边界或晶界进入孔核和扩大作用的结果。据此提出了减少孔洞的工艺途径。更多还原

【Abstract】 The mechanism of forming the voids in the boronized layer by packing method was investigated. Firstly, the morphological characters of voids have been observed and the micro-area composition in the void has been accurately determined on several materials. Then the factors influencing the formation of voids and the mechanism of voids formation have been discussed. The results have shown that the voids are polyhedral defect and congenital hair line source in which some silicon, sulfur and trace elements of boronizing agents are contained. Some voids slipping or cleaviag along the grain boundaries of borides lead to form microcrack. It was considered by the authors that the formation of voids is due to the gathering nucleation of supersaturated lattice voids in the surface layer during the initial stage of boronization and also the boronizing atmosphere leading into the voids aucleus along the boundaries of boride needles and grains with expansion. Basing upon the above considerations, the process to diminish the voids was suggested.更多还原