气体渗硼工件的表面形貌及其与渗硼层孔洞的关系

利用扫描电子显微镜观察了经不同气体渗硼工艺处理的工件表面,研究了影响工件表面形貌的因素及表面形貌与渗层孔洞的关系。研究表明:恰当的工艺参数使工件表面由规则,细小,均匀的硼化物颗粒构成,否则,工件表面的硼化物颗粒将会粗化,甚至产生一种针状颗粒。本文重点研究了这种针状硼化物的形成机理及其影响因素。此外,表面较光滑的工件往往具有较致密的渗硼层,而粗糙的表面,尤其是表面产生针状硼化物的工件则对应孔洞较多的渗硼层。

The Surface Mophology of Specimen Boronized with Gas Medium and the Relationship Between the Mophology and the Layer Quality

The surface of the specimen boronized with different process is examined with SEM and the facts which influenses the surface mophology and the relationship between the mophology and the layer quality are also concerned with in this paper. It shows that if the process paremeters selected are resonablc, a simoother surface of specimen will form with regular small welldistributed boridc grains on it. Otherwise,a kind of needle-shaped boride will appcar on the surface of specimen. The paper enphasisly expounds the forming mechanism of this needle-shaped boride and effective factors on it. Moreover, a speciman with a smoother surface usually possesses a denser layer; conversely, a speciman with a coarser surface especially the needle-shaped boride on it is often companied with more serious corrosion voids in the layer. Therefore, a study of the surface mophology is significant for selecting boronizing processes and prejudging the quality of the boronized layer.