不锈钢千层刀表面剥层的原因

Surface delamination causes of stainless steel melaleuca knife

采用XRD物相分析、显微组织观察及能谱成分分析等方法对不锈钢千层刀表面出现明显剥层的原因进行了分析。结果表明,千层钢中存在马氏体和奥氏体两种不同成分和不同结构的不锈钢层,表面剥层出现在两种不锈钢的基体层之间,剥层的裂纹扩展在较软的奥氏体层内进行。千层刀不锈钢层间出现了大块氧化物颗粒,显著降低了两种基体层间的界面结合强度,是引起剥层的主要原因。氧化物颗粒是在千层钢折叠锻打过程中引入的,因此在热加工过程中控制氧化物夹杂是解决不锈钢千层刀出现剥层的必要措施。

Microstructure,composition and the reasons for the delamination on surface of a melaleuca knife were analyzed by means of SEM observation,EDS detecting and XRD phase analysis. The results show that the melaleuca steel is composed of layered marten site and austenite with different composition and structure,the delamination occurred between the two matrix layers. The propagation of the cracks was in the austenite matrix with lower hardness. The main cause of the delamination is the presence of oxide particles at the boundaries between the two stainless steel layers,which significantly reduced the bonding strength between them. The oxide particles mightbe mixed in the process of folding and forging of the melaleuca steel. In order to solve the delamination of the melaleuca steel,it should be a necessary measure to control the oxidation during thermal processing.