ISIJ International ( IF 1.8 ) Pub Date : 2021-09-15 , DOI: 10.2355/isijinternational.isijint-2020-680 Hongying Du 1 , Andrey Vladimirovich Karasev 1 , Pär Göran Jönsson 1
The focus of this study is to investigate non-metallic inclusions (NMIs) in stainless steels before (in steel samples) and after machining (in steel chips). In this study, the electrolytic extraction (EE) technique was used to extract non-metallic inclusions from steel samples. This makes it possible to investigate NMIs on film filters as three-dimensional objects by using SEM. The characteristics of NMIs in steel and chips have been systematically investigated and compared. Based on the results, it was found that the morphology of NMIs was significantly changed after machining. Overall, three different main shapes of NMIs were found: 1) a similar shape, 2) a stretched shape, and 3) a brittlely fractured shape. Furthermore, the degree of deformation of MnS and soft oxide NMIs in different zones of the chips depends on the distances from the contact zone of the tool and the chip. The total areas of MnS and soft oxides in the secondary deformation zone were increased by up to 2–3 times compared to that of the reference steel sample. This study also shows the advantages of the EE method in investigating NMIs in chips compared to using the conventional two-dimensional investigations of NMIs on the polished metal surface.
中文翻译:
不锈钢加工前后非金属夹杂物的三维调查
本研究的重点是研究不锈钢加工前(钢样品中)和加工后(钢屑中)中的非金属夹杂物 (NMI)。在本研究中,电解萃取 (EE) 技术用于从钢样品中提取非金属夹杂物。这使得可以使用 SEM 将薄膜滤波器上的 NMI 作为 3D 对象进行研究。已系统地研究和比较了钢和切屑中 NMI 的特性。结果表明,加工后NMI的形貌发生了显着变化。总的来说,发现了三种不同的 NMI 主要形状:1) 相似的形状,2) 拉伸的形状,和 3) 脆性断裂的形状。此外,MnS和软氧化物NMI在切屑不同区域的变形程度取决于刀具与切屑接触区的距离。与参考钢样品相比,二次变形区中 MnS 和软氧化物的总面积增加了 2-3 倍。本研究还显示了 EE 方法在研究芯片中的 NMI 与使用传统二维研究在抛光金属表面上的 NMI 相比的优势。