电渣重熔GCr15SiMn轴承钢轧材夹杂物特征研究

STUDY ON INCLUSIONS IN THE ROLLED METAL OF BEARING STEEL GCr15SiMn THROUGH ESR PROCESS

以转炉-LF精炼-VD-模铸－轧机开坯－电渣重熔为工艺流程生产的GCr15SiMn轧材为对象，利用扫描电镜和能谱仪（SEM-EDS）分别对钢材垂直和平行轧制方向边缘、112半径处和中心部位夹杂物的类型、形貌、数量和尺寸进行了分析和讨论。结果表明，轴承钢GCr15SiMn轧材中夹杂物主要为单一镁铝尖晶石夹杂物、单一氮化钛夹杂物以及以镁铝尖晶石为核心，以氮化钛为外围的复合夹杂物和少量的钙铝酸盐夹杂物等；垂直轧制方向夹杂物数量在边缘部位分布最多，在1／2半径处分布最少，夹杂物总体尺寸由边缘部位到中心部位逐渐增大，夹杂物长宽比多分布在1～2之间；平行轧制方向夹杂物数量也是在边缘部位分布最多，在1／2半径处分布最少，相比边缘和中心部位，1／2半径处夹杂物总体尺寸在≥4μm范围内的比例以及夹杂物长宽比在≥3范围内的比例都最大。

The composition, morphology, number and size of inclusions in edge, 1/2 radius and center area in vertical and parallel rolling direction of bearing steel GCr15SiMn produced with the BOF-LF-VD-IC-ESR process, was studied and discussed by means of scanning electronic microscopy （SEM） and energy dispersive spectroscopy （EDS）. The results showed that the inclusions were mainly MgO · Al2O3, TiN, duplex inelusions with MgO · Al2O3 as the core and TiN as the periphery, CaO · Al2O3 and so on; In the vertical rolling direction, the number of inclusions in the edge area was maximum and in the 1/2 radius area was minimum, from the edge area to the center area, the overall size of inclusions demonstrated an increased tendency, the length-width ratio of inclusions was mainly between 1 and 2; In the parallel rolling direction, the number of inelusions in the edge area was also maximum and in the 1/2 radius area was minimum, for 1/2 radius area, the proportions of the inclusions＇overall size exceeding 4 μm and the length-width ratio exceeding 3 were both maximum eompared with that of the edge and eenter area.