Effect of electromagnetic stirring on metallurgical quality of GCr15 electroslag ingot
Xiaofang Shi, Tao Xu, Lizhong Chang
Abstract
To further improve the metallurgical quality of electroslag remelting, remove the large inclusions in electroslag ingot and refine the solidification structure of electroslag ingot, an electroslag remelting furnace with electromagnetic stirring was designed, and the influence of different magnetic induction intensities on metallurgical quality of GCr15 electroslag ingot was studied. Inclusions with different sizes and types were analyzed by an ASPEX scanning electron microscope, and the morphology and composition of inclusions were further observed by a JSM-6510LV scanning electron microscope. The distribution of alloying elements on the cross section of electroslag ingot was analyzed by original position analysis (OPA). The results show that whether or not electromagnetic stirring is used, the inclusions in electroslag ingot are mainly composed of Al 2 O 3 , MnS, MnS-oxide and other oxides, among which Al 2 O 3 is the most. Compared with an electroslag ingot without electromagnetic stirring, the number of inclusions decreases considerably, and the proportion of small inclusions increases while the proportion of large inclusions decreases when the electromagnetic stirring with remelting current of 1.1 kA and magnetic induction intensity of 62 Gs is applied. However, excessive electromagnetic force will cause the number and diameter of inclusions to increase again. Electromagnetic stirring has different effects on the segregation of different elements. Under the experimental conditions, the weak electromagnetic force with 1.1 kA and magnetic induction intensity of 108 Gs has little effect on the segregation of C, but decreases the segregation of P, and the excessive electromagnetic force aggravates the segregation of alloy elements.