Analysis of inclusions in cast slab for high-strength engineering machinery steel
ZHU Hong-xin1, YANG Xin-long2, WANG Ru-dong1, YU Wei3, CUI Heng1
1. Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; 2. Gansu Jiugang Steel Group Hongxing Iron and Steel Co., Ltd., Jiayuguan 735100, Gansu, China; 3. National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing, University of Science and Technology Beijing, Beijing 100083, China
Abstract：In order to understand the source of inclusions in Q550MD cast slab of high-strength engineering machinery steel in a plant, optimize the production process and improve slab quality, the number, size, morphology and composition of inclusions in the cast slab were studied by means of slime extraction, automated SEM-EDS inclusion analysis. The results show that the size of macro inclusions in slime extraction sample is concentrated in 80-140 μm. The shape of inclusion is mostly spherical, and the main component is calcium aluminate. Before forming the final composite inclusions, the macro inclusions in the cast slab come from the ladle, and the mold flux entrapment may occur. The inclusion aggregation is found at 1/4 position in the width direction of cast slab, and the number of inclusions is significantly higher than that at the edge and 1/2 position, which is related to the unreasonable flow field of the mold.
YANG Z, ZHANG J, LI S, et al. On the critical inclusion size of high strength steels under ultra-high cycle fatigue[J]. Materials Science and Engineering A, 2006, 427(1/2):167.
CHI Y, DENG Z, ZHU M. Effects of refractory and ladle glaze on evolution of non-metallic Inclusions in Al-killed steel[J]. Steel Research International, 2017, 88(9): 1600470.
WANG H, LI J, SHI C, et al. Formation and evolution of non-metallic inclusions in calcium treatment H13 steel during electroslag remelting rrocess[J]. ISIJ International, 2019, 59(5):828.
2022, Vol. 32 
