Study on the Formation of Sliver Crystal Defect in Single Crystal Superalloy

Author of the article:WEI Wei, LI Hong, ZHANG Yuting, HUANG Fengze, ZHANG Zhiqiang

Author's Workplace：Shigang Jingcheng Equipment Development and Manufacturing Co., Ltd., Yingkou 115100, China

Key Words：Cr5; ingot; [Al]≤0.010%

Abstract：By adjusting the alloy composition and slag materials, optimizing the slag system of LF refining, cleaning up the ladle residual steel residue, and strictly controlling the slag from the converter. The composition range of LF refining slag was 52%～56% CaO、15%～20% Al2O3、13%～18% SiO2、5%～10% MgO、 (TFe+MnO)≤0.5%, R 3.2~3.6. The mold temperature was controlled from 50 ℃ to 80 ℃, the pouring speed of ingot was 1.2~1.5 t/min, and the pouring speed of riser was 0.3~0.7 t/min, so as to ensure the smooth rise of molten steel level and the argon protection during the casting process. The results show that can realize Cr5 backup roll with ingot products [P]≤0.012%, [S]≤0.005%, [Al]≤0.010% and [Ti]≤0.005%.