Solidification Behavior Of Incoloy 825 Superalloy Under Linear Electromagnetic Stirring

Incoloy 825 superalloy has good resistance to high temperature capability, good resistance to oxidation and hot corrosion resistance, fatigue resistance, fracture toughness resistance and other fine features. Therefore, Incoloy 825 is applied widely in aviation, Aerospace, Energy, transportation industry, chemical industry and other industrial fields. It has become an indispensable metallic materials for industrial Construction. While with a substantial increasing demand of Incoloy 825, continuous casting technology becomes the preferred option to produce large quantities of Incoloy 825. Electromagnetic stirring(EMS) technology is the most important method in continuous casting technology, applying EMS to the process of continuous casting technology of superalloy is an inevitable trend. Consequently, As research subjects of Incoloy 825 superalloy in this paper, using unilateral water-cooled technology combined with electromagnetic stirring, simulates electromagnetic casting process of incoloy 825 superalloy. By testing the magnetic field of linear electromagnetic stirrer, analysis of the electromagnetic force, casting experiments, macroscopic and microscopic solidification organizations, precipitated phase and the degree of elements segregation of Incoloy 825 with EMS. Investigation the effect of linear electromagnetic stirring on the solidification behavior of Incoloy 825. The main conclusions show:(1) There has been a large number of straight-growing columnar dendrite in Incoloy 825 without EMS, the proportion of center equiaxed grain is only 16.7%, grain size is about 0.58mm, primary dendritic arm spacing is about 265.8μm, Secondary dendritic arm spacing is about 93.4um; With EMS, columnar dendrite significantly reduced and growth direction tilted in Incoloy 825, grain size refined to 0.21mm, primary dendritic arm spacing is about 215.4μm, Secondary dendritic arm spacing is about 74.6μm, dendritic structure was refined. The proportion of center equiaxed grain decreased slightly, grain size refined, secondary dendritic arm spacing become shorter after increasing the cooling rate.(2) The precipitation phase of Incoloy 825 are TiN with(without) EMS, Which includes two types of TiN, i.e., containing core and non-core, containing core of TiN’s main component is Al2O3. The shape of TiN is mostly square or polygon. Without EMS, the number of TiN in Incoloy 825 is about 8.97×10-4 per μm2, the size is approximately 11.9μm2; With EMS, the number of TiN in Incoloy 825 is about 4.29×10-4per μm2, the size is approximately 9.1μm2. Precipitated phases in Incoloy 825 distribute uniform and the size become smmaller. The size of TiN decreased after increasing the cooling rate.(3) Without EMS, the elements of titanium and molybdenum in Incoloy 825 show serious segregation between dendrite; With EMS, the segregation of titanium and molybdenum between dendrite in Incoloy 825 reduces apparently, distribution of elements is more uniform.