The invention relates to a synthesis and preparation process for a high-
silicon-
molybdenum ductile iron material. The synthesis and preparation process specially comprises the following steps that raw materials are prepared, and the raw materials comprise, by
mass, 60%-70% of
scrap steel, 25%-35% of
cast iron, 1%-1.2% of
silicon iron, 1%-1.3% of ferro-
molybdenum and 2%-2.5% of carburant; in the
raw material melting process, furnace burdens are added in three batches; all the
cast iron and 1 / 3
mass part of
scrap steel are added in the first batch of furnace burdens, 5 / 11
mass part of carburant and 1 / 3 mass part of
scrap steel are added in the second batch of furnace burdens, and 5 / 11 mass part of carburant and 1 / 3 mass part of scrap steel are added in the third batch of furnace burdens; after the third batch of furnace burdens are completely molten down, all the
silicon iron and ferro-
molybdenum are added, and when the temperature of molten iron rises to 1400-1410 DEG C, the remaining 1 / 11 mass part of carburant is added in a mirror
surface mode after slagging-off
impurity removal; and sampling analysis, blending, tapping, nodulizing and
inoculation treatment are performed until pouring is completed. According to the process, the scrap steel is used as a main
raw material, and the joint carbon adding mode of middle adding and mirror surface adding is adopted for preparing high-silicon-molybdenum ductile
cast iron with high strength and high
impact toughness.