The composition and melting process of gray cast iron used in this experiment are jointly optimized and designed by our research group and the Institute of process and materials of YITUO Group. The experimental materials mainly include pig iron, scrap steel, 75sife inoculant, SRSI inoculant, basi inoculant, composite inoculant and alloy additives. The main chemical components of some experimental raw materials.
The experiment adopts 250 kg acid medium frequency induction furnace melting, quartz sodium silicate sand molding and 50 kg pouring ladle pouring. Raw materials and quality ratio: pig iron: Scrap = 3:1. The alloying of gray cast iron adopts multi-element alloy additive and pure Cu respectively, and the addition amount is 0.6 wt.%. Consult the data and calculate the absorption rate of each alloy element in combination with practical experience. The particle size of inoculant is 15-17 mm, the capacity of molten iron ladle is 50 kg, the addition amount (mass fraction) of inoculant is 0.6%, the discharge temperature is 1510 ℃, and the pouring temperature is 1480 ℃. The inoculant is inoculated in the package, and the alloy elements are directly added into the furnace in the form of ferroalloy. The composition of molten iron was determined by direct reading spectrum analyzer ARL4460. Casting of each type of cast iron Φ 100 mm × One 350 mm machinability test specimen, one step specimen for section sensitivity test, and four tensile specimens in GB / T 228-2002. The experimental pouring site is shown in the figure.