Spheroidization and inoculation of ductile iron

The spheroidizing treatment was carried out by the method of in package charging. The spheroidizing temperature is 1450 ~ 1500 ℃, the particle size of spheroidizing agent is 5 ~ 10 mm, and the dosage is 1.3%. The inoculation process is in package inoculation + with current inoculation.

The particle size of inoculant in the ladle is 3 ~ 5mm, the amount of inoculant added is 1.05%, and the particle size of inoculant with flow is 0.3mm ~ 0.7mm, and the addition amount is 0.15%. The specific method is as follows: firstly, the ladle is baked to 300 ℃ and kept for 10 h to ensure that the ladle is sufficiently dry. Then, the nodularizing agent is placed in the bottom pit of the ladle, covered with inoculant particles and compacted, and then covered with appropriate amount of nodular iron beans and tamped.

In the process of spheroidizing, because the total amount of molten iron is less, in order to ensure the quality of molten iron spheroidizing, the molten iron mass is 30kg. After the reaction is stable, a layer of cryolite is covered on the surface of molten iron for slag removal. After that, the copper mold was used to make the white sample and measure the temperature, and then pouring was carried out. The pouring temperature was controlled at 1350 ~ 1400 ℃, and the feeding method of hand-held funnel was used to inoculate with the flow.