Novel spheroidizing inoculation treatment method

Abstract

The invention discloses a novel spheroidizing inoculation treatment method which comprises the following steps: selecting two hot metal ladles as a transfer ladle and a spheroidizing ladle respectively; after the components of the molten iron in the furnace are qualified, overheating the molten iron to 1480-1500 DEG C, discharging the molten iron into the transfer ladle, pouring out a required weight, and adding a primary inoculant into the transfer ladle, wherein a spheroidizing agent and a secondary nucleating agent are preset in the spheroidizing bag; transporting the transfer ladle and the spheroidizing ladle to a pouring site, lifting the transfer ladle to measure the weight and the temperature, rapidly pouring the molten iron into the spheroidizing ladle when the temperature of the molten iron ranges from 1400 DEG C to 1460 DEG C, and adding a third-time inoculant into the spheroidizing ladle while the molten iron is poured into the spheroidizing ladle; and during pouring, adding a nucleating agent for four times along with the molten iron. According to the method, by adopting a ladle-to-ladle spheroidizing inoculation treatment process and controlling the adding amount of the inoculant every time reasonably, the inoculation treatment effect is obviously improved, the spheroidizing effect is more ideal, the number of graphite is large, the graphite form is good, the mechanical property and the metallographic structure are stable, and finally qualified large ductile iron castings can be stably produced.

Description

technical field [0001] The invention relates to the technical field of casting, in particular to a novel spheroidizing inoculation treatment method. Background technique [0002] Due to thick and large section ductile iron castings are prone to abnormal graphite such as blooming, fragmented, and coarse, and due to the long liquid cooling and solidification time, there will be phenomena such as spheroidization decline and gestation decline, which will have an impact on the matrix structure. , seriously deteriorating the mechanical properties of castings. [0003] At present, when producing large-scale ductile iron parts, the traditional flushing method is generally used for spheroidization process, that is, nodulizer and inoculant are added to the bottom of the nodularization bag, and the process of adding secondary flow with the flow is used for production. The disadvantage of this process is that The controllability of the spheroidization temperature is small and the numbe...

AI Technical Summary

Problems solved by technology

This invention adds an inverted inoculation process between the two steps of inoculation in the original spheroidizing bag and inoculation with flow, and realizes the special process of instantaneous multiple inoculation; but this method of inoculation by inversion is more suitable for the production of small ductile iron castings , it is not obvious for the production of large and large tonnage ductile iron castings

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