Nucleating agent for cast iron

Abstract

The invention discloses a nucleating agent for cast iron and relates to the field of metal materials. The nucleating agent comprises, by weight, 50%-63% of Si, 15%-20% of Ga, 1.5%-2.5% of Al, 0.2%-0.8% of RE, 2.0%-3.0% of Mg, 0.2%-0.8% of Sn and the balance Fe and inevitable microelements. The nucleating agent can promote nucleation of graphite and improve the inoculation effect; the chilling tendency of the cast iron is obviously reduced; and the refining property of the graphite is better. It is shown through practice that the pearlite content of the inoculated cast iron is obviously increased, and therefore the tensile strength of gray cast iron is improved.

Description

technical field [0001] The invention relates to the field of metal materials, in particular to an inoculant for cast iron. Background technique [0002] Cast iron is a well-known Fe-Po-Si alloy and is widely used in the manufacture of mechanical parts. It is well known that in order to obtain good mechanical properties of these parts, it is necessary to obtain an iron+graphite structure at the end and prevent the alloy from becoming brittle as much as possible Formation of Fe3C-type broken iron. Therefore if a cast iron with nodular graphite called "SG iron" is desired, it is preferred that the graphite formed be spherical rather than lamellar, whereas if a cast iron with lamellar graphite called "LG iron" is desired, the basic prerequisite to be met is to prevent The formation of broken iron. [0003] In this regard, inoculation of liquid cast iron prior to casting will favor the appearance of graphite rather than broken iron as it cools. [0004] The inoculant is a proc...

AI Technical Summary

Problems solved by technology

[0005]With the development of the machinery industry, the strength requirements for gray cast iron are getting higher and higher. The existing SiFe75 alloy and other inoculants cannot improve the strength of gray cast iron, so they cannot Meet the strength requirements of castings