Inoculant for refining gray cast iron texture and preparation method and application thereof

The invention relates to application of an inoculant in a gray cast iron. The inoculant comprises the following components in percentage by mass: 40-50% of Si, 5-8% of Mn, 5-8% of Zr, 2-5% of Ca, 2-3% of Al and the balance of Fe. The iron alloy containing Si, Mn, Zr, Ca, Al and the like is mixed, smelted, cooled and broken into 4-8mm particles which are then added into the gray cast iron solution by an in-casting ladle inoculation method. The strength of the easy-processing high-strength gray cast iron subjected to the inoculation treatment by the inoculant provided by the invention exceeds 400MPa. The inoculant can promote the kernel generation of primary austenite in the solidification process of hypo eutectic gray cast iron and increase the number of primary austenite dendritic crystals; and meanwhile, the inoculant can refine the graphite texture in the gray cast iron and reduce the piece space of the pearlitic structure of the base body so as to improve the strength of the hypo eutectic gray cast iron. The inoculant has the characteristics of small addition amount, low cost, simple technology and the like.