Modificator for changing growth morphology of primary austenite of gray cast irons, preparation method and application thereof

Abstract

The invention relates to a modificator for changing growth morphology of primary austenite of gray cast irons, a preparation method and application thereof. The modificator consists of the following components by mass percent: 10-20% of vanadium, 3-5% of nitrogen, 10-20% of silicon, 2-5% of calcium, 2-5% of chromium and the balance of iron. The preparation method of the modificator comprises the following steps: mixing, smelting and cooling iron alloy containing vanadium, nitrogen, chromium, silicon and calcium elements, grinding into particles with particle size of 4-8 mm and adding gray cast iron solution by using an in-casting ladle modification method. The modificator is used for processing easily-processed high-strength gray cast irons. Treatment using the modificator can expectedly improve the growth morphology of the primary austenite of the hypo eutectic gray cast irons and simultaneously obtain fine and bent graphite tissues so as to greatly improve the mechanical property of the gray cast irons.

Description

technical field [0001] The invention relates to a modifier for changing the growth morphology of primary austenite in gray cast iron, which is used to change the growth mode of primary austenite precipitated during the solidification process of hypoeutectic gray cast iron, and to obtain primary austenite in a criss-cross space network body, so as to restrict the development of eutectic solidification of gray cast iron, and obtain fine and curved graphite structure, so as to improve the mechanical properties of gray cast iron. Background technique [0002] Due to its good wear resistance, shock absorption and machinability, gray cast iron is widely used in foundry production, especially in the automotive industry. Most of the cylinder blocks and cylinder heads of high-horsepower engines are made of high-strength gray cast iron, and the general engine materials are also widely used in gray cast iron. According to statistics, in 1995, the world's major automobile companies prod...

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Problems solved by technology

However, there are key theories such as poor casting process performance; increased whitening tendency, difficult to process; large stress, easy to produce cracks; large shrinkage of molten iron, easy to produce shrinkage porosity, resulting in leakage; high sensitivity of casting cross section, easy to produce waste products and other key theories. and technical problems

(2) Alloying gray cast iron with high carbon equivalent (adding Mo, Ni, etc.), but due to the rapid rise in prices of Mo, Ni, etc. worldwide, there are key theoretical and technical problems of high cost and poor processability, Restricting the competitiveness of products in the market

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