SU1456480A1 - Alloying composition - Google Patents

Abstract

This invention relates to the field of foundry, in particular, to compositions of ligatures for producing high-strength nodular cast iron. The purpose of the invention is to increase the degree of absorption of magnesium by the cast iron and to improve the plastic properties of high-strength nodular cast iron. Ligature contains, wt%: magnesium 14-20; manganese 5-25; copper 20-40; rare earth metals 0.5-5; phosphorus 0.1-0.5; bismuth 0.01-0.5; nickel else. Additional input into the composition of bismuth ligature allows to increase the elongation of cast iron by 2-2.5 times, increase the degree of assimilation of magnesium from the ligature by 15-20%, ensure the degree of spheroidization of graphite by at least 95%. The use of ligature is recommended for crankshafts for cars and other castings. 2 tab. with $ SL

Description

one

The invention relates to foundry, in particular, to the development of compositions of master alloys for the production of nodular cast iron.

The purpose of the invention is to increase the degree of absorption of magnesium and improve the plastic properties of high-strength nodular cast iron.

The master alloy containing magnesium, manganese, copper, rare earth metals, phosphorus, nickel, additionally contains bismuth in the following ratio, wt.%:

Magnesium Manganese - Copper

Rare earth metals

H-20

5-25

20-40

0.5-5.0

Phosphorus, 5 Bismuth 0.01-0.5 Nickel Else Due to the additional input of bismuth cast iron, the number of graphitization centers increases during the secondary modification of cast iron and the formation of cementite in the structure is prevented, the relative elongation of nodular cast iron increases.

An increase in the bismuth content (over 0.5%) leads to the formation of cementite, since bismuth, with its excess, is a strong cast iron bleaching element. When the bismuth content is less than 0.01%, its positive effect is not detected.

U1

Su

about

When the content of magnesium in the ligature of 14-20% provides the necessary efficiency in the production of nodular cast iron. When the content of magnesium is less than 14%, the consumption of the atura increases, and when the content of magnesium exceeds 20%, the degree of absorption of magnesium decreases. The selected manganese content limits reduce the melting temperature of the master alloy and reduce the temperature of the original cast iron, thereby improving the absorption of magnesium from the master alloy. With a decrease in the manganese content (below 5%), the absorption of magnesium decreases, and an increase in the manganese content in the ligature (more than 25%) leads to waste and a decrease in the plastic properties of the iron. Entering phosphorus into the composition of the ligature in an amount of 0.1-0.5% improves its crushability. When the phosphorus content is more than 0.5%, the plastic properties and cold resistance of cast iron are reduced, and when the content is less than 0.1%, crushing of the ligature is impaired.

Conduct testing of the proposed ligatures.

The ligature was melted in an induction furnace on a mixture consisting of nickel, copper and phosphorous copper, pig iron, manganese metal, cerium mischmetal MC40.

Cast iron was smelted in a crucible induction electric furnace with a capacity of Yu t. Chemical composition of the initial cast iron,%: С 3.45-3.61; Si 2.05-2.35; Mp 0.9-0.95; S 0,012-0,0185; Ni 0.35-0.5; P 0.04-0.05; C 0.35-0.45.

The test ligatures, the compositions of which are listed in Table 1, were injected onto the bottom of the bucket with a capacity of 0.5 tons together with the FS75L-6 modifier. Samples were cast for mechanical testing of crankshaft castings on an automatic molding line.

The number of input ligatures from

0 Fzschey input into the cast iron 0.1% magnesium was in the range of 0.5-1.0% by weight of liquid iron, the amount of input FS 75L-6 - 0.5% by weight of iron.

5 The test results are presented in table 2.

From the data presented in Table 2, it can be seen that in the processing of cast iron with a ligature of the proposed composition of 2-2.5

0 times the relative elongation of cast iron increases, the degree of magnesium absorption increases by 15–20%.

five

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five

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Claims (1)

Invention Formula A ligature containing magnesium, manganese, copper, rare earth metals, phosphorus, and nickel, is characterized in that, in order to increase magnesium absorption and to improve the plastic properties of high-strength nodular iron, bismuth in the following ratio of components. May .%: Magnesium 14-20 Manganese 5-25 Copper 20-40 Rare Earth Metals Phosphorus Bismuth Nickel 0.5-5.0 0.1-0., 5 0.01-0.5 Else Magnesium ten Manganese - ten Table 1 17 20 13 21 20 25 4 26 Components The content of components in the composition of the ligature 1 (known 20 9 five five eight five eight 20 Beyond Limit Continuation of table 1 20 thirty 40 30 30 0.5 2.5 2.5 2.5 0.3 0.5 0.25 0.5 0.09 0.6 0.005 0.55 Osta-Os-Os-Os-estetal-metal-optal new table 2