SU1458417A1 - Cast iron - Google Patents

Abstract

The invention relates to metallurgy and can be used in the manufacture of traverses. The purpose of the invention is to increase the shock fatigue life. New cast iron contains, wt%: C 3.61-3.95; Si 1.25-2.8; Mp 0.51-1,; 1; 0.85-1.55; REM 0.01-0.04; A1 0.02-0.05; Ca 0.002-0.02; barium oxide 0.02-0.05; Mg 0.02-0.07, Fe - the rest. The addition of barium and magnesium oxide to the cast iron provides an increase in impact fatigue life by 1.37-1.62 times. 2 tab.

Description

This invention relates to metallurgy, in particular, to the development of a cast iron composition for cast wear-resistant parts.

The purpose of the invention is to increase the shock fatigue life.

The invention is illustrated by examples of specific performance.

The choice of the boundary limits of the content of components in the pig iron of the proposed composition is due to the following.

The use of barium oxide in the composition of the proposed cast iron is associated with the fact that it is soda (fzhit barium ions with increased mobility and activity in the melt, contributing to the increase in the homogenization of cast iron, stability and dispersion of the structure, which increases the toughness and impact-fatigue life. When the concentration of barium oxide to

0, Q2 wt.% The stability of the structure and impact-fatigue durability are insufficient, and when its concentration exceeds 0.05 masD, the waste of the components increases, the content of non-metallic inclusions in the iron and its impact. fatigue properties.

The additional introduction of magnesium is associated with its high chemical activity, degassing and modifying ability and spheroidizing effect of the cast iron structures, which significantly increases the plastic properties and impact fatigue life. At the end of the magnesium up to 0.02 wt.% Modifying it -. thinning and degassing capacity are insufficient, and the fatigue impact life is low, and at a concentration of more than 0.07 wt.%, chill is increased, the crack resistance decreases and

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impact strength leads to a reduction in impact fatigue durability and operational durability.

The calcium content in the pig iron is limited to 0.02 wt.% Due to its low solubility, and the aluminum concentration is 0.05 May.% Due to its severe tendency to scaling and porosity in the magnesium cast iron with more than high concentrations, which leads to a decrease in impact fatigue life.

The carbon content in the pig iron is 0;

20

Grinding, and with an increase in the aluminum concentration of more than 0.05 wt.%, the hardness of castings decreases, their rolling properties and relative wear resistance.

The content of the main modifying components (magnesium 0.02 -;: 0.07 wt.% And REM 0.01-0.04 wt.%) Ensures the degassing of the melt and the spheroidization of graphite and pearlite and an increase in the strength and elastic-plastic properties. Sulfur and chromium increase chill, reduce shock-fatigue to 3.61-3.95 wt.% For exceptionally. 15th durability, therefore they are, from the time of churning in the castings of the traders, the keys are cast iron and pulleys. At lower concentrations of manganese, the increase in concentrations of manganese is noted by the formation of a selection of 0.51–1.1 wt.% And the limited and reduced impact-fatigue life is limited, and with a carbon concentration of more than 3.9.5 wt.% structure and plastic properties and impact fatigue life are reduced.

Copper, with a content of 0.85-1.55 wt% 25, stabilizes perlite, increases spheroidization, increases hardness and wear resistance, their stability during operation and the operational resistance of cast parts. When increased, smelting is 1480-1510 s. As a charge for the copper concentration of more exhausted materials, casting and

 pig iron, electrical steel waste, steel chips, return of own production, 35 carburizer (pitch coke), ferrophosphorus, ferromanganese, ferrosilicon, silicobarium, silicocalcium, copper, LCKK type ligatures, FSZORMM, EKMKBa. The magnesium content in ligatures is 6–9%, 40 barium oxide is 4.8–9.3%, cerium is 3.5–6%. The ligature was crushed to a fraction of 4-20 mm.

Concentrations, below which a high spheroidization of per-, litta and a significant increase in wear resistance are not achieved, and the content of cementite and chill is increased above the upper limit, the stability of the structure, impact-fatigue durability and plastic properties decrease.

Experienced high-strength cast iron crushers. held in induction furnaces with a capacity of 10 tons. Overheating of the melt at

1.55 wt.%, The liquation begins to appear, the impact fatigue durability decreases, and at a concentration of up to 0.85 wt.% The hardness decreases and the wear resistance of castings, plate perlite with a dispersity of 1.0 1.0 predominates in the castings. 1.4 (according to GOST 3443-77).

Barium oxide is introduced into the casting ladle when discharged into it from an induction furnace as a crushed (4-20 mm fraction) complex master alloy containing 4.8–9.3 wt.% Oxide

Modification of cast iron with RZM-containing ligatures is carried out in plates, 6–9% by weight of magnesium and 3.5–6% by weight of the kiln furnace. Refining the cerium melt. Additional mixing of fluorspar and modification

cast iron spheroidizing ligatures, silicobarium, copper and ferrosilicon

is not required since the absorption and distribution of barium oxide and modifying components (magnesium, cerium) in the iron is stable.

Aluminum in the amount of 0.02 0.05 wt.% Has a thinning and stabilizing effect, contributing to a decrease in the content of non-metallic inclusions and an increase in impact-fatigue life, hardness, and wear resistance. At an aluminum concentration of up to 0.02 wt.%, The deoxidizing and stabilizing effect thereof is not passed in the casting ladles.

gQ Traction sheaves, process samples and impact fatigue tests are cast from modified cast irons.

Table 1 shows the chemical mixtures of high-strength cast irons of the experimental heats. The assimilation of the components was as follows: feed units 86%, phosphorus 95%, calcium 84%, barium oxide 89%, cerium 58% and magnesium 48%.

0

The content of the main modifying components (magnesium 0.02 -;: 0.07 wt.% And REM 0.01-0.04 wt.%) Ensures the degassing of the melt and the spheroidization of graphite and pearlite and an increase in the strength and elastic-plastic properties. Sulfur and chromium increase chill, reduce shock-fatigue durability, therefore they are excluded from the composition of cast iron, the manganese content is increased to 0.51-1.1 wt.% And is limited to

25 smelting 1480-1510 s. Casting materials are used as batch materials.

Concentrations, below which a high spheroidization of per-, litta and a significant increase in wear resistance are not achieved, and the content of cementite and chill is increased above the upper limit, the stability of the structure, impact-fatigue durability and plastic properties decrease.

Experienced high-strength cast iron crushers. held in induction furnaces with a capacity of 10 tons. Overheating of the melt at

conducted in casting ladles.

Rope pulleys, process samples and shock fatigue tests are cast from modified cast irons.

Table 1 shows the chemical compositions of high-strength cast irons of the experimental heats. The assimilation of the components was as follows: feed units 86%, phosphorus 95%, calcium 84%, barium oxide 89%, cerium 58% and magnesium 48%.

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Determination of component content of elements, aluminum, calcium and iron,

in cast irons carried out by differential methods, characterized in that, with

chemical analysis. goal of increasing shock fatigue

Table 2 shows the data on the mechanism of durability, it additionally has sonic properties and characteristics that will keep the oxide of barium and magnesium in the cast structure of the cast iron of the experimental heats in the following ratio of components, in May.%:

castings. Mechanical tests were performed by standard methods, and analysis of the structure of cast irons according to GOST 3443-77,10

As follows from the data of Table 2, the additional input of barium and magnesium oxide into the composition of cast iron ensures the impact-fatigue durability to be carried 1.37-1.62 times.

Claims (1)

Invention Formula Cast iron containing carbon, silicon, manganese, copper, rare earth Carbon Silicon Manganese Copper Rare Earth Elements Calcium Aluminum Barium Oxide Magnesium Iron 3.61-3.95 1.25-2.8 0.51-1.1 0.85-1.55 0.01-0.04 0.02-0.05 0.002-0.02 0.02-0.05 0.02-0.07 Else flax and 3.61-3.95 1.25-2.8 0.51-1.1 0.85-1.55 0.01-0.04 0.02-0.05 0.002-0.02 0.02-0.05 0.02-0.07 Else Carbon Silicon Manganese Magnesium Copper Rare earth elements Barium oxide Aluminum Phosphorus Calcium Iron 3.6 2.0 0.9 1.2 3.61 2.8 0.51 0.02 0.85 3.76 1.47 0.77 0.05 0.98 3.95 1.25 1.1 0.07 1.55 3.51 1.18 0.45 0.01 0.7 4.05 2.86 1.16 0.08. 1.64 0.12 0.010.03 0.04 0.006 0.05 0.020.03 0.05 0.01 0.07 0.3 0.020.04 0.020.07 0.2 0.05 0.01 0.12 0.11 0.01 0.15 0.002 0.01 0.02 0.001 0.06 Ostal-Ostal-Ostal-Os-Oss- The rest of it is more taltalno Nano Known cast iron also contains 0.2% vanadium, 0.3% titanium, 0.2 chromium. Table 1 3.95 1.25 1.1 0.07 1.55 3.51 1.18 0.45 0.01 0.7 4.05 2.86 1.16 0.08. 1.64 340 s 705. 732,735 810 21-35 1285 46-48 1314 52-55 1326 54-57 55 58 59 Table 2 Front 1,0 70 1,3 103 0.3 91 0.3 98 0.3 96 2.1 2.4 2.5 132 146 150