SU724593A1 - Cast iron - Google Patents

Description

The invention relates to metallurgy and the foundry industry, in particular to the search for special cast irons and can be used in electrical engineering, suprostroitelnoy and Others and ampli fi cations, where increased demands on the strength and non-magnetism of products are made .:

Cast iron containing MrijCu t Ni, AQ, Cr t having austenitic cTJpyxTypy and used as a non-magnetic material is widely known. Mapnit permeability (jU) their value is 1.05-1.5 g / E. Cast iron with a jU below 1, O1 g / E, have reduced mechanical properties, in particular low strength.

Known cast iron 1 of the following chemical composition, weight o;

Carbon.2.1-2.7

Silicon1.5-2.0

Manganese10.0-16.0

Chrome8.0-14.0

Aluminum0,2-0,3

BorO, O02-O, OOZ.

IronErest

The specified cast iron has the following physical and mechanical properties: tensile strength of 30-35 kg / mm% hardness 4О-45 f bending strength of 45-55 kg / mm | ij 1, О09-1, 005 g / E.

The presence of coarse carbide inclusions (Pe, Mn 1 C g) -f C, the absence of a uniform structure of cast iron does not allow to apply it to the Responsible Netals, to whom increased strength requirements are imposed.

The closest to the invention of the technical essence and the achieved effect is cast iron of the following chemical composition, which is. %:

Carbon2,8-4,2

Silicon. .1,7-2,8

Manganese6.0-7.5

Nickel8, O-9.0

MagnesiumNot less than 0.03

Calcium - Not more than 0.2 Reako earth metals0, 12 IronEstal. As an optional component, cast iron may contain copper, sulfur and phosphorus. A disadvantage of the known iron is that its magnetic permeability is at a level of 1.05 g / O. The purpose of the invention is to reduce magnetic permeability while maintaining strength at the same level. This goal is achieved by the fact that iron, containing carbon, silicon, manganese, magnesium, calcium, rare earth metals and iron, contains chromium and barium in the following ratio of components , weight. %: 1.7-3.5 Carbon 0.5-2.5 Silicon 31.0-42.0 Manganese 0.015-0.09 Magnesium 0.01-0.12 Calcium 0.1-3.0 0.0001 -0.12 Rare-earth metals 0.001-0.15, Other Iron At the same time, the content of Md; Ca, Ba, REM is maintained at the average level of the proposed limits (composition No. 4). With an increased content of one or two modifying components, for example, with magnesium and calcium, the upper level (0.09 and 0.12 weight,%, respectively), the content of barium and RH may be at the lower level. At the same time, the properties of the SAVE are quite high When the content of the modifiable material of the components (at least one of them) is lower than the lower claimed limit, the strength characteristics fall. If the amount of magnesium, barium, schlzi and rare-earth metals in cast iron is higher than the apparent upper limit, then the cast iron will sharply increase. E content should not exceed 42% (upper limit). Otherwise, large needle-like inclusions of free manganese carbide appear in the matrix, which leads to embrittlement of the iron. Its quantity is growing rapidly and fragility increases accordingly. With an increase in the carbon concentration in cast iron above 3.5%, the strength characteristics sharply fall, especially when the Mp content is at the upper limit. Cast iron becomes very fragile and hard, so its use is impractical. When the content of Mn is lower than 34% and carbon is 3.2%, the magnetic permeability slightly increases due to a decrease in cone. manganese concentration in carbide (Fe, Mn) C and its transition to ferromagnetic COCTOS. Therefore, it is necessary to increase the chromium content to 3% with the Mfi content at the lower limit of 31%. Further reduction of the content of copper, manganese in cast iron (31%) leads to a sharp increase in ju, which is not eliminated by increased doping of chromium. The chemical composition and physico-mechanical properties of the proposed cast iron and known ll, 2 are given in the table,

invention formula

Iron containing silicon, manganese, iron, calcium, rare-earth metals and iron, so that, in order to reduce magnetic permeability while maintaining shchyuchnosti at a high level, it also contains barium with the following ratio of components, weight. %;

Carbon 1.7-3.5

Silicon 0.5-2.5

Manganese31-42

0.015-0.09 0.01-0.12

fi

0.001-0.15 0.1-3

0.0001-0.12 Else

Sources of information taken into account in the examination

1. USSR author's certificate

No. 459627, cl. C 22 C 27 / 1O, 1975.

2. Certificate of CCCF

No. 348635, cl. C 22 C 37/00, 1972.

Claims (1)

Claim' Cast iron containing carbon, silicon, manganese, magnesium, calcium, rare-earth metals and iron, with the result of the fact that, in order to reduce magnetic permeability while maintaining strength at a high level, it is additionally contains ch'rom and barium at the following ratio of components, ¹⁰ weight. %: Carbon 1.7-3.5 Silicon 0.5-2.5 Manganese 31–42 Magnesium 0.015-0.09 Calcium 0.01-0.12 Rare earth metals 0.001-0.15 Chrome 0.1-3 Barium _p 0.0001-0.12 Iron Else