SU1214772A1 - Mixture package - Google Patents

Description

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The invention relates to metallurgy, specifically to steelmaking, and can be used in steel production in open-hearth and electric arc furnaces.

The aim of the invention is the development of such a package for the charge, the use of which for melting steel will provide a lower content of hydrogen in the metal,

When steel scrap is melted, for example, in an open-hearth furnace, as the metal is heated, the water vapor of the furnace atmosphere and flame is saturated with hydrogen. When a package consisting of steel scrap, a strong hydride forming element — titanium in the form of titanium chips or waste of titanium in crushed form, which are evenly mixed with steel scrap, is present, the hydrogen contained in the water vapor of the furnace atmosphere or torch is largely combined. with titanium. In this case, titanium hydrides are formed. chiometric composition.

When the charge is melted, titanium hydrides are partially decomposed, and partially transferred into slag. Thus, the metal is less saturated with hydrogen,

As a carbon-containing material in the proposed package for the charge, pyrocarbon is used - a product of solid household and industrial waste pyrolysis, which is black powder or granules, non-toxic, containing,%: carbon 30-40; sulfur 1.2 and mineral mass 55-60, and fasting

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214772 J

technical specification ADI 165-TU,

The composition of pyrocarbon contains organic matter, containing limiting and unsaturated hydrocarbons, which determine the low temperature of destruction of this material with the formation of a reducing atmosphere around pieces of titanium.

10 on, protect them from oxidation. The decomposition temperature of pyrocarbon is in the range of 500-700 ° C, and the oxidation of carbon in other carbon-containing materials, including

13 pyrocarbon, occurs at 900-1000 ° C, m, e, at such a temperature at which titanium is oxidized.

The test results are shown in the table, from which it follows

20 that the most rational limits for the titanium content in a package is 2-8%. When introducing less than 2% titanium into a package, the content of hydrogen in the metal does not decrease, and an increase in the titanium content above 8% is impractical because it does not lead to further reducing the concentration of hydrogen in steel. When the content of pyrocarbon in the steam cell is less than 1%, the oxidation of iron increases, while increasing the pyrocarbon over 10% reduces the mechanical strength of the package.

The use of the proposed batch package for steelmaking reduces the hydrogen content in the metal, which in turn reduces the duration of the anti-flock annealing of forgings made of such steel.

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Prototype 9

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Editor L.Povkhan

Compiled by L. Shashenkov. Tehred T. Tulik

Order 859/39 Circulation 567 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Filial PPP Patent, g, Uzhgorod, st. Project, 4

12147724

Table continuation

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Proofreader M.Maksimishinets

Claims (1)

MIXTURE PACKAGE containing steel scrap and a carbon-containing material-carburizer, characterized in that, in order to reduce the hydrogen concentration in the steel, it additionally contains titanium, and as a carbon-containing material-carburizer pyrocarbon in the following ratio, wt.%: Pyrocarbon 1-10 Titanium 2-8 Steel scrap Rest