SU1404542A1 - Surface-refining flux for gold, silver or carbon base alloys - Google Patents

Abstract

The invention relates to the metallurgy of non-ferrous metals and can be used in the smelting and casting of gold, silver or copper alloys. The purpose of the invention is to reduce the content of non-metallic inclusions in castings and to exclude their porosity. The goal is achieved due to the low gas permeability of the flux, high refining properties and increased viscosity of the flux in the molten state. The flux contains 19-23 May L Na, CO ,; May 19 - 23. Na3AlF6 and the rest is SiO. 2 tab.

Description

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with

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The invention relates to the metallurgy of non-ferrous metals and alloys and can be used in the smelting and casting of gold, silver, copper and their alloys.

The purpose of the invention is to reduce the content of non-metallic inclusions in castings and exclude the porosity of castings

The proposed flux contains 19–23 wt.% Soda ash, 19–23 May. % cryolite and the rest is silica.

The experimental fluxes, the composition of which is given in Table 1, are prepared by moving powdered charge components (SiO - in the form of a silica powder) in a dry state, followed by melting in a graphite crucible a high-frequency induction furnace. The readiness of the flux is monitored by taking a sample on a steel bar. Easy separation from the rod of a homogeneous hardened flux crust indicates its readiness.

In order to determine the technological properties of the fluxes, experimental melting of the ZlSrm 583-80, CfM 875 h LAAF 94-0.5-0.15 alloy was carried out. Melting followed by pouring into the dinas-plaster forms of jewelry of complex shape (openwork rings and pendants) is performed on a centrifugal casting installation. Melting of the caustic alloy using the proposed and known fluxes is carried out from the alloy of the same batch with the same quality indicators in the initial state. The results of the experienced swimming trunks evaluate the visa.

Kaltsinirov anna

soda

Cryolite Silica

g

five

Q

five

0

real control and metallographic analysis of the obtained castings.

The results of the experimental heats are given in table 2.

According to the data given in table 2, it is clear that fluxes 3-5 provide the optimal combination of quality indicators of castings. A decrease in the silica content leads to the appearance of flux inclusions due to a decrease in the viscosity of the flux. Increasing the silica content impairs the protective and refining properties of the flux.

Thus, the use of smelting followed by a forced pouring of complex-shaped products from alloys of gold, silver or copper of the proposed flux provides high quality indicators of castings due to the optimal combination of coating-refining properties and viscosity of the flux in the molten state.

Claims (1)

Invention Formula Cover-refining flux for alloys based on gold, silver or copper, including cryolite and soda ash, characterized in that, in order to reduce the content of non-metallic inclusions in the castings and exclude the porosity of the castings, the flux additionally contains silica in the following ratio of components, wt.% : Cryolite19-23 Kaltsinirov Anna Soda19-23 SilicaOther Table 1 Famous there is Alloy ElSrM 583-80 1-22 offerable 1 No 2 3 4 5 6 7 tt there is 3 2 2 1 - 2 1 2 1 famous there is offerable 1 No 2 3 4 5 6 7 famous eleven t there is eleven there is Alloy CpM 875 2-32 32-3 2-31-2 2-31-2 1-2О O1 2-31-2 21 LAF alloy 94-0,5-0,15 22 Proposed 1No 2 four Table 2 3 3 2 2 Porosity Porosity Captivity, porosity Porosity Flux Flux inclusions Quality indicators of metal castings d 11B. that neither ul and z in im. rm Other defects Copper oxide scores Points of non-metallic inclusions there is 2-3 2-3 2 Continuation of table 2 Points of non-metallic inclusions 12 1-2