SU1098731A1 - Composition of charge for obtaining fused welding flux - Google Patents

Abstract

1. COMPOSITION OF CHARGE FOR PREPARING WELDED MELTED FLUX containing magnesite powder, marble, quartz sand, sodium fluoride, fluorite concentrate, as well as alumina-manganese oxide components, which, in order to reduce the chemical activity of the flux, in order to reduce the chemical activity of the flux, it will be a good way to reduce the amount of fluorescent fluorescent material that is used in order to reduce the chemical activity of the flux from the flux. , as an alumina-manganese oxide components, the mixture contains alumina zirconium-containing by-product of the enrichment of titanium placers and manganese slag of ferroalloy production with refined oxidant Rator in the following ratio of components, May. %: Alumina zirconium-containing 26-33 by-product of titanium placer enrichment Manganese slag of ferroalloy production with a refining oxidizer 10-34 rum 7-8.5 Magnesite powder Marble (in terms of CaO) 3-11 Quartz sand7-17 Sodium fluoride6-7.5 Fluorite concentrate 14-16, while the mass ratio of the oxidizing agent to the manganese ingredient of the mixture is {@ l 0.5-5.00 / 0. /) 2. Composition of the charge according to claim I, characterized in that the alumina zirconium-containing by-product contains, May. %: Aluminum oxide 48-70 Zirconium dioxide 0.5-3 Silicon dioxide 27-51.5 3. The composition of the charge according to claim 1, characterized in that the manganese slag of the ferroalloy production contains, in May, Manganese monoxide Calcium oxide, magnesium oxide Aluminum oxide Monoxide Iron Phosphorus Sulfur Silica

Description

The invention relates to the field of welding, namely, compositions for producing fluxes, and can be used for automatic welding in various fields of engineering, in particular in nuclear and power engineering for submerged-arc welding into narrow cutting of 15H2NMFA type steels.

Charges for obtaining fused fluxes are known, for example, a mixture for producing welding fluxes containing

P /

Mas.7o:

Quartz sand 23-24

Lime17-18

Manganese concentrate 3-4 Gly-nozem22-23

Magnesite 10-11

Fluorite concentrate Else

This mixture allows to obtain a flux for

automatic welding of low and medium alloyed steels 1.

The disadvantage of this mixture is the absence of sodium fluoride in its composition, which reduces the efficiency of using the flux obtained from it for automatic welding due to the impossibility of producing weld metal of the weld with a reduced content of oxide silicate inclusions.

Closest to the proposed technical entity is the charge, consisting of May. %:

Manganese concentrate 4,5-9

Magnesite 7-9.

Marble (in

in terms of Cao) 16-20

Aluminum oxide

anhydrous 18-20

Quartz sand27-32

Sodium fluoride 3-7,5

Fluorite concentrate II -15 The known charge provides for obtaining a flux used for multilayer automatic welding of ring welds of the hull structures of nuclear power plants in a narrow section 2.

However, the flux obtained from the known schicht is characterized by a relatively high value of chemical activity for manganese monoxide, which does not allow for a more profound refining of the metal of the weld pool for oxygen due to the manganese reduction process in the process of automatic submerged-arc welding.

In addition, the known solids contain manganese concentrate, which is the main flux contaminant with sulfur and phosphorus, whose content in the concentrate reaches 0.25 and 0.3%, respectively. The composition of the mixture does not provide a decrease in sulfur and a decrease in the concentration of phosphorus in the source materials due to

close chemical connection of the latter with manganese ore minerals, which leads to the redistribution of sulfur and phosphorus between the slag and metal baths in the process of automatic welding under flux.

A disadvantage of the known composition is also the development of the process of saturating the flux with nitrogen, which occurs during the smelting of the flux in the furnace from the mixture of this composition, with the formation of cyanide compounds.

The use of unrelated alumina in the charge leads to a decrease in the content of the latter in the flux due to the mechanical removal of light alumina particles with waste gases, with the fly off reaching 3%, which makes it difficult to obtain a flux with a stable chemical composition.

The aim of the invention is to reduce the chemical activity of the flux, refining it from harmful substances.

The goal is achieved by the fact that the mixture for obtaining welding fused flux containing magnesite powder, marble, quartz sand, sodium fluoride, fluorite concentrate, and also alumina-manganese oxide components, contains alumina-zirconium-containing bead, as the alumina-manganese oxide components. enrichment of titanium placers and manganese schlak ferroalloy production with oxidizer-refiner in the following ratio of components, May. %:

Aluminous

zirconium-containing

by-product26-33

Manganese slag

ferroalloy

production with

oxidant

refiner 10-34

Magnesite Powder7-8,5

Marble (in

in terms of Cao) 3-11

Quartz sand7-17

Sodium fluoride6-7,5

Fluorite

concentrate14-16

wherein the mass ratio of the oxidizing agent to the manganese blend ingredient is 0.5-5.0%.

In this case, in the mixture using alumina zirconium-containing product containing, in May. %:

Alumina 48-70

Zirconia 0.5-3

Silica 27-51.5 In addition, manganese slag from ferroalloy production contains, May. %: Manganese monoxide 15-20 Calcium oxide 20-45 Magnesium oxide 3-5.5 2-5 Aluminum oxide Iron oxide 0.1-0.2 0.003-0.03 Phosphorus 0.1 - 1.2 23.07-59,797 Dioxide silicon Oxides and gaseous oxygen are used as oxidizing refractor. Aluminous zirconium-containing by-product is formed during the enrichment of titanium placers by the method of magnetic separation. Manganese slag is produced in the production of iron and manganese alloys. The chemical activity of welding flux on manganese monoxide is directly dependent on the content of MpO in the flux and on the basicity of the flux. Mathematically, this relationship is described by the following equation: AK 0.42- (MpO) .p-B, where AipO is the chemical activity of manganese monoxide flux; (MpO) f-content of manganese monoxide in the flux; -substantial flux. The introduction of zirconium dioxide into the mixture by the alumina product makes it possible to reduce the basicity of the flux melt, which leads to a decrease in the chemical activity of the flux on manganese monoxide without decreasing its concentration and decreasing the thermodynamic activity of the oxide in the flux. In addition, a decrease in the basicity of the flux when a zirconium-containing product is introduced into the blender helps to reduce its oxidizing ability with respect to the weld metal. The transition of oxygen into a metal bath during submerged-arc welding is described in the following scheme. 02 O + 2e, O-anion of oxygen in the slag; COJ - atomic oxygen dissolved in metal; 2e is the number of electrons released. The addition of zirconium dioxide with the introduction of the aluminous product into the composition of the proposed mixture leads to a significant increase in the bond of oxygen ions with sclac, reduces the tendency of anions 0 to transition to metal during submerged-arc welding. This is due to the formation of complex zirconium – oxygen anions in the liquid flux, which are stable both during its smelting and during the welding process. (Zr04), (ZrOa) +2 (02 where (2p02) is zirconium dioxide; ZfO is zirconium-oxygen anion. The formation of complex zirconium-oxygen anions results in a decrease in the concentration of oxygen anions in the flux and a decrease in their activity, which causes a decrease in oxygen in metal during submerged-arc welding. The use of manganese slag from ferroalloy production in the proposed charge, together with an oxidizing agent, makes it possible to refine the flux from sulfur and prevent nitration during its melting in a furnace As an oxidizing agent, iron oxides can be desulfurized in a flux melt in a furnace according to the following (CaS) +4 (FeO) + 3 (CaPr) (CaO) + + {SFfe; (CaS + (FeaOj) - (CaO) + ( SOj) The use of gaseous oxygen as an oxidant leads to the desulfurization of the flux melt according to the (CaS) + 1, S (CaO) + (SOgj) method. The mass ratio of the oxidizer to the manganese blend ingredient is 0.5-5.0%. an oxidizing agent with respect to manganese slag of less than 0.5% leads to an insufficient degree of desulfurization. When the oxylitel is exceeded 5%, the oxidative capacity of the flux increases dramatically, which is associated with an increase in the concentration of oxygen anions in the flux melt. in the slag, and partial recovery from the flux melt, which provides a flux with a phosphorus content of 0.006-0.009%. The use of iron oxides as a charge component inhibits the process of nitriding the flux when it is discharged in a furnace that proceeds according to the following scheme (Ca (CNi) + (FeO) (CaO) + (Nj) + (C) + Application in the mixture of alumina, bound to aluminosilicates, allows

eliminate its removal from the furnace with waste gases.

The use of manganese slag and alumina product excludes from the composition of the mixture expensive and scarce components - manganese concentrate and alumina. At the same time, the consumption of marble and quartz sand is significantly reduced, since calcium and silicon oxides in large quantities are part of the proposed charge components.

Being multi-component, slags have a low melting point. As a consequence, they are easily fused with other components of the charge, which leads to a significant reduction in the specific energy consumption. In addition, material costs for the production of fluxes are significantly reduced, since the cost of slags is 8-10 times lower than the cost of alumina and manganese concentrate.

The selected ratio of the components of the charge is optimal for obtaining standard fluxes of the FC-16 type and ensures the variation of the components of the charge within the prescribed limits.

The introduction of an alumina by-product in an amount of less than 26% does not provide the necessary degree of micro-alloying of the flux with zirconium dioxide and leads to an increased consumption of fluorite concentrate, which is uneconomical. When using manganese slag in an amount of less than 10%, the MpO content in the flux at the lower limit of 1.8-2.0% is not achieved, and when it is reached, the increase in manganese in the weld metal is reduced. The introduction of magnesite powder and marble in the amount of less than 7 and 3%, respectively, leads to the need to increase fluorite in the charge. When using sand in an amount of less than 7%, the requirement of the technological instruction on the content of silicon dioxide in the flux is not fulfilled. The use of sodium fluoride in an amount of less than 6% leads to non-standard content of it in the flux due to the significant volatility of this compound.

The introduction of an alumina product in an amount of more than 335 & does not provide the standard content of silica in the flux. The introduction of manganese slag in an amount of more than 34% is impractical because of the violation of the optimal amount of charge components, in particular, a decrease in the estimated amount of calcium fluoride set by the technological instruction equal to 16%, which is explained by a decrease in the content of the latter in the flux melt due to the formation of volatile fluoride compounds, for example SiF. The use of magnesite powder in the charge in an amount of more than 8.5% does not provide the standard content of magnesia in the flux, taking into account the permissible deviation by the process instruction. When using marble and sand in an amount of more than II and 17%, respectively, the standard content of silicon dioxide in the flux is violated. The use of sodium fluoride in an amount of more than 7.5% results in non-standard flux of sodium fluoride.

The advantages of the proposed charge are a decrease in the chemical activity of the resulting flux, a decrease in its oxidizing ability, the flow of smelting processes from harmful impurities in the smelting of the flux in the furnace, as well as low cost components, environmental improvement and expansion of raw materials for welding materials.

The mixture is prepared by mixing the pre-weighed components in the ratios required to obtain a flux of a given grade in accordance with the chemical composition governed by the technological conditions for their supply.

Example. The weighed initial components of the proposed mixture for smelting flux FTs-16 — an alumina product, manganese slag, magnesite powder, marble, quartz sand, sodium fluoride, fluorite concentrate — are mixed and loaded into a flux-smelting furnace. The composition of the mixture is given in table. one.

Electric mode of the melting furnace V 60 V, I (1.5-2.0) kA. After melting with the batch injected into the furnace, the flux melt is superheated for 10 minutes, and then the aqueous granulation of the flux is performed. Flux receive pumice.

In identical pilot conditions, a mixture of a known composition was prepared and FC-16 flux was melted.

Comparative data on the chemical composition and technology (o-economic indicators of experimental fluxes of the type obtained using the proposed and

known composition of the mixture, are given in table. 2

Thus, it is possible to completely replace alumina and manganese concentrate with an alumina by-product and manganese slag.

The introduction of an aluminous by-product of titanium alluvial and manganese slag into the mixture makes it possible to completely eliminate the expensive and scarce components from the composition of the mixture.

aluminum oxide and manganese concentrate, and, in addition, reduce the consumption of input marble and sand. Microalloying of the zirconia flux has a positive effect on its metallurgical properties due to a decrease in the activity of oxygen anions in the flux, which contributes to a decrease in the oxygen content in the weld metal. In addition, the use of manganese slag in the mixture together with an oxidizing agent provides refined low-phosphorus welding flux, which causes a decrease in the increase in phosphorus in the weld metal during automatic welding (surfacing) under the flux.

The advantages of the proposed composition of the mixture are a decrease in the activity of oxygen in the flux due to the formation of zirconium-oxygen anions; ensuring the production of refined low-phosphorus flux, improving the kinetic conditions for refining the weld pool, as well as lower the cost of its components, improving the ecology and expanding the mineral resource base of welding fluxes.

Table 1

Aluminous byproduct

Manganese slag with an oxidizing agent.

Magnesite Powder

Marble

Quartz sand

Sodium fluoride

Fluorite concentrate

31.5 19.2 16.7 9.02.0 15.62 5.50.31 28.5 19.6 16.9 8.9 3.8 15.1 27.3 17.4 17.2 9 , 16.0 15.2

(known) 29.4 18.5 19.3 8.6

26.0

BEHIND

8.5

3

7

7.5 14

table 2

0.15

0.14

4.3 15.1 4.6 6,50,280,21 7,30,260,20

0.014

15

Continued table. 2

0.83

100

Gray

Claims (3)

1. The composition of the mixture for the production of welding fused flux containing magnesite powder, marble, quartz sand, sodium fluoride, fluorite concentrate, as well as aluminum-manganese oxide components, characterized in that, in order to reduce the chemical activity of the flux, refining it from harmful impurities , as aluminum-manganese oxide components, the mixture contains aluminous zirconium-containing by-product of the enrichment of titanium placers and manganese slag of ferroalloy production with an oxidizing-refining agent with the following ratio of components, May. %: 26–33 10—34 7-8.5 3-11 7-17 6-7.5 14-16, the oxidizing agent to Alumina zirconium-containing by-product of the enrichment of titanium placers Manganese slag of ferroalloy production with a refining oxidizer Magnesite powder Marble (in terms of CaO) Quartz sand Sodium fluoride Fluorite concentrate, while the mass ratio of the charge to the manganese ingredient is 0.5-5.0%. 2. The composition of the mixture in π. 1, characterized in that the alumina zirconium-containing by-product Alumina Zirconia Silica 3. The composition of the mixture in that the manganese slag ferroalloy production contains. Manganese Monoxide Calcium oxide Magnesium oxide Aluminum oxide Iron monoxide Phosphorus Sulfur Silicon dioxide contains, May. %: 48–70 0.5-3 27-51.5 π. 1, characterized in May. %: 15-20 20-45 3-5.5 2-5 0.1-0.2 0.003-0.03 ' 0.1-1.2 23.07-59.797 SU „„ 1098731