RU2448824C1 - Charge for producing welding fused flux - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in machine welding and pad welding carbon steel with low-alloyed welding wire. The charge for making welding fused flux used is gabbro-diabase rock from the Lomovsky deposit in Perm region, having the following composition, wt %: SiO₂ - 48.56, MnO - 0.22, CaO - 8.33, MgO - 3.71, Al₂O₃ - 12.44, Na₂O - 2.37, K₂O - 1.23, TiO₂ - 4.42, Fe₂O₃ - 8.55, P₂O₅ - 0.47, S_total - less than 0.03. Use of the gabbro-diabase enables to obtain high-silica non-manganiferous flux.

EFFECT: flux has high removability of slag the surface of the joint, and ensures quality joint formation and arcing stability.

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Description

The invention relates to the welding industry, namely, the composition of the mixture to obtain a welding fused flux, and can be used in mechanized welding and surfacing of carbon steels for general purposes with low alloy welding wire.

Known mixture for producing fused welding flux (Technological instructions for the manufacture of fused flux brand FTs-16 TI-30-03-80, M., NPO TSNIITMash, 01.07.80), containing, wt.%:

Quartz sand 27-32 Marble (CaO) 16-20 Manganese Concentrate 4,5-9 Anhydrous Alumina (18-20) Magnesite 7-9 Fluorite concentrate 11-15 Sodium fluoride 3-7.5

This charge is designed to produce fused flux welding, which is used in multilayer automatic welding of ring welds of hull structures.

The disadvantage of the charge is that its composition uses expensive components (manganese concentrate, alumina, magnesite). In addition, the manganese concentrate, which is part of the charge, is the main contaminant of flux sulfur (up to 0.25%) and phosphorus (up to 0.3%). Moreover, the composition of the charge does not provide both a decrease in sulfur and a decrease in the concentration of phosphorus in the starting materials due to strong chemical bonds of phosphorus with minerals in manganese ore, which leads to the spread of sulfur and phosphorus both in the slag crust and in the metal bath during welding. The high content of sulfur and phosphorus in the welds leads to the formation of cracks, i.e. affects the quality of the weld.

In addition, the use of alumina in the mixture leads to the removal of light alumina particles during the smelting process, and the amount of alumina reaches 3%, which makes it difficult to obtain a flux of stable chemical composition and requires an additional operation to control the composition of the smelted flux.

Closest to the proposed mixture in composition and technological properties is a mixture (A.S. No. 1098731, IPC 5 V23K 35/362, 1984), consisting, wt.%:

Alumina by-product 26-33 Ferroalloy Manganese Slag production with an oxidizing agent refiner 10-34 Magnesite powder 7-8.5 Marble 3-11 Quartz sand 7-17 Sodium fluoride 6-7.5 Fluorite concentrate 14-16

The disadvantage of the charge is that it contains slag materials that have an unstable composition and a high content of harmful impurities in terms of sulfur content (0.1-1.2%), which affects (reduces) the quality of the flux and, accordingly, the quality of the welds. The composition of the charge uses expensive raw materials, which leads to the high cost of the resulting fused welding flux.

The objective of the invention is to reduce the cost of flux, obtaining high-quality welding fused flux, expanding the mineral resource base of the Perm region for the production of welding materials.

The problem was solved due to the fact that the gabbro-diabase rock of the Lomovskoye deposit in the Perm Territory was used as a mixture of welding fused flux.

Gabbro-diabase of the Lomovskoye deposit in the Perm Territory contains the oxides shown in Table 1.

Table 1 Items SiO ₂ MnO Cao MgO Al ₂ O ₃ Na ₂ O K ₂ O TiO ₂ Fe ₂ O ₃ P ₂ O ₅ S _total Content, wt.% 48.56 0.22 8.33 3.71 12.44 2,37 1.23 4.42 8.55 0.47 <0.03

Gabbro-diabase of the Lomovskoye deposit in the Perm Territory, with some approximation, corresponds to the flux compositions of FTs-16, FTs-16A, AN-47 and AN-15. The region of these fluxes in the three-component state diagram of the CaO-MgO-SiO _{2 system} lies between the isotherms of 1400 and 1500 ° С, but the melting point of these fluxes is 1300-1350 ° С due to the introduction of additional oxides MnO, Na ₂ O, K ₂ O and fluorides CaF ₂ and NaF. Gabbro-diabase in the state diagram is located above the region of welding fluxes between the isotherms of 1300-1500 ° С, but its melting temperature does not exceed 1400 ° С due to the low content of magnesium oxide (3.71%). That is, the melting temperature of the proposed flux and the above fluxes, into which additional expensive raw materials (CaF ₂ , MnO, etc.) are introduced, are the same.

The use of gabbro-diabase as a charge makes it possible to exclude expensive and scarce components from the composition of the charge — magnesite powder, alumina, quartz sand, and marble, since oxides of silicon, aluminum, calcium, and magnesium, which are contained in sufficient quantities in the gabbro-diabase of the Lomovsky deposit Perm region. The cost of gabbro-diabase is 8-12 times less than the cost of alumina, manganese concentrate and marble, which can significantly reduce the material costs of producing fused welding flux.

The advantage of gabbro-diabase is also its low content of sulfur impurities (<0.03%) and phosphorus (up to 0.61% pentavalent phosphorus oxide). The low content of harmful impurities can improve the quality of the obtained flux and, accordingly, the quality of the welds.

An advantage of the proposed one-component composition of the charge is also the improvement of the environment, since the composition of the charge does not contain artificial chemical components, the igneous rock gabbro-diabase does not emit harmful substances during melting. During melting, it is not necessary to introduce additional refining components, since gabbro-diabase has a low content of harmful impurities. And before melting there is no need to calculate the recipe composition of the mixture.

In addition, the use of gabbro-diabase from the Lomovskoye deposit in the Perm Territory will expand the mineral resources base of the Perm Territory for the production of welding materials.

It is known to use gabbro-diabase of the Lomovskoye deposit in the Perm Territory in construction as a building material (Danilevich I.S., Zakharov L.I., Kozlov A.S., Pushkin S.A. Facing and ornamental stones of the Perm Region. Reference. Perm State geological enterprise "Permgeolerud", Perm, 1998).

The use of gabbro-diabase of the Lomovskoye deposit in the Perm Territory in the welding industry, namely, as a mixture of fused welding flux, is not known from the prior art. For the first time, such properties of this rock as a stable chemical composition, low content of harmful impurities, and a stable melting temperature were revealed, which can reduce the cost of the resulting welding flux, improve the production environment, improve the quality of the flux and, accordingly, the quality of the welds.

An example of a specific implementation.

In laboratory conditions, prototypes of fused welding flux in a graphite crucible were obtained. The gabbro-diabase of the Lomovskoye deposit in the Perm Territory, the composition of which is given in Table 1, was used as a charge.

Gabbro-diabase was crushed to a fraction of not more than 4 mm, and then melted. Melting mode: I = 150-160 A, time 30 min. After melting, dry granulation was carried out to a fraction of 0.4-2 mm. The result was a high-silicon manganese-free flux, dark brown.

Using the obtained flux, welding of steel plates of the St3sp brand with a thickness of 14 mm was carried out, which showed: the flux has good separability of the slag crust from the surface of the weld, which is ensured by a less oxidizing effect of the flux on the hardening weld metal, because the formation of an oxide film on the surface of the weld is slower and adhesion of the slag to this surface is difficult.

According to RD 03-613-03, it was found that the proposed fused welding flux has a 5-point rating for the following welding properties: separability of the slag crust, the quality of the weld formation and the stability of the arc burning.

Claims (1)

The use of gabbro-diabase of the Lomovskoye field in the Perm Territory as a charge for producing fused welding flux.