SU925599A1 - Ceramic flux - Google Patents

Description

(54) CERAMIC FLUX

I

The invention can be used in the welding of components and structures of high-alloy corrosion-resistant and heat-resistant chromium-nickel-molybdenum steels of the austential class.

Known ceramic flux 1, containing the following components, wt.%:

Magnesite (magnesia) 4-5

Hydrofluoric board

(fluoride fluids) 9-11

Alumina (oxide

aluminum) 29-32

Hematite 3-5

Rutile (titanium dioxide) 30-42

Potash2-4

Chromium oxide1-2

Sodium aluminate 10-11.

The composition of such a flux contains silica, which is included in the form of impurities in such minerals as magnesite, fluorspar, alumina and hematite. In the presence of a silicon-reducing process, the transition of silicon to a welded bath occurs, which can lead to the formation of hot cracks in the weld metal,

especially when welding steels of big tolirsch. In addition, the presence of hematite and chromium oxide in the flux composition determines the increased metallurgical activity of the flux, which results in burnout of elements with a high agent for oxygen.

The aim of the invention is to create a ceramic flux with a complex of good welding and technological properties, neutral to the metal of the weld pool and

to ensure high resistance of the weld metal to hot cracks.

This goal is achieved by the composition of a ceramic flux containing fluoride ka; (cc, alumina, titanium dioxide

IS and sodium aluminate additionally introduced aluminum fluoride and magnesium oxide at a ratio of flux components, wt.%: Aluminum oxide 12-22

Aluminum fluoride11-29

Magnesium oxide 1-8

Titanium dioxide2-7

Sodium aluminate 7-12

Claims (1)

Calcium fluoride22-67 3 Calcium fluoride, alumina, magnesia, titanium dioxide and aluminum fluoride together form the slag base of the flux, contributing to the stable and steady flow of the arc process. good formation of the weld roll resistant to hot cracks and easy separation of the slag crust. Sodium aluminate is a binder and stabilizing arc process. Within the specified limits of the content of the flux components, its welding-technological properties remain good. With a ratio of flux components at a minimum level in wt.%: Alumina .12 Aluminum fluoride 11 Magnesium oxide 1 Titanium dioxide2 Sodium aluminate 7 Calcium fluoride The remaining arc process is stable and stable, the weld bead is good. The seam is dense, without cracks, pores and slag inclusions. An increase in the amount of calcium fluoride with a ratio of components at a minimum level leads to a deterioration in the separability of the slag crust, and a decrease in the remaining components below the minimum level to a deterioration in the formation of a weld bead. A further decrease in sodium aluminate flux reduces the mechanical strength of the granules and impairs the technological properties of the raw flux mass. When the ratio of the components of the ceramic flux is at its maximum, wt.% Alumina 22 Aluminum fluoride-29 Magnesium oxide 8 Titanium dioxide7 Sodium aluminate 12 Calcium fluoride The rest of the welding process is stable and stable. The seam bead has a good appearance and is covered with a uniform slag Crust, easily removed afterwards. There are no trags, pores or lhlakovye inclusions in the weld metal. A further decrease in the calcium fluoride content and an increase in the number of the remaining components impair the welding technological properties of the flux, leading to the appearance of bruising of the surface of the weld bead. The optimum composition is flux, wt.%: Alumina 16, Aluminum fluorine18 Magnesium oxide 4 Titanium dioxide5 Sodium aluminate 9 Calcium fluoride48 as it provides good welding properties and high resistance of the weld metal to hot cracks. Slag inclusions and pores are absent in the seams. The welded joints are resistant against sheathing and local corrosion and satisfy the requirements of GOST on mechanical properties. The use of a predagged ceramic flux leads to a decrease in scrap during welding of high-alloyed chromium-nickel-molybdenum steels and an increase in the service life of welded structures as a result of an increase in the performance characteristics of welded joints. Invention Ceramic flux mainly for welding high carbon steels containing calcium fluoride, alumina, titanium dioxide, sodium aluminate, characterized in that, in order to improve the welding-technological properties of the flux, to ensure its neutrality to the metal of the weld pool and to increase the resistance of the C1v metal to hot cracks, the flux additionally contains magnesium oxide and aluminum fluoride in the following ratio, wt.%: Aluminum oxide 12-22 Aluminum fluoride 11 -29 Magnesium oxide 1-8 Dioxide titanium2-7 sodium aluminate 7-12 calcium fluoride22-67 Sources of information taken into account during the examination 1. USSR author's certificate № 585022 cl. In 23 K 35/362 (prototype).