SU937119A1 - Flux for soldering alloyed steels and alloys - Google Patents

Description

(54) FLUSHING FOR SUSTAINABLE STEELS AND ALLOYS

The invention relates to soldering, in particular, to the composition of the flux for soldering alloy steels.

Fluxes are known, consisting of a mixture of borax and boric acid, to increase the activity of which active ingredients such as fluorides or fluoroborates of alkali and alkaline earth metals are added to their composition, which help to remove oxide films when brazing high-alloy steels and alloys.

The disadvantage of fluxes is the high temperature of the onset of the active action / 1 reduction of oxides of the scorched material and solder over 500 s, which causes oxidation of alloyed steels and alloys to the moment of the onset of fluxes during the heating process for brazing.

Also known is flux 2 with a temperature of onset of active action, used for soldering steels, nickel and copper alloys with silver solders, containing, in wt.%;

Potassium fluoride 33-37 Fluoroborate potassium 40-44 Boric anhydride 23-25

The disadvantage of the flux is its high temperature of onset of active action in the process of furnace brazing in the atmosphere of protective gases, which causes oxidation of alloyed steels and alloys before the flux begins to act. When the temperature of the beginning of the active flux is reached, the oxide films of titanium, aluminum, chromium, molybdenum and other metals forming the steels and alloys that are formed on the surface of alloyed steels are not fully restored.

15 solder spreading and forging high-quality joint seams.

The purpose of the invention is to increase the flow of solder by reducing the temperature of the onset of active

20 actions when soldering in an inert gas atmosphere.

This goal is achieved by the fact that the flux containing potassium fluoroborate, boric anhydride, and LI fluoride additionally contain phosphine oxide in the following component assignment, wt%:

Fluoroborate potassium 34-38 Boric anhydride 18-20 phosphine oxide 16-18

30 Potassium fluoride Else Temperature range of active action of the flux 350-850С. The phosphonic oxide contained in the flux is in a liquid state and prevents the oxidation of alloyed steels and alloys, and upon reaching it begins to evaporate intensively and actively interact with oxides of metals of alloyed steels and alloys. When heated above phosphine oxide, it begins to lose its activity, but the gaseous decomposition products of potassium fluoroborate and boric anhydride in the liquid state continue to reduce the oxides on the alloyed steels and alloys. The optimum content of phosphine | Sid in the flux is 16-18%. With a smaller amount, the flux is not sufficiently active, and its higher content practically does not alter the activity of the flux. The flux is made by mechanically mixing the components. Before use, ftsch is mixed with water or alcohol and applied

18

34

19 20

36 38

The use of the proposed flux from steels and alloys with high heat resistance makes it possible to reduce their weight by 12-15%, the labor intensity of manufacturing by 8-10%, as well as to improve the operational characteristics.,

Claims (2)

Invention Formula Flux for soldering alloyed steels and alloys containing fluorinated borons 3.6 850 380 thirty, 850 350 3.2 850 350 potassium, boric anhydride, potassium fluoride, characterized in that, in order to increase the flow of solder by lowering the temperature of the onset of its active action when soldering in an atmosphere of inert gases, it additionally contains phosphine oxide in the following ratio of components, weight. %: n on the connection surfaces of parts. Brazing using the proposed flux is carried out in an air resistance furnace in a steel brewing container in an argon atmosphere. In order to check the properties of solder compounds, flux compositions were made at the minimum, maximum, and optimum ratio of the flux components. Determination of the mechanical properties of brazed joints was carried out on overlap and butt specimens of alloyed steel of the EP679VD brand, soldered with PM17 solder in the form of a foil 0.08 mm thick. Before soldering, a thin layer of flux was applied to the surface of the solder, diluted in ethyl alcohol to a paste-like state. The samples were brazed in a steel, brewed container in an air resistance furnace in a stagnant argon atmosphere at 1000. The chemical composition of the flux and the properties of soldered compounds are listed in the table. Fluoroborate potassium 34-38 Boric anhydride 18-20 Phosphine oxide 16-18 Potassium fluoride Else Sources of information taken into account in the examination5 1, Lashko NF, Lashko-Avak N S, V. Soldering of metals, N., Mashiostroenie, 1959, p. 150-154. 2. Lashko N.F., Lashko S.V. Soldering metals. M., Maiginostroenie, i967, p.275, Table. 83 (prototype).