SU1581528A1 - Paste for high-temperature brazing of steel - Google Patents

Abstract

The invention relates to the soldering of metals, in particular, to the composition of the paste for high-temperature soldering, and can be used in mechanical engineering in the manufacture of brazing structures made of carbon and low alloy steels. The purpose of the invention is to increase the productivity of the process by applying a metal coating on the soldered parts during the soldering process. Pa flax paste contains components in the following ratio, wt.%: Copper acetylacetonate 0.2-16.5

metal powder 52-84

binder - the rest. Copper-phosphorus solder, copper and iron powders are used as metal powder. The paste makes it possible to obtain practically defect-free solder compounds. 3 hp ff, 1 tab.

Description

The invention relates to the soldering of metals, in particular to the composition of a paste for high-temperature soldering, and can be used in the manufacture of brazing structures from carbon and alloyed steels.

The purpose of the invention is to increase the productivity of the process by applying a metal coating on the soldered parts during the soldering process.

The paste contains components in the following ratio, wt.%:

Acetylacetonate

med0,2-16,5

Metal

powder52-84

Organic

binder

When using composite solder to solder steel parts, simultaneously with the copper plating of parts, the non-melting component of the solder located in the assembly gap is copper plating. Pa flax paste as a metal powder may contain copper-phosphorus solder (68- 78%), copper (78-84%) or iron

(52-76%) powders with different amounts of copper acetic acetonate and a binder.

The paste is prepared by mixing the components in a glass or stainless steel mixer. The separately prepared binder is first mixed with copper acetyl acetonate powder, and then metal is gradually added to the resulting mass.

the cue powder and the whole mixture are mixed until uniform. Cooked pasta should be stored in an airtight container. Depending on the binder used, the pas- sage retains its technological properties for 6–48 h, therefore, it can be used for mechanized dosing into assembly gaps using syringes, feeders, etc.

Examples of the paste are presented in the table.

20

25

When the content of acetylacetonate is 55% and more than 6.5%, the amount of copper dissolved in the solder is superfluous. In this case, due to the uncontrolled displacement of the temperature of the liquidus solder, the soldering process becomes technologically uncontrollable and quality is not ensured.

In the case of using, for example, a paste of powdered copper-phosphorus solder, it is not possible to achieve its complete melting at the brazed solder temperatures.

In addition, at the required paste consistency, the excessive content (over 16.5%) of copper acetylacetonate powders reduces the amount of metal powder (solder or filler) in the paste, resulting in an increase in the number of discontinuities in the weld after brazing. When the content of copper acetyl acetonate is less than 0.2%, copper plating of the soldered surfaces is not obtained.

For an experimental test of the composition of the fused paste, samples of low carbon steel soldered in endogas and argon were tested. Before heating the telescopic samples, the assembly gap was filled with pastes containing copper acetylacetonate and metallic powders of copper solder, copper phosphorus solder, or iron. In the latter case, a brass solder ring was placed over the filled gap. Binder - a solution of polyvinyl butyral in ethyl cel 30

35

40

45

50

lozolve and acetone - has a temperature range of destruction of 120-500 ° C, the size of the assembly gap was - / la: when brazing with copper - up to 0.06 mm, when brazing with copper-phosphorus solder to 0.14 mm, when brazing with brass - to 0 4 mm.

Copper cutting was done after time.

0

five

0

five

but with solder heating. The heating was carried out at different rates in order to test the effectiveness of the copper in various temperature ranges. At temperatures above 600 ° C, heat up; increased, at a temperature of soldering produced an exposure of 3-5 minutes.

The table shows that the pastes according to examples 2-4, 7-9, 14-16 provide an increase in quality: the number of defects in the joints is reduced several times, and in some cases, almost defect-free seams were obtained.

Thus, the use of the proposed paste will increase productivity by 1.8-2 times by combining the processes of copper plating and heating-soldering; and also to improve the quality of the seams,

Claims (4)

1. Paste for high-temperature soldering of steel, consisting of metal powder and organic binder, characterized in that, in order to increase the productivity of the process by applying a metal coating on the soldered parts during the soldering process, it additionally contains copper acetylacetonate powder in the following ratio of components, wt%: Acetylacetonate 0 five 0 five copper Metallic Powder Organic Binder 0.2-16.5 52.0-84.0 Rest 2, The paste according to claim 1, about tl and h a torn, and so that, in order to improve the quality of the solder joint when soldering the joints with capillary assembly gaps, it contains copper powder as a metal powder in the following ratio components, wt,%: Acetylacetonate copper 0 j 2-2,6 Copper powder 78-84 Organic binder Remaining 3, Pasta pop.1, distinguish of the paste in the gap is compatible with the fact that, for the purpose of higher neither the quality of the solder joints when soldering compounds with non-capillary assembly gaps, as the metal of the glued sleep powder contains iron powder with the following ratio of components, wt,%: Acetylacetonate Editor L. Veselovska Compiled by L.Abrosimova Tehred L. Oliynykh Corrector S.Shekmar Order 2056 Circulation 645 VNIIPI of the State Committee for Inventions and Discoveries under the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk Nab. 4. An agent according to claim 1, characterized in that, as a metal powder of a metal powder, it contains a powder of copper-phosphorus solder in the following ratio of components, wt.%: Acetylacetonate medi12 16.5 Copper powder Subscription