RU2335386C2 - Solder on nickel base - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention can be used at fabrication of soldered parts of hot tracts of turbines of GTE (gas turbine engines) out of heat resistant nickel alloys. For decreasing of erosion activity of solder, increasing of heat strength and heat resistance of connections solder contains components at a following combinations, wt %: chromium 12.0-15.0; boron 0.8-1.3; silicon 0.1-0.6; molybdenum 0.9-2.0; tungsten 0.6-2.5; aluminium 6.5-12.0; cobalt 7.0-12.0; carbon 0.04-0.2; nickel - the rest.

EFFECT: upgraded efficiency of soldered connections and facilitating significant economy effect from increased resource of GTE.

2 tbl, 3 ex

Description

The invention relates to the field of engineering, namely to nickel-based solders, which can be used in the manufacture of soldered parts of a hot gas turbine engine path from heat-resistant nickel alloys

Known solder based on Nickel, having the following chemical composition, wt.%:

Chromium 8.5-10.0 Iron 3,5-5,0 Boron 0.2-0.4 Silicon 6.0-7.2 Molybdenum 10.0-12.0 Tungsten 8.0-10.0 Nickel rest

(Handbook of soldering. Engineering. 2003, p. 76).

The disadvantages of solder are large values of erosion when soldering products from heat-resistant nickel alloys, low heat resistance of compounds at temperatures above 900 ° C.

Known solder based on Nickel of the following chemical composition, wt.%:

Chromium 13.0-25.0 Silicon 2.0-3.0 Manganese 5.0-15.0 Molybdenum 6.0-15.0 Nickel rest

(USSR AS No. 485846).

Solder is not heat resistant at temperatures above 900 ° C.

Known solder of the following chemical composition, wt.%:

Chromium 6.0-7.0 Boron 0.2-0.3 Silicon 2.5-3.0 Tungsten 8.5-9.5 Molybdenum 1.6-2.0 Aluminum 4.0-5.0 Niobium 10.0-11.0 Titanium 1,0 Nickel rest

(Handbook of soldering. Engineering. 2003, p. 74).

The disadvantages of this solder are the large values of erosion during soldering of products from heat-resistant nickel alloys, the low level of heat resistance of compounds at temperatures above 1000 ° C and low values of heat resistance of compounds at operating temperatures.

The closest analogue taken as a prototype is a nickel-based solder for joining products from heat-resistant nickel alloys of the following chemical composition, wt.%:

Chromium 6.0-10.0 Boron 0.6-1.3 Silicon 0.05-0.15 Tungsten 2.0-5.0 Cobalt 8.0-10.0 Aluminum 4.0-6.0 Carbon 0.05-0.2 Molybdenum 1.8-2.2 Niobium 3.0-5.0 Iron 0.1-0.7 Nickel rest

(RF patent No. 2283741).

The disadvantage of this solder is the interdendritic penetration of the solder into the base material, as well as the tendency to recrystallize the surfaces of the base material along the boundaries with the solder and, accordingly, a decrease in the heat resistance of the joints.

An object of the invention is to eliminate the interdendritic penetration of solder into the base material and increase the heat resistance of soldered joints of products of heat-resistant nickel alloys.

The stated technical problem is achieved by the fact that a nickel-based solder is proposed for joining products from heat-resistant nickel alloys containing chromium, boron, silicon, molybdenum, tungsten, aluminum, cobalt and carbon, which contains components in the following ratio, wt.%:

Chromium 12.0-15.0 Boron 0.8-1.3 Silicon 0.1-0.6 Molybdenum 0.9-2.0 Tungsten 0.6-2.5 Aluminum 6.5-12.0 Cobalt 7.0-12.0 Carbon 0.04-0.2 Nickel rest

The proposed alloy with the stated content and ratio of components eliminates the interdendritic penetration of solder into the main material and increases the heat resistance of soldered joints of products from heat-resistant nickel alloys.

Examples of implementation

The proposed solder, as well as the prototype solder was smelted in a vacuum induction furnace. Table 1 presents the compositions of the proposed solder (examples 1-3) and the solder prototype.

Soldering was carried out by heating in a vacuum oven. The vacuum during the exposure was at least 5 · 10 ^-4 mm Hg. The main material is alloys ZhS32, ZhS36, VKNA-25. The soldering temperature of the ZhS32 alloy was 1270-1280 ° С, of the ZhS36 alloy - 1290-1300 ° С, and the VKNA-25 alloy - 1300-1320 ° С. Exposure at this temperature was 60 minutes. A portion of each solder in the form of pieces was placed near the gap.

Interdendritic penetration was determined on thin sections of compounds made perpendicular to the connecting surfaces and along the axes of the dendrites of single crystals by metallographic analysis.

The properties of the proposed solder and made by this solder compounds in comparison with the properties of the prototype are presented in table 2.

The heat resistance of butt soldered joints was determined on samples from alloys ZhS32 and ZhS36, VKNA-25. The diameter of the working part of the sample was 5 mm. The brazed seam was in the middle of the sample and was perpendicular to the axis of the sample.

Short-term heat resistance of butt joints of products from alloys ZhS32 at 1100 ° C and ZhS36 at 1150 ° C, made by the proposed solder, approaches the heat resistance of basic materials. Compounds of alloy products ЖС36 and VKNA-25 made by solder-prototype, due to the formation of recrystallized grains along the boundaries of the base material with solder, have significantly lower values of the strength of the joints. The ZhS32 single-crystal alloy contains carbon and recrystallized grains during soldering appear in it only with significant plastic deformation of the connecting surfaces at the stage of preparation for soldering. Short-term strength values of the ZhS32 alloy joints made by the proposed solder are at the level of the properties of the joints made by the prototype solder, and the long-term strength values (100-hour strength) of the joints made by the proposed solder are significantly higher than the values of such strength of the joints made by the solder prototype.

The use of the proposed solder when connecting products of the hot gas turbine engine and repairing castings made of heat-resistant nickel alloys will significantly increase the reliability of soldered joints and provide a significant economic effect from increasing the gas-turbine engine resource.

Table 1 No. p / p Cr AT Si Mo W Al With FROM Nb Fe Ni one 12.0 1.3 0.1 1.4 1,5 6.5 9.5 0.04 - - rest 2 13.5 1,0 0.35 0.9 2,5 9.2 7.0 0.12 - - ″ - ″ 3 15.0 0.8 0.6 2.0 0.6 12.0 12.0 0.2 - - ″ - ″ Prototype 8.0 0.95 0.1 2.0 3,5 5,0 9.0 0.11 4.0 0.4 ″ - ″

Claims (1)

Nickel-based solder for joining products from heat-resistant nickel alloys containing chromium, boron, silicon, molybdenum, tungsten, aluminum, cobalt and carbon, characterized in that it contains components in the following ratio, wt.%: Chromium 12.0-15.0 Boron 0.8-1.3 Silicon 0.1-0.6 Molybdenum 0.9-2.0 Tungsten 0.6-2.5 Aluminum 6.5-12.0 Cobalt 7.0-12.0 Carbon 0.04-0.2 Nickel Rest