CS231135B1 - Solder additive for brazing high strength alloys - Google Patents

Abstract

Additive to solder for soldering high-strength, especially nickel-based heat-resistant and refractory alloys, characterized by its composition being identical to the composition of the material of the connecting parts, with the weight ratio of the additive in the solder ranging from 10 to 1 to 10.

Description

The invention relates to a solder additive for soldering high-strength alloys, in particular nickel.

The range of high-strength refractory and refractory nickel alloys is very difficult to weld. Some of the last types of these alloys are virtually non-weldable, or? even when using the latest knowledge in the field of welding technology and heat treatment around the weld, cracks occur that preclude the use of these weldments in most of their applications. The use of solders with similar chemical composition to the soldered parts can be considered as one of the last and very promising processes. In contrast to the chemical composition of the material of the brazed parts, however, they do not contain those elements that make diffusion processes more difficult, such as titanium and aluminum, but they also contain those elements that significantly reduce their melting or have a high diffusion coefficient such as boron, silicon, phosphorus and the like. The melting-reducing elements have a very favorable effect on the solder flowability and run-in, but on the other hand, they cause brittle intermetallic phases to occur in the joint region, significantly reducing some of the mechanical properties of the joint. In order to reduce the brittleness of the joint, it is recommended to use solder gaps as small as possible. Solder gaps in the range of 0.02 to 0.08 mm are considered optimum. In these solder gaps, brittle intermetallic phases occur to a limited extent and can be dissolved by a subsequent heat treatment for a certain, operationally acceptable time, thus improving the quality of the joint. Although this process is of great benefit for the permanent joining of parts of said nickel alloys, it has a number of drawbacks. It is essential that although the solder is supplied in excess and in the vicinity of the solder gap, very often it does not result in perfect and reliable flow between the pieces to be joined; The repair is then problematic and expensive. Some joints are even

231 135 unrecoverable and the part must be scrapped. The second, economically significant disadvantage is the unconditional requirement for the accuracy of the solder gap production. This disadvantage is evident when it comes to joining rugged surfaces where it is difficult to ensure a constant solder gap thickness within the desired tolerances. Compliance with the prescribed narrow tolerances is then very costly and often problematic.

These disadvantages are overcome by the brazing additive for brazing the high-strength alloys of the invention. In particular, these are nickel alloys with an approximate weight composition of 5 to 30% by weight. % of chromium, from 0.01 to 0.25 wt. % carbon, not more than 1 wt. % silicon, 1.5 wt. % manganese, 5 wt.% titanium, 7 wt. % Of nickel base, optionally at most 10 wt. % tungsten, 30 wt. % cobalt, 10 wt. molybdenum, 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnium, 7 wt. irons. Boron, zirconium and cerium are present, individually or in combination, not more than 0.5% by weight. Solder with a guide weight composition from 3 to 30 wt. % of chromium, from 0.01 to 0.5 wt. % carbon, not more than 1.5 wt. of manganese, nickel base. The boron, phosphorus and silicon are present singly or in combination with each other from 1 to 12% by weight or not more than 16% by weight. % tungsten, wt. % cobalt, 10 wt. molybdenum, 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnium, 7 wt. % iron and 2 wt. copper. The zirconium and cerium are contained, individually or in combination, not more than 0.5% by weight. The present invention provides an additive containing from 5 to 30 wt. % of chromium, from 0.01 to 0.25 wt. % carbon, not more than 1 wt. % silicon, 1.5 wt. % manganese, 5 wt. % titanium, wt. % aluminum, nickel base, or at most 30 wt. % cobalt, 10 wt. % tungsten, 10 wt. molybdenum, 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnium, 7 wt. irons. Boron, zirconium and ocular individually or in combination with each other not more than 0,5% by weight, with a solder / additive weight ratio ranging from 1: 10 to 10 ϊ 1.

The addition of a base material in the form of a solder powder makes it possible to increase the solder gap size to a technically and economically acceptable value without compromising the properties of the joint. By keeping the optimum ratios in the choice of the chemical composition and the grain size of the solder and the added base material, the diffusion annealing time after soldering can be reduced, because even a wider solder gap reduces the path that the atoms have to overcome.

231 135 elements reducing solder melting in order to remove or at least reduce the concentration gradients during the subsequent homogenization annealing and thereby to even the mechanical properties of the joint. Another advantage of the additive according to the invention is the perfect filling of the solder gap) and thus the reduction of rejects. The addition of powdered material having the same chemical composition as the brazed parts is also externally as if a solder with a lower concentration of elements was used to be dispersed by subsequent heat treatment, but the original solder, i.e. its relatively low “Melting remains fully preserved.

Example 1

The brazed parts were made of a nickel-based alloy with a chemical composition of 0.05% by weight. % carbon, 12 wt. % chromium, 4.5 wt. molybdenum, 2 wt. % niobium and tantalum, 5.9 wt. % aluminum, 0.6 wt. % titanium, 0.01 wt. % boron, 0.1 wt. zirconium, nickel - base. For brazing, a solder with a chemical composition of 7 wt. % by weight,% wt. % iron, 4.5 wt. % of silicon, 2.9 wt. % boron, 0.03 wt. carbon, nickel - base, the solder had a grain size of max.

0,05 mm. A base metal having a chemical composition of 0.05 wt. % carbon, 12 wt. % chromium, 4.5 wt. % molybdenum, wt. % niobium + tantalum, 5.9 wt. % aluminum, 0.6 wt. % titanium, 0.01 wt. % boron, 0.1 wt. zirconium, nickel - base, this material was added in the form of powder with grain size max.

0.05 mm * weight ratio of the solder powder and the base material in the resulting blend was 2: 1. Soldering is carried out in vacuo Procedure 10 * ^t Pa at 1,070 ° C for 20 minutes.

Example 2

The brazed parts were made of a nickel-based alloy with a chemical composition of 0.1% by weight. % of carbon, 0.5 wt. % manganese, 0.4 wt. % silicon, 19 wt. % by weight, 2.1 wt. % titanium, 0.9 wt. % aluminum, 1.5 wt. % iron, 0.001 wt. boron, nickel - basis.

For brazing, a solder with a chemical composition of 7 wt. % chromium, 3 wt. % iron, 4.5 wt. % of silicon, 2.9 wt. boron,

0.03 wt. carbon, nickel - base, the solder had a grain size of max. 0.05 mm. A base metal with a chemical composition of 0.1% by weight was added to the solder. % of carbon, 0.5 wt. % manganese, 0.4 wt. % silicon, 19 wt. % by weight, 2.1 wt. % titanium, 0.9 wt. aluminum,

- 4 231 135

1.5 wt. % iron, 0.001 wt. boron, nickel - base, this material was added in the form of powder with a grain size of max.

0,05 mm. The weight ratio of the solder powder and the base material in the resulting mixture, one with the first soldering is carried out in vacuo Procedure ** 10 ² Pa at 1060 ° C for 20 minutes.

Example 3

The brazed parts were made of a nickel-based alloy with a chemical composition of 0.04% by weight. % carbon, 12.0 wt. % chromium, 4.4 wt. molybdenum, 2 wt. % niobium + tantalum, 5.9 wt. % aluminum, 0.55 wt. % titanium, 0.01 wt. % boron, 0.1 wt. zirconium, nickel - base. A 0.12 mm thick film made of a 7% by weight solder blend was used for soldering. % chromium, 3 wt. % iron, 4.5 wt. % of silicon, 2.9 wt. % boron, 0.03 wt. % carbon, nickel base and base material of 0.04 wt. % carbon, 12.0 wt. % chromium, 4.4 wt. molybdenum, 2 wt. % niobium + tantalum, 5.9 wt. % aluminum, 0.55 wt. % titanium, 0.01 wt. % boron, 0.1 wt. zirconium, nickel - base. The ratio by weight of solder to the mass of the base material in the sheet was 2 t third Brazing was done in vacuo order of 10 ^"2 mbar at 1090 ° C for 30 minutes.

Claims (1)

A brazing additive for brazing high strength alloys, in particular nickel alloys having a guide weight composition of from 5 to 30% by weight. % of chromium, from 0.01 to 0.25 wt. % carbon, not more than 1 wt. % silicon, 1.5 wt. % manganese, 5 wt. % titanium, 7 wt. Atin / fei, nickel base,. optionally not more than 10 wt. % tungsten, 30 wt. % cobalt, 10 wt. molybdenum, 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnium, 7 wt. iron and boron, zirconium and cerium, individually or in combination with not more than 0.5% by weight, of a solder having a standard weight composition of 3 to 30% by weight; % of chromium, from 0.01 to 0.5 wt. % to about 1.5 wt. % of manganese, nickel base, boron, phosphorus and silicon individually or in combination with each other from 1 to 12% by weight or not more than 16% by weight; % tungsten, 30 wt. % cobalt, 10 wt. molybdenum, 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnia, 7 wt. % iron and 2 wt. Copper, zirconium and cerium individually or in combination with each other not more than 0.5% by weight, characterized in that its composition by weight consists of 5 to 30% by weight. % of chromium, from 0.01 to 0.25 wt. % carbon, not more than 1 wt. % silicon, 1.5 wt. % manganese, 5 wt. % titanium, 7 wt. % aluminum, nickel base, possibly at most 30 wt. % cobalt, 10 wt. % tungsten, 10 wt. molybdenum 7 wt. niobium, 7 wt. tantalum, 2.5 wt. hafnium, 7 wt. iron and boron, zirconium and cerium individually or in combination with each other not more than 0.5% by weight, the solder to additive weight ratio being in the range of 1:10 to 10%.