DE1103594B - High temperature and long-term stable alloy - Google Patents

Description

GERMAN

The invention relates to a high-temperature and long-term stable nickel-chromium alloy with aluminum and titanium content, which is particularly suitable for the manufacture of turbine blades for gas turbines is, and represents an improvement and further development of the alloy according to patent application G8036VIa / 40b.

The main patent application discloses a highly heat-resistant and permanently stable nickel-chromium alloy with aluminum and titanium content, which is characterized by the following composition:

0.0 until 0.25%, preferably 0.10 until O ', 20%, Carbon, 1.5 until 3.0% Titanium, 0.0 until 1.0%, preferably 0.0 until 0.25%, Manganese, 1.0 until 4.0%, preferably 2.0 until 4.0%, Aluminum, 0.0 until 1.0%, preferably 0.0 until 0.75%, Silicon, 0.01 until 0.50%, preferably 0.01 until 0.10%, Boron, 13th until 17% Chrome, 8th until 12% Iron, 4th until 6% Molybdenum, rest Nickel.

According to the invention, the iron content of such an alloy is 0.1 to less than 8.0% degraded. It has been found that by reducing the iron content to half its the value given in the main patent application is the creep strength of the alloy obtained is increased by a third.

A restriction of the boron content, which is 0.01 to 0.15%, also acts in this direction.

In certain applications, the carbon can be completely absent, while the carbon content for other uses is up to 0.25%. The silicon and manganese content can be a maximum up to 1% each and the aluminum content can be reduced to 1%.

The invention makes a further advance in the development of high temperature and long-term stable Alloys achieved in which additives of sparing materials, such as. B. cobalt, tungsten and tantalum plus niobium, can be avoided, but on the other hand the heat resistance is significantly increased without having to accept special restrictions in the manufacturing method.

The following are examples of alloys typical of the invention, with results of the

High temperature and long-term stable alloy

Addendum to patent application G 8036 VI / 40 b (Auslegeschrift 1 093 995)

Applicant:

General Motors Corporation, Detroit, Mich. (V. St. A.)

Representative: Dr. W. Muller-Bore

and Dipl.-Ing. H. Gralfs, patent attorneys,

Braunschweig, Am Bürgerpark 8

Claimed priority:
V. St. v. America June 28, 1954

Dean Kneale Hanink, Birmingham, Mich.,

and Fred John Webbere, Pontiac, Mich. (V. St. A.),

have been named as inventors

Tests carried out on these alloys are described.

Example I.

The test pieces were manufactured by precision molding and consisted of the following alloy:

0.18% carbon,
0.10% manganese,
0.60% silicon,
15.5%. Chrome,

Molybdenum,

Iron,

Aluminum,

Titanium,

5.0%
0.5%
3.0%
2.0%
0.075% boron,
Remainder nickel.

The test pieces were exposed to a static tensile load of 19.7 kg / mm ^{2 at a temperature of 870 ° C.} Under these test conditions, it took an average of 86 hours to tear the specimen. The average percent rotation of the specimen at break was 10.4.

Example II

The test pieces were manufactured by precision molding and had a composition as in

109 538/473

Example I, except that the iron content was 4.5%. A test piece of this composition was subjected to a static tensile load of 19.7 kg / mm ^{2 at a temperature of 870 ° C.} Under these test conditions, it took 100 hours to tear the cast test piece. At break, the test piece had a percentage elongation of 13.4. Another test piece with this composition was ^{tempered for 1 hour at a temperature of 1150 °} C. and cooled in air. This tempered test specimen was subjected to a static tensile load of 19.7 kg / mm ^{2 at a temperature of 870 ° C.} Under these test conditions, it took 155 hours for the test item to break. The percent elongation was 13.2.

Example III

The test pieces were manufactured by precision molding and had the following composition:

0.12% carbon, ^ao

0.12% manganese,
0.57% silicon,
14.9% chromium,
5.03% molybdenum,

4.80% iron,

2.39% aluminum,
2.16% titanium,
0.056% boron,

Remainder nickel.

30th

Some of these test pieces were subjected to a static tensile load of 24.6 kg / mm ^{2 at 815 ° C.} Under these test conditions, the average time to breakage of the test specimens was 104 hours. The average percent elongation was 16.2. Another test piece of this composition was subjected to a tensile load of 14.6 kg / mm ^{2 at 925 ° C.} Under these test conditions, it took 17.2 hours for the test piece to break. At break, the test specimen had a percentage elongation of 19.8.

Alloys according to the present invention can be used in any desired within the specified range Wise put together or coordinated. Any melting furnace can be used. Typical examples of melting furnaces which have been used for this purpose are Indirect arc melting furnaces and induction melting furnaces. When melting are preferred Protective gases used. It is also advantageous to use protective gas when pouring the material into the Shapes to use. As a molding material, it is expedient to use the usual one for high-melting alloys to use.

Claims (6)

55 claims: 1. Highly heat-resistant and long-term stable nickel-chromium alloy with aluminum and titanium content according to patent application G 8036 VI a / 40b, characterized by the following composition: 0.0 to 0.25% carbon, 0.0 to 1.00% manganese, 0.0 to 1.00% silicon, 13.0 to 17.00% chromium, 4.0 to 6.00% molybdenum, 60 1.50 to 3.00% titanium, 1.0 to 4.00% aluminum, 0.01 to 0.15% boron, 0.1 to less than 8.0% iron, Remainder nickel. 2. Alloy according to claim 1, characterized by the following composition: 0.10 to 0.20% carbon, maximum 0.25% manganese, maximum 0.75% silicon, 13.00 to 17.00% chromium, 4.00 to 6.00% molybdenum, 1.5 to 3.00% titanium, 2.00 to 4.00% aluminum, 0.01 to 0.15% boron, 0.1 to less than 8.00% iron, Remainder nickel. 3. Alloy according to claim 1, characterized by the following composition: 0.18% carbon, 0.10% manganese, 0.60% silicon, 15.5% chromium, 5.0% molybdenum, 0.5% iron, 3.00% aluminum, 2.00% titanium, 0.075% boron, the balance nickel. 4. Alloy according to claim 1, characterized by the following composition: 0.18% carbon, 0.10% manganese, 0.60% silicon, 15.5% chromium, 5.0% molybdenum, 4.5%. Iron, 3.00% aluminum, 2.00% titanium, 0.075% boron, balance nickel. 5. Alloy according to claim 1, characterized by the following composition: 0.12% carbon, 0.12% manganese, 0.57% silicon, 14.9% chromium, 5.03% molybdenum, 4.80% iron, 2.39% aluminum, 2.16% titanium, 0.056% boron, balance nickel. 6. Use of alloys according to one of claims 1 to 5 for the production of turbine blades for gas turbines. Considered publications: Swiss patent specifications No. 267 448, 003; French Patent No. 932,273; British Patent Nos. 583 807, 607 616. © 109 538/473 3.