DE102015008322A1 - Process for producing a nickel-iron-chromium-aluminum wrought alloy with an increased elongation in the tensile test - Google Patents

Abstract

Method for producing a nickel-iron-chromium-aluminum alloy with (in wt .-%) 12 to 40% chromium, 0 to 4.0% aluminum, 0.01 to 75.0% iron, 0.001 to 3.0 % Silicon, 0.001 to 4.0% manganese, 0.0 to 1.0% titanium, 0.0001 to 0.05% each magnesium and / or calcium, 0.005 to 0.25% carbon, 0.0005 to 0.050% Nitrogen, max. 0.020% oxygen, max. 0.030% phosphorus, max. 0.010% sulfur, optionally 0 to 4% niobium, optionally 0 to 30% molybdenum, optionally 0-30% tungsten, optionally between 0.0 to 15.0% cobalt, optionally between 0 and 0.008% boron, balance nickel and the usual process-related contamination, a) by means of melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant or by melting in the vacuum induction furnace (VIM) b) and then subsequently purified by electroslag remelting (ESC), optionally also in addition is cleaned with VAR, wherein the electroslag remelting, optionally also VAR, an increased elongation in the tensile test in the temperature range of 500 to 900 ° C is achieved, resulting in a reduction of the sensitivity to stress relaxation cracks (SRC) in this temperature range.

Description

The invention relates to a method for producing a nickel-iron-chromium-aluminum wrought alloy with an increased elongation in the tensile test in the temperature range from 500 to 900 ° C.

In the chemical process industry, temperatures between 500 ° C and 900 ° C are often used. In this case, components, in particular thick-walled components, can fail in many austenitic alloys by Stress Relaxation Cracking (SRC). This usually occurs within one to two years, but longer periods are possible ( Hans van Wortel, Control of Relaxation Cracking austenitic high Temperature Components, paper no. 07423, Corrosion 2007 ). SRC is known z. For example, for iron alloys such as AISI 304H, AISI 316H, AISI 347, 1.4910, Alloy 800H and for nickel alloys such as Alloy 617 or Alloy 601, in particular in the welded state or after cold-forming. SRC can occur after relaxation deformations of less than 0.1%. Methods have been developed to control it, such as: B. by a stabilizing heat treatment after welding or before or after cold forming of base material at temperatures of about 980 ° C for several hours. The exact treatment is alloy-dependent (see, for example, Hans van Wortel, Control of Relaxation Cracking austenitic high Temperature Components, paper no. 07423, Corrosion 2007 ) or developments have been made to achieve a lower sensitivity for SRC in terms of alloying technology (see, for example, US Pat. Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6176 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 ).

A cold deformation introduced during the processing of the semifinished product, or stresses arising during welding, cause an increased dislocation density. In the temperature range from 500 ° C to 900 ° C, in particular from 550 to 750 ° C, very fine carbides separate from it. By means of a stabilizing heat treatment, at high temperatures, a large proportion of these carbides is precipitated in coarser form in the grain and on the grain boundaries, so that only a significantly smaller proportion is eliminated when used in the critical temperature range. In this state, an SRC sensitive alloy component can then sustain relaxation strains of more than 2% without cracking.

Among the alloying measures, mention should be made in particular of the addition of boron to Alloy 617, as described in US Pat. Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 617B for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 - Is described.

In summary, SRC is a problem of creep ductility. Materials with a large Kriechduktilität in the corresponding temperature range from 500 ° C to 900 ° C do not show this phenomenon.

• – Die Risse sind immer auf den Korngrenzen und vor den Rissspitzen bilden sich Poren.
• – Die Risse sind in der Wärmeeinflusszone, im Schweißgut oder in kaltumgeformten Bereichen.
• – Die Risse treten nur in Bereichen mit einer Vickershärte größer 200 HV auf.
• – SRC tritt meistens zwischen 550°C und 750°C auf.
• – Bei einigen Legierungen zeigen sich metallische Filme auf den Korngrenzen, die in eine chromreiche Oxidschicht eingeschlossen sind (Insbesondere bei hoch oxidationsbeständigen Nickel Legierungen wie Alloy 617 tritt dieses Phänomen aber nicht auf).

SRC looks like this:

• - The cracks are always on the grain boundaries and in front of the crack tips form pores.
• - The cracks are in the heat-affected zone, in the weld metal or in cold-formed areas.
• - The cracks occur only in areas with a Vickers hardness greater than 200 HV.
• - SRC usually occurs between 550 ° C and 750 ° C.
• - In some alloys, metallic films are present on the grain boundaries encased in a chromium-rich oxide layer (but this phenomenon does not occur in high-oxidation-resistant nickel alloys such as Alloy 617).

The phenomenon of the SRC is not yet fully understood. The fact that the cracks only occur at hardnesses higher than 200 HV shows that in particular alloys that cure during use, ie. H. have a high heat resistance are at risk, such as the already mentioned alloys Alloy 800, Alloy 617 Alloy 601 or Alloy 602 CA (composition see Table 1) The hot strength or creep strength in the temperature range above 500 ° C u. a. improved by a high carbon content, such as. B. Alloy 800, Alloy 617, Alloy 45, Alloy 602CA and Alloy 603. But also high levels of solid solution strengthening elements such as chromium, aluminum, silicon, molybdenum and tungsten improve the heat resistance such. For example, Alloy 617 and Alloy 696. In the range of 500 ° C to 900 ° C, additions of aluminum, titanium, and / or niobium can improve strength by excreting the γ 'and / or γ' 'phase. Examples are Alloy 800, Alloy 617 Alloy 601, Alloy 693, Alloy 602CA or Alloy 603. The analyzes of these prior art examples are listed in Table 1.

Other potentially endangered alloy compositions are z. As described in:
In DE 10 2012 011 161 A1 is a nickel-chromium-aluminum-iron alloy with (in wt .-%) 24 to 33% chromium, 1.8 to 4.0% aluminum, 0.10 to 7.0% iron, 0.001 to 0.50 % Silicon, 0.005 to 2.0% manganese, 0.00 0.60% titanium, 0.0002 to 0.05% magnesium and / or calcium, 0.005 to 0.12% carbon, 0.001 to 0.050% nitrogen, 0.0001-0.020% oxygen, 0.001 to 0.030% phosphorus, Max. 0.010% sulfur, max. 2.0% molybdenum, max. 2.0% tungsten, balance nickel and the usual process-related impurities, wherein the following relationships must be satisfied: Cr + Al ≥ 28 (2a) and Fp ≦ 39.9 (3a) with Fp = Cr + 0.272 * Fe + 2, 36 * Al + 2.22 * Si + 2.48 * Ti + 0.374 * Mo + 0.538 * W - 11.8 * C (4a) where Cr, Fe, Al, Si, Ti, Mo, W and C are the Concentration of the elements in mass%.

By the DE 600 04 737 T2 For example, a heat-resistant nickel-based alloy has been known, including ≤ 0.1% C, 0.01-2% Si, ≤ 2% Mn, ≤ 0.005% S, 10-25% Cr, 2.1- <4.5% Al, ≤ 0.055% N, in total 0.001-1% of at least one of the elements B, Zr, Hf, wherein said elements may be present in the following contents: B ≤ 0.03%, Zr ≤ 0.2%, Hf <0.8 %. Mo 0.01-15%, W 0.01-9%, where a total Mo + W content of 2.5-15% may be given, Ti 0-3%, Mg 0-0.01%, Ca 0- 0.01%, Fe 0-10%, Nb 0-1%, V 0-1%, Y 0-0.1%, La 0-0.1%, Ce 0-0.01%, Nd 0- 0.1%, Cu 0-5%, Co 0-5%, remainder nickel. For Mo and W the following formula must be fulfilled: 2.5 ≤ Mo + W ≤ 15 (1)

The object underlying the invention is, in addition to the method described in the introduction, to reduce the risk of SRC find another method that significantly reduces the sensitivity to SRC in nickel-iron-chromium-aluminum alloys.

• a) mittels Erschmelzung in einem Induktions- oder Lichtbogenofen gefolgt von einer Behandlung in einer VOD- oder VLF-Anlage oder mittels Erschmelzung im Vakuuminduktionsofen (VIM)
• b) und die dann anschließend mittels Elektroschlackeumschmelzen (ESU) gereinigt wird, wahlweise auch zusätzlich mit VAR gereinigt wird,

wobei durch die Elektroschlackeumschmelzung, wahlweise auch VAR, eine erhöhte Dehnung im Zugversuch im Temperaturbereich von 500 bis 900°C erreicht wird, was zu einer Verringerung der Empfindlichkeit gegen Spannungsrelaxationsrisse (SRC) in diesem Temperaturbereich führt.This object is achieved by a method for producing a nickel-iron-chromium-aluminum alloy with (in wt .-%) 12 to 40% chromium, 0 to 4.0% aluminum, 0.01 to 75.0% iron , 0.001 to 3.0% silicon, 0.001 to 4.0% manganese, 0.0 to 1.0% titanium, each 0.0001 to 0.05% magnesium and / or calcium, 0.005 to 0.25% carbon, 0.0005 to 0.050% nitrogen, max. 0.020% oxygen, max. 0.030% phosphorus, max. 0.010% sulfur, optionally 0 to 4% niobium, optionally 0 to 30% molybdenum, optionally 0-30% tungsten, optionally between 0.0 to 15.0% cobalt, optionally between 0 and 0.008% boron, balance nickel and the usual process-related impurities,

• a) by melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant or by melting in a vacuum induction furnace (VIM)
• b) and which is then subsequently cleaned by means of electroslag remelting (ESC), optionally also additionally cleaned with VAR,

wherein the electroslag remelting, optionally also VAR, achieves an increased elongation in the tensile test in the temperature range from 500 to 900 ° C., which leads to a reduction in the sensitivity to stress relaxation cracks (SRC) in this temperature range.

Advantageous developments of the subject invention can be found in the associated dependent claims.

Process for producing a nickel-iron-chromium-aluminum alloy

• a) by melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant or medium melting in a vacuum induction furnace (VIM)
• b) and which is then subsequently cleaned by means of electroslag remelting (ESC), optionally also additionally with VAR whereby an increased elongation in the tensile test in the temperature range from 500 to 900 ° C. is achieved by the electroslag remelting, optionally also VAR, which leads to a reduction of the sensitivity to stress relaxation cracks (SRC) in this temperature range, the temperature range preferably being:
• -> 500 to <900 ° C
• -> 500 or ≥ 500 to <850 or ≤ 850 ° C
• -> 500 or ≥ 500 to <800 or ≤ 800 ° C
• -> 500 or ≥ 500 to <750 or ≤ 750 ° C
• -> 550 or ≥ 550 to <750 or ≤ 750 ° C

Process for producing a nickel-iron-chromium-aluminum alloy

• a) by melting in an induction or electric arc furnace open followed by a treatment in a VOD or VLF plant or medium melting in the vacuum induction furnace (VIM) and which is then poured into blocks, electrodes or as a continuous casting to form a precursor.

• – > 500 bis < 900°C
• – > 500 oder ≥ 500 bis < 850 oder ≤ 850°C
• – > 500 oder ≥ 500 bis < 800 oder ≤ 800°C
• – > 550 oder ≥ 500 bis < 750 oder ≤ 750°C
• – > 550 oder ≥ 550 bis < 750 oder ≤ 750°C

A process for producing a nickel-iron-chromium-aluminum alloy, which has a Vickers hardness greater than or equal to 200 HV after cooling to room temperature after use in the temperature range of 500 to 900 ° C. This temperature range is preferably included

• -> 500 to <900 ° C
• -> 500 or ≥ 500 to <850 or ≤ 850 ° C
• -> 500 or ≥ 500 to <800 or ≤ 800 ° C
• -> 550 or ≥ 500 to <750 or ≤ 750 ° C
• -> 550 or ≥ 550 to <750 or ≤ 750 ° C

After remelting, the alloy is annealed in the desired semifinished product, where appropriate, at temperatures between 900 ° C and 1270 ° C for 0.1 h to 70 h, then hot formed, optionally with intermediate annealing between 900 ° C and 1270 ° C for 0 , 05h to 70h. The surface of the material may optionally (also several times) be removed chemically and / or mechanically in between and / or at the end for cleaning. After the end of the hot forming, if necessary, a cold forming with degrees of deformation up to 98% in the desired semi-finished strip, sheet metal, rod wire, longitudinally welded tube and seamless tube, possibly with intermediate annealing between 700 ° C and 1250 ° C for 0.1 min 70 h, possibly under inert gas, such. As argon or hydrogen, followed by cooling in air, carried out in the moving annealing atmosphere or in a water bath. Thereafter, a solution annealing in the temperature range of 700 ° C to 1250 ° C for 0.1 min to 70 h, optionally under inert gas, such as. As argon or hydrogen, followed by cooling in air, in the moving annealing atmosphere or in a water bath instead. Possibly. In between and / or after the last annealing chemical and / or mechanical cleaning of the material surface can take place.

The semifinished products strip, sheet, rod wire, longitudinally welded tube and seamless tube are produced with a mean grain size of 5 microns to 600 microns. The preferred range is between 20 μm and 200 μm.

The semifinished products thus produced can be subjected to a stabilizing annealing between 880 ° C. and 1000 ° C. for times of 1 to 24 h. Preferably you can be subjected to an annealing between 920 ° C and 990 ° C.

Preferred times are between 1 and 5 hours, or between 1 and 3 hours.

• – > 12 bis < 40%
• – > 15 oder ≥ 15 bis < 35 oder ≤ 35%
• – > 18 oder ≥ 18 bis < 33 oder ≤ 33%
• – > 20 oder ≥ 20 bis < 33 oder ≤ 33%
• – > 22 oder ≥ 22 bis < 33 oder ≤ 33%
• – > 24 oder ≥ 24 bis < 33 oder ≤ 33%
• – > 25 oder ≥ 25 bis < 33 oder ≤ 33%
• – > 26 oder ≥ 26 bis < 33 oder ≤ 33% > 27 oder ≥ 27 bis < 32 oder ≤ 32%
• – > 28 oder ≥ 28 bis < 32 oder ≤ 32%
• – > 29 oder ≥ 29 bis < 31 oder ≤ 31%

The spreading range for the element chromium is between 12 and 40% for the alloy produced by the process according to the invention, it being possible to set preferred ranges as follows:

• -> 12 to <40%
• -> 15 or ≥ 15 to <35 or ≤ 35%
• -> 18 or ≥ 18 to <33 or ≤ 33%
• -> 20 or ≥ 20 to <33 or ≤ 33%
• -> 22 or ≥ 22 to <33 or ≤ 33%
• -> 24 or ≥ 24 to <33 or ≤ 33%
• -> 25 or ≥ 25 to <33 or ≤ 33%
• -> 26 or ≥ 26 to <33 or ≤ 33%> 27 or ≥ 27 to <32 or ≤ 32%
• -> 28 or ≥ 28 to <32 or ≤ 32%
• -> 29 or ≥ 29 to <31 or ≤ 31%

• – > 0 bis < 4,0% > 0,001 oder ≥ 0,001 bis < 4,0 oder ≤ 4,0% > 0,005 oder ≥ 0,005 bis < 3,2 oder ≤ 3,2% > 0,01 oder ≥ 0,01 bis < 3,0 oder ≤ 3,0% > 0,05 oder ≥ 0,05 bis < 2,8 oder ≤ 2,8% > 0,10 oder ≥ 0,10 bis < 2,6 oder ≤ 2,6% > 0,20 oder ≥ 0,20 bis < 2,6 oder ≤ 2,6%
• – > 0,50 oder ≥ 0,50 bis < 2,5 oder ≤ 2,5% > 0,80 oder ≥ 0,80 bis < 2,6 oder ≤ 2,6% > 1,0 oder ≥ 1,0 bis < 2,6 oder ≤ 2,6% > 1,2 oder ≥ 1,2 bis < 2,6 oder ≤ 2,6% > 1,5 oder ≥ 1,5 bis < 2,6 oder ≤ 2,6% > 1,8 oder ≥ 1,8 bis < 4,0 oder ≤ 4,0% > 1,8 oder ≥ 1,8 bis < 3,2 oder ≤ 3,2%
• – > 2,0 oder ≥ 2,0 bis < 3,2 oder ≤ 3,2%
• – > 2,0 oder ≥ 2,0 bis < 3,0 oder ≤ 3,0% > 2,0 oder ≥ 2,0 bis < 2,8 oder ≤ 2,8% > 2,2 oder ≥ 2,2 bis < 2,8 oder ≤ 2,8%
• – > 2,2 oder ≥ 2,2 bis < 2,6 oder ≤ 2,6%

The aluminum content is between 0 and 4.0%, whereby here too, depending on the area of use of the alloy, preferred aluminum contents can be set as follows:

• -> 0 to <4.0%> 0.001 or ≥ 0.001 to <4.0 or ≤ 4.0%> 0.005 or ≥ 0.005 to <3.2 or ≤ 3.2%> 0.01 or ≥ 0.01 to <3.0 or ≤ 3.0%> 0.05 or ≥ 0.05 to <2.8 or ≤ 2.8%> 0.10 or ≥ 0.10 to <2.6 or ≤ 2.6 % > 0.20 or ≥ 0.20 to <2.6 or ≤ 2.6%
• -> 0.50 or ≥ 0.50 to <2.5 or ≤ 2.5%> 0.80 or ≥ 0.80 to <2.6 or ≤ 2.6%> 1.0 or ≥ 1.0 to <2.6 or ≤ 2.6%> 1.2 or ≥ 1.2 to <2.6 or ≤ 2.6%> 1.5 or ≥ 1.5 to <2.6 or ≤ 2.6 %> 1.8 or ≥ 1.8 to <4.0 or ≤ 4.0%> 1.8 or ≥ 1.8 to <3.2 or ≤ 3.2%
• -> 2.0 or ≥ 2.0 to <3.2 or ≤ 3.2%
• -> 2.0 or ≥ 2.0 to <3.0 or ≤ 3.0%> 2.0 or ≥ 2.0 to <2.8 or ≤ 2.8%> 2.2 or ≥ 2.2 up to <2.8 or ≤ 2.8%
• -> 2.2 or ≥ 2.2 to <2.6 or ≤ 2.6%

• – > 0,1 oder ≥ 0,1 bis < 4,0 oder ≤ 4,0%
• – > 0,1 oder ≥ 0,1 bis < 3,0 oder ≤ 3,0%
• – > 0,1 oder ≥ 0,1 bis < 2, 5 oder ≤ 2, 5%
• – > 0,1 oder ≥ 0,1 bis < 2,0 oder ≤ 2,0%
• – > 0,1 oder ≥ 0,1 bis < 1,0 oder ≤ 1,0%

The iron content is between 0.01 and 75%, whereby, depending on the field of application, preferred contents can be set within the following spreading ranges:
> 0.01 to <75.0%
> 0.01 or ≥ 0.01 to <70.0 or ≤ 70.0%
> 0.01 or ≥ 0.01 to <65.0 or ≤ 65.0%
> 0.01 or ≥ 0.01 to <60.0 or ≤ 60.0%
> 0.01 or ≥ 0.01 to <55.0 or ≤ 55.0%
> 0.01 or ≥ 0.01 to <50.0 or ≤ 50.0%
> 0.01 or ≥ 0.01 to <45.0 or ≤ 45.0%
> 0.01 or ≥ 0.01 to <40.0 or ≤ 40.0%
> 0.01 or ≥ 0.01 to <35.0 or ≤ 35.0%
> 0.01 or ≥ 0.01 to <30.0 or ≤ 30.0%
> 0.01 or ≥ 0.01 to <25.0 or ≤ 25.0
> 0.01 or ≥ 0.01 to <20.0 or ≤ 20.0%
> 0.01 or ≥ 0.01 to <15.0 or ≤ 15.0%
> 0.01 or ≥ 0.01 to <12.0 or ≤ 12.0%
> 0.01 or ≥ 0.01 to <10.0 or ≤ 10.0%
> 0.1 or ≥ 0.1 to <7.0 or ≤ 7.0%

• -> 0.1 or ≥ 0.1 to <4.0 or ≤ 4.0%
• -> 0.1 or ≥ 0.1 to <3.0 or ≤ 3.0%
• -> 0.1 or ≥ 0.1 to <2, 5 or ≤ 2, 5%
• -> 0.1 or ≥ 0.1 to <2.0 or ≤ 2.0%
• -> 0.1 or ≥ 0.1 to <1.0 or ≤ 1.0%

• – > 0,001 – < 3,0%
• – > 0,001 oder ≥ 0,001 bis < 2,50 oder ≤ 2,50%
• – > 0,001 oder ≥ 0,001 bis < 2,0 oder ≤ 2,0%
• – > 0,001 oder ≥ 0,001 bis < 1,50 oder ≤ 1,50%
• – > 0,001 oder ≥ 0,001 bis < 1,0 oder ≤ 1,0%
• – > 0,001 oder ≥ 0,001 bis < 0,80 oder ≤ 0,80%
• – > 0,001 oder ≥ 0,001 bis < 0,50 oder ≤ 0,50%
• – > 0,001 oder ≥ 0,001 bis < 0,20 oder ≤ 0,20%
• – > 0,001 oder ≥ 0,001 bis < 0,10 oder ≤ 0,10%
• – > 0,001 oder ≥ 0,001 bis < 0,05 oder ≤ 0,05%

The silicon content is between 0.001 and 3.0%. Preferably, Si can be adjusted within the spreading range in the alloy as follows:

• -> 0.001 - <3.0%
• -> 0.001 or ≥ 0.001 to <2.50 or ≤ 2.50%
• -> 0.001 or ≥ 0.001 to <2.0 or ≤ 2.0%
• -> 0.001 or ≥ 0.001 to <1.50 or ≤ 1.50%
• -> 0.001 or ≥ 0.001 to <1.0 or ≤ 1.0%
• -> 0.001 or ≥ 0.001 to <0.80 or ≤ 0.80%
• -> 0.001 or ≥ 0.001 to <0.50 or ≤ 0.50%
• -> 0.001 or ≥ 0.001 to <0.20 or ≤ 0.20%
• -> 0.001 or ≥ 0.001 to <0.10 or ≤ 0.10%
• -> 0.001 or ≥ 0.001 to <0.05 or ≤ 0.05%

• – > 0,001 – < 4,00% > 0,001 oder ≥ 0,001 bis < 3,00 oder ≤ 3,00%
• – > 0,001 oder ≥ 0,001 bis < 2,00 oder ≤ 2,00%
• – > 0,001 oder ≥ 0,001 bis < 1,00 oder ≤ 1,00%
• – > 0,005 oder ≥ 0,005 bis < 0,50 oder ≤ 0,50%
• – > 0,005 oder ≥ 0,005 bis < 0,20 oder ≤ 0,20%
• – > 0,005 oder ≥ 0,005 bis < 0,10 oder ≤ 0,10%
• – > 0,005 oder ≥ 0,005 bis < 0,05 oder ≤ 0,05%

The same applies to the element manganese, which may be present in the alloy at 0.001 to 4.0%. Alternatively, the following spread range is conceivable:

• -> 0.001 - <4.00%> 0.001 or ≥ 0.001 to <3.00 or ≤ 3.00%
• -> 0.001 or ≥ 0.001 to <2.00 or ≤ 2.00%
• -> 0.001 or ≥ 0.001 to <1.00 or ≤ 1.00%
• -> 0.005 or ≥ 0.005 to <0.50 or ≤ 0.50%
• -> 0.005 or ≥ 0.005 to <0.20 or ≤ 0.20%
• -> 0.005 or ≥ 0.005 to <0.10 or ≤ 0.10%
• -> 0.005 or ≥ 0.005 to <0.05 or ≤ 0.05%

• – > 0,001 oder ≥ 0,001 bis < 0,50 oder ≤ 0,50%, > 0,01 oder ≥ 0,01 bis < 0,50 oder ≤ 0,50%,
• – > 0,05 oder ≥ 0,05 bis < 0,50 oder ≤ 0,50%,
• – > 0,10 oder ≥ 0,10 bis < 0,50 oder ≤ 0,50%,
• – > 0,001 oder ≥ 0,001 bis < 0,30 oder ≤ 0,30%,
• – > 0,01 oder ≥ 0,01 bis < 0,30 oder ≤ 0,30%,
• – > 0,01 oder ≥ 0,01 bis < 0,25 oder ≤ 0,25%.

The titanium content is between 0.0 and 1.0%. Preferably, Ti within the spreading range can be adjusted in the alloy as follows:
> 0.0 to <1.0%,
> 0.0 or ≥ 0.0 to <0.80 or ≤ 0.80%,

• -> 0.001 or ≥ 0.001 to <0.50 or ≤ 0.50%,> 0.01 or ≥ 0.01 to <0.50 or ≤ 0.50%,
• -> 0.05 or ≥ 0.05 to <0.50 or ≤ 0.50%,
• -> 0.10 or ≥ 0.10 to <0.50 or ≤ 0.50%,
• -> 0.001 or ≥ 0.001 to <0.30 or ≤ 0.30%,
• -> 0.01 or ≥ 0.01 to <0.30 or ≤ 0.30%,
• -> 0.01 or ≥ 0.01 to <0.25 or ≤ 0.25%.

• – 0,0001–0,03%.
• – 0,0001–0,02%.
• – 0,0002–0,02%.
• – 0,0005–0,02%.

Also magnesium and / or calcium is contained in contents of 0.0001 to 0.05%. It is preferably possible to adjust these elements in the alloy as follows:

• - 0.0001-0.03%.
• - 0.0001-0.02%.
• - 0.0002-0.02%.
• - 0.0005-0.02%.

• – > 0,01 oder ≥ 0,01 bis < 0,10 oder ≤ 0,10%.
• – > 0,015 oder ≥ 0,015 bis < 0,10 oder ≤ 0,10%.

The alloy contains 0.005 to 0.25% carbon. Preferably, this can be set within the spreading range in the alloy as follows:
> 0.005 to <0.25%.
> 0.01 or ≥ 0.01 to <0.20 or ≤ 0.20%.
> 0.01 or ≥ 0.01 to <0.12 or ≤ 0.12%.

• -> 0.01 or ≥ 0.01 to <0.10 or ≤ 0.10%.
• -> 0.015 or ≥ 0.015 to <0.10 or ≤ 0.10%.

• – 0,001–0,050%.
• – 0,003–0,040%.

This applies equally to the element nitrogen, which is contained in contents between 0.0005 and 0.05%. Preferred contents can be given as follows:

• - 0.001-0.050%.
• - 0,003-0,040%.

• – max. 0,020%.

The element phosphor is with max. 0.030% contained in the alloy. Preferred contents can be given as follows:

• - Max. 0.020%.

The element oxygen is with max. 0.020%, contained in the alloy. Preferred contents can be given as follows:
Max. 0.010%.

• – Schwefel max. 0,010%

The element sulfur is given in the alloy as follows:

• - sulfur max. 0.010%

• – > 0,0 bis < 4,0%
• – > 0,0 oder ≥ 0,0 bis < 3,5 oder ≤ 3,5%
• – > 0,0 oder ≥ 0,0 bis < 3,0 oder ≤ 3,0%
• – > 0,0 oder ≥ 0,0 bis < 2,5 oder ≤ 2,5%
• – > 0,0 oder ≥ 0,0 bis < 2,0 oder ≤ 2,0%
• – > 0,0 oder ≥ 0,0 bis < 1,5 oder ≤ 1,5%
• – > 0,001 oder ≥ 0,001 bis < 1,10 oder ≤ 1,10%
• – > 0,001 oder ≥ 0,001 bis < 0,70 oder ≤ 0,70%
• – > 0,001 oder ≥ 0,001 bis < 0,50 oder ≤ 0,50%
• – > 0,001 oder ≥ 0,001 bis < 0,30 oder ≤ 0,30%
• – > 0,01 oder ≥ 0,01 bis < 0,30 oder ≤ 0,30%
• – > 0,10 oder ≥ 0,10 bis < 1,10 oder ≤ 1,10%.

Optionally, the element Nb may be adjusted at levels of 0.0 to 4.0%. Preferably, Nb can be adjusted within the spreading range in the alloy as follows:

• -> 0.0 to <4.0%
• -> 0.0 or ≥ 0.0 to <3.5 or ≤ 3.5%
• -> 0.0 or ≥ 0.0 to <3.0 or ≤ 3.0%
• -> 0.0 or ≥ 0.0 to <2.5 or ≤ 2.5%
• -> 0.0 or ≥ 0.0 to <2.0 or ≤ 2.0%
• -> 0.0 or ≥ 0.0 to <1.5 or ≤ 1.5%
• -> 0.001 or ≥ 0.001 to <1.10 or ≤ 1.10%
• -> 0.001 or ≥ 0.001 to <0.70 or ≤ 0.70%
• -> 0.001 or ≥ 0.001 to <0.50 or ≤ 0.50%
• -> 0.001 or ≥ 0.001 to <0.30 or ≤ 0.30%
• -> 0.01 or ≥ 0.01 to <0.30 or ≤ 0.30%
• -> 0.10 or ≥ 0.10 to <1.10 or ≤ 1.10%.

• – Mo > 0 bis < 30%
• – W > 0 bis < 30%
• – Mo > 0 oder ≥ 0 bis < 25 oder ≤ 25%
• – W > 0 oder ≥ 0 bis < 25 oder ≤ 25%
• – Mo > 0 oder ≥ 0 bis < 20 oder ≤ 20%
• – W > 0 oder ≥ 0 bis < 20 oder ≤ 20%
• – Mo > 0 oder ≥ 0 bis < 15 oder ≤ 15%
• – W > 0 oder ≥ 0 bis < 15 oder ≤ 15%
• – Mo > 0 oder ≥ 0 bis < 10 oder ≤ 10%
• – W > 0 oder ≥ 0 bis < 10 oder ≤ 10%
• – Mo > 0 oder ≥ 0 bis < 5,0 oder ≤ 5,0%
• – W > 0 oder ≥ 0 bis < 5,0 oder ≤ 5,0%
• – Mo > 0 oder ≥ 0 bis < 2,0 oder ≤ 2,0%
• – W > 0 oder ≥ 0 bis < 2,0 oder ≤ 2,0%
• – Mo > 0 oder ≥ 0 bis < 1,0 oder ≤ 1,0%
• – W > 0 oder ≥ 0 bis < 1,0 oder ≤ 1,0%
• – Mo > 0 oder ≥ 0 bis < 0,50 oder ≤ 0,50%
• – W > 0 oder ≥ 0 bis < 0,50 oder ≤ 0,50
• – Mo > 0 oder ≥ 0 bis < 0,05 oder ≤ 0,05%
• – W > 0 oder ≥ 0 bis < 0,05 oder ≤ 0,05%

Molybdenum and tungsten are optionally contained singly or in combination in the alloy each containing 0 to 30%. Preferred contents can be given as follows:

• - Mo> 0 to <30%
• - W> 0 to <30%
• - Mo> 0 or ≥ 0 to <25 or ≤ 25%
• - W> 0 or ≥ 0 to <25 or ≤ 25%
• - Mo> 0 or ≥ 0 to <20 or ≤ 20%
• - W> 0 or ≥ 0 to <20 or ≤ 20%
• - Mo> 0 or ≥ 0 to <15 or ≤ 15%
• - W> 0 or ≥ 0 to <15 or ≤ 15%
• - Mo> 0 or ≥ 0 to <10 or ≤ 10%
• - W> 0 or ≥ 0 to <10 or ≤ 10%
• - Mo> 0 or ≥ 0 to <5.0 or ≤ 5.0%
• - W> 0 or ≥ 0 to <5.0 or ≤ 5.0%
• - Mo> 0 or ≥ 0 to <2.0 or ≤ 2.0%
• - W> 0 or ≥ 0 to <2.0 or ≤ 2.0%
• - Mo> 0 or ≥ 0 to <1.0 or ≤ 1.0%
• - W> 0 or ≥ 0 to <1.0 or ≤ 1.0%
• - Mo> 0 or ≥ 0 to <0.50 or ≤ 0.50%
• - W> 0 or ≥ 0 to <0.50 or ≤ 0.50
• - Mo> 0 or ≥ 0 to <0.05 or ≤ 0.05%
• - W> 0 or ≥ 0 to <0.05 or ≤ 0.05%

• – > 0,0 bis < 1 5,0%
• – > 0,0 oder ≥ 0,0 bis < 13,0 oder ≤ 13,0%
• – > 0,0 oder ≥ 0,0 bis < 10,0 oder ≤ 10,0%
• – > 0,0 oder ≥ 0,0 bis < 5,0 oder ≤ 5,0%
• – > 0,01 oder ≥ 0,01 bis < 5,0 oder ≤ 5,0%
• – > 0,01 oder ≥ 0,01 bis < 2,0 oder ≤ 2,0%
• – > 0,1 oder ≥ 0,1 bis < 2,0 oder ≤ 2,0%
• – > 0,01 oder ≥ 0,01 bis < 0,5 oder ≤ 0,5%.

Furthermore, optionally between 0.0 to 15.0% of cobalt may be contained, which may be further limited as follows:

• -> 0.0 to <1 5.0%
• -> 0.0 or ≥ 0.0 to <13.0 or ≤ 13.0%
• -> 0.0 or ≥ 0.0 to <10.0 or ≤ 10.0%
• -> 0.0 or ≥ 0.0 to <5.0 or ≤ 5.0%
• -> 0.01 or ≥ 0.01 to <5.0 or ≤ 5.0%
• -> 0.01 or ≥ 0.01 to <2.0 or ≤ 2.0%
• -> 0.1 or ≥ 0.1 to <2.0 or ≤ 2.0%
• -> 0.01 or ≥ 0.01 to <0.5 or ≤ 0.5%.

• – Bor 0,0–0,008%

Optionally, the element boron may be included in the alloy as follows:

• - Boron 0.0-0.008%

• – Bor 0,0001–0,008%
• – Bor 0,0005–0,008%
• – Bor 0,0005–0,004%

Preferred contents can be given as follows:

• - Boron 0,0001-0,008%
• - Boron 0,0005-0,008%
• Boron 0.0005-0.004%

• – > 0,0 bis < 5,0%
• – > 0,0 oder ≥ 0,0 bis < 3,0 oder ≤ 3,0%
• – > 0,0 oder ≥ 0,0 bis < 2,5 oder ≤ 2,5%
• – > 0,0 oder ≥ 0,0 bis < 2,0 oder ≤ 2,0%
• – > 0,0 oder ≥ 0,0 bis < 0,5 oder ≤ 0,5%
• – > 0,0 oder ≥ 0,0 bis < 0,15 oder ≤ 0,15%.

Furthermore, optionally between 0.0 to 5.0% copper may be included, which may be further limited as follows:

• -> 0.0 to <5.0%
• -> 0.0 or ≥ 0.0 to <3.0 or ≤ 3.0%
• -> 0.0 or ≥ 0.0 to <2.5 or ≤ 2.5%
• -> 0.0 or ≥ 0.0 to <2.0 or ≤ 2.0%
• -> 0.0 or ≥ 0.0 to <0.5 or ≤ 0.5%
• -> 0.0 or ≥ 0.0 to <0.15 or ≤ 0.15%.

Furthermore, <0.5 or ≤ 0.5% vanadium may be included.

• – > 15%.
• – > 20 oder ≥ 20%.
• – > 24 oder ≥ 24%.
• – > 29 oder ≥ 29%.
• – > 35 oder ≥ 35%.
• – > 40 oder ≥ 40%.
• – > 45 oder ≥ 45%.
• – > 50 oder ≥ 50%.
• – > 55 oder ≥ 55%.
• – > 58 oder ≥ 58%.
• – > 60 oder ≥ 60%.
• – > 65 oder ≥ 65%.
• – > 68 oder ≥ 68%.
• – > 70 oder ≥ 70%.
• – > 75 oder ≥ 75%.

The nickel content should be greater than or equal to 15%. Preferred contents can be given as follows:

• -> 15%.
• -> 20 or ≥ 20%.
• -> 24 or ≥ 24%.
• -> 29 or ≥ 29%.
• -> 35 or ≥ 35%.
• -> 40 or ≥ 40%.
• -> 45 or ≥ 45%.
• -> 50 or ≥ 50%.
• -> 55 or ≥ 55%.
• -> 58 or ≥ 58%.
• -> 60 or ≥ 60%.
• -> 65 or ≥ 65%.
• -> 68 or ≥ 68%.
• -> 70 or ≥ 70%.
• -> 75 or ≥ 75%.

• – 0,01–0,15%
• – 0,01–0,10%
• – 0,01–0,08%
• – 0,01 – < 0,045%.

Optionally, the element yttrium can be adjusted in levels of 0.01 to 0.20%. Preferably, Y can be set within the spread range as follows:

• - 0.01-0.15%
• - 0.01-0.10%
• - 0,01-0,08%
• - 0.01 - <0.045%.

• – 0,001–0,15%
• – 0,001–0,10%
• – 0,001–0,08%
• – 0,001–0,04%.
• – 0,01–0,04%.

Optionally, the element lanthanum can be adjusted in levels of 0.001 to 0.20%. Preferably, La within the spreading range can be set as follows:

• - 0.001-0.15%
• - 0.001-0.10%
• - 0.001-0.08%
• - 0.001-0.04%.
• - 0.01-0.04%.

• – 0,001–0,15%
• – 0,001–0,10%
• – 0,001–0,08%
• – 0,001–0,04%.
• – 0,01–0,04%.

Optionally, the element Ce may be adjusted in amounts of 0.001 to 0.20%. Preferably, Ce can be adjusted within the spread range as follows:

• - 0.001-0.15%
• - 0.001-0.10%
• - 0.001-0.08%
• - 0.001-0.04%.
• - 0.01-0.04%.

• – 0,001–0,15%
• – 0,001–0,10%
• – 0,001–0,08%
• – 0,001–0,04%.
• – 0,01–0,04%.

Optionally, with simultaneous addition of Ce and La, cerium mischmetal may also be used in amounts of from 0.001 to 0.20%. Preferably, cerium mischmetal within the spreading range can be set in the alloy as follows:

• - 0.001-0.15%
• - 0.001-0.10%
• - 0.001-0.08%
• - 0.001-0.04%.
• - 0.01-0.04%.

• – 0,01–0,15%.
• – 0,01 – < 0,10 oder ≤ 0,10%.
• – 0,01–0,07%.
• – 0,01–0,04%.

Optionally, the zirconium content is between 0.01 and 0.20%. Preferably, Zr can be adjusted within the spread range as follows:

• - 0.01-0.15%.
• - 0.01 - <0.10 or ≤ 0.10%.
• - 0.01-0.07%.
• - 0.01-0.04%.

• – 0,01–0,15%.
• – 0,01 – < 0,10 oder ≤ 0,10%.
• – 0,01–0,07%.
• – 0,01–0,04%.

Optionally, in the alloy, the element Hf may be adjusted in amounts of from 0.01 to 0.20%. Preferably, Hf can be set within the spread range as follows:

• - 0.01-0.15%.
• - 0.01 - <0.10 or ≤ 0.10%.
• - 0.01-0.07%.
• - 0.01-0.04%.

Optionally, 0.001 to 0.60% tantalum may be included

Finally, impurities may still contain the elements lead, zinc and tin in amounts as follows:
Pb max. 0.002%
Zn max. 0.002%
Sn max. 0.002%.

The alloy produced by the process according to the invention should preferably be used as a component in the chemical process industry, the petrochemical industry, in power plant construction, in furnace construction and in the construction of solar thermal systems.

Accomplished tests:

• a) Brucheinschnürung: Z < 5% = extreme empfindlich bezgl. SRC
• b) Brucheinschnürung: Z 5–10% = stark empfindlich bezgl. SRC
• c) Brucheinschnürung: Z 10–20% = leichte Empfindlichkeit bezgl. SRC
• d) Brucheinschnürung: Z >> 20% = Nicht merklich empfindlich bezgl. SRC (nach Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6178 for Components in 700°C Power Plants, paper no. 2284, Corrosion 2013 ) Analog kann man ein ähnliches Ranking für A erstellen.

In Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6176 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 It is reported that susceptibility to SRC can also be assessed by slow strain rate testing (SSRT or Constant Strain Rate Tests - CSR) at 10-6 1 / s as this strain rate is in the range of strain rate induced by Creep is determined lies. Where:

• a) Fracture necking: Z <5% = extremely sensitive with respect to SRC
• b) Fracture necking: Z 5-10% = very sensitive with respect to SRC
• c) Fracture necking: Z 10-20% = slight sensitivity with respect to SRC
• d) Fracture necking: Z >> 20% = Not appreciably sensitive with respect to SRC (acc Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6178 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 Similarly one can create a similar ranking for A.

The slow tensile tests were after DIN EN ISO 6892-2 at a rate of 10-6 1 / s at temperatures of 600 to 800 ° C performed. The yield strength R _p0.2 , the tensile strength R _m and the elongation A up to the break and the break constriction Z are determined. The elongation A is determined on the broken sample from the extension of the original measuring section L ₀ : A = (L _U - L ₀ ) / L ₀ 100% = ΔL / L ₀ 100% With L _u = measuring length after the break.

Depending on the measuring length, the elongation at break is provided with indices: For example, for A ₅ the measuring length L ₀ = 5 · d ₀ with d ₀ = initial diameter of a round sample.

The Brucheinschnürung Z (largest relative change in cross section) is determined from the residual cross-sectional area at the constricted point S _U and the output cross section So: Z = (S _{0 -Su} ) / S ₀ 100%

The tests were carried out on round samples with a diameter of 6.7 or 8 mm in the measuring range and a measuring length L of 33.5 or 40 mm. The sampling took place transversely to the forming direction of the semifinished product.

Examples:

production:

On a large scale, two batches of Alloy 601 (156656 and 314975) were melted by melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant. Batch 314975 was then subsequently purified according to the invention by means of electroslag remelting (ESR). Table 2 shows the analyzes that are very similar. Both batches were then between 900 ° C and 1270 ° C annealed for 8 h and hot rolled by hot rolling and further intermediate annealing between 900 ° C and 1270 ° C for 0.1 to 1 h to a final thickness of 13 mm or 6 mm. The sheets produced in this way were solution-annealed between 900 ° C. and 1270 ° C. for 1 h. These plates were used to prepare the samples needed for the measurements.

Batch 156656 had a particle size of 136 μm, batch 314975 had a particle size of 114 μm.

For the example batches in Table 2, slow tensile tests were performed at 600, 700 and 800 ° C.

Figure 1 shows that the yield strength of the ESU molten charge is slightly better. The tensile strength in Figure 2 is approximately the same for both lots.

Figure 3 shows a strong increase in Z and Figure 4 shows a large increase in A for the ESU remelted charge of the present invention as compared to the non-ESU remelted charge. This increase is particularly pronounced at the lowest break constriction at 700 ° C. In this example, Z or A is increased by the remelting by ESC at 700 ° C so that thus Alloy 601 instead of in the range "slight sensitivity to SRC" for the unmelted batch with inventively remelted batch in the range "not noticeable sensitive to SRC ".

Analogously, alloys with a pronounced minimum ductility of 5 to 10% (strongly sensitive to SRC) can then be pushed into the range of slight sensitivity to SRC by remelting by ESC.

figure description

1 : _Yield strength R _p0.2 in the slow tensile test of Alloy 601 with and without ESU.

2 : Tensile strength R _m in the slow tensile test of Alloy 601 with and without ESU.

3 : Fractional Z in the slow tensile test of Alloy 601 with and without ESU.

4 : Elongation A in the slow tensile test of Alloy 601 with and without ESU.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012011161 A1 [0008]
• DE 60004737 T2 [0009]

Cited non-patent literature

• Hans van Wortel, Control of Relaxation Cracking in Austenitic High Temperature Components, paper no. 07423, Corrosion 2007 [0002]
• Hans van Wortel, Control of Relaxation Cracking in Austenitic High Temperature Components, paper no. 07423, Corrosion 2007 [0002]
• Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6176 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 [0002]
• Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 617B for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 [0004]
• Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6176 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 [0047]
• Jutta Klöwer, Juliane Mentz, Manuela Zinke, Development of Crack-Resistant Alloy 6178 for Components at 700 ° C Power Plants, paper no. 2284, Corrosion 2013 [0047]
• DIN EN ISO 6892-2 [0048]

Claims (25)

Method for producing a nickel-iron-chromium-aluminum alloy with (in wt .-%) 12 to 40% chromium, 0 to 4.0% aluminum, 0.01 to 75.0% iron, 0.001 to 3.0 % Silicon, 0.001 to 4.0% manganese, 0.0 to 1.0% titanium, 0.0001 to 0.05% each magnesium and / or calcium, 0.005 to 0.25% carbon, 0.0005 to 0.050% Nitrogen, max. 0.020% oxygen, max. 0.030% phosphorus, max. 0.010% sulfur, optionally 0 to 4% niobium, optionally 0 to 30% molybdenum, optionally 0-30% tungsten, optionally between 0.0 to 15.0% cobalt, optionally between 0 and 0.008% boron, balance nickel and the usual process-related impurities, a) by melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant or by melting in a vacuum induction furnace (VIM) b) and which is then subsequently cleaned by means of electroslag remelting (ESC), optionally also additionally cleaned with VAR, wherein the electroslag remelting, optionally also VAR, achieves an increased elongation in the tensile test in the temperature range from 500 to 900 ° C., which leads to a reduction in the sensitivity to stress relaxation cracks (SRC) in this temperature range. A method according to claim 1, characterized in that in the production of a nickel-iron-chromium-aluminum alloy a) by means of melting in an induction or electric arc furnace followed by treatment in a VOD or VLF plant or medium melting in the vacuum induction furnace (VIM) b ) and which is then subsequently cleaned by means of electroslag remelting (ESC), optionally also additionally cleaned with VAR. c) whereby an increased elongation in the tensile test in the temperature range from 500 to 850.degree. C. is achieved by the electroslag remelting, optionally also VAR, resulting in a Reducing the susceptibility to Stress Relaxation Cracks (SRC) in this temperature range. Method according to one or more of claims 1 to 2, characterized in that from this nickel-iron-chromium-aluminum alloy strip, sheet metal, rod, wire, longitudinally welded tube and seamless tube is produced. Method according to one or more of claims 1 to 3, characterized in that said nickel-iron-chromium-aluminum alloy has a chromium content of 15 to 35%. Method according to one or more of claims 1 to 4, characterized in that said nickel-iron-chromium-aluminum alloy has an aluminum content of 0.001 to 4%. Method according to one or more of claims 1 to 5, characterized in that said nickel-iron-chromium-aluminum alloy has an iron content of 0.01 to 70%. Method according to one or more of claims 1 to 6, characterized in that said nickel-iron-chromium-aluminum alloy has a silicon content of 0.001 to 2.50%. Method according to one or more of claims 1 to 7, characterized in that said nickel-iron-chromium-aluminum alloy has a manganese content of 0.001 to 3.0%. Method according to one or more of claims 1 to 8, characterized in that said nickel-iron-chromium-aluminum alloy has a titanium content of 0.0 to 0.80%. Method according to one or more of claims 1 to 9, characterized in that said nickel-iron-chromium-aluminum alloy has a carbon content of 0.01 to 0.20%. Method according to one or more of claims 1 to 10, characterized in that this nickel-iron-chromium-aluminum alloy optionally has a niobium content of 0.0 to 3.5%. Method according to one or more of claims 1 to 11, characterized in that said nickel-iron-chromium-aluminum alloy has a molybdenum content of 0.0 to 25%. Method according to one or more of claims 1 to 12, characterized in that said nickel-iron-chromium-aluminum alloy has a tungsten content of 0.0 to 25%. Method according to one or more of claims 1 to 13, characterized in that said nickel-iron-chromium-aluminum alloy has a cobalt content of 0.0 to 13%. Method according to one or more of claims 1 to 14, characterized in that said nickel-iron-chromium-aluminum alloy has a boron content of 0.0001 to 0.008%. Method according to one or more of claims 1 to 15, characterized in that said nickel-iron-chromium-aluminum alloy has a copper content of 0.0 to 3.0%. Method according to one or more of claims 1 to 16, characterized in that said nickel-iron-chromium-aluminum alloy has a vanadium content of <0.5 or ≤ 0.5%. Method according to one or more of claims 1 to 17, characterized in that said nickel-iron-chromium-aluminum alloy has a nickel content equal to or greater than 15%. Method according to one or more of claims 1 to 18, characterized in that said nickel-iron-chromium-aluminum alloy has an yttrium content of 0.01 to 0.20%. Method according to one or more of claims 1 to 19, characterized in that said nickel-iron-chromium-aluminum alloy has a lanthanum content of 0.01 to 0.20%. Method according to one or more of claims 1 to 20, characterized in that said nickel-iron-chromium-aluminum alloy has a cerium content of 0.01 to 0.20%. Method according to one or more of claims 1 to 21, characterized in that said nickel-iron-chromium-aluminum alloy has a zirconium content of 0.01 to 0.20%. Method according to one or more of claims 1 to 22, characterized in that said nickel-iron-chromium-aluminum alloy has a hafnium content of 0.01 to 0.20%. Method according to one or more of claims 1 to 23, characterized in that in this nickel-iron-chromium-aluminum alloy, the impurities in contents of max. 0.002% Pb, max. 0.002% Zn, max. 0.002% Sn are set. Use of the alloy produced according to one of claims 1 to 25 as a component in the chemical process industry, the petrochemical industry, in power plant construction, in furnace construction and in the construction of solar thermal systems.

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