EP1979501B1 - Iron-nickel alloy - Google Patents

Abstract

Disclosed is a creep-resistant low-expansion iron-nickel alloy that is provided with increased mechanical resistance and contains 40 to 43 wt. % of Ni, a maximum of 0.1 wt. % of C, 2.0 to 3.5 wt. % of Ti, 0.1 to 1.5 wt. % of Al, 0.1 to 1.0 wt. % of Nb, 0.005 to 0.8 wt. % of Mn, 0.005 to 0.6 wt. % of Si, a maximum of 0.5 wt. % of Co, the remainder being composed of Fe and production-related impurities. Said alloy has a mean coefficient of thermal expansion <5×10<−6>/K in the temperature range of 20 to 200 DEG C.

Description

The invention relates to the use of a creep-resistant and low-expansion iron-nickel alloy with higher mechanical strength.

Increasingly, components for safety-related products, such as in aircraft, made of carbon fiber reinforced plastics (CFRP) produced. For the production of such components, large-sized frame supports are required as tool moldings, with hitherto low-expansion iron-nickel alloys having about 36% nickel (Ni36) being processed.

Although the alloys used to date have a coefficient of thermal expansion below 2.0 × 10 ^-6 / K, their mechanical properties are considered too low.

By the US 5,688,471 A is a high-strength alloy with a coefficient of expansion of the highest 4.9 x 10 ^-6 m / m / ° C at 204 ° C has become known, which is composed of (in% by mass) 40.5 to 48% Ni, 2 to 3, 7% Nb, 0.75 to 2% Ti, not more than 3.7% total content of Nb + Ta, 0 to 1% Al, 0 to 0.1% C, 0 to 1% Mn, 0 to 1% Si, 0 to 1% Cu, 0 to 1% Cr, 0 to 5% Co, 0 to 0.01% B, 0 to 2% W, 0 to 2% V, 0 to 0.01 total content of Mg + Ca + Ce, 0 to 0.5% Y and rare earths, 0 to 0.1% S, 0 to 0.1% P, 0 to 0.1% N and residual iron and minor impurities. The alloy is intended to be used to make molds for low expansion coefficient composites, eg, carbon fiber composites, or to make electronic strips, thermoset leadframes, or screen mask masks.

Of the JP 04180542 A1 is a high-strength, low-expansion alloy, of the following composition (in% by mass): ≤ 0.2% C, ≤ 2.0% Si, ≤ 2.0% Mn, 35-50% Ni, ≤ 12% Cr, 0, 2 - 1.0% Al, 0.5-2.0% Ti, 2.0-6.0% Nb, balance Fe. If necessary, the following elements may be provided ≤ 0.02% B and / or ≤ 0.2% Zr. The alloy can be used, among other things, for metal molds for precision flat glass production.

The WO 01/07673 A1 discloses a creep-resistant and low-expansion iron-nickel alloy, which (in mass%) in addition to max. 0.2 C, max. 0.3% Mn and max. 0.3% Si has an Al content of 0.05 to 3.0%, a Ti content of 0.1 to 3.0%, ≤ 1.0 Nb and a Ni content of 39.0 to 45, 0%, the remainder iron and production-related admixtures, which in the temperature range of 20 to 100 ° C has a thermal expansion coefficient <6.0 x 10 ^-6 / K. This iron-nickel alloy can be used for passive components of thermo-bimetals, components for the production, storage and transport of liquefied gases, components in laser technology, leadframes, metal glass melts, frame parts of screen or shadow masks and components of electron guns, especially in television tubes , be used.

$$0\%\le \mathrm{Co}\le 5\%$$

$$0\%\le \mathrm{Cu}\le 3\%$$

$$1,5\%\le \mathrm{Ti}\le 3,5\%$$

$$0,05\%\le \mathrm{Al}\le 1\%$$

$$\mathrm{C}\le 0,05\%$$

$$\mathrm{Si}\le 0,5\%$$

$$\mathrm{Mn}\le 0,5\%$$

$$\mathrm{S}\le 0,01\%$$

$$\mathrm{P}\le 0,02\%$$

Rest Eisen und herstellungsbedingte Verunreinigungen.In the EP 1 063 304 A1 For example, there is described a flat screen CRT apparatus comprising a shadow mask support frame and a shadow mask mounted on the support frame so as to be live at ambient temperature. The support frame consists of a hardened iron-nickel alloy with a thermal expansion coefficient in the temperature range of 20 to 150 ° C <5 x 10 ^-6 / K. The same applies to the shadow mask, which should have a similar coefficient of thermal expansion in the temperature range mentioned. The iron-nickel alloy has the following composition (in% by mass): $$40.5\%\le \mathrm{Ni}+\mathrm{Co}+\mathrm{Cu}\le 44.5\%$$

$$0\%\le \mathrm{Co}\le 5\%$$

$$0\%\le \mathrm{Cu}\le 3\%$$

$$1.5\%\le \mathrm{Ti}\le 3.5\%$$

$$0.05\%\le \mathrm{al}\le 1\%$$

$$\mathrm{C}\le 0.05\%$$

$$\mathrm{Si}\le 0.5\%$$

$$\mathrm{Mn}\le 0.5\%$$

$$\mathrm{S}\le 0.01\%$$

$$\mathrm{P}\le 0.02\%$$

Remaining iron and manufacturing impurities.

By the JP 10310845 A1 For example, a high-strength alloy with a low coefficient of thermal expansion has become known which has the following composition (in% by mass): ≦ 0.15 C, ≦ 0.5 Si, ≦ 0.5% Mn, 0.5 to 4% Ti and 0 , 2% Al, 30.7 to 43.0% Ni, ≤ 14% Co. If necessary, at least one of the elements V, W, Nb and Mo ≤ 1.0% and at least one of the elements S, Pb, Ca and SE ≤ 0.5%. The rest is formed by iron.

In addition to a low coefficient of thermal expansion, mold makers in aircraft construction, in particular, would like an improved alloy which should have a higher mechanical strength compared to Ni36.

The invention is therefore based on the object to find a new application for an Fe-Ni alloy, wherein the alloy should also have a higher mechanical strength in addition to a low thermal expansion coefficient.

This object is achieved by the use of a creep-resistant and low-expansion iron-nickel alloy with higher mechanical strength, with (in% by mass) Ni 40 to 43% C Max. 0.1% Ti 2.0 to 3.5% al 0.1 to 1.5% Nb 0.1 to 1.0% Mn 0.005 to 0.8% Si 0.005 to 0.6% Co Max. 0.5% Cr Max. 0.1% Not a word Max. 0.1% Cu Max. 0.1% mg Max. 0.005% B Max. 0.005% N Max. 0.006% O Max. 0.003% S Max. 0.005% P Max. 0.008% Ca Max. 0.005%. Remainder Fe and production-related admixtures,
in the temperature range of 20 to 200 ° C has a mean thermal expansion coefficient <5 x 10 ^-6 / K in the CFRP mold.

This object is alternatively achieved by the use of a creep-resistant and low-expansion iron-nickel alloy with higher mechanical strength, with (in% by mass) Ni 37 to 41% C Max. 0.1% Ti 2.0 to 3.5% al 0.1 to 1.5% Nb 0.1 to 1.0% Mn 0.005 to 0.8% Si 0.005 to 0.6% Co 2.5 to 5.5% Cr Max. 0.1% Not a word Max. 0.1% Cu Max. 0.1% mg Max. 0.005% B Max. 0.005% N Max. 0.006% O Max. 0.003% S Max. 0.005% P Max. 0.008% Ca Max. 0.005% Remainder Fe and production-related admixtures,
the following condition is sufficient
Ni + ½ Co> 38 to <43.5%, wherein the alloy in the temperature range of 20 to 200 ° C has a mean thermal expansion coefficient <4 x 10 ^-6 / K in the CFRP mold.

Advantageous developments of the alternative, on the one hand, cobalt-free and, on the other hand, cobalt-containing use can be found in the associated subclaims.

The alloy can be provided for similar applications, on the one hand cobalt-free and on the other hand with additions of defined cobalt contents. Alloys with cobalt are characterized by even lower coefficients of thermal expansion, but have the disadvantage that they are associated with an increased cost factor compared to cobalt-free alloys.

Compared with previously used alloys based on Ni 36, the invention can meet the wishes of the mold makers, in particular in aircraft construction, for a low coefficient of thermal expansion which is acceptable for the application, with simultaneously higher mechanical strength.

If the alloy is to be cobalt-free, it advantageously has the following composition (in% by mass) Ni 40.5 to 42% C 0.001 to 0.05% Ti 2.0 to 3.0% al 0.1 to 0.8% Nb 0.1 to 0.6% Mn 0.005 to 0.1% Si 0.005 to 0.1% Co Max. 0.1% Remainder Fe and production-related admixtures,
in the temperature range of 20 to 200 ° C has a coefficient of thermal expansion <4.5 x 10 ^-6 / K.

Depending on the application, the contents of said alloying elements to achieve thermal expansion coefficients <4.0 x 10 ^-6 / K, in particular <3.5 x 10 ^-6 / K, in their contents can be further limited. Such an alloy is characterized by the following composition (in% by mass): Ni 41 to 42% C 0.001 to 0.02% Ti 2.0 to 2.5% al 0.1 to 0.45% Nb 0.1 to 0.45% Mn 0.005 to 0.05% Si 0.005 to 0.05% Co Max. 0.05% Remaining Fe and production-related admixtures.

The following table shows the rather unwanted accompanying elements with their maximum contents (in mass%): Cr Max. 0.1% Not a word Max. 0.1% Cu Max. 0.1% mg Max. 0.005% B Max. 0.005% N Max. 0.006% O Max. 0.003% S Max. 0.005% P Max. 0.008% Ca Max. 0.005%.

die im Temperaturbereich von 20 bis 200°C einen mittleren Wärmeausdehnungskoeffizienten < 3,5 x 10^-6/K aufweist.If an alloy with cobalt is to be used for the mold construction, it can be composed of the same (in mass%) according to a further aspect of the invention: Ni 37.5 to 40.5% C Max. 0.1% Ti 2.0 to 3.0% al 0.1 to 0.8% Nb 0.1 to 0.6% Mn 0.005 to 0.1% Si 0.005 to 0.1% Co > 3.5 to <5.5% Remainder Fe and production-related admixtures,
the following condition is sufficient $$\mathrm{Ni}+\mathrm{½\; co}>38\mathrm{to}<43\%.$$

in the temperature range of 20 to 200 ° C has a mean thermal expansion coefficient <3.5 x 10 ^-6 / K.

die im Temperaturbereich von 20 bis 200°C einen mittleren Wärmeausdehnungskoeffizienten < 3,5 x 10^-6/K aufweist.Another alloy has the following composition (in% by mass): Ni 38.0 to 39.5% C 0.001 to 0.05% Ti 2.0 to 3.0% al 0.1 to 0.8% Nb 0.1 to 0.6% Mn 0.005 to 0.1% Si 0.005 to 0.1% Co > 4 to <5.5% Remaining Fe and production-related admixtures, the following condition is sufficient $$\mathrm{Ni}+\mathrm{½\; co}>38.5\mathrm{to}<43\%.$$

in the temperature range of 20 to 200 ° C has a mean thermal expansion coefficient <3.5 x 10 ^-6 / K.

For special applications, in particular for reducing the coefficient of thermal expansion in ranges <3.2 x 10 ^-6 / K, in particular <3.0 x 10 ^-6 / K, individual contents of the elements can be further restricted as follows (in% by mass): Ni 38.0 to 39.0% C 0.001 to 0.02% Ti 2.0 to 2.5% al 0.1 to 0.45% Nb 0.1 to 0.45% Mn 0.005 to 0.05% Si 0.005 to 0.5% Co > 4 to <5.5% Residual Fe and production-related admixtures satisfying the following condition $$\mathrm{Ni}+\mathrm{½\; co}>40\mathrm{to}<42\%\mathrm{,}$$

For the cobalt-containing alloys, the accompanying elements should not exceed the following max. Contents (in% by mass): Cr Max. 0.1% Not a word Max. 0.1% Cu Max. 0.1% mg Max. 0.005% B Max. 0.005% N Max. 0.006% O Max. 0.003% S Max. 0.005% P Max. 0.008% Ca Max. 0.005%.

Both the cobalt-free and the cobalt-containing alloy should be used in CFRP mold making, in the form of sheet metal, strip or pipe material.

Also conceivable is the use of the alloy as a wire, in particular as a welding filler material, for connecting the semi-finished products forming the mold.

Particularly advantageously, the alloy should be used as a molded part for the production of CFRP aircraft parts, such as wings, fuselages or tail units.

It is also conceivable to use the alloy only for those parts of the mold which are subjected to high mechanical loading. The less loaded parts are then carried out in an alloy having a thermal expansion behavior, which is adapted to the material to be used.

Advantageously, the molds are machined out as milled parts from thermoformed (forged or rolled) or cast solid material and subsequently annealed as needed.

In the following, preferred alloys are compared in terms of their mechanical properties with a prior art alloy.

The following Table 1 shows the chemical composition of two investigated cobalt-free laboratory melts in comparison to two prior art alloys Pernifer 36. Table 1 alloy Pernifer 36 MoSo2 Pernifer 36 Pernifer 40 Ti HS Pernifer 41 Ti HS LB-Charge 151292 50576 1018 1019 Element (%) Cr 0.20% 0.03 12:01 12:01 Ni 36.31 36.07 40.65 41.55 Mn 0.12 0.31 12:01 12:01 Si 0.12 0.07 12:01 12:01 Not a word 0.61 0.06 12:01 12:01 Ti <0.01 <0.01 2.29 2:34 Nb 0.08 <0.01 12:38 12:39 Cu 0.03 0.03 12:01 12:03 Fe rest rest R 56.24 R 55.31 al 0.02 <0.01 12:35 12:31 mg 0.0016 <0.001 0.0005 0.0005 Co 0.02 0.02 12:01 12:01 B 0.0005 0.0005 C 0003 0003 N 0002 0002 Zr 0003 0002 O 0004 S 0002 0002 P 0002 0002 Ca 0,003 0.0003 0.0005 0.0005

Table 2 compares cobalt-containing laboratory melts with a prior art Pernifer 36 alloy. Table 2 alloy Pernifer 36 Pernifer 37 TiCo HS Pernifer 39 TiCo HS Pernifer 40 TiCo HS Pernifer 37 TihCo HS Pernifer 39 TihCo HS Pernifer 40 TihCo HS LB-Charge 50576 1020 1021 1022 1023 1024 1025 Element (%) Cr 0.20% 12:01 0.1 12:01 12:01 12:01 12:01 Ni 36.31 37.28 38.48 40.54 37.01 38.54 40.15 Mn 0.12 12:01 12:01 12:01 12:01 12:01 12:01 Si 0.12 12:01 12:01 12:01 12:01 12:01 12:01 Not a word 0.61 12:01 12:01 12:01 12:01 12:01 12:01 Ti <0.01 2:33 2.31 2.28 2:41 2:36 2:39 Nb 0.08 12:37 12:37 12:37 12:43 12:42 12:43 Cu 0.03 12:01 12:01 12:01 12:01 12:01 12:01 Fe rest R 55.55 R 54.38 R 52.35 R 54.63 R 53.18 R 51.57 al 0.02 12:29 12:28 12:27 12:29 12:29 12:28 mg 0.0016 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 Co 0.02 4.10 4.10 4.11 5.15 15:13 5.10 B 0.0005 0.0005 0.0006 0.0005 0.0006 0.0006 C 0002 0002 0002 0003 0003 0002 N 0002 0002 0002 0002 0002 0002 Zr 0002 0005 0006 0004 0006 0005 O 0004 0004 0004 0003 0005 0005 S 0002 0002 0002 0002 0002 0002 P 0002 0002 0002 0002 0002 Ca 0,003 0005 0.0005 0.0005 0.0006 0.0006 0.0006

The laboratory melts LB1018 to LB1025 were melted and cast in the block. The blocks were hot rolled to 12 mm plate thickness. One half each of the blocks was left at 12 mm and solution annealed. The second half was further rolled to 5.1 mm.

Tables 3 / 3a and 4 / 4a show the mechanical properties on the one hand of the two and on the other hand the six laboratory batches compared to the two Pemifer comparison batches at room temperature.

According to Table 3 / 3a, measured values were cold-rolled and solution annealed on cold-rolled material with a thickness of 4.1 to 4.2 mm in the states. The respective samples were cold rolled, starting from the hot rolled state, which were hot rolled from the 12 mm thick sheets. Table 3 - Mechanical properties (cobalt-free alloys) Rolled condition charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 715 801 11 100 LB 1019 Pernifer 41 Ti HS 743 813 11 101 151292 Pernifer 36 Mo So 2 693 730 12 95 50576 Pernifer 36 558 592 13 90 Solution annealed 1140 ° C / 3min charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 394 640 40 82 LB 1019 Pernifer 41 Ti HS 366 619 40 85 151292 Pernifer 36 Mo So 2 327 542 38 79 50576 Pernifer 36 255 433 38 66 Rolled condition charge alloy Rp0.2
(MPa) rm
(MPa) A50 (%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 762 819 11 100 LB 1021 Pernifer 39 TiCo HS 801 813 12 98 LB 1022 Pernifer 40 TiCo HS 782 801 13 98 LB 1023 Pernifer 37 TihCo HS 719 790 12 98 LB 1024 Pernifer 39 TihCo HS 727 801 13 99 LB 1025 Pernifer 40 TihCo HS 706 781 15 97 151292 Pernifer 36 Mo So 2 693 730 12 95 50576 Pernifer 36 558 592 13 90 Solution annealed 1140 ° C / 3min charge alloy Rp0.2
(MPa) rm
(MPa) A50 (%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 439 660 38 84 LB 1021 Pernifer 39 TiCo HS 415 645 37 85 LB 1022 Pernifer 40 TiCo HS 401 655 42 83 LB 1023 Pernifer 37 TihCo HS 453 675 36 87 LB 1024 Pernifer 39 TihCo HS 437 667 37 83 LB 1025 Pernifer 40 TihCo HS 436 680 41 81 151292 Pernifer 36 Mo So 2 327 542 38 79 50576 Pernifer 36 255 433 38 66

According to Table 4 / 4a, the mechanical properties of the two or six laboratory batches compared to Pernifer 36 are shown at room temperature in the solution-annealed and cured state and in the only cured state. Measurements were taken on cold-rolled samples of thickness 4.1 to 4.2 mm rolled in the states and solution annealed. The samples were cold rolled starting from hot rolled material, which was hot rolled from the 12 mm thick sheets. Table 4: Mechanical properties at room temperature (cobalt-free alloys) Hardened 732 ° C / 1h charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 1205 1299 3 113 LB 1019 Pernifer 41 Ti HS 1197 1286 2 112 151292 Pernifer 36 Mo So 2 510 640 23 91 50576 Pernifer 36 269 453 40 73 Solution annealed + hardened
1140 ° C / 3min + 732 ° C / 1h charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 896 1135 12 110 LB 1019 Pernifer 41 Ti HS 901 1125 10 112 151292 Pernifer 36 Mo So 2 319 539 38 77 50576 Pernifer 36 242 427 43 65 Hardened 732 ° C / 1h charge alloy Rp0.2
(MPa) rm
(MPa) A50 (%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 1182 1304 4 114 LB 1021 Pernifer 39 TiCo HS 1144 1257 3 111 LB 1022 Pernifer 40 TiCo HS 1185 1290 3 111 LB 1023 Pernifer 37 TihCo HS 1183 1308 6 112 LB 1024 Pernifer 39 TihCo HS 1147 1248 4 111 LB 1025 Pernifer 40 TihCo HS 1173 1277 3 114 151292 Pernifer 36 Mo So 2 510 640 23 91 50576 Pernifer 36 269 453 40 73 Solution annealed + hardened
1140 ° C / 3min + 732 ° C / 1h charge alloy Rp0.2
(MPa) rm
(MPa) A50 (%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 986 1180 12 111 LB 1021 Pernifer 39 TiCo HS 946 1148 9 112 LB 1022 Pernifer 40 TiCo HS 899 1133 11 111 LB 1023 Pernifer 37 TihCo HS 980 1183 11 111 LB 1024 Pernifer 39 TihCo HS 946 1155 9 110 LB 1025 Pernifer 40 TihCo HS 911 1148 11 111 151292 Pernifer 36 Mo So 2 319 539 38 77 50576 Pernifer 36 242 427 43 65

Table 5 / 5a shows the mechanical properties of the two or six laboratory batches compared to Pernifer 36 at room temperature in the solution annealed (1140 ° C / 3min) and cured state (732 ° C / 6h, top; 600 ° C / 16h) ., below). Measurements were taken on cold-rolled samples of thickness 4.1 to 4.2 mm rolled in the states and solution annealed. The samples were cold rolled starting from hot rolled material, which was hot rolled from the 12 mm thick sheets. Table 5: Mechanical properties at room temperature (cobalt-free alloys) Solution annealed + hardened
1140 ° C / 3min + 732 ° C / 6h / OK charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 926 1152 12 111 LB 1019 Pernifer 41 Ti HS 929 1142 12 112 151292 Pernifer 36 Mo So 2 326 542 37 76 50576 Pernifer 36 260 441 38 66 Solution annealed + hardened
1140 ° C / 3min + 600 ° C / 16h charge alloy R _p0.2 (MPa) R _m (MPa) A ₅₀ (%) hardness
HRB LB 1018 Pernifer 40 Ti HS 815 1007 20 105 LB 1019 Pernifer 41 Ti HS 814 1031 18 106 151292 Pernifer 36 Mo So 2 330 544 36 78 50576 Pernifer 36 257 442 37 66 Solution annealed + hardened
1140 ° C / 3min + 732 ° C / 6h / OK charge alloy Rp0.2
(MPa) rm
(MPa) A50
(%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 949 1164 14 112 LB 1021 Pernifer 39 TiCo HS 921 1141 13 110 LB 1022 Pernifer 40 TiCo HS 916 1142 14 111 LB 1023 Pernifer 37 TihCo HS 950 1179 14 111 LB 1024 Pernifer 39 TihCo HS 927 1157 13 110 LB 1025 Pernifer 40 TihCo HS 930 1151 12 111 151292 Pernifer 36 Mo So 2 326 542 37 76 50576 Pernifer 36 260 441 38 66 Solution annealed + hardened
1140 ° C / 3min + 600 ° C / 16h charge alloy Rp0.2
(MPa) rm
(MPa) A50
(%) hardness
HRB LB 1020 Pernifer 37 TiCo HS 905 1068 16 107 LB 1021 Pernifer 39 TiCo HS 915 1075 13 107 LB 1022 Pernifer 40 TiCo HS 871 1065 14 107 LB 1023 Pernifer 37 TihCo HS 983 1125 13 107 LB 1024 Pernifer 39 TihCo HS 939 1096 14 107 LB 1025 Pernifer 40 TihCo HS 884 1060 15 105 151292 Pernifer 36 Mo So 2 330 544 36 78 50576 Pernifer 36 257 442 37 66

A)

warm gewalztes 12 mm dickes Blech, lösungsgeglüht

B)

warm gewalztes 12 mm dickes Blech, lösungsgeglüht und 1 Stunde bei 732°C ausgehärtet

C,D,E,F)

an 5 mm warm gewalzt (ausgehend vom 12 mm Blech), kalt an 4,15 mm gewalzt.

C)

ausgehärtet bei 732°C/1 Std.

D)

lösungsgeglüht, 1140°C/3 min. und ausgehärtet 732°C/1 Std.

E)

lösungsgeglüht, 1140°C/3 min. und ausgehärtet 732°C/6 Std.

F)

lösungsgeglüht, 1140°C/3 min. und ausgehärtet 600°C/16 Std.

Tabelle 6 Probe 12mm 12mm 4,15m 4,15m 4,15m 4,15 Zustand A B C D E F Legierung Charge Pernifer 40 Ti HS LB 1018 3,19 2,72 3,45 3,55 3,18 4,26 Pernifer 41 Ti HS LB 1019 3,48 3,11 3,01 2,98 3,63 3,43 Pernifer 36 Mo So 2 151292 1,6 1,97 1,98 2,03 2,13 Pernifer 36 50576 1,2 1,43 1,44 1,5 1,23 Tabelle 6a Probe 12mm 12mm 4,15m 4,15m 4,15m 4,15 Zustand A B C D E F Legierung Charge Pernifer 37 TiCo HS LB 1020 2,90 3,00 2,83 3,33 3,04 3,59 Pernifer 39 TiCo HS LB 1021 3,33 2,73 2,52 2,87 2,63 2,89 Pernifer 40 TiCo HS LB 1022 4,81 3,48 3,28 3,53 3,48 3,31 Pernifer 37 TihCo HS LB 1023 3,15 2,50 2,42 3,09 2,68 3,22 Pernifer 39 TihCo HS LB 1024 3,91 2,93 2,61 3,24 2,87 2,71 Pernifer 40 TihCo HS LB 1025 5,04 3,64 3,46 3,59 3,77 3,48 Pernifer 36 Mo So 2 151292 1,6 1,97 1,98 2,03 2,13 Pernifer 36 50576 1,2 1,43 1,44 1,5 1,23 Table 6 / 6a shows average coefficients of thermal expansion (20 to 200 ° C) in 10 ^-6 / K) of the two and six laboratory batches compared to Pernifer 36 in different states:

A)

hot-rolled 12 mm thick sheet, solution treated

B)

hot-rolled 12 mm thick sheet, solution-treated and cured at 732 ° C for 1 hour

C, D, E, F)

Hot rolled to 5 mm (starting from the 12 mm sheet), cold rolled to 4.15 mm.

C)

Hardened at 732 ° C / 1 hr.

D)

solution annealed, 1140 ° C / 3 min. and cured 732 ° C / 1 hr.

e)

solution annealed, 1140 ° C / 3 min. and cured 732 ° C / 6 hours

F)

solution annealed, 1140 ° C / 3 min. and cured at 600 ° C / 16 hrs.

Table 6 sample 12mm 12mm 4,15m 4,15m 4,15m 4.15 Status A B C D e F alloy charge Pernifer 40 Ti HS LB 1018 3.19 2.72 3.45 3.55 3.18 4.26 Pernifer 41 Ti HS LB 1019 3.48 3.11 3.01 2.98 3.63 3.43 Pernifer 36 Mo So 2 151292 1.6 1.97 1.98 2.03 2.13 Pernifer 36 50576 1.2 1.43 1.44 1.5 1.23 sample 12mm 12mm 4,15m 4,15m 4,15m 4.15 Status A B C D e F alloy charge Pernifer 37 TiCo HS LB 1020 2.90 3.00 2.83 3.33 3.04 3.59 Pernifer 39 TiCo HS LB 1021 3.33 2.73 2.52 2.87 2.63 2.89 Pernifer 40 TiCo HS LB 1022 4.81 3.48 3.28 3.53 3.48 3.31 Pernifer 37 TihCo HS LB 1023 3.15 2.50 2.42 3.09 2.68 3.22 Pernifer 39 TihCo HS LB 1024 3.91 2.93 2.61 3.24 2.87 2.71 Pernifer 40 TihCo HS LB 1025 5.04 3.64 3.46 3.59 3.77 3.48 Pernifer 36 Mo So 2 151292 1.6 1.97 1.98 2.03 2.13 Pernifer 36 50576 1.2 1.43 1.44 1.5 1.23

discussion of the results A cobalt-free alloys

In the cold rolled state (Table 3, top), the yield strength R _p0.2 in the case of the LB batches is between 715 and 743 MPa. The tensile strength R _m is between 801 and 813 MPa. The elongation values A ₅₀ are 11%, the hardnesses HRB between 100 and 101.

In contrast, in the case of Pernifer 36 Mo So 2, the mechanical strength values are lower (R _p0.2 = 693 MPa, R _m = 730 MPa) and significantly lower for Pernifer 36 (R _p0.2 = 558 MPa, R _m = 592%). ,

In the solution-annealed condition (Table 3, bottom), the values of the yield strength are between 366 and 394 MPa in the case of LB batches, the tensile strengths R _m are between 619 and 640 MPa. Correspondingly higher are the elongation values or lower the hardness values. The strength of Pernifer 36 Mo So 2 is lower in the solution- _annealed state (R _p0.2 = 327 MPa, R _m = 542 MPa) and that of Pernifer 36 is significantly lower (R _p0.2 = 255 MPa, R _m = 433 MPa) ,

The highest strength values are achieved when the LB batches are cured eg at 732 ° C./1 h in the previously rolled state (ie without prior solution annealing) (Table 4, top). In this case, the LB batches reach values of the yield strength R _p0.2 of 1197 to 1205 MPa and for the tensile strength R _m values between 1286 and 1299 MPa. The expansion values are then only at 2 to 3%. The hardness HRB increases to values of 111 to 113. In the same rolling and annealing state, the alloys Pernifer 36 Mo So 2 and Pernifer 36 have significantly lower strength _values (R _{p 0.2} = 510 MPa or 269 MPa, R _m = 640 MPa) or 453 MPa).

Since the solution-annealed state is suitable for sheet-forming, the mechanical properties in the solution-annealed + cured state are relevant. In Tab. 4, below the corresponding values for a heat treatment of 1140 ° C / 3min + 732 ° C / 1h are listed. In this case, the LB batches reach values of yield strength R _p0.2 of 896 to 901 MPa and tensile strengths R _m between 1125 and 1135 MPa. In this annealing condition, the alloys Pernifer 36 Mo So 2 and Pernifer 36 have significantly lower strength values.

An extension of the annealing time to 6 h of the hardening heat treatment at 732 ° C. changes the strength values (see Table 5, above) to areas R _p0.2 of _926-929 MPa and tensile strengths R _m between 1142 and 1152 MPa. Again, the comparative alloys have significantly lower strength values.

The lowering of the annealing temperature to 600 ° C. of the hardening heat treatment with an annealing time of 16 h generally reduces the strength values more clearly in the LB batches, in particular in the case of the tensile strength R _m (see Table 5, bottom).

Table 6 shows the values of the mean thermal expansion coefficient CTE (20-100 ° C) for the investigated alloys in the considered states.

The chemical composition influences the Curie temperature and thus the break point temperature, above which the thermal expansion curve increases more steeply.

illustration 1 shows expansion coefficients (CTE) 20-100 ° C and 20-200 ° C of LB batches in Condition B (see Table 6), ie hot rolled 12mm sheet, solution annealed + 1h cured at 732 ° C, depending on Ni Content of the laboratory melt.

The charge LB 1018 with a Ni content of 40.65% has a lower coefficient of expansion than the batch LB 1019 with a Ni content of 41.55%. A test melt with even lower Ni content (Ni: 39.5%, Ti: 2.28%, Nb: 0.37%, Fe: balance, Al: 0.32%) showed that the optimum was about 41% nickel is reached. For the coefficient of thermal expansion between 20 ° C and 200 ° C, the optimum shifts to slightly higher Ni content (~41.5%).

B Cobalt-containing alloys

In the rolled state (Table 3a, top), the yield strength R _p0.2 in the case of the LB batches is between 706 and 801 MPa. The lowest value is the batch LB 1025, the highest value is the batch LB 1021. The tensile strength R _m is between 730 and 819 MPa (lowest value for LB 1025, highest value for LB 1020). The elongation values A ₅₀ range between 11 and 15%, the hardnesses HRB between 97 and 100.

In contrast, in the case of Pernifer 36 Mo So 2, the mechanical strength values are lower (Rp _0.2 = 693 MPa, R _m = 730 MPa) and significantly lower for Pernifer 36 (R _p0.2 = 558 MPa, R _m = 592 MPa) ,

In the solution-annealed condition (Table 3a, bottom), the values of the yield strength lie between 401 and 453 MPa in the case of LB batches, and the tensile strengths R _m are between 645 and 680 MPa. Correspondingly higher are the elongation values or lower the hardness values. The strength of Pernifer 36 Mo So 2 is lower in the solution- _annealed state (R _p0.2 = 327 MPa, R _m = 542 MPa) and that of Pernifer 36 is significantly lower (R _p0.2 = 255 MPa, R _m = 433 MPa) ,

The highest strength values can be achieved if the LB batches z. B. at 732 ° C / 1h in the previously rolled state (ie without previous solution annealing) are cured (Table 4a, above). In this case, the LB batches reach values of the yield strength R _p0.2 of 1144 to 1185 MPa and for the tensile strength R _m values between 1248 and 1308 MPa. The expansion values are then only at 3 to 6%. The hardness HRB increases to values of 111 to 114. In the same rolling and annealing state, the alloys Pernifer 36 Mo So 2 and Pernifer 36 have significantly lower strength _values (R _{p 0.2} = 510 MPa or 269 MPa, R _m = 640 MPa) or 453 MPa).

Since the solution-annealed state is suitable for sheet-forming, the mechanical properties in the solution-annealed + cured state are relevant. In Tab. 4a, below, the corresponding values for a heat treatment of 1140 ° C / 3min + 732 ° C / 1h are listed. In this case, the LB batches reach values of yield strength R _p0.2 of 899 to 986 MPa and tensile strengths R _{m of} between 1133 and 1183 MPa. In this annealing condition, the alloys Pernifer 36 Mo So 2 and Pernifer 36 have significantly lower strength values.

An extension of the annealing time to 6 h of the hardening heat treatment at 732 ° C. changes the strength values (see Table 5a, above) in such a way that values of the yield strength R _p0.2 between 916 and 950 MPa and tensile strengths R _m between 1142 and 1179 MPa are reached become.

The lowering of the annealing temperature to 600 ° C. of the hardening heat treatment with an annealing time of 16 h generally reduces the strength values more clearly in the LB batches, in particular in the case of the tensile strength R _m (see Table 5a, bottom).

Table 6a shows the values of the mean thermal expansion coefficient CTE (20-100 ° C) for the tested alloys in the considered states. Good values are shown by e.g. LB1021 u. LB1023.

The chemical composition influences the Curie temperature and thus the break point temperature, above which the thermal expansion curve increases more steeply.

In Figures 2 and 3, the coefficients of expansion are 20 - 100 ° C ( Fig. 2 ) and 20-200 ° C ( Fig. 3 ) of the 6 LB batches in the series with Co contents 4.1% and 5.1% in state B (see Table 6a), ie hot-rolled 12 mm sheet, solution-treated + 1 h at 732 ° C hardened, in Dependence on Ni content of the laboratory melt shown.

In the 4.1% Co series, a minimum expansion coefficient in the T range between 20 and 100 ° C is found at about 38.5% Ni, in the T range 20-200 ° C at 39.5% Ni. In the case of the 5.1% Co series, the coefficient of expansion for the three LB lots investigated decreases with decreasing Ni content.

In particular, the T-range 20-200 ° C is interesting for use in mold making, since the curing of the CFRP takes place at about 200 ° C. The differences in the coefficient of thermal expansion between the 4% Co and 5% Co-containing alloys is so small that, for reasons of cost, the alloys with the higher co-content can not be justified.

Claims (13)

1. A use of a creep-resistant and low-expansive iron-nickel alloy having a higher mechanical stability and comprising (in % by mass) Ni 40 to 43 % C max. 0.1 % Ti 2.0 to 3.5 % Al 0.1 to 1.5 % Nb 0.1 to 1.0 % Mn 0.005 to 0.8 % Si 0.005 to 0.6 % Co max. 0.5 % Cr max. 0.1 % Mo max. 0.1 % Cu max. 0.1 % Mg max. 0.005 % B max. 0.005 % N max. 0.006 % O max. 0.003 % S max. 0.005 % P max. 0.008 % Ca max. 0.005 % the rest being Fe and admixtures due to manufacturing,
   which comprises an average coefficient of thermal expansion of < 5 x 10^-6/K in the temperature range comprised between 20 and 200°C in carbon fiber reinforced plastic mould making.
2. A use of a creep-resistant and low-expansive iron-nickel alloy having a higher mechanical stability and comprising (in % by mass) Ni 37 to 41 % C max. 0.1 % Ti 2.0 to 3.5 % Al 0.1 to 1.5 % Nb 0.1 to 1.0 % Mn 0.005 to 0.8 % Si 0.005 to 0.6 % Co 2.5 to 5.5 % Cr max. 0.1 % Mo max. 0.1 % Cu max. 0.1 % Mg max. 0.005 % B max. 0.005 % N max. 0.006 % O max. 0.003 % S max. 0.005 % P max. 0.008 % Ca max. 0.005 % the rest being Fe and admixtures due to manufacturing,
   which meets the following condition $$\mathrm{Ni}+\mathrm{½\; Co}>38\mathrm{to}<43.5\%,$$

   

   
   wherein the alloy comprises an average coefficient of thermal expansion of < 4 x 10^-6/K in the temperature range comprised between 20 and 200°C in carbon fiber reinforced plastic mould making.
3. A use according to claim 1, comprising (in % by mass) Ni 40.5 to 42 % C 0.001 to 0.05 % Ti 2.0 to 3.0 % Al 0.1 to 0.8 % Nb 0.1 to 0.6 % Mn 0.005 to 0.1 % Si 0.005 to 0.1 % Co max. 0.1 % the rest being Fe and admixtures due to manufacturing,
   which comprises an average coefficient of thermal expansion of < 4.5 x 10^-6/K in the temperature range comprised between 20 and 200°C.
4. A use according to claim 3, comprising (in % by mass) Ni 41 to 42 % C 0.001 to 0.02 % Ti 2.0 to 2.5 % Al 0.1 to 0.45 % Nb 0.1 to 0.45 % Mn 0.005 to 0.05 % Si 0.005 to 0.05 % Co max. 0.05 % the rest being Fe and admixtures due to manufacturing,
   which comprises an average coefficient of thermal expansion of < 4.0 x 10^-6/K, in particular of < 3.5 x 10^-6/K in the temperature range comprised between 20 and 200°C.
5. A use according to claim 2, comprising (in % by mass) Ni 37.5 to 40.5 % C max. 0.1 % Ti 2.0 to 3.0 % Al 0.1 to 0.8 % Nb 0.1 to 0.6 % Mn 0.005 to 0.1 % Si 0.005 to 0.1 % Co > 3.5 to < 5.5 % the rest being Fe and admixtures due to manufacturing,
   which meets the following condition $$\mathrm{Ni}+\mathrm{½\; Co}>38\mathrm{to}<43\%,$$

   

   
   which comprises an average coefficient of thermal expansion of < 3.5 x 10^-6/K in the temperature range comprised between 20 and 200°C.
6. A use according to claim 5, comprising (in % by mass) Ni 38.0 to 39.5 % C 0.001 to 0.05 % Ti 2.0 to 3.0 % Al 0.1 to 0.7 % Nb 0.1 to 0.6 % Mn 0.005 to 0.1 % Si 0.005 to 0.1 % Co > 4.0 to < 5.5 % the rest being Fe and admixtures due to manufacturing,
   which meets the following condition $$\mathrm{Ni}+\mathrm{½\; Co}>38.5\mathrm{to}<43.0\%,$$

   

   
   which comprises an average coefficient of thermal expansion of < 3.5 x 10^-6/K in the temperature range comprised between 20 and 200°C.
7. A use according to claim 5 or 6, comprising (in % by mass) Ni 38.0 to 39.0 % C 0.001 to 0.02 % Ti 2.0 to 2.5 % Al 0.1 to 0.45 % Nb 0.1 to 0.45 % Mn 0.005 to 0.05 % Si 0.005 to 0.05 % Co > 4.0 to < 5.5 % the rest being Fe and admixtures due to manufacturing,
   which meets the following condition $$\mathrm{Ni}+\mathrm{½\; Co}>40.0\mathrm{to}<42.0\%,$$

   

   
   which comprises an average coefficient of thermal expansion of < 3.2 x 10^-6/K, in particular of < 3.0 x 10^-6/K in the temperature range comprised between 20 and 200°C.
8. A use according to one of the claims 1 through 7, wherein large sized semifinished products in form of sheet metal, strip or tube material will be used.
9. A use according to one of the claims 1 through 7, wherein wire, in particular in the form of weld filler will be used.
10. A use according to one of the claims 1 through 7 as mould component for manufacturing aircraft parts made of carbon fiber reinforced plastic.
11. A use according to one of the claims 1 through 7, wherein only those parts of the mould will be made of this alloy which are subject to a high mechanical stress.
12. A use according to one of the claims 1 through 7 as forged pieces.
13. A use according to one of the claims 1 through 7 as cast components.

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