KR20020016649A - Iron-nickel alloy with creep resistance and low thermal expansion - Google Patents

Abstract

The present invention is characterized in that it contains 0.2% or less of C, 0.3% or less of Mn and 0.3% or less of Si, 0.05-3.0% by weight of Al, 0.1-3.0% by weight of Ti, 1.0% by weight of Nb and 39.0-45.0% And the remainder being products of irons and blends and having a coefficient of thermal expansion of less than 6.0 x 10 < ^-6 > / K in the temperature range of 20-100 [deg.] C.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a creep-resistant iron nickel alloy having a low thermal expansion rate,

The present invention relates to a creep-resistant iron nickel alloy having a low coefficient of thermal expansion, which is used for manufacturing a frame part for a screen shadow mask in particular.

Iron master alloys containing about 36% nickel are known to have low coefficients of thermal expansion at temperatures of 20-100 < 0 > C. Thus, these alloys have been used for decades in products that require constant length despite temperature variations, such as for example precision instruments, watches, bimetals. The development of computer monitors and color televisions with high resolution even under undesirable lighting conditions and the tendency for the development of increasingly flat and large screens, are increasingly being used with iron nickel materials in shadow masks. Industrial iron nickel alloys containing about 36% nickel soft-annealed at a temperature of 20-100 < 0 > C were prepared using the Stahl-Eisen-Werkstoffblatt (Steel Iron Material Paper) (SEW-385 , Published in 1991) has a thermal expansion coefficient of 1.2 - 1.8x10 ^-6 / K or more. In particular, the shadow mask uses an advanced material containing about 36% nickel with a coefficient of thermal expansion of 0.6-1.2x10 ^-6 / K at a temperature of 20-100 ° C.

There is a demand for a low expansion material having improved creep resistance as compared with alloys used so far for a shadow mask subjected to stress in a frame in advance. Frame parts for shadow mask and shadow sphere mask are subjected to so-called blackening annealing at a temperature of about 580 DEG C or less. At this time, a dark iron oxide layer is produced, so that the visual image quality becomes better.

Iron master alloys containing about 36% of nickel used so far show creep resistance A ₈₀ of about 2.6% under the test condition of 138 MPa loading at 580 ° C for 1 hour.

The initial vertical stress of the shadow mask is created as a vertical frame part. Up to now, iron nickel alloys containing about 41% nickel have been used as materials, and these alloys are known as metal glass seals or lead frame materials. The technical characteristics are as follows: Creep resistance A ₈₀ , measured under the same conditions as described above for a 36% nickel-containing alloy, under the same conditions as 138 MPa loading for 1 hour at 580 ° C., is about 0.5%. According to the coefficient of thermal expansion of about 4.8 x 10 ^-6 / K in the temperature range of 20-100 ° C, the vertical frame component made of this alloy expands more than the shadow mask made of iron nickel alloy containing about 36% nickel.

The horizontal frame part will exhibit the same thermal expansion properties as the shadow mask, so the same iron nickel alloy containing about 36% nickel is used for horizontal frame parts and shadow mask.

As for the shadow mask, it is required that the creep resistance of the frame component material is better at temperatures up to 580 캜 as compared with the alloys used so far. The change in coefficient of expansion with size and temperature will be nearly equivalent to the materials used so far.

It is also known that adding an appropriate additive to the iron nickel alloy can produce a precipitate. Titanium and aluminum, for example, are used together as such additives. The formation of γ (Ni ₃ Ti / Ni ₃ Al) phase obviously increases the yield and strength.

However, if the total content of titanium and aluminum elements is too high, the thermal expansion coefficient may increase too much.

According to DE-C 29 40 532, age-hardening nickel iron cast alloys having a linear expansion coefficient of less than 5 x 10 ^-6 / ° C at 20-300 ° C and an apparent yield point of 350 N / mm ² or greater at 20 ° C are 35-45% Nickel, less than 4% by weight of free titanium, 0-1% by weight of niobium, and 1.5-2.5% by weight of cobalt, the remainder being irons and impurities upon melting. Such alloys are suitable for machine parts that are mechanically thermally stressed, such as, for example, a rotor of a gas dynamic pressure wave machine.

The object of the present invention is to optimize creep-resistant iron nickel alloys with low expansion rates, which do not show the disadvantages of the current technology described above and which are inexpensive to manufacture and which can be used particularly for frame parts for shadow masks.

The object of the present invention is to provide a method of manufacturing a semiconductor device, which comprises 0.2% or less of C, 0.3% or less of Mn, and 0.3% or less of Si, 0.05-3.0 wt% of Al, 0.1-3.0 wt% of Ti, 1.0 wt% of Nb and 39.0-45.0 wt% of Ni And the remainder being products of irons and blends and having a thermal expansion coefficient of less than 6.0 x 10 < ^-6 > / K in the temperature range of 20-100 [deg.] C.

The advantages of the invention alloys are described in the relevant subclaims.

Surprisingly, it has been found that an intended improvement in creep resistance at 580 占 폚 under 138 MPa loading is obtained with an iron nickel alloy alloyed with aluminum and titanium, respectively.

In particular, the technical features required for use as a material for a vertical frame part for a shadow mask can be obtained with the iron nickel alloy of the present invention having a nickel content of 39.0-45.0 wt%.

A preferred composition comprises 1.0-2.5 wt.% Aluminum, up to 0.02 wt.% Carbon in addition to nickel and iron, optionally up to 0.1 wt.% Manganese, up to 0.1 wt.% Silicon, Contains the product. The alloys of the invention are excellent in processability and require no additional processing steps in their manufacture. It also shows the long-term stability of the thermal properties corresponding to the requirements.

The present invention alloy E1 exhibits significantly improved creep resistance (A ₈₀ = 0.17%) at a test temperature of 580 ° C for 1 hour at 138 MPa loading compared to the current conventional iron nickel alloy T2 containing 41% nickel.

The object of the present invention can be suitably used in the following products:

- Temperature control bimetal

- Laser technology parts

- Lead frame

- Metal glass seal

- Frame parts of screen or monitor shadow mask

- Structural components of electron guns, especially in TV tubes

- Parts for manufacturing, storage and transport liquefied gases.

Table 1: Mechanical properties, offset yield stress, yield strength, breaking elongation at 580 [deg.] C measured by hot drawing test, loading of the present invention alloy E1 compared to current alloys T1 and T2, loading Creep at 580 [deg. Resistance, Coercivity and Thermal Expansion Coefficient. The test sample is made of 1.4 mm cold rolled strip.

In the case of alloy E2, the test sample was soft-annealed to age harden and then tested (loading at 200 MPa in creep resistance test).

The coercive force strength (H _c ) of the present invention alloy E1 as well as the alloys T1 and T2 of the present invention are almost the same after the heat treatment at 580 DEG C for 15 minutes. The coercive force strength (H _c ) of the present invention alloy E1 after heat treatment at 580 캜 for 1 hour is sufficiently low for use as a material for a frame part for a shadow mask.

In the case of the present invention alloy E1, the thermal expansion coefficient is 4.8 x 10 < ^-6 > / K in the temperature range of 20-100 [deg.] C. The change of the expansion coefficient of the present invention alloy E1 according to the temperature is similar to that of the present technology alloy T2. This is illustrated in FIG. 1, whereby the coefficient of expansion of the alloys E1 and T2 at 270-320 DEG C intersects the coefficient of expansion of the alloy T1, so that the coefficient of thermal expansion of the alloy with the lower nickel content is greater than the coefficient of thermal expansion of the alloy with the higher nickel content It can be seen that it is smaller than the temperature. Above the crossover temperature, the behavior reverses. The breakpoint temperature of the thermal expansion coefficient roughly corresponds to the Curie temperature (T _c ) of the alloy.

Figure 1 shows the expansion coefficients of the inventive alloys E1 and E2 with temperature and the expansion coefficients of the present alloys T1 and T2.

The exemplary chemical compositions of the alloys E1 and E2 of the present invention are shown in Table 2 in comparison with the compositions of current alloys T1 and T2.

Table 2: Exemplary chemical compositions of the inventive alloys E1 and E2 compared to the exemplary compositions of current alloys T1 and T2

The following table shows the limits of the chemical composition of the inventive alloy E1.

Table 3: Chemical composition limits of the inventive alloy E1

Another embodiment of the present invention alloy is variant E2. A preferred composition contains 1.5-2.5% of Ti, 0.05-0.3% of Al and 0.2-1.0% of Nb in addition to 39.0-45.0% of Ni, the remainder being products of iron and mixing according to Table 4.

The following table shows the limits of the chemical composition of the inventive alloy E2.

Table 4: Chemical composition limits of the present invention alloy E2

First, alloy E2 can be rebuilt as a frame part in a soft-annealed state. The creep resistance test at 580 ° C for 1 hour is then increased to 200 MPa in the age-hardened state (eg, about 30 minutes at 750 ° C.) to meet the high requirement of less than 0.1% of A ₈₀ . Mechanical, magnetic and thermal expansion properties are shown in Table 1. The general composition of the present invention alloy E1 is shown in Table 2.

Claims (12)

0.05-3.0 wt% of Al, 0.1-3.0 wt% of Ti, 1.0 wt% of Nb, and 39.0-45.0 wt% of Ni in addition to 0.2 wt% or less of C, 0.3 wt% or less of Mn, and 0.3 wt% or less of Si The remainder are creep resistant low expansion iron nickel alloys which are products of irons and blends and have a thermal expansion coefficient of less than 6.0 x 10 ^-6 / K at a temperature range of 20-100 ° C. The iron nickel alloy of claim 1, wherein C is fixed to a maximum of 0.02 wt% and the Al content is 1.5-2.5 wt%. The iron nickel alloy according to claim 1, characterized in that it contains C of up to 0.02 wt.% And Ti content of 1.5-2.5 wt.%. 4. The iron nickel alloy according to any one of claims 1 to 3, characterized in that it contains Mn limited to a maximum of 0.05 wt.% And Si content is at most 0.05 wt.%. The iron nickel alloy according to any one of claims 1 to 4, wherein 0.5 wt% or less of Co is added. Use of the iron nickel alloy of any one of claims 1 to 5 as a passive component of a temperature-controlled bimetal. Use of the iron nickel alloy of any one of claims 1 to 5 as a component for the manufacture, storage and transport of liquefied gases. Use of the iron nickel alloy of any one of claims 1 to 5 as a component in laser technology. Use of the iron nickel alloy of any one of claims 1 to 5 as a lead frame. Use of the iron nickel alloy of any one of claims 1 to 5 as a metal glass seal. Use of the iron nickel alloy of any one of claims 1 to 5 as a frame part of a screen or monitor shadow mask. Use of the iron nickel alloy of any one of claims 1 to 5 as a structural component of an electron gun, especially in a television tube.