KR102244229B1 - Manufacturing method of Fe-Ni alloy thin plate and Fe-Ni alloy thin plate - Google Patents

Abstract

It provides an Fe-Ni-based alloy thin plate capable of having isotropic mechanical properties even if the width is increased, and a method of manufacturing the same. By mass% Ni+Co: 35.0 to 43.0% (however, Co is 0 to 6.0%), Si: 0.5% or less, Mn: 1.0% or less, the balance is made of Fe and impurities, and a hot-rolled material having a thickness of 2 mm or more Using as a cold rolling material, performing the first cold rolling with a reduction ratio of 85% or more with respect to the cold rolling material, and after the first cold rolling, a temperature of 800°C or more, and a holding time of 0.1 to 1.2 minutes Recrystallization annealing is performed at, and after the recrystallization annealing, final cold rolling with a reduction ratio of 40% or less is performed to obtain an Fe-Ni alloy thin plate having a thickness of 0.25 mm or less, and no heat treatment is performed after the final cold rolling. Method for producing a thin Fe-Ni alloy plate and a thin Fe-Ni alloy plate.

Description

Manufacturing method of Fe-Ni alloy thin plate and Fe-Ni alloy thin plate

The present invention relates to, for example, a thin Fe-Ni alloy plate used for a lead frame or a metal mask, and a method of manufacturing the same.

In order to improve the performance of the Fe-Ni alloy thin plate used for a lead frame, a metal mask, etc., various studies have been conducted than before. For example, in Patent Document 1, in order to improve the etching accuracy, cold rolling and annealing are performed on a hot-rolled sheet at least once, respectively, the cold rolling rate of cold rolling before final recrystallization annealing is 90% or more, and the annealing temperature of the final recrystallization annealing is Disclosed is a method of manufacturing an Fe-Ni-based thin plate, characterized in that it is manufactured at 850°C or higher and a final cold-pressing rate of 30% or lower. Further, in Patent Document 2, in order to obtain good etching property and high strength, a cold rolling rate of 85% or more and annealing of 700°C or more are performed at least once, and thereafter, cold rolling and 850°C of a rolling rate not exceeding the cold rolling rate. A method for producing a shadow mask material is disclosed, characterized in that annealing at a temperature not exceeding is performed in this order.

Japanese Patent Application Publication No. 2003-253398 Japanese Patent Laid-Open No. Hei 06-279946

The Fe-Ni-based alloy thin plate as described above is cut to a desired size and used according to the intended use. However, due to the demand for higher precision of products, the dimensional tolerances of metal masks and the like become increasingly strict, and there is a possibility that products that exceed the dimensional tolerances after cutting may increase. The inventions of Patent Document 1 or Patent Document 2 described above are useful inventions having an effect of improving the etching performance, but regarding suppressing fluctuations in the characteristics of the thin plate after cutting, it is not described in Patent Document 1 or Patent Document 2, There is room for review.

Therefore, it is an object of the present invention to provide a thin Fe-Ni alloy sheet having a thickness of 0.25 mm or less, and a method of manufacturing the same, which has less anisotropy of the mechanical properties of the rolled surface and is capable of providing good shape workability. To provide.

In one aspect of the present invention, in mass%, Ni+Co: 35.0 to 43.0% (however, Co is 0 to 6.0%), Si: 0.5% or less, Mn: 1.0% or less, the balance consists of Fe and impurities, Using a hot rolled material having a thickness of 2 mm or more as a material for cold rolling, with respect to the material for cold rolling,

First cold rolling of 85% or more of a reduction ratio was performed,

After the first cold rolling, recrystallization annealing was performed under conditions of a temperature of 800° C. or higher and a holding time of 0.1 to 1.2 minutes,

After the recrystallization annealing, a final cold rolling having a reduction ratio of 40% or less is performed to obtain an Fe-Ni alloy thin plate having a thickness of 0.25 mm or less, and no heat treatment is performed after the final cold rolling. It is a method of manufacturing a thin plate.

Another aspect of the present invention,

Ni+Co by mass%: 35.0 to 43.0% (however, Co is 0 to 6.0%), Si: 0.5% or less, Mn: 1.0% or less, the balance consisting of Fe and impurities, and a thickness of 0.25 mm or less Fe- In the Ni-based alloy thin plate, the difference between the 0.2% yield strength in each of the three directions in the width direction, the length direction, and the 45° direction of the Fe-Ni alloy thin plate is 5% of the average value of the 0.2% proof strength in the three directions. It is an Fe-Ni-based alloy thin plate, which is within the range, wherein each elongation value in the three directions is 0.90 to 1.10 times the average elongation value in the three directions.

According to the present invention, in a thin Fe-Ni alloy thin plate having a thickness of 0.25 mm or less, since there is little variation in mechanical properties depending on the cutting direction, good workability can be exhibited.

Hereinafter, an embodiment of the present invention will be described. First, a method of manufacturing a thin Fe-Ni alloy plate of the present invention will be described.

<Composition of hot rolled material>

In the present invention, by mass% Ni + Co: 35.0 to 43.0% (however, Co is 0 to 6.0%), Si: 0.5% or less, Mn: 1.0% or less, the balance is a hot-rolled material having a composition consisting of Fe and impurities Prepare. The Fe-Ni-based alloy having the composition specified in the present invention has a composition necessary to obtain a desired coefficient of thermal expansion.

[Ni+Co: 35.0 to 43.0% (however, Co is 0 to 6.0%)]

As described above, Ni and Co are elements necessary to obtain a desired coefficient of thermal expansion. When the Ni+Co content is less than 35.0%, the austenite structure is liable to become unstable, whereas when it exceeds 43.0%, the coefficient of thermal expansion increases and the low thermal expansion property is not satisfied, so the content of Ni+Co is 35.0 to 43.0%. It should be. In addition, Co is not necessarily added, but since Co has an action of making an Fe-Ni alloy high strength, particularly strict handling properties are required, in the range of up to 6.0% in thin plate thickness, part of Ni Can be substituted with Co.

[Si: 0.5% or less, Mn: 1.0% or less]

Si and Mn are usually contained in a small amount for the purpose of deoxidation in an Fe-Ni-based alloy, but when contained excessively, segregation tends to occur, so that Si is 0.5% or less, and Mn is 1.0% or less. Further, the lower limit of Si and Mn is not particularly limited, but 0.05% of Si and 0.05% of Mn remain in a small amount in that they are added as deoxidation elements as described above.

[The balance is Fe and impurities]

Except for the above-described elements, it is substantially sufficient to include Fe, but impurities that are unavoidably contained in production are included. C is an impurity element that needs to be particularly limited, and if it is used for etching, for example, the upper limit may be set to 0.05%.

Further, in the case of improving press punchability, free-machining elements such as S may be contained in an amount of 0.020% or less. An element such as B, which improves hot workability, may be contained in an amount of 0.0050% or less.

<Hot-rolled material thickness: 2mm or more>

The hot-rolled material used in the present invention has a thickness of 2 mm or more. When the thickness of the hot-rolled material is less than 2 mm, there is a fear that cold rolling of 85% or more of the reduction ratio specified in the present invention cannot be performed. In addition, if the thickness of the hot-rolled material is to be less than 2 mm, special rolling equipment may be required. Therefore, in the present invention, the thickness of the hot-rolled material is 2 mm or more.

In addition, if the thickness of the hot-rolled material is increased, it is possible to increase the reduction ratio, but on the other hand, the number of passes during the cold-rolling process may increase, or the shape of the Fe-Ni-based alloy during rolling may become difficult to adjust. It is realistic to set the upper limit to 5mm.

This hot-rolled material has an oxide layer formed on its surface, and the thickness of the hot-rolled material is the thickness including the oxide layer.

<Material for cold rolling>

In the present invention, the above-described hot-rolled material is used as a cold-rolling material. Since an oxide layer is formed in the hot-rolled material, the oxide layer is removed mechanically or chemically, for example. Further, an edge may be provided so that defects such as cracks do not occur from the edge of the cold-rolled material during cold rolling. Such processing is performed to obtain a cold rolling material.

Next, the cold rolling process is demonstrated in detail.

<1st cold rolling>

In the present invention, the reduction ratio in the first cold rolling, which is cold rolling before recrystallization annealing, is set to 85% or more. By increasing the reduction ratio before recrystallization annealing in this way, it is easy to align the crystal plane orientation of the alloy thin plate obtained after final rolling to be described later in one direction, and the anisotropy of mechanical properties can be suppressed. Moreover, since the number of cold rolling and annealing steps can be reduced, manufacturing at a lower cost is also possible. When the reduction ratio is less than 85%, mechanical properties are deteriorated. In addition, the number of cold rolling or annealing steps having an excessively low reduction ratio increases, and the cost increases. A preferable reduction ratio is 87% or more, more preferably 90% or more. In addition, the upper limit of the reduction ratio is not particularly determined, but when the reduction ratio exceeds 99%, there is a possibility that an increase in cost due to an excessive rolling time may be caused, so that the upper limit is practically set to 99%.

<Recrystallization Annealing>

In the present invention, after the first cold rolling described above, recrystallization annealing is performed at a temperature of 800°C or higher. By this step, the stress of the thin sheet that has been work-hardened under reduced pressure is removed and softened, and the desired sheet thickness and mechanical properties are easily obtained by the subsequent final cold rolling. If the annealing temperature is less than 800°C, there is a concern that the material may not be sufficiently softened. In addition, the upper limit of the annealing temperature is not particularly limited, but if it is too high, since there is a possibility that the desired characteristics may not be obtained, it can be set to 1100°C.

In addition, the present invention is also characterized in that the heating holding time of the annealing of the thin plate is adjusted to 0.1 to 1.2 minutes. By setting the heating holding time within the above-described temperature range in a relatively short period of time, it is possible to obtain desired isotropic properties of yield strength and elongation without deteriorating production efficiency. If the annealing time is less than 0.1 minutes, the stress may not be sufficiently removed. If it exceeds 1.2 minutes, there is a possibility that the mechanical properties of the thin alloy sheet will fluctuate, or the cost will increase due to an increase in annealing time. It is preferable that the lower limit of the annealing time is 0.2 minutes. In addition, the upper limit of the annealing time is preferably 0.9 minutes, and more preferably 0.6 minutes, aiming at further cost reduction.

In addition, this recrystallization annealing can be performed by continuously passing the first cold-rolled material through a heating furnace set to a desired temperature. For example, it can be carried out by a method in which the first cold-rolled material is taken out from a rolled state, passed through a heating furnace, and wound in a roll shape.

<Final cold rolling>

In the manufacturing method of the present invention, it is possible to obtain an Fe-Ni-based alloy thin plate with suppressed anisotropy of mechanical properties by performing final cold rolling with a reduction ratio of 40% or less on the above-described material after recrystallization annealing. When rolling in excess of 40% is performed, the anisotropy of mechanical properties tends to increase due to the application of excessive stress, which is not preferable. Although the lower limit of the reduction ratio is not particularly limited, if the reduction ratio is too low, it becomes difficult to adjust to the desired plate thickness, and thus it can be set to 15% or more. At this time, in order to facilitate obtaining the above-described mechanical properties, it is preferable that the rolling front tension in the final cold rolling is 200 to 500 MPa, the rolling rear tension is 100 to 200 MPa, and the rolling speed is 250 m/min or less. A more preferable lower limit of the rolling front tension is 250 MPa, and a more preferable upper limit of the rolling front tension is 400 MPa. Further, a more preferable lower limit of the rolling rear tension is 120 MPa, and a more preferable upper limit of the rolling rear tension is 180 MPa. Moreover, although it does not specifically limit about the lower limit of a rolling speed, In consideration of workability, it is preferable to be about 100 m/min. In addition, about the manufacturing method of this embodiment, in final cold rolling, in order to obtain desired properties while suppressing flaws on the surface of a thin plate, it is preferable to roll in one pass.

The thickness of the steel strip after the final cold rolling is 0.25 mm or less. When the Fe-Ni-based alloy thin plate of the present invention is used for, for example, a lead frame, it is easy to cope with polyfinization, and when it is used for, for example, a metal mask, it is possible to cope with high precision by etching processing. Because. The upper limit of the preferred thickness is 0.15 mm. A more preferable upper limit is 0.1 mm, and a more preferable upper limit is 0.08 mm. In addition, the lower limit is not particularly limited, but it can be set to 0.02 mm since there is a tendency that a change in shape tends to occur when the material is too thin. It is particularly preferable that the Fe-Ni-based alloy thin plate of the present invention has a wide width (for example, a plate width of 500 to 1200 mm).

<Omit stress relief annealing>

In the present invention, heat treatment is not performed after the above-described final cold rolling. This heat treatment is, for example, stress relief annealing performed at or below the recrystallization temperature. By omitting the heat treatment, it is possible to suppress a change in the shape of a thin plate or a change in mechanical properties due to the release of residual stress. In the present invention, even if the stress is not removed by the above-described manufacturing method, since the product has no anisotropy in terms of mechanical properties, it can be omitted. In addition, the omission of the heat treatment increases the energy saving effect and is economical.

Subsequently, the Fe-Ni-based alloy thin plate of the present invention, which can be obtained by the production method of the present invention described above, will be described.

<0.2% proof stress, elongation value>

The Fe-Ni-based alloy thin plate of the present invention is in the width direction (the first direction of the surface of the thin plate, a direction corresponding to the direction orthogonal to the rolling direction), the longitudinal direction (the second direction of the surface of the thin plate, and orthogonal to the width direction). 0.2% yield strength in each of the three directions, which is a direction that corresponds to the rolling direction) and a 45° direction (the third direction of the surface of the thin plate, and a direction having a relationship of 45° to the width and length directions) The difference is 5% or less of the average value of the 0.2% proof stress in the three directions, and each elongation value in the three directions is 0.90 to 1.10 times the average elongation value in the three directions. The 0.2% proof stress is a parameter that affects workability such as plastic deformation, and the elongation value is a parameter that affects the shape of the product after processing. By adjusting within the above range, the thin plate of the present invention has good characteristics with little fluctuation in strength or shape depending on the cutting direction, and suppresses fluctuations in cutting conditions, for example, when cutting an alloy thin plate from various directions. , It is possible to obtain good workability. When the difference between 0.2% proof strength in each of the three directions exceeds 5% of the average value in the three directions, the anisotropy becomes strong, so the difference in shape according to the cutting direction increases. Therefore, the desired characteristics are satisfied depending on the cutting direction. There is a high likelihood that a thin plate that does not occur will occur. Preferably, the difference between each 0.2% proof strength in the three directions is set to 3% or less of the average value of the 0.2% proof strength in the three directions. The difference between each 0.2% proof stress and the difference between each elongation difference is most preferably 0% (the same characteristic in each direction), but since it is difficult to make the difference between them 0%, for example, 0.2% each The lower limit of the difference between the proof strengths can be set to 0.1%. Moreover, since the anisotropy of an alloy thin plate can be further suppressed by making the average value of 0.2% proof stress in three directions of the thin plate of this invention 580 MPa or less, it is preferable. In addition, it is preferable that the average elongation value of the present invention be 2% or less to suppress the shape of the product after cutting.

<Crystal orientation>

It is preferable that the Fe-Ni alloy thin plate of the present invention has a (200) plane integration degree of 90% or more. Due to the above characteristics, the Fe-Ni-based alloy thin plate of the present invention tends to be capable of suppressing the anisotropy of mechanical properties. In addition to the above, for example, when processing a lead frame or the like by press working, it becomes possible to manufacture regardless of direction. More preferably, the (200) plane integration degree is 95% or more. In addition, the (200) plane integration degree in this embodiment is (111), (200), (220) on the rolled surface of the Fe-Ni-based alloy thin plate using, for example, X-ray diffraction (XRD) method. X-ray diffraction integral intensity I(111), I(200), I(220), I(311) of (311) were measured, and I(200)/ (I(111)+I(200)+I( It can be found by using the equation 220)+I(311)}.

[Example]

Vacuum melting, temperature equalization heat treatment, hot pressing and hot rolling were performed to prepare a hot rolled material having a thickness of 3.0 mm. Table 1 shows the chemical composition of the hot-rolled material.

The above-described hot-rolled material is chemically polished and mechanically polished to remove the oxide layer on the surface of the hot-rolled material, and by trimming, cracks during hot-rolling at both ends of the material width direction are removed to prepare a material for cold rolling with a thickness of 1.55 mm. I did. In addition, the width of the cold rolling material is 860 mm.

Next, the above-described cold rolling material was divided into an example of the present invention and a comparative example, and the steps shown in Table 2 were performed to obtain an Fe-Ni-based alloy thin plate. In the present invention example, it was set as 1st cold rolling, recrystallization annealing, and final cold rolling, and in Comparative Example 1, it was set as intermediate rolling (1), recrystallization annealing, intermediate rolling (2), recrystallization annealing, and final cold rolling. In Comparative Example 2, although the steps of the examples of the present invention were the same, the reduction ratio at the time of final cold rolling was set larger than that of the present invention.

In the first cold rolling of the present invention example and the comparative example 2, and the intermediate rolling of the comparative example 1 (1) and (2), the number of passes was 10 at the rolling reduction ratio shown in Table 2 using the above-described cold rolling material. I made it a pass. Thereafter, recrystallization annealing was performed in both the present invention examples and the comparative examples at a temperature of 900°C and a holding time of 0.36 minutes. Then, final cold rolling was performed under conditions of a rolling front tension of 320 MPa, a rolling rear tension of 140 MPa, and a rolling speed of 200 m/min. In addition, in Comparative Example 1, recrystallization annealing was performed twice. In Comparative Example 3, although the steps of the examples of the present invention were the same until the final cold rolling, stress relief annealing was performed at a temperature of 600° C. after the final cold rolling. In the present invention example, the comparative example 1, and the comparative example 2, the stress relief annealing after the final cold rolling was not performed.

Various test pieces were taken from the Fe-Ni-based alloy thin plate after the above-described final cold rolling was completed, and were subjected to each test. The results of the test are put together in Table 3 and shown. 0.2% proof stress and elongation were performed according to the method specified in JIS-Z2241. The test piece is a JIS 13 B test piece. In addition, in the present invention example and the comparative example 1, the (200) plane integration degree of the thin plate surface was measured using an X-ray diffraction apparatus. This (200 plane) degree of integration is measured by measuring the X-ray diffraction integral intensity I(111), I(200), I(220), I(311), and I(200)/ (I(111)+I(200) It was derived using the equation )+I(220)+I(311)}. As a result, the (200) plane integration degree of the present invention example was 98%, and the (200) plane integration degree of the comparative example 1 was 68%. Thereby, it was confirmed that the Fe-NI-based alloy thin plate of the example of the present invention has a very high (200) plane integration degree.

As described above, in the Fe-Ni-based alloy thin plate of the present invention, the difference between each 0.2% proof strength in the width direction, the length direction, and the 45° direction was 7 MPa at the maximum, and was a value of about 1.3% of the average value. The elongation values in the three directions are also about 0.92 to 1 times the average value, and it was confirmed that the alloy thin plate of the present invention has excellent properties with very little anisotropy. On the other hand, in the Fe-Ni alloy thin plate of Comparative Example 1, the difference between each 0.2% proof strength in the width direction, the length direction, and the 45° direction was 52 MPa at the maximum, and was a value of about 8.8% of the average value. The elongation values in the three directions were also about 0.89 to 1.13 times the average value, and it was confirmed that the anisotropy of mechanical properties was greater than that of the alloy thin plate of the example of the present invention. In the Fe-Ni-based alloy thin plate of Comparative Example 2, the difference between each 0.2% proof strength in the width direction, length direction, and 45° direction was at most 22 MPa, and was within the specified range at a value of about 3.8% of the average value. However, it was confirmed that the elongation value in the three directions was about 0.67 to 1.33 times the average value, and the anisotropy of the elongation characteristic was higher than that of the alloy thin plate of the example of the present invention. The Fe-Ni alloy thin plate of Comparative Example 3 also had a 0.2% yield strength within the specified range, but it was confirmed that the elongation values in the three directions were largely irregularly dispersed.

Claims (2)

In mass%,
Ni+Co: 35.0 to 43.0%, provided that Co is 0 to 6.0%,
Si: 0.5% or less,
Mn: 1.0% or less,
C: contains 0.05% or less,
The remainder is made of Fe and impurities, and a hot rolled material having a thickness of 2 mm or more is used as a material for cold rolling, and with respect to the cold rolling material,
First cold rolling of 85% or more of a reduction ratio was performed,
After the first cold rolling, recrystallization annealing was performed under conditions of a temperature of 800° C. or more and 1100° C. or less and a holding time of 0.1 to 1.2 minutes,
After the recrystallization annealing, final cold rolling with a reduction ratio of 40% or less was performed under conditions of a rolling front tension of 200 to 500 MPa and a rolling rear tension of 100 to 200 MPa to obtain an Fe-Ni-based alloy thin plate having a thickness of 0.1 mm or less. A method for producing an Fe-Ni-based alloy thin plate, characterized in that no heat treatment is performed after cold rolling. In mass%,
Ni+Co: 35.0 to 43.0%, provided that Co is 0 to 6.0%,
Si: 0.5% or less,
Mn: 1.0% or less,
C: contains 0.05% or less,
The balance consists of Fe and impurities, and in the Fe-Ni alloy thin plate having a thickness of 0.1 mm or less, 0.2% yield strength in each of the three directions in the width direction, the length direction, and the 45° direction of the Fe-Ni alloy thin plate Fe-Ni, characterized in that the difference between them is within 5% of the average value of the 0.2% proof stress in the three directions, and the elongation values in the three directions are 0.90 to 1.10 times the average elongation value in the three directions. Based alloy thin plate.