KR20210141144A - Metal sheet having excellent handling property - Google Patents

Abstract

The present invention aims to provide a metal sheet with excellent handling property, for a thin metal plate with a plate thickness of 0.5 mm or less. To this end, the metal sheet of the present invention is a metal sheet wherein a plate thickness is equal to or less than 0.5 mm and a half width of an intensity peak representing the maximum intensity in X-ray diffraction at a position where a thickness from the surface is 1/4 of the plate thickness is 0.3-1.0°. The metal sheet is, for example, a thin metal plate made of carbon steel, stainless steel, etc., or an iron based alloy thin plate made of Fe-Ni based alloy or Fe-Ni-Co based alloy, which is a metal sheet used for a metal component such as a mechanical component, an electric component, and an electronic component.

Description

Metal sheet having excellent handling property

The present invention relates to a metal thin plate widely used in various mechanical parts, electrical parts, electronic parts, and the like.

Conventionally, as a metal thin plate used for metal parts such as mechanical parts, electric parts, and electronic parts, "thin steel plate" made of carbon steel, stainless steel, etc., Fe-Ni alloy, Fe-Ni-Co alloy, etc. "Iron-based alloy thin plate" is representative. Metal parts made of such a thin metal plate, for example, after the final material (strip material) of the thin metal plate wound in a coil shape is developed, it is manufactured through various processing such as cutting or forming, and processes such as surface treatment (e.g. For example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-193539

When the thin metal plate is conveyed in each process, when an unexpected impact is applied to the thin metal plate, there is a concern that the thin metal plate is bent and deformed. In recent years, thin metal plates are becoming thinner due to the staticization of various parts, and the above-mentioned bending deformation requires "bending deformation resistance" higher than that of the prior art. And, when the thin metal plate is conveyed, if the suction by the magnet is used, depending on the degree of "magnetism" that the thin metal plate has, there is a concern that the metal thin plate unexpectedly falls from the magnet. In addition, the bending deformation is also concerned that the metal thin plate separated from the magnet falls and an impact is applied. Due to these facts, the "handling property" of the thin metal plate is lowered.

An object of the present invention is to provide a thin metal plate having excellent handling properties for a thin metal plate having a plate thickness of 0.5 mm or less.

The present invention is a metal thin plate having a plate thickness of 0.5 mm or less and a half width of the intensity peak representing the maximum intensity in X-ray diffraction at a position of 1/4 of the plate thickness from the surface of 0.3 to 1.0°.

According to the thin metal plate of the present invention, even if it is thin, it is difficult to bend and deform, and since it is also excellent in magnetization, handling properties of the thin metal plate having a small thickness can be improved.

1 is a schematic diagram showing an aspect of a bending test of a thin metal plate.

The present inventors investigated the factors affecting the bending deformability and magnetization of the thin metal plate. As a result, it was found that the bending deformation resistance of the thin metal plate was improved because the “springback (the amount of return from the position after bending)” when the thin metal plate was bent was large. In addition, as the "maximum magnetic flux density" of the thin metal plate was large, it was found that the magnetization of the thin metal plate was improved. In addition, the values of springback and maximum magnetic flux density depend on the "internal strain" of the thin metal plate, and this internal strain can be quantified as an index value of the "full width at half maximum in X-ray diffraction", which will be described later. It has been found that the handling properties of thin metal plates can be improved with good reproducibility by optimizing the index values.

First, the difficulty of bending deformation of the thin metal plate can be evaluated as a springback when the thin metal plate is bent. That is, since the springback is large, it is easy to return to the original shape even if the thin metal plate is bent. And, in particular, in the case of a "thin" metal sheet having a plate thickness of 0.5 mm or less, the springback when a 60° bending test at room temperature is approximately “25° or more” is assumed in an environment in which the thin metal sheet is conveyed. It was found that bending deformation can be sufficiently suppressed even without excessively (sensibly) strengthening the metal thin plate against the impact. If the springback is approximately "29 degrees or more", it is more sufficient. And, the springback depends on the internal deformation of the thin metal plate, the greater the internal deformation, the greater the springback. Therefore, by introducing an appropriate internal strain to the thin metal plate, the springback of “25° or more” can be adjusted.

In addition, the difficulty of magnetization of the thin metal plate can be evaluated by the maximum magnetic flux density of the thin metal plate. That is, since the maximum magnetic flux density is large, the thin metal plate is easily magnetized. And, in the thin metal plate having a plate thickness of 0.5 mm or less, the maximum magnetic flux density when the external magnetic field is 2,000 A/m is approximately “0.1 T or more”, so that the thin metal plate is conveyed using the adsorption by the magnet. It was found that sufficient magnetic properties corresponding to If the maximum magnetic flux density is approximately "0.3 T or more", it is more sufficient. And, the maximum magnetic flux density also depends on the internal strain of the thin metal plate, and the smaller the internal strain, the larger the maximum magnetic flux density. Therefore, by introducing an appropriate internal strain to the thin metal plate, the maximum magnetic flux density of the thin metal plate having various component compositions can be adjusted to the above “0.1 T or more”.

And, since the internal strain of the metal thin plate can be quantified as an index value of “the half width of the intensity peak in X-ray diffraction” to be described later, the best internal strain is introduced to achieve excellent bending deformability and magnetization at the same time The state can be expressed "numerically", so that the handling properties of the thin metal plate can be improved with good reproducibility.

The full-width-at-half-maximum (FWHM) refers to an index indicating the degree of spread of the mountain-shaped function. Incidentally, in the present invention, in the intensity peak of the X-ray diffraction spectrum obtained from the metal, it refers to the width connecting both ends at half the intensity value, and is a value for evaluating the strain distribution in the crystal grain. And it is a state with a large internal distortion, so that this half width is large.

And, in the X-ray diffraction spectrum obtained from the metal thin plate, a plurality of intensity peaks are usually identified, and when the strain distribution of the metal thin plate is evaluated "numerically" by the half width of the intensity peak, the peak height is low (that is, a small crystal plane). The half width of the intensity peak (corresponding to . Therefore, in order to realize a more accurate and reproducible internal deformation (handling property) in a thin metal plate, the half width of the intensity peak showing the maximum strength is adopted in the present invention. As the intensity peak showing this maximum strength, for example, if the material is a ferritic stainless steel, an Fe-Ni alloy having an Ni content of 5 mass% or more and 20 mass% or less, a Fe-Ni-Co alloy, As shown, it may be an intensity peak of the (211) crystal plane of the bcc phase. In addition, if the material is an Fe-Ni-based alloy or a Fe-Ni-Co-based alloy in which the amount of Ni is greater than about 20% by mass and not more than 50% by mass, as shown in Examples, it may be the strength peak of the (200) crystal plane of the fcc phase.

In addition, in the case of the present invention, the position of the thin metal plate for measuring the half width is "a position where the depth from the surface (rolling surface) is 1/4 of the plate thickness". In general, when considering that a thin metal plate is manufactured by rolling, the internal deformation introduced to the thin metal plate may be different in its thickness direction, and the internal deformation of the surface or the center of the plate thickness on the surface of the thin metal plate compared to other positions of the plate thickness Since this "local" fluctuates easily, it is not suitable for the measurement of the full width at half maximum.

And, in the case of the metal thin plate having a plate thickness of 0.5 mm or less of the present invention, by setting the half width at a position of 1/4 of the plate thickness from the surface to "0.3° or more", the internal deformation of the metal thin plate is moderately It becomes large, and it is effective in making the said springback "25 degrees or more". However, if the half width is excessively large, not only the local variation of internal deformation increases, but also when the press forming process enters the manufacturing process up to the metal part, the shape freezeability is reduced (for example, the springback is "50 ° Exceeded”), it is necessary to adjust the amount of press displacement or consider warm forming. And, by setting the half width to "1.0 degrees or less", the internal strain of the thin metal plate is moderately small, and it is sufficient to set the maximum magnetic flux density to "0.1 T or more". Therefore, in the thin metal plate of the present invention, the half width of the intensity peak showing the maximum intensity in X-ray diffraction at a position where the depth from the surface is 1/4 of the plate thickness is "0.3 to 1.0 degrees". Preferably it is "0.4 degrees or more", More preferably, it is "0.5 degrees or more". More preferably, it is "0.6 degrees or more." Moreover, Preferably it is "0.9 degrees or less", More preferably, it is "0.8 degrees or less". More preferably, it is "0.7 degrees or less".

Since the thin metal plate of the present invention is not easily bent and deformed even though it is thin, and also has excellent magnetization, excellent handling properties can be achieved corresponding to the environment when such a thin metal plate is conveyed. And, since the excellent handling property can be achieved even with a thinner metal sheet, it is also suitable for a metal sheet having a thickness of preferably 0.4 mm or less. More preferably, it is 0.3 mm or less, More preferably, it is 0.2 mm or less. And more preferably, it is 0.15 mm or less, Especially preferably, it is 0.1 mm or less. In addition, although special designation is not required about the lower limit of plate|board thickness, in reality, it is about 0.05 mm.

In the metal thin plate of the present invention, for example, a thin steel plate made of ferritic stainless steel, an Fe-Ni alloy having an Ni content of 5 mass% or more and 50 mass% or less, or an iron-based alloy thin plate made of an Fe-Ni-Co alloy. can be heard

When the thin metal sheet of the present invention is the thin steel sheet, it is effective to adjust the half width at half maximum of the present invention "a little higher". For example, it is preferable that the said half width is "0.5 degrees or more", and it is more preferable that it is "0.6 degrees or more." This is considered to be due to the fact that the Young's modulus (eg, 170 GPa or more) of the thin steel sheet is larger than that of the iron-based alloy thin sheet (eg, 120 GPa or more). First, by satisfying the half width of the present invention, the thin metal plate of the present invention can achieve a sufficiently large springback. However, among the thin metal plates achieving sufficiently large springback, the springback of the thin metal plate having a large Young's modulus tends to be small. Therefore, in the case of a thin metal plate having a large Young's modulus, by adjusting the half width of the present invention "a little higher", it is effective to guarantee a sufficiently large springback.

Example

Manufacturing shown in Table 1 using an intermediate material of ferritic stainless steel (SUS430) and Fe-Ni alloy (Fe-10 mass% Ni alloy, Fe-36 mass% Ni alloy, Fe-39 mass% Ni alloy) The final material of the thin metal plate was manufactured by the process. The intermediate material was hot-rolled at a heating temperature of 1,150° C. to a plate thickness of 3 mm.

A test piece was taken from the vicinity of the center of the width of each of the produced thin metal plates. Then, at a position where the depth from the rolled surface of the sampled test piece is 1/4 of the plate thickness, the surface parallel to the rolling surface is mirror polished, and further electropolishing is performed, and the diffraction spectrum by the X-ray diffraction method (each crystal surface) of the abundance ratio and the half width at half maximum) of the intensity peak).

The diffraction spectrum was measured using an X-ray diffractometer "RINT2500" manufactured by Rigaku Corporation. Co was used as the source, and the conditions were a voltage of 40 kV and a current of 200 mA. Then, for a plurality of crystal planes in which the intensity peaks were confirmed in the diffraction spectrum, the abundance ratio of each crystal plane was determined from their intensity ratio, and the half width of the intensity peak showing the maximum intensity among those intensity peaks was determined.

Then, the springback by the bending test and the maximum magnetic flux density were measured for these thin metal plates. The test piece was also taken from the vicinity of the center of the width of the thin metal plate. And in the bending test, each dimension corresponds to the length and width of the thin metal plate, a bending test piece of length 20 mm × width 10 mm, the one end in the longitudinal direction of the thin metal plate 1 as shown in FIG. The spring back (θ) was measured when it was sandwiched and fixed (bending radius: 0.38 mm, protrusion: 10 mm), and bent at 60° at room temperature. The maximum magnetic flux density was measured as the maximum magnetic flux density when the externally applied magnetic field was 2,000 A/m. The above results are shown in Table 2 together with the abundance ratio and full width at half maximum of the crystal planes.

In the metal thin plate of the present invention, by the fine adjustment of the manufacturing process (rolling and annealing execution timing, rolling rate and annealing temperature) shown in Table 1 in the type of the material, the intensity peak showing the maximum intensity in X-ray diffraction By setting the half width to "0.3 degrees or more", a springback of "25 degrees or more" was achieved in a metal thin plate having a plate thickness of 0.5 mm or less. In addition, a sufficient maximum magnetic flux density of "0.1 T or more" was also maintained.

From the above results, even if the thin metal plate of the present invention is thin, it is difficult to bend and deform, and since it is also excellent in magnetization, it can be expected that the handling property of the thin metal plate corresponding to the environment when the thin metal plate is conveyed is improved.

1 metal sheet
2 blocks

Claims (1)

A metal with excellent handling properties, characterized in that the plate thickness is 0.5 mm or less and the half width of the intensity peak showing the maximum intensity in X-ray diffraction at a position of 1/4 of the plate thickness from the surface is 0.3 to 1.0° lamination.

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