阅读说明：本技术 钟表用部件以及钟表 (Timepiece component and timepiece ) 是由 古里大喜 于 2021-06-02 设计创作，主要内容包括：提供钟表用部件以及钟表,在硬度、耐腐蚀性的基础上,还具有外观设计性高的表面装饰。该钟表用部件由具有如下部分的奥氏体化铁素体系不锈钢构成：基部(15),其由铁素体相构成；表面层(16),其由奥氏体化相构成；混合层(17),其形成在基部(15)与表面层(16)之间,混合存在有铁素体相和奥氏体化相,表面层(16)具有镜面(10)和纹路(14a),在设镜面(10)的平均粗糙度为Sa-m、纹路(14a)的平均粗糙度为Sa、最大粗糙度为Sz时,Sa-m/Sa为0.01以上0.2以下,Sa/Sz为0.03以上0.1以下。(Provided are a timepiece component and a timepiece, which have a surface decoration having high design properties in addition to hardness and corrosion resistance. The timepiece component is composed of an austenitized ferritic stainless steel having: a base (15) composed of a ferrite phase; a surface layer (16) consisting of an austenitized phase; and a mixed layer (17) formed between the base (15) and the surface layer (16) and in which a ferrite phase and an austenitizing phase are mixed, wherein the surface layer (16) has a mirror surface (10) and a texture (14a), and when the average roughness of the mirror surface (10) is Sa _ m, the average roughness of the texture (14a) is Sa, and the maximum roughness is Sz, the Sa _ m/Sa is 0.01 to 0.2, and the Sa/Sz is 0.03 to 0.1.)

1. A timepiece component characterized in that,

the timepiece component is composed of an austenitized ferritic stainless steel having: a base portion composed of a ferrite phase; a surface layer composed of an austenitized phase; a mixed layer formed between the base portion and the surface layer, in which the ferrite phase and the austenitizing phase are present in a mixed state,

the surface layer has a mirror surface and a grain,

when the average roughness of the mirror surface is Sa _ m, the average roughness of the grain is Sa, and the maximum roughness of the grain is Sz, Sa _ m/Sa is 0.01 to 0.2, and Sa/Sz is 0.03 to 0.1.

2. The timepiece component according to claim 1,

sz is 6 to 15 μm.

3. The timepiece component according to claim 1,

the hardness of the surface layer is 350Hv or more and 400Hv or less.

4. The timepiece component according to claim 2,

the hardness of the surface layer is 350Hv or more and 400Hv or less.

5. The timepiece component according to claim 3,

the nitrogen concentration of the surface layer is 1 wt% or more and 1.6 wt% or less.

6. The timepiece component according to claim 4,

the nitrogen concentration of the surface layer is 1 wt% or more and 1.6 wt% or less.

7. A timepiece having the timepiece component of claim 1.

8. A timepiece having the timepiece component of claim 2.

9. A timepiece having the timepiece component of claim 3.

10. A timepiece having the timepiece component of claim 4.

11. A timepiece having the timepiece component of claim 5.

12. A timepiece having the timepiece component of claim 6.

Technical Field

The invention relates to a timepiece component and a timepiece.

Background

Stainless steel is widely used for cases as parts for timepieces. Patent document 1 discloses a timepiece in which an austenitizing treatment using nitrogen gas is performed on a case. Thus, the surface layer of the ferritic stainless steel contains nitrogen and is austenitized, whereby hardness and corrosion resistance required for a timepiece case can be obtained.

Patent document 1: japanese patent laid-open publication No. 2013-101157

However, in the timepiece component of patent document 1, decoration of the surface is not considered. Timepiece components such as housings are required to have surface decorations with design properties in addition to hardness and corrosion resistance.

Disclosure of Invention

The timepiece component is composed of an austenitized ferritic stainless steel having: a base portion composed of a ferrite phase; a surface layer composed of an austenitized phase; and a mixed layer formed between the base portion and the surface layer, in which the ferrite phase and the austenite phase are mixed, wherein the surface layer has a mirror surface and grains, and when an average roughness of the mirror surface is Sa _ m, an average roughness of the grains is Sa, and a maximum roughness of the grains is Sz, the Sa _ m/Sa is 0.01 to 0.2, and the Sa/Sz is 0.03 to 0.1.

The timepiece has the timepiece component described above.

Drawings

Fig. 1 is a schematic plan view showing the structure of the timepiece according to embodiment 1.

Fig. 2 is a schematic view showing the surface appearance of the outer case.

Fig. 3 is a schematic side sectional view showing a cross-sectional structure of the outer case.

Fig. 4 is a graph for explaining the relationship between the surface roughness of the grain and the appearance.

Fig. 5 is a diagram for explaining the relationship between the surface roughness of the mirror surface and the surface roughness of the grain and the appearance.

Fig. 6 is a flowchart of a method of manufacturing the exterior case.

Description of the reference symbols

1: a timepiece; 3: a timepiece band as a timepiece component; 4: an outer case as a timepiece component; 6: a glass edge portion as a timepiece component; 10: a mirror surface; 14 a: lines; 15: a base; 16: a surface layer; 17: and a mixed layer.

Detailed Description

Embodiment 1

As shown in fig. 1, the timepiece 1 has a timepiece body 2. A band 3 as a timepiece component connected to the timepiece body 2 is disposed on the upper side and the lower side of the timepiece body 2 in the drawing. The watch band 3 is wound around a person's arm for use.

The timepiece 1 has a cylindrical outer case 4 as a timepiece component. A glass cover 5 is disposed at one end of the outer case 4 along the cylindrical axis. A glass rim 6 as a timepiece component is disposed on the outer periphery of the glass cover 5. In the timepiece main body 2, the side on which the glass cover 5 is disposed is the front side. A circular and flat dial 7 is disposed on the back surface side of the glass cover 5. On the surface side of the dial 7, a scale 8 is arranged.

A pointer shaft 9 is disposed at the center of the dial 7 in a plan view of the dial 7. A second hand 11, a minute hand 12, and an hour hand 13 are attached to the hand shaft 9 to indicate time. The hand shaft 9 is constituted by 3 rotation shafts to which a second hand 11, a minute hand 12, and an hour hand 13 are attached.

As shown in fig. 2, the pattern in which the ridges 14a are arranged substantially in parallel is referred to as a ridge pattern. The surface on which the grain is formed is set as a grain installation surface 14. A mirror surface 10 and a grain installation surface 14 are formed on a surface 4a of the outer case 4. The spacing of adjacent ridges 14a is random. The normal direction of the surface 4a is defined as the Z direction. A direction perpendicular to the Z direction and perpendicular to the wale 14a is set as the X direction. The direction perpendicular to the X direction and the Z direction is the Y direction. The mirror surface 10 has a small surface roughness.

As shown in fig. 3, the outer case 4 includes a base portion 15 made of a ferrite phase, a surface layer 16 made of an austenitizing phase formed on the surface 4a side of the base portion 15, and a mixed layer 17 in which the ferrite phase and the austenitizing phase are mixed. The mixed layer 17 is formed between the base 15 and the surface layer 16. The outer case 4 is made of austenitized ferritic stainless steel. Surface layer 16 has a mirror surface 10 and a grain 14 a.

According to this structure, the surface 4a of the outer case 4 is hard and less likely to be damaged since it is made of an austenitized phase that is solid-solution hardened by nitrogen. The inner surface of the outer case 4 is a ferrite phase, and thus can have magnetic resistance.

The hardness of the surface layer 16 is 350Hv or more and 400Hv or less. The surface layer 16 is harder than SUS316L, which is corrosion-resistant stainless steel, for example, in hardness of 180Hv to 220 Hv. According to this structure, the surface layer 16 is high in hardness and is therefore less likely to be damaged, and thus the mirror surface 10 and the grain 14a are less likely to deteriorate.

The base 15 is made of a ferritic stainless steel containing, in mass%, Cr: 18-22%, Mo: 1.3-2.8%, Nb: 0.05 to 0.50%, Cu: 0.1 to 0.8%, Ni: less than 0.5%, Mn: less than 0.8%, Si: less than 0.5%, P: less than 0.10%, S: less than 0.05%, N: less than 0.05%, C: less than 0.05%, the remainder being made up of Fe and unavoidable impurities.

Cr, Mo, and Nb are elements that increase the rate of nitrogen migration into the ferrite phase and the rate of nitrogen diffusion in the ferrite phase in the nitrogen absorption treatment. Cu is an element that controls nitrogen absorption in the ferrite phase in the nitrogen absorption treatment. Ni, Mn, Si, P, S, N, and C are elements that hinder the movement of nitrogen to the ferrite phase and the diffusion of nitrogen in the ferrite phase in the nitrogen absorption treatment.

In the present embodiment, the base portion 15 is formed using a metal made of a ferritic stainless steel containing, for example, Cr: 20%, Mo: 2.1%, Nb: 0.2%, Cu: 0.1%, Ni: 0.05%, Mn: 0.5%, Si: 0.3%, P: 0.03%, S: 0.01%, N: 0.01%, C: 0.02%, and the balance of Fe and inevitable impurities.

The surface layer 16 is formed by applying nitrogen absorption treatment to the surface of the base 15. The nitrogen concentration of the surface layer 16 is 1 wt% or more and 1.6 wt% or less. According to this structure, since the nitrogen concentration of the surface layer 16 is 1 wt% or more and 1.6 wt% or less, the hardness of the surface layer 16 can be 350Hv or more and 400Hv or less.

In the process of forming the surface layer 16, the mixed layer 17 is generated due to a variation in the moving speed of nitrogen entering the base portion 15 composed of a ferrite phase. That is, at a portion where the nitrogen movement speed is high, nitrogen enters a deep portion of the base portion 15 to be austenitized, and at a portion where the nitrogen movement speed is low, only a shallow portion of the base portion 15 is austenitized, so that the mixed layer 17 in which the ferrite phase and the austenitized phase are mixed in the depth direction is formed.

The surface layer 16 and the mixed layer 17 are formed as follows: when the exterior case 4 is cut in a depth direction from the surface 4a, that is, when the exterior case 4 is cut in a direction perpendicular to the surface 4a, the mixed layer thickness 17a, which is the thickness of the mixed layer 17, is 45% or less of the surface layer thickness 16a, which is the thickness of the surface layer 16. If the mixed layer thickness 17 a/surface layer thickness 16a is 45% or less, that is, the mixed layer thickness 17a is 45% or less of the surface layer thickness 16a, 85G or more, which can secure the magnetic resistance performance of the 1 st magnetic resistant timepiece, can be secured substantially.

In fig. 4, the horizontal axis represents the average roughness Sa of the streaks 14 a. The average roughness Sa of the vein 14a represents the average of the absolute values of the differences in height of the points of the vein 14a relative to the average plane of the surface 4 a. The vertical axis represents the maximum roughness Sz of the grain 14 a. The maximum roughness Sz of the vein 14a represents the distance from the highest point to the lowest point of the vein 14 a. The measurement range is not particularly limited, but in the present embodiment, the measurement is performed in a range of 1.35mm × 1.0 mm.

The appearance of the grain arrangement surface 14 is divided into three regions for the average roughness Sa and the maximum roughness Sz. The maximum roughness Sz of the 1 st region 18 is 6 μm to 15 μm. The average roughness Sa/maximum roughness Sz is 0.03 to 0.1. In the outer case 4, the textured mounting surface 14 has a surface roughness shown in a 1 st region 18. In the region 18, the grain in the grain pattern appears uniform, so that the grain installation surface 14 has a highly designable appearance.

In the 2 nd region 19, the maximum roughness Sz exceeds 15 μm. Alternatively, in the 2 nd region 19, the maximum roughness Sz is 6 μm or more, and the average roughness Sa/maximum roughness Sz is less than 0.03. In the 2 nd region 19, since the surface roughness is too rough, the vein installation surface 14 is strongly diffusely reflected to have a dazzling and rough appearance. In the 2 nd region 19, light may be diffusely reflected, and a multicolor stripe pattern may be visible.

In region 3, the maximum roughness Sz is less than 6 μm. Alternatively, in the 3 rd region 21, the maximum roughness Sz is as small as 15 μm or less, and the average roughness Sa/maximum roughness Sz exceeds 0.1. In the region 21, since the grain 14a is shallow, the appearance of the grain 14a becomes difficult to see.

When the maximum roughness Sz of the grain 14a is less than 6 μm, the grain 14a is shallow, so that the grain 14a is difficult to see. When the maximum roughness Sz of the grain 14a exceeds 15 μm, the grain 14a is strongly and diffusely reflected to have a dazzling and rough appearance. According to this configuration, Sz is 6 μm to 15 μm, so that the outer case 4 has luster, and the outer case 4 can form a surface that appropriately diffusely reflects light and has high design properties.

In fig. 5, the horizontal axis represents the average roughness Sa of the grain 14 a. The vertical axis represents the average roughness Sa _ m of the mirror surface 10. The appearance of the mirror 10 and the grain 14a is divided into three regions for the average roughness Sa of the grain 14a and the average roughness Sa _ m of the mirror 10. The average roughness Sa _ m of the mirror surface 10 is not particularly limited, but is usually 0.02 μm to 0.04 μm, and preferably less than 0.05. mu.m. In the 4 th region 22, the average roughness Sa _ m of the mirror surface 10/the average roughness Sa of the grain 14a is 0.01 to 0.2. In the outer case 4, the mirror surface 10 and the texturing installation surface 14 have a relationship of surface roughness shown in the 4 th region 22. In the 4 th region 22, the mirror surface 10 and the grain 14a are recognized to be different, and the grain 14a has a highly designable appearance.

In the 5 th region 23, the average roughness Sa _ m of the mirror surface 10/the average roughness Sa of the grain 14a exceeds 0.2. When the ratio of the average roughness Sa _ m of the mirror surface 10 to the average roughness Sa of the grain 14a exceeds 0.2, the grain 14a is shallow, so that the difference in appearance between the mirror surface 10 and the grain 14a is small.

In the 6 th region 24, the average roughness Sa _ m of the mirror 10/the average roughness Sa of the ridges 14a is less than 0.01. When the ratio of the average roughness Sa _ m of the mirror surface 10 to the average roughness Sa of the grain 14a is less than 0.01, the grain 14a is too deep, and therefore light is diffusely reflected, resulting in a dazzling and rough appearance. And the processing time of the vein 14a becomes long, productivity is lowered.

In the outer case 4, the average roughness Sa of the mirror surface 10 Sa _ m/average roughness Sa of the grain 14a is 0.01 to 0.2. Further, the average roughness Sa of the streaks 14a is 0.03 to 0.1 inclusive with respect to the maximum roughness Sz. At this time, the grain 14a has luster, and the grain 14a can appropriately diffuse light to form a surface with high design.

With this configuration, the surface 4a of the outer case 4 of the timepiece 1 is less likely to be damaged, and has a design appearance. Therefore, the timepiece 1 can be a timepiece 1 having an exterior case 4 in which the surface 4a of the exterior case 4 is not easily damaged and which has an appearance with high design.

Next, a method for manufacturing the outer case 4 will be described with reference to fig. 6. In the flowchart of fig. 6, step S1 is a shape forming process. In this step, the member having the ferrite phase is forged to form the shape of the outer case 4. A member as a raw material is held by a die and deformed by pressing with a press machine. Further, the shape of the outer case 4 may be formed by cutting a member having a ferrite phase by a milling machine. Subsequently, the process proceeds to step S2.

Step S2 is a nitrogen absorption treatment process. In this step, the housing case 4 is subjected to nitrogen absorption treatment. In the nitrogen absorption treatment, a nitrogen absorption treatment apparatus is prepared, which has a treatment chamber surrounded by a heat insulating material such as glass fiber, a heating unit for heating the inside of the treatment chamber, a pressure reducing unit for reducing the pressure of the inside of the treatment chamber, and a nitrogen gas introducing unit for introducing nitrogen gas into the treatment chamber. Next, the outer case 4 was installed in the treatment chamber of the nitrogen absorption treatment apparatus, and then the pressure in the treatment chamber was reduced to 2Pa by the pressure reduction means.

Then, the pressure reducing unit exhausts the inside of the processing chamber, and the nitrogen gas introducing unit introduces nitrogen gas into the processing chamber. The pressure in the processing chamber is maintained at 0.08-0.12 MPa. In this state, the heating unit increased the temperature in the treatment chamber to 1200 ℃ at a rate of 5 ℃/min.

The temperature of 1200 ℃ was maintained for 4.0 hours, which was the treatment time obtained, so that the surface layer thickness 16a became 450 μm. The treatment time of 4.0 hours was determined by a previous experiment.

Then, the outer case 4 is cooled rapidly by water cooling. Thereby, the surface layer 16 having the austenitizing phase is formed on the surface 4a side of the base portion 15, and the mixed layer 17 in which the austenitizing phase and the ferrite phase are mixed is formed between the base portion 15 and the surface layer 16. Subsequently, the process proceeds to step S3.

Step S3 is a polishing and grinding process. In this step, the surface 4a of the outer case 4 is polished. The motor rotates the polishing wheel containing the alumina abrasive, and the operator presses the outer case 4 against the polishing wheel. The polishing wheel is special cotton cloth for grinding. The outer case 4 is polished to a mirror surface 10. For the polishing wheel, a pink polishing wheel for jewelry was used. Subsequently, the process proceeds to step S4.

Step S4 is a texturing process. In this process, a plurality of streaks 14a are formed on a part of the mirror 10. In this step, a ring processing machine is used. The endless working machine rotates an endless abrasive cloth belt. The operator presses the outer case 4 against the polishing cloth tape while applying the alumina polishing agent to the polishing cloth tape. For example, No. 240 was used as the alumina abrasive. The operator controls the pressing force to set the surface roughness of the outer case 4 in the 1 st region 18 and the 4 th region 22. If the pressing force is too strong, the state of the 2 nd region 19 and the 6 th region 24 is established. If the pressing force is weak, the 3 rd region 21 and the 5 th region 23 are in a state. Subsequently, the process proceeds to step S5.

Step S5 is a cleaning process. This step is a step of removing the alumina polishing agent and dust adhering to the outer case 4. Through the above steps, the vein installation surface 14 is formed on the surface 4a of the outer case 4. According to the above method, the exterior case 4 having the grain installation surface 14 can be provided, the grain installation surface 14 has luster on the surface 4a which is solution-hardened by nitrogen, and the grain 14a makes light appropriately diffuse and reflect, so that the grain installation surface 14 has design.

Embodiment 2

In the above embodiment 1, the textured mounting surface 14 is formed on the exterior case 4. The timepiece component forming the vein installation surface 14 may be applied to the glass rim portion 6, the band 3 for a timepiece, the crown, or the back cover.

Embodiment 3

In the embodiment 1, the maximum roughness Sz of the ridges 14a is 6 μm to 15 μm. The average roughness Sa of the mirror surface 10, Sa _ m/grain 14a, is defined to be 0.01 to 0.2, and Sa/Sz is defined to be 0.03 to 0.1. At this time, the maximum roughness Sz of the grain 14a may be less than 6 μm according to the preference of the appearance. The maximum roughness Sz of the ridges 14a may also exceed 15 μm.