Manufacturing method of rolling device

Abstract

To provide a rolling device with high performance by using a material that has high non-magnetic properties, high corrosion resistance and high rigidity and of which workability and Young's modulus are equivalent to steel.SOLUTION: A member that constitutes at least one of an inner member, an outer member and a rolling element, constituting a rolling device, is constituted by nickel-based alloy comprising 35-45 wt.% of Cr, 3.7-5 wt.% of Al, balance Ni and unavoidable impurities. Rockwell hardness in a surface layer of the nickel-based alloy constituting at least one of the inner member, the outer member and the rolling element is 40 HRC or less after solid solution treatment, and is 58 HRC or more after precipitation hardening treatment. An average KAM (Kernel Average Misorientation) value in the surface layer of the nickel-based alloy constituting at least one of the inner member, the outer member and the rolling element is 0.35 or less after the solid solution treatment, and is 0.5 or more after the precipitation hardening treatment.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This invention relates to rolling reefs. Place This concerns the manufacturing method. [Background technology]

[0002] Conventional mechanical elements include rolling devices such as ball screws, linear guides, linear bearings, and ball splines. Such rolling devices consist of an inner member having a raceway surface on its outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member and positioned outside the inner member, and a plurality of rolling elements arranged to roll freely between the two raceway surfaces, thereby allowing the outer member to reciprocate or rotate freely in the axial or circumferential direction of the inner member.

[0003] In this type of rolling mechanism, multiple rolling elements are arranged between an inner member and an outer member and repeatedly perform rolling motion. As a result, repeated contact stress is applied to the components of this rolling mechanism. Therefore, the materials that make up the inner member, outer member, and rolling elements are generally made of metals or other materials that have excellent fatigue life and wear resistance.

[0004] Furthermore, because this type of rolling mechanism is sometimes used in applications requiring a clean environment, such as cleanrooms, semiconductor manufacturing equipment, LCD panel manufacturing equipment, and food processing equipment, or in special environments such as medical equipment, the materials constituting the inner and outer components and the rolling elements may require high corrosion resistance and non-magnetic properties. Conventional materials that are both non-magnetic and highly corrosion-resistant include beryllium copper and austenitic stainless steel, and attempts have been made to apply these non-magnetic and highly corrosion-resistant materials to rolling mechanisms. For example, Patent Document 1 below discloses a rolling mechanism (motion guide device) using an austenitic metal and a method for manufacturing the same. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2006 / 112213 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, materials such as beryllium copper and austenitic stainless steel have a low maximum hardness of around 40 HRC on the Rockwell hardness scale. Therefore, when rolling gears are manufactured using these materials, there is a problem in that the rated load is lower than that of conventional products. As a countermeasure to this problem, conventional technology has been used to increase the rated load by selecting a rolling gear model with a larger size than that of conventional products.

[0007] Furthermore, while ceramic materials exist as non-magnetic, highly corrosion-resistant, and sufficiently hard materials, their poor machinability makes it difficult to manufacture high-precision rolling mechanisms. In addition, ceramic materials have the drawback of having a high Young's modulus and low toughness, making it impossible to implement a configuration that applies pre-pressure to the rolling mechanism.

[0008] The present invention has been made in view of the various problems present in the prior art described above, and its objective is to obtain a rolling device with high performance by obtaining a material that has high non-magnetic properties and high corrosion resistance, while also having high hardness suitable for use as a rolling device, and furthermore, has workability and a Young's modulus comparable to that of steel. [Means for solving the problem]

[0010] A method for manufacturing a rolling device according to the present invention comprises an inner member having a raceway surface on its outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member and disposed on the outside of the inner member, and a plurality of rolling elements disposed to be rotatable between the two raceway surfaces, wherein a nickel-based alloy consisting of 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being Ni and unavoidable impurities is selected as the component constituting at least one of the inner member, the outer member and the rolling elements, the Rockwell hardness of the surface layer of the nickel-based alloy constituting at least one of the inner member, the outer member and the rolling elements is set to 40 HRC or less after solution treatment and to 58 HRC or more after precipitation hardening treatment, and the average KAM (Kernel Average) of the surface layer of the nickel-based alloy constituting at least one of the inner member, the outer member and the rolling elements The Misorientation value is set to 0.35 or less after solution treatment, and to 0.5 or more after precipitation hardening treatment. The average KAM (Kernel Average Misorientation) value was calculated by EBSD measurement using a SEM. A KAM map was created, displaying the calculated KAM value at different distances from the lower end of the test piece, making it visually recognizable. The KAM map was then quantified based on the calculated crystal orientation difference shown in the KAM map. This allowed for the creation of a diagram showing the average KAM (Kernel Average Misorientation) values ​​after solution treatment and precipitation hardening treatment obtained using test pieces from the Jominy test, at different distances from the lower end of the test piece. From this diagram, the average KAM values ​​at the surface of the nickel-based alloy after solution treatment and precipitation hardening treatment, which meet the conditions for a hardness of 58 HRC or higher after precipitation hardening treatment, were determined. It is characterized by the following: [Effects of the Invention]

[0011] According to the present invention, a rolling device with high performance can be obtained by obtaining a material that has high non-magnetic properties and high corrosion resistance, while also possessing high hardness suitable for use as a rolling device, and furthermore, having processability and a Young's modulus comparable to that of steel. [Brief explanation of the drawing]

[0012] [Figure 1] This is a flowchart illustrating the processing steps for the nickel-based alloy according to this embodiment. [Figure 2] This diagram shows the test piece used in the Jominy test, with subdivision (a) showing a top view and subdivision (b) showing a front view. [Figure 3] This is a flowchart illustrating the testing method for the Jominy test. [Figure 4] This figure shows the temperature measurements taken over time using test pieces from the Jominy test. [Figure 5] It is a diagram showing the measured hardness values after solution treatment and after precipitation hardening treatment, measured using a test piece for the Jominy test, for each distance from the lower end of the test piece. [Figure 6] It is a diagram showing a KAM map indicating the measured KAM values in a visually recognizable manner, for each distance from the lower end of the test piece. [Figure 7] It is a diagram showing the average KAM (Kernel Average Misorientation) values after solution treatment and after precipitation hardening treatment obtained using a test piece for the Jominy test, for each distance from the lower end of the test piece. [Figure 8] It is a diagram graphing the measurement results of the relative permeability for each magnetic field strength of the nickel-based alloy according to this embodiment, using a vibrating sample magnetometer. [Figure 9] It is a flowchart diagram for explaining the test procedure of a hydrogen fluoride corrosion test conducted to verify the corrosion resistance of the nickel-based alloy of this embodiment. [Figure 10] It is a diagram summarizing the test results for the nickel-based alloy according to this embodiment obtained by the hydrogen fluoride corrosion test. [Figure 11] It is a diagram summarizing the test results for SUS304 as a comparative example obtained by the hydrogen fluoride corrosion test. [Figure 12] It is a diagram summarizing the test results for HPM75 as a comparative example obtained by the hydrogen fluoride corrosion test. [Figure 13] It is a diagram summarizing the test results for SUS316L as a comparative example obtained by the hydrogen fluoride corrosion test. [Figure 14] It is a diagram summarizing the test results for SUS440C as a comparative example obtained by the hydrogen fluoride corrosion test. [Figure 15] It is an external perspective view exemplifying one form when the rolling device according to this embodiment is configured as a linear guide device. [Figure 16] It is a cross-sectional view for explaining the infinite circulation path provided in the linear guide device shown in FIG. 15. [Figure 17] This figure illustrates an example where the rolling device according to this embodiment is configured as a ball screw device. [Figure 18] This figure illustrates an example where the rolling device according to this embodiment is configured as a spline device. [Figure 19] This is a partial longitudinal perspective view illustrating one configuration in which the rolling device according to this embodiment is configured as a rotary bearing device. [Figure 20] This figure shows a longitudinal cross-section of the rotary bearing device shown in Figure 19. [Figure 21] This is an external perspective view illustrating one configuration in which the rolling mechanism according to this embodiment is configured as a sliding screw mechanism. [Figure 22] This figure illustrates various application examples of the present invention and is a partial cross-sectional view showing an external perspective of a rolling device in which a linear motion guide and a ball screw are combined to form an integrated structure. [Modes for carrying out the invention]

[0013] The inventors, in selecting a material that possesses high non-magnetic properties and high corrosion resistance, while also having high hardness suitable for use as a rolling device, and furthermore, having workability and a Young's modulus comparable to steel, focused on nickel-based alloys during their research and testing of various materials. This nickel-based alloy is a metallic material belonging to the non-ferrous metal category, and its material can be softened by solution treatment and then hardened by precipitation hardening treatment. It is also known to have workability and a Young's modulus comparable to steel. Furthermore, although nickel itself is a magnetic material, it becomes non-magnetic by adding chromium. In addition, nickel is known to be a highly corrosion-resistant element. Therefore, it was anticipated that nickel-based alloys could achieve properties such as high non-magnetic properties and high corrosion resistance, which are difficult to achieve with iron-based metals such as steel. However, mass production is not possible unless the conditions for heat treatment processes such as solution treatment and precipitation hardening treatment are clarified, as well as the manufacturing conditions. Having grasped these challenges, the inventors conducted various tests and studies to determine the manufacturing conditions for mass production of nickel-based alloys, and succeeded in discovering the nickel-based alloy of the present invention that can be applied to rolling devices. The details of this invention are described below.

[0014] First, the nickel-based alloy of the present invention, discovered by the inventors through diligent testing and research, consists of 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being Ni, and unavoidable impurities. More specifically, various tests and studies were conducted based on the nickel-based alloy of this embodiment that satisfies the component conditions shown in Table 1 below.

[0015] [Table 1]

[0016] The nickel-based alloy according to this embodiment has the following compositional conditions, as shown in Table 1: 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being 55% by weight or more of Ni, and unavoidable impurities (however, Fe is less than 1% by weight). However, the inventors have confirmed that the properties of the nickel-based alloy according to this embodiment, described later, are similar to those of any nickel-based alloy consisting of 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being Ni, and unavoidable impurities. Therefore, the compositional conditions for determining the non-ferrous metal species applicable to the nickel-based alloy of the present invention are as long as they consist of 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being Ni, and unavoidable impurities.

[0017] Next, the inventors considered the processing steps for applying the nickel-based alloy of this embodiment to a rolling mechanism. As a result, they concluded that by adopting the processing steps shown in Figure 1, it would be possible to manufacture machined nickel-based alloy parts applicable to rolling mechanisms. Here, Figure 1 is a flowchart showing the processing steps for the nickel-based alloy of this embodiment.

[0018] The processing steps shown in Figure 1 involve first preparing a rolled material made of a nickel-based alloy (step S10), and then performing a first heat treatment, a solution treatment, on this rolled material to soften it (step S11). Next, rough machining is performed on the material that has been softened by the solution treatment (step S12) to obtain a shape close to the shape of the internal members, external members, or rolling elements that constitute the rolling gear. Furthermore, a second heat treatment, a precipitation hardening treatment, is performed on the roughly machined material to obtain a hardness sufficient for use as a component of the rolling gear (step S13). After that, grinding is performed to process the material into the shape of the internal members, external members, or rolling elements that constitute the rolling gear (step S14), and the obtained processed parts are assembled (step S15) to complete the internal members, external members, or rolling elements that constitute the rolling gear (step S16). By performing these processing steps, the nickel-based alloy of this embodiment can be applied to the rolling gear. However, in order to make the processing steps shown in Figure 1 feasible, it is necessary to know the conditions for performing the first heat treatment, solution treatment, shown in step S11, the conditions for performing the second heat treatment, precipitation hardening treatment, shown in step S13, and to what depth near the surface the material after the second heat treatment, precipitation hardening treatment, shown in step S13, has a hardness useful for the rolling device. If these conditions are known, the machinable range of the grinding process shown in step S14 can be determined. Therefore, in order to make the processing steps shown in Figure 1 feasible, the inventors decided to perform the Jominy test shown in Figures 2 and 3 in order to evaluate the characteristics of the heat treatment process.

[0019] Here, Figure 2 shows the test piece used in the Jominy test, with subdivision (a) showing a top view and subdivision (b) showing a front view. Figure 3 is a flowchart illustrating the Jominy test procedure.

[0020] As shown in Figure 2, the test piece 10 used in the Jominy test conducted by the inventors has a cylindrical body with dimensions of φ25mm × 100mm, and six thermocouple mounting holes 11 are formed longitudinally from the top surface to the bottom end. A thermocouple is installed in each of the six thermocouple mounting holes 11. In the Jominy test of this embodiment, the test piece 10 is heated and then cooling water is applied to the bottom end of the test piece 10. At this time, the thermocouples installed in each of the six thermocouple mounting holes 11 are used to measure the temperature at a total of six locations at 1.8mm, 5mm, 10mm, 25mm, 50mm, and 75mm from the bottom end of the test piece 10. This allows for the evaluation of the heat treatment characteristics by measuring the temperature at each elapsed time at the six temperature measurement positions set upward from the bottom end of the test piece 10, as well as the hardness of the test piece 10 after heat treatment and water cooling.

[0021] Next, with reference to Figure 3, the inventors' Jominy test method will be described. In the Jominy test of this embodiment, first, a test piece 10 shown in Figure 2 is prepared (step S30), and this test piece 10 is heated at 1,150°C for 1 hour (step S31). After the heating in step S31 is completed, the test piece 10 is subjected to a solution treatment by applying 20°C cooling water from the lower end of the test piece 10 (step S32). In addition, the temperature is measured over time using six thermocouples installed on the test piece 10 while the cooling water is continuously applied (step S33). Furthermore, after the cooling with the cooling water is completed, the hardness of the test piece 10 after the solution treatment is completed is measured (step S34). Subsequently, the test piece 10 is heated at 585°C for 16 hours, and then air-cooled to perform a precipitation hardening treatment (step S35). After the precipitation hardening treatment in step S35 is completed, the hardness of the test piece 10 after precipitation hardening is measured (step S36). The Jominy test is completed by performing the above steps.

[0022] The Jominy test shown in Figures 2 and 3 is originally a test method for evaluating the hardenability of steel, and is not generally applied to non-ferrous metal materials. However, the inventors succeeded in evaluating the heat treatment properties of the nickel-based alloy of this embodiment by using the Jominy test for the first time on a non-ferrous metal material. Next, the heat treatment properties of the nickel-based alloy of this embodiment obtained using the Jominy test will be explained.

[0023] First, Figure 4 shows the temperature measurement results over time using a test piece from the Jominy test. The results shown in Figure 4 are a graph of the measurement results performed in step S33 in Figure 3. From the results shown in Figure 4, it was confirmed that the closer the test piece 10 is to the lower end being cooled by the cooling water, the faster the cooling, and the further away it is, the longer the cooling takes. In other words, when solution treatment is performed on the nickel-based alloy of this embodiment, it became clear that the cooling rate is faster the closer the nickel-based alloy is to the surface (i.e., shallower) and slower the further away it is from the surface (i.e., deeper). From these results, it became clear that the effect of solution treatment to soften the material is higher the closer it is to the surface (i.e., shallower) of the nickel-based alloy, thus reducing hardness, and lower the further away it is from the surface (i.e., deeper), thus maintaining hardness.

[0024] After reviewing the results shown in Figure 4, the measured hardness values ​​after solution treatment and precipitation hardening treatment in the Jominy test were compared. Here, Figure 5 shows the measured hardness values ​​after solution treatment and precipitation hardening treatment, measured using the Jominy test piece, at different distances from the lower end of the test piece.

[0025] As can be seen from Figure 5, conventional knowledge in this field held that only precipitation hardening treatment contributed to an increase in hardness. However, Figure 5, which summarizes the results of the Jominy test conducted by the inventors, revealed that the hardness after precipitation hardening treatment depends on the hardness after solution treatment. Specifically, it became clear that in order to satisfy the condition that the hardness after precipitation hardening treatment should be 58 HRC or higher on the Rockwell hardness scale, which the inventors considered necessary for use as a component of a rolling mechanism, the hardness after solution treatment must be 40 HRC or lower on the Rockwell hardness scale. Thus, the finding that the hardness after the second heat treatment, precipitation hardening treatment, must not reach 58 HRC or higher unless the hardness is reduced to 40 HRC or lower in the first heat treatment, solution treatment, is a fact that was only revealed by adopting a completely new test evaluation method: applying the Jominy test to nickel-based alloys, which are non-ferrous metals.

[0026] Furthermore, as can be seen from Figure 5, it was revealed that the condition for achieving a hardness of 58 HRC or higher after precipitation hardening treatment when water-cooled is met if the nickel-based alloy is cut to a depth of 35 mm from the surface. This fact is an important finding in the grinding process shown in step S14 of the processing process of the nickel-based alloy in this embodiment shown in Figure 1. This finding indicates that when cutting components of a rolling gear from a rolled material undergoing rough machining or grinding, if the raceway surface, which needs to have a hardness of 58 HRC or higher, is located deeper than 35 mm, a hardness of 58 HRC or higher cannot be obtained after precipitation hardening treatment. In that case, the material should be cut in advance so that the raceway surface is within 35 mm from the material surface before solution treatment. In other words, the heat treatment characteristics of the nickel-based alloy in this embodiment have been clarified by the findings obtained, making it possible to apply the nickel-based alloy as a component of a rolling gear and mass-produce it.

[0027] Based on the findings in Figure 5, the inventors conducted further investigations. Specifically, they performed measurements and analyses using EBSD (Electron Backscatter Diffraction), an additional function of SEM (Scanning Electron Microscope), to perform an analytical evaluation based on a new evaluation method called KAM (Kernel Average Misorientation) value. This KAM value is an index adopted to define the cooling rate after solution treatment. More specifically, the KAM value is a value that can be calculated by EBSD measurement using SEM, and it indicates the orientation difference of the crystal. The EBSD measurement data was obtained under analytical conditions of an acceleration voltage of 15kV, a step size of 0.1μm, and an MMA threshold of 5. After cutting the sample, it was polished to a mirror finish by mechanical and chemical polishing, and then ion milled at an acceleration voltage of 40kV for 10 minutes. Figure 6 shows a KAM map, which visually displays the measured KAM values ​​in a recognizable manner, at different distances from the lower end of the test piece 10. In Figure 6, the darker the hatching in the KAM map, the higher the value calculated for the crystal orientation difference (an indicator of the amount of dislocations), and the higher the hardness value.

[0028] Furthermore, the inventors quantified the KAM map shown in Figure 6 and created the diagram shown in Figure 7. Here, Figure 7 shows the average KAM (Kernel Average Misorientation) values ​​obtained using Jominy test pieces, after solution treatment and after precipitation hardening treatment, at different distances from the lower end of the test piece. As can be seen from Figure 7, at a depth of 35 mm from the surface of the nickel-based alloy, which is the condition for the hardness after precipitation hardening to be 58 HRC or higher, the average KAM value after solution treatment is 0.35 or less, and the average KAM value after precipitation hardening treatment is in the range of 0.5 or higher. In other words, it has become clear that the conditions for applying the nickel-based alloy according to this embodiment as a component of a rolling mechanism and mass-producing it are an average KAM value of 0.35 or less after solution treatment and 0.5 or higher after precipitation hardening treatment. By finding a new indicator for applying the nickel-based alloy as a component of a rolling mechanism, the applicability of the nickel-based alloy according to this embodiment can be expanded.

[0029] The inventors' tests and research described above revealed that the nickel-based alloy according to this embodiment, after undergoing a predetermined heat treatment process, possesses high hardness suitable for use as a rolling device, and can also be used as a material with processability and a Young's modulus comparable to steel. Next, the inventors verified whether the nickel-based alloy according to this embodiment possesses high non-magnetic properties.

[0030] The inventors prepared a nickel-based alloy according to this embodiment, in which the Rockwell hardness in the surface layer (up to a depth of 35 mm from the surface) is 40 HRC or less after solution treatment and 58 HRC or more after precipitation hardening treatment, and the average KAM (Kernel Average Misorientation) value in the surface layer (up to a depth of 35 mm from the surface) is 0.35 or less after solution treatment and 0.5 or more after precipitation hardening treatment. They then evaluated the non-magnetic properties of this nickel-based alloy by measuring its relative permeability.

[0031] First, the inventors measured the relative permeability using a ferromaster permeator, a measuring instrument commonly used to measure the relative permeability of low-permeability materials. The measurement conditions are shown in Table 2.

[0032] [Table 2]

[0033] Table 3 shows the measurement results using the ferromaster permeability meter shown in Table 2. In addition to the nickel-based alloy according to this embodiment, measurements using the ferromaster permeability meter were also performed for comparative purposes: Comparative Example 1: solution-treated SUS304; Comparative Example 2: HPM75; and Comparative Example 3: work-hardened SUS304.

[0034] [Table 3]

[0035] As shown in Table 3, the relative permeability of the nickel-based alloy according to this embodiment was 1.001 μF, as measured using a ferromaster permeability meter. r This demonstrated that the nickel-based alloy according to this embodiment is suitable for a magnetic field strength of 3.5 × 10⁻⁶. 4 Relative permeability μ in A / m r However, μ r It was found that the inequality <1.001 is satisfied. Furthermore, it was found that the nickel-based alloy according to this embodiment is a material with higher non-magnetic properties than the other comparative examples 1 to 3.

[0036] However, in measurements using the ferromaster permeability meter shown in Tables 2 and 3, the lower limit of the measurable relative permeability is 1.001 μF. r Therefore, it is not possible to obtain more detailed values. Thus, the inventors decided to measure the magnetic properties of the nickel-based alloy according to this embodiment in detail using a vibrating sample magnetometer (VSM). Table 4 shows the measurement conditions for the vibrating sample magnetometer.

[0037]

Table 4

[0038] The measurement results by the vibrating sample type magnetometer shown in Table 4 are shown in Table 5. Regarding the measurement by the vibrating sample type magnetometer as well, in addition to the nickel-based alloy according to the present embodiment, for comparison, annealed SUS304 as Comparative Example 1, HPM75 as Comparative Example 2, and cold-worked SUS304 as Comparative Example 3 were used.

[0039]

Table 5

[0040] In addition, a graph of the measurement results by the vibrating sample type magnetometer is shown in FIG. 8. FIG. 8 is a graph showing the measurement results of the relative permeability for each magnetic field strength of the nickel-based alloy according to the present embodiment by the vibrating sample type magnetometer. As shown in FIG. 8 and Table 5, as a result of the measurement by the vibrating sample type magnetometer, the nickel-based alloy according to the present embodiment has a maximum relative permeability of 1.00035 μ, which is lower than the lower limit value of the measurement using the ferrumaster permeameter. r It became clear that it shows a very low value of. This result shows that the nickel-based alloy according to the present embodiment has very high non-magnetic properties even compared with the materials of Comparative Examples 1 to 3. Also, in the measurement by the vibrating sample type magnetometer, the applied magnetic field is -7.8×10 5 ~7.8×10 5 A / m in a wide range, it became clear that the nickel-based alloy according to the present embodiment shows a very low relative permeability. From this result, it was found that the nickel-based alloy according to the present embodiment has a relative permeability μ 4 at a magnetic field strength of 3.5×10 r that satisfies the inequality μ r ≦1.0004, and further, this inequality was found to hold also in the range where the applied magnetic field is -7.8×10 5 ~7.8×10 5 A / m.

[0041] The inventors' tests and research described above revealed that the nickel-based alloy according to this embodiment, after undergoing a predetermined heat treatment process, possesses high hardness suitable for use as a rolling device, and can be used as a material with processability and a Young's modulus comparable to steel. Furthermore, it was revealed that the nickel-based alloy according to this embodiment has high non-magnetic properties. Next, the inventors verified whether the nickel-based alloy according to this embodiment has high corrosion resistance.

[0042] The inventors will now explain the test procedures for verifying the corrosion resistance of the nickel-based alloy according to this embodiment, using Figure 9 as a reference. Figure 9 is a flowchart illustrating the test procedure for the hydrogen fluoride corrosion test conducted to verify the corrosion resistance of the nickel-based alloy of this embodiment.

[0043] The hydrogen fluoride corrosion test conducted by the inventors was performed to evaluate the corrosion resistance of the test materials to hydrofluoric acid (HF). The test materials were five types: the nickel-based alloy according to this embodiment, and SUS304, HPM75, SUS316L, and SUS440C. Two test pieces were prepared for each material, and two solutions were prepared by diluting hydrofluoric acid with ultrapure water, with solution concentrations of 0.1% and 1%. The specific procedure for the hydrogen fluoride corrosion test was as shown in Figure 9: first, the surface of the test piece was ground to a uniform roughness Ra of 0.1 to 0.2 μm (step S90), and then the surface of the test piece was washed with n-hexane (step S91). The prepared test specimens were masked with masking seals with φ30 mm holes (step S92), and 0.1% and 1% solutions were dripped onto each sample for contact with the liquid, followed by air drying for 24 hours (step S93). During the air drying in step S93, no additional solution was added even if the solution dried out. After that, the test specimens were washed with ultrapure water and then air dried for another 24 hours (step S94). Finally, photographs of the test specimen surfaces obtained through the process from steps S90 to S94 were taken with a digital camera and a digital microscope (step S95), and the corrosion resistance of the test material was evaluated by visually observing the photographs.

[0044] Figures 10 to 14 show the test results obtained from the hydrogen fluoride corrosion test described using Figure 9. Here, Figure 10 is a summary of the test results for the nickel-based alloy according to this embodiment obtained from the hydrogen fluoride corrosion test, Figure 11 is a summary of the test results for SUS304 as a comparative example obtained from the hydrogen fluoride corrosion test, Figure 12 is a summary of the test results for HPM75 as a comparative example obtained from the hydrogen fluoride corrosion test, Figure 13 is a summary of the test results for SUS316L as a comparative example obtained from the hydrogen fluoride corrosion test, and Figure 14 is a summary of the test results for SUS440C as a comparative example obtained from the hydrogen fluoride corrosion test. In Figures 10 to 14, for two types of hydrogen fluoride solution concentrations, 0.1% and 1%, the overall appearance is shown in the upper row, a magnified photograph at 20x magnification is shown in the middle row, and a magnified photograph at 100x magnification is shown in the lower row.

[0045] As is clear from Figures 10 to 14, the nickel-based alloy according to this embodiment maintained an extremely clean state without rust formation or deterioration of surface properties, even after being exposed to 0.1% and 1% hydrogen fluoride solutions and air-dried. On the other hand, among the comparative materials, HPM75 shown in Figure 12 and SUS440C shown in Figure 14 showed rust formation on the entire surface of the test specimens. In addition, SUS304 shown in Figure 10 and SUS316L shown in Figure 13 showed little rust formation, but deterioration of surface properties was observed. The hydrogen fluoride corrosion tests described above confirmed that the nickel-based alloy according to this embodiment has extremely high corrosion resistance.

[0046] As described above, the inventors' test studies have revealed that the nickel-based alloy according to this embodiment possesses the following characteristics: high non-magnetic properties and high corrosion resistance, while also having high hardness suitable for use as a rolling device, and furthermore, it is a material with workability and a Young's modulus comparable to that of steel. The alloying components of the nickel-based alloy according to the present invention consist of 35-45% by weight of Cr, 3.7-5% by weight of Al, the remainder being Ni and unavoidable impurities. The Rockwell hardness of the surface layer of nickel-based alloys is 40 HRC or less after solution hardening and 58 HRC or more after precipitation hardening. The average KAM (Kernel Average Misorientation) value on the surface of the nickel-based alloy is 0.35 or less after solution treatment and 0.5 or more after precipitation hardening treatment. The surface layer of the nickel-based alloy includes at least the area from the surface of the nickel-based alloy to a depth of 35 mm. • Magnetic field strength of nickel-based alloy: 3.5 × 10⁻⁶ 4 Relative permeability μ in A / m r μ r This satisfies the inequality < 1.001. Furthermore, the magnetic field strength of the nickel-based alloy is 3.5 × 10⁻⁶. 4 Relative permeability μ in A / m r μ r It satisfies the inequality ≤ 1.0004. By applying the nickel-based alloy according to the present invention, which has the above-described configuration, to a rolling device, a rolling device with high performance can be obtained. Next, we will explain an example of applying a component made from the nickel-based alloy according to the present invention to a rolling device.

[0047] [Examples of application to rolling mechanisms] Specific embodiments of a rolling device using a component made of a nickel-based alloy according to the present invention as a rolling and sliding component will be described with reference to the drawings. Note that the embodiments of the rolling device illustrated below are not intended to limit the invention as defined in each claim, and not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, the term "rolling device" in this specification includes all devices involving rolling and sliding movements, such as rolling bearings used in machine tools, lubrication-free bearings used in vacuum, linear guides and linear guide devices, ball spline devices, ball screw devices, roller screw devices, and cross-roller rings.

[0048] (Example of application to linear guide devices) The rolling mechanism according to this embodiment can be configured as a linear guide device as shown in Figures 15 and 16. By using components made from the nickel-based alloy according to the present invention as described above for the components of such a linear guide device, it is possible to realize a rolling mechanism with high performance, including high non-magnetic properties, high corrosion resistance, high hardness suitable for use as a rolling mechanism, and materials with workability and a Young's modulus comparable to steel. Here, Figure 15 is an external perspective view illustrating one form of the rolling mechanism according to this embodiment when configured as a linear guide device. Figure 16 is a cross-sectional view illustrating the infinite circulation path provided by the linear guide device shown in Figure 15.

[0049] First, the configuration of the linear guide device 40 illustrated in Figures 15 and 16 will be described. The linear guide device 40 as a rolling device according to this embodiment comprises a track rail 41 as an inner member and a movable block 43 as an outer member that is slidably attached to the track rail 41 via a plurality of balls 42 installed as rolling elements. The track rail 41 is a long member with a cross section perpendicular to its longitudinal direction that is roughly rectangular in shape, and a rolling element running surface 41a, which serves as a track surface for the balls 42 to roll on, is formed on its surface (top surface and both sides) along the entire length of the track rail 41.

[0050] Here, the track rail 41 may be formed to extend in a straight line or in a curved line. Also, although there are a total of four rolling element running surfaces 41a, two on each side, as illustrated in Figures 15 and 16, the number of these surfaces can be arbitrarily changed depending on the application of the linear guide device 40.

[0051] On the other hand, the moving block 43 is provided with load-operated rolling surface 43a as a track surface at positions corresponding to the rolling surface 41a. A load-operated rolling surface 52 is formed by the rolling surface 41a of the track rail 41 and the load-operated rolling surface 43a of the moving block 43, and multiple balls 42 are sandwiched between them. Furthermore, the moving block 43 is provided with four unloaded rolling surfaces 53 extending parallel to each rolling surface 41a, and direction-changing paths 55 connecting each unloaded rolling surface 53 to each load-operated rolling surface 52. A single infinite loop is formed by the combination of one load-operated rolling surface 52 and one unloaded rolling surface 53, and the pair of direction-changing paths 55 connecting them (see Figure 16).

[0052] Furthermore, by installing multiple balls 42 in an infinite circulation path consisting of a load-loaded track 52, an unloaded track 53, and a pair of direction-changing tracks 55, 55, the movable block 43 is able to reciprocate relative to the track rail 41.

[0053] In the linear guide device 40 according to this embodiment, which has the above-described configuration, it is preferable to apply the nickel-based alloy according to the present invention to the members constituting the track rail 41 as an inner member, the moving block 43 as an outer member, and at least one of the balls 42 which are installed as a plurality of rolling elements.

[0054] In this embodiment of the linear guide device 40, the nickel-based alloy of the present invention may be used for all components, or it may be used for some components. This selection can be made according to the operating environment, application, or manufacturing cost of the linear guide device 40.

[0055] (Example of application to rolling element screw devices) Furthermore, the rolling device according to this embodiment can be configured as a ball screw device 56, for example, as shown in Figure 17. Figure 17 is a diagram illustrating the case in which the rolling device according to this embodiment is configured as a ball screw device. Such a ball screw device 56 is a device comprising a screw shaft 57 as an internal member and a nut member 59 as an external member that is rotatably attached to the screw shaft 57 via a plurality of balls 58.

[0056] The screw shaft 57 is an inner member with a helical raceway surface, or rolling element groove 57a, formed on its outer circumference, while the nut member 59 is an outer member with a helical raceway surface, or load racing groove, corresponding to the rolling element groove 57a, formed on its inner circumference. The nut member 59 is able to reciprocate relative to the screw shaft 57 as the screw shaft 57 rotates relative to the nut member 59.

[0057] Furthermore, by using the nickel-based alloy according to the present invention described above for the screw shaft 57, nut member 59, ball 58 and other components constituting the ball screw device 56, it is possible to realize a ball screw device 56 with high performance, which includes materials in its components that have high non-magnetic properties and high corrosion resistance, high hardness suitable for use as a rolling device, and machinability and Young's modulus comparable to steel.

[0058] (Example of application to spline devices) Furthermore, the rolling device according to this embodiment can be configured as a spline device 60, for example, as shown in Figure 18. Figure 18 is an example illustrating the case in which the rolling device according to this embodiment is configured as a spline device.

[0059] To briefly explain the configuration of the spline device 60 shown in Figure 18, the spline device 60 has a spline shaft 61 as an internal member and a cylindrical outer cylinder 63 as an external member that is movably attached to the spline shaft 61 via a plurality of balls 62 as rolling elements. On the surface of the spline shaft 61, a rolling element racing surface 61a is formed, which serves as the raceway for the balls 62 and extends in the axial direction of the spline shaft 61. On the outer cylinder 63 attached to the spline shaft 61, a load rolling element racing surface is formed as a raceway corresponding to the rolling element racing surface 61a. Multiple protrusions are formed on these load rolling element racing surfaces, extending in the direction in which the rolling element racing surface 61a extends. A load racing path is formed between the load rolling element racing surface formed on the outer cylinder 63 and the rolling element racing surface 61a formed on the spline shaft 61. Adjacent to the load racing path, an unloaded return passage is formed, on which the balls 62 move after being released from the load. The outer cylinder 63 incorporates a retainer 64 that aligns and holds a plurality of balls 62 in a circuit-like manner. The plurality of balls 62 are rotatably installed between the load rolling surface of the outer cylinder 63 and the rolling surface 61a of the spline shaft 61, and are installed to circulate indefinitely through the unloaded return passage, thereby enabling the outer cylinder 63 to reciprocate relative to the spline shaft 61.

[0060] Furthermore, in the case of the spline device 60 shown in Figure 18, by using the nickel-based alloy according to the present invention described above for the spline shaft 61, outer cylinder 63, ball 62, and other components that constitute the spline device 60, it is possible to realize a spline device 60 with high performance that includes materials in its components that have high non-magnetic properties and high corrosion resistance, high hardness suitable for use as a rolling device, and machinability and Young's modulus comparable to steel.

[0061] (Example of application to rotary bearing devices) Furthermore, the rolling mechanism according to this embodiment can be configured as a rotary bearing device 70, for example, as shown in Figures 19 and 20. Here, Figure 19 is a partial longitudinal perspective view illustrating one form in which the rolling mechanism according to this embodiment is configured as a rotary bearing device. Figure 20 is a diagram showing a longitudinal cross-section of the rotary bearing device shown in Figure 19.

[0062] As shown in Figures 19 and 20, the rolling mechanism configured as a rotary bearing device 70 includes an inner ring 71 as an inner member having an inner raceway surface 72 with a V-shaped cross-section on its outer circumference, an outer ring 73 as an outer member having an outer raceway surface 74 with a V-shaped cross-section on its inner circumference, and a plurality of rollers 77 as rolling elements arranged in a cross shape between a raceway path 75 with a substantially rectangular cross-section formed by the inner raceway surface 72 and the outer raceway surface 74, thereby enabling the inner ring 71 and the outer ring 73 to perform relative rotational motion in the circumferential direction.

[0063] By using the nickel-based alloy according to the present invention described above for the components constituting such a rotary bearing device 70, it is possible to realize a rotary bearing device 70 with high performance, which includes materials in its components that have high non-magnetic properties and high corrosion resistance, high hardness suitable for use as a rolling device, and machinability and Young's modulus comparable to steel.

[0064] (Example of application to sliding screw devices) The above-described devices were explained using examples of devices in which multiple rolling elements are interposed between an inner member and an outer member. However, the scope of application of the present invention, which is characterized by the configuration of a rolling device having high performance, including high non-magnetic properties and high corrosion resistance, high hardness suitable for use as a rolling device, and a material with workability and Young's modulus comparable to steel, by incorporating constituent members made of nickel-based alloy as described above, is not limited to those using such rolling elements, and can also be suitably used in devices in which an inner member and an outer member are in direct contact and capable of relative movement without the interposition of rolling elements.

[0065] For example, as shown in Figure 21, the present invention can also be applied to a rolling device configured as a sliding screw device 80. Here, Figure 21 is an external perspective view illustrating one form in which the rolling device according to this embodiment is configured as a sliding screw device. The sliding screw device 80 shown in Figure 21 has a screw shaft 81 as an inner member with a screw groove as a helical raceway surface formed on its outer circumference, and a nut member 83 as an outer member with a nut groove as a helical raceway surface corresponding to the screw groove formed on its inner circumference. The nut member 83 is configured to reciprocate relative to the screw shaft 81 as the screw shaft 81 rotates relative to the nut member 83.

[0066] Furthermore, in the case of the sliding screw device 80 shown in Figure 21, it is possible to use the nickel-based alloy according to the present invention described above for either or all of its constituent components, the screw shaft 81 and the nut member 83. By using the nickel-based alloy according to the present invention for the components of such a sliding screw device 80, it is possible to realize a sliding screw device 80 with high performance, including materials in its constituent components that have high non-magnetic properties, high corrosion resistance, high hardness suitable for use as a rolling device, and machinability and Young's modulus comparable to steel.

[0067] Although preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the embodiments described above. Various modifications or improvements can be made to the above embodiments.

[0068] For example, the present invention can be applied to a rolling device 90 of the type shown in Figure 22, in which a linear motion guide and a ball screw are combined to form an integrated structure. In the rolling device 90 shown in Figure 22, the screw shaft 91 and the moving block 93 are connected via a plurality of balls 95, but it is also possible to configure the screw shaft 91 and the moving block 93 as a sliding screw without the use of a plurality of balls 95.

[0069] It is clear from the claims that such modified or improved forms may also fall within the technical scope of the present invention. [Explanation of symbols]

[0070] 10 Test piece, 11 Thermocouple mounting hole, 40 Linear guide device (rolling device), 41 Track rail (inner member), 41a Rolling element running surface (track surface), 42 Ball (rolling element), 43 Moving block (outer member), 43a Loaded rolling element running surface (track surface), 48, 49 Screw hole, 52 Loaded running path, 53 Unloaded running path, 55 Direction change path, 56 Ball screw device (rolling device), 57 Screw shaft (inner member), 57a Rolling element running groove (track surface), 58 Ball (rolling element), 59 Nut member (outer member), 60 Spline device (rolling device), 61 Spline shaft (inner member), 61a Rolling element running surface (track surface), 62 Ball (rolling element), 63 Outer cylinder (outer member), 64 Cage, 70 Rotary bearing device (rolling device), 71 Inner ring (internal member), 72 Inner raceway surface (raceway surface), 73 Outer ring (external member), 74 Outer raceway surface (raceway surface), 75 Raceway path, 77 Roller (rolling element), 80 Sliding screw device, 81 Screw shaft (internal member), 83 Nut member (external member), 90 Rolling device, 91 Screw shaft (internal member), 93 Moving block (external member), 95 Ball (rolling element).

Claims

1. An inner member having a raceway surface on its outer surface, An outer member having a raceway surface facing the raceway surface of the inner member and positioned outside the inner member, A plurality of rolling elements are arranged to be rotatable between the two raceway surfaces, A method for manufacturing a rolling device comprising: As a component constituting at least one of the inner member, the outer member, and the rolling element, a nickel-based alloy consisting of 35 to 45% by weight of Cr, 3.7 to 5% by weight of Al, the remainder being Ni and unavoidable impurities is selected. The Rockwell hardness of the surface layer of the nickel-based alloy constituting at least one of the inner member, the outer member, and the rolling element is set to 40 HRC or less after solution treatment and to 58 HRC or more after precipitation hardening treatment, and further, The average KAM (Kernel Average Misorientation) value on the surface of the nickel-based alloy constituting at least one of the inner member, the outer member, and the rolling element shall be 0.35 or less after solution treatment and 0.5 or more after precipitation hardening treatment. The method for manufacturing a rolling device is characterized by determining the average KAM (Kernel Average Misorientation) value by calculating the KAM value by EBSD measurement using SEM, creating a KAM map as a diagram that displays the calculated KAM value at each distance from the lower end of the test piece so that it can be visually recognized, and quantifying the KAM map based on the calculated crystal orientation difference shown in the KAM map, thereby creating a diagram that shows the average KAM (Kernel Average Misorientation) value after solution treatment and precipitation hardening treatment obtained using a test piece of the Jominy test at each distance from the lower end of the test piece, and determining the average KAM value after solution treatment and precipitation hardening treatment on the surface layer of a nickel-based alloy that meets the conditions for a hardness of 58 HRC or higher after precipitation hardening treatment from this diagram.

2. A method for manufacturing a rolling device according to claim 1, The magnetic field strength of the nickel-based alloy constituting at least one of the inner member, the outer member, and the rolling element is 3.5 × 10⁻¹⁰. ４ Relative permeability μ at A / m ｒ However, μ ｒ A method for manufacturing a rolling device, characterized in that it satisfies the inequality <1.

001.

3. A method for manufacturing a rolling device according to claim 1, The magnetic field strength of the nickel-based alloy constituting at least one of the inner member, the outer member, and the rolling element is 3.5 × 10⁻¹⁰. ４ Relative permeability μ at A / m ｒ However, μ ｒ A method for manufacturing a rolling device, characterized in that it satisfies the inequality ≤ 1.0004.

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