Damping functional device including steel excellent in high-strength damping and fatigue resistance properties

Abstract

To provide a component or device having a damping function, which includes a steel excellent in high-strength damping and fatigue resistance properties.SOLUTION: The damping steel of the high-Mn, high-N system according to the present invention ("HIDAS alloy") is a high-manganese stainless steel having the composition comprising Mn of 3-18%, Si of 0.1-3.0%, Cr of 5-20% and N of 0.1-1.2%. The steel of this composition is subjected to predetermined heat treatment and processing so as to generate stacking faults. This structure absorbs external vibration or strain, thereby exhibiting excellent damping performance and fatigue resistance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to vibration damping functional parts or devices such as cutting tools, linear guide devices, ball screws, low-rebound steel balls, bearings, gear transmission devices, spring devices, and rotating bodies with vibration suppression functions, which are composed of high-strength steel with excellent vibration damping properties and fatigue resistance, and contain the steel.

Background Art

[0002]

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

[0004]

Non-Patent Documents

Non-Patent Documents

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to develop a high-Mn high-N damping steel and cause it to exhibit the property of absorbing vibration (hereinafter referred to as "damping property") due to the laminated defects generated in the material ([shown in FIG. 1]).

Means for Solving the Problem

[0006] The high-Mn high-N damping steel (hereinafter referred to as "HIDAS alloy") according to the present invention is a high-manganese stainless steel having a composition of Mn: 3 to 18%, Si: 0.1 to 3.0%, Cr: 5 to 20%, and N: 0.1 to 1.2%. By subjecting the steel of this composition to predetermined heat treatment and processing, laminated defects are generated. Since this structure absorbs external vibration or strain, it is excellent in damping property and fatigue resistance.

Effect of the Invention

[0007] The effect of the invention is that it is possible to manufacture materials that can be used in the following applications. That is, it is possible to develop materials applicable to damping tools comparable to super steel, energy-saving linear guides, low-rebound steel balls, energy-saving gear devices, low-dust chains, low-surge spring devices, high-speed combined lightweight machines, non-loosening bolts, and damping function devices / parts.

[0008] The following shows an overview of the HIDAS alloy. The HIDAS alloy (High Damping Stainless Alloy) has Cr: 5 to 20%, Mn: 3 to 18%, Si: 0.10 to 3.0%, and N: 0.1 to 1.2%, and its mechanical properties and manufacturing process are similar to those of stainless steel. [FIG. 1] is the slip line of the laminated defect generated on the (111) plane of the austenite matrix phase. This structure is obtained by lowering the stacking fault energy (SFE*) (Non-Patent Document). * Stacking fault energy SFE (mJ / m 2 ) = 25.7 + 2(%Ni) + 410(%C) - 0.9(%Cr) - 77(%N) - 13(%Si) - 1.2(%Mn) Table 1 shows SFE (mJ / m 2) and the relationship with the generated phases by cold working. The HIDAS alloy is the generation of laminated defects, while SUS304 remains as α' martensite (α'-Ms phase) and SUS316 remains as the γ phase.

Table 1

[0009] 2. Vibration damping property of HIDAS alloy Figure 2 shows the relationship between the cold working rate, hardness (HRC), and vibration damping performance (logarithmic decrement α). The logarithmic decrement and hardness increase by cold working. The measurement of vibration damping property used the measurement device shown in Figure 3. Vibration can be detected by the acceleration sensors at the excitation part and the tip of the sample, and the vibration damping property can be measured quantitatively (Table 2). Accordingly, the resonance frequency (f) and decay time (T) are measured, and the logarithmic decrement (α) can be obtained by the following formula. α = Ln(A n / A n+1 ) = (1 / f·T)·Ln(A0 / A n )

Table 2

[0010] Table 3 is a comparison of the vibration damping ability index (δ). The product of the hardness (Young's modulus E) and vibration damping ability (logarithmic decrement α) of the material (δ = E*α) indicates the vibration damping ability of the material. It can be expected that the HIDAS alloy will exhibit better cutting vibration damping ability than carbide.

Table 3

[0011] 3. Fatigue resistance characteristics of HIDAS alloy (1) Test method Figure 4 shows the test device of the Kanagawa Institute of Industrial Science and Technology. Figure 5 shows the hysteresis curve of the fatigue test. Test A is high strain low cycle (1.0% strain control). (2) Test results For TIFF2025101696000005.tif9170, the fatigue life cycles were about 20 times that of SUS316. As shown in FIGS. 7 and 8, it is considered that the strain of the fatigue test is absorbed by the laminated defects. On the other hand, SUS304 generates magnetism due to the generation of the α'-Ms phase and shows the same behavior as ordinary steel. This is an event that should be noted in practical applications. FIG. 7 shows the microstructure of the HIDAS test piece after 5 million breakages. The threaded part has the crystal structure of the raw material, and the broken part is the microscopic structure of the 5 million fatigue test results. FIG. 8 shows the results of the 5 million fatigue test. Due to the absorption of slip in the crystal structure, no elongation is observed between the scoring points of the HIDAS test piece. On the other hand, SUS316 continued to elongate due to the fatigue test and broke extremely early at 3000 cycles. 4, Application Development of HIDAS Alloy

[0012] (1) Vibration Damping Coil Spring FIG. 10 shows an example of a seismic isolation base made of HIDAS. Since it was confirmed that the constituent material itself absorbs vibration and has excellent fatigue resistance characteristics, it has excellent reliability as a device. The vibration damping ability of the coil spring can be compared by the logarithmic decrement rate (α) shown in Table 2. The HIDAS coil spring stops vibrating about 5 times faster than the steel coil spring (see Table 2 and FIG. 11). This can be effectively applied to seismic isolation bases for buildings.

[0013] (2) Boring Bit · Testing Institution: Kanagawa Institute of Industrial Technology (Tokushoku) · Workpiece Material: S45C, φ60mm × 30mm thick · Conditions: v = 64m / min, ap = 0.2mm, f = 0.1mm / rev FIG. 12 shows the state of the cutting test. FIG. 13 shows the cutting test results. FIG. 13 shows HIDAS, steel, and carbide boring bits. When the cutting speed of steel is increased, the cutting vibration becomes large. The HIDAS boring tool shows cutting and vibration behavior similar to that of cemented carbide. This is because the HIDAS tool body absorbs cutting vibrations. The HIDAS boring tool has the effect of reducing chip wear and extending tool life (see Figure 14). Figure 13 shows the cutting vibrations of HIDAS, steel, and cemented carbide. For steel, cutting vibrations increase as the cutting speed is increased. The HIDAS boring tool shows cutting and vibration behavior similar to that of cemented carbide. This is because the HIDAS tool body absorbs cutting vibrations. The HIDAS boring tool has the effect of reducing chip wear and extending tool life (see Figure 14). Figure 13 verifies the influence of cutting chatter vibrations on tool life and shows that reducing chatter during cutting is important for reducing the cutting pitch. Since the HIDAS vibration-damping tool absorbs cutting vibrations with the material body, there is less cutting chatter (Figure 12), and it has the effect of reducing chip wear and extending tool life.

[0014] 8 Comparison with vibration-damping tools of other companies Figure 14 shows a comparison with vibration-damping tools of other companies (16 mm φ x 1800 mm L, boring tool). Other companies use vibration damping due to the structure of the tool body, but HIDAS absorbs vibrations with its steel structure, so it has excellent reliability and is low in price.

[0015] 9 Mass production system for "HIDAS alloy" Regarding the mass production system for "HIDA alloy", it is possible to obtain "DNM140 for non-magnetic drill collar" from Daido Steel Co., Ltd. and use it as the material for HIDAS. "DNM140" is mass-produced at the company's Shibukawa factory at 200 t / M. The material for "high-hardness HIDAS alloy" is manufactured by cold drawing of "DNM140" by Shield Co., Ltd. http: / / www.sild.co.jp )

Brief description of the drawings

[0016]

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Claims

1. The mass percentage of carbon [%C] is 0.001 to 0.10 [%], the mass percentage of silicon [%Si] is 0.10 to 3.0 [%], the mass percentage of manganese [%Mn] is 3.0 to less than 18.0 [%], the mass percentage of chromium [%Cr] is 3.0 to 20.0 [%], the mass percentage of nitrogen [%N] is 0.10 to 1.20 [%], the balance consists of iron and inevitable impurities, The stacking fault energy (SFE) (mJ / m) calculated by Equation 1 ２ satisfies Equation 2, 【Number 1】 【Number 2】 and a high-strength vibration-damping steel characterized in that the loss coefficient (η) representing the vibration-damping property measured by the cantilever beam method satisfies Formula 3. 【Mathematics 3】

2. A high-strength vibration-damping steel excellent in fatigue characteristics, characterized in that in a fatigue test, it exhibits a fracture-resistant cycle of 500,000 times at a repeated load stress of 350 MPa.

3. A cutting tool or a rock bit composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

4. A linear guide composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

5. A low-rebound steel ball or a bearing composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

6. A gear transmission device composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

7. A chain transmission device composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

8. A spring device composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

9. A parts feeder device composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

10. A component or device with a vibration-damping function composed of the steel excellent in high-strength vibration-damping property and fatigue resistance described in Claims 1 and 2.

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