JP2000345304A - Drive rivet and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive rivet high in toughness and hardness, capable of joining a member of a thick plate, excellent in corrosion resistance and free from the need of plating treatment. SOLUTION: This is a method for producing a drive rivet composed of a head and a hollow and cylindrical leg prolonged in the lower direction of the head, and by subjecting a wire rod composed of alloy steel contg. 0.1 to 0.2% C, <=1.0% Mn, <=1.0% Si, 1.0 to 2.5% Ni, 12.0 to 14.0% Cr, 1.8 to 2.3% Mo and 0.05 to 0.15% N to cold heading, a rivet having a desired shape is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving rivet and a method for manufacturing the same, and has an object to fasten a member having a high toughness and a high hardness and a large thickness, and is excellent in corrosion resistance. It is an object of the present invention to provide a driving rivet and a method for manufacturing the driving rivet, which do not require the above.

[0002]

2. Description of the Related Art Conventionally, a driving rivet for fastening an aluminum plate or a SUS plate has been made of SUSXM7 or SUS.
A material made of a highly corrosion-resistant material such as 385 was used. However, rivets made of these materials have low strength (proof strength) and can only be driven into thin plates. To drive into thick plates, rivets with large diameters that are unbalanced with the plate thickness are required. In this case, there is a problem that the driven plate is greatly distorted. Therefore, in order to improve the strength of the rivet, a material such as SUS410 or SUS420 may be subjected to heat treatment before use, but in this case, there is a problem that the rivet is easily rusted. Of course, it is possible to perform plating to improve the corrosion resistance,
At the time of the driving, the plating is easily peeled, and there is a possibility that the plating may be peeled off during use. In this case, there is a problem that rust is generated from the portion where the plating has been peeled.

[0003]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, using a stainless steel containing a specific element in a specific ratio as a material, and performing heat treatment under a specific condition. S35C, S
Strength equivalent to or higher than carbon steel or alloy steel such as CM435 and SCM440, superior to surface treatment products such as SUS410, SUS420, corrosion resistance equivalent to or higher than SUS304, and significantly superior toughness than these materials. It has been found that a driving rivet equipped with the rivet can be obtained, and the present invention has been completed.

[0004]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 has a head and a hollow cylinder extending below the head. A driving rivet having a leg-like shape, wherein C: 0.1-0.
2%, Mn: 1.0% or less, Si: 1.0% or less, N
i: 1.0 to 2.5%, Cr: 12.0 to 14.0%,
The present invention relates to a driving rivet obtained by cold forging a wire made of an alloy steel containing Mo: 1.8 to 2.3% and N: 0.05 to 0.15%. Claim 2
The invention described in claim 1 relates to a driving rivet according to claim 1, wherein a quenching treatment under a reduced pressure atmosphere of nitrogen and a tempering treatment under atmospheric pressure are performed after cold heading. The invention according to claim 3 relates to the driving rivet according to claim 2, wherein an immobilization process is performed after the quenching / tempering process.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a driving rivet comprising a head and a hollow cylindrical leg extending below the head, wherein C: 0.1 to 0.1. 2%, M
n: 1.0% or less, Si: 1.0% or less, Ni: 1.0
~ 2.5%, Cr: 12.0 ~ 14.0%, Mo: 1.
A method for manufacturing a driving rivet, characterized in that a rivet having a desired shape is obtained by cold-forging a wire made of an alloy steel containing 8 to 2.3% and N: 0.05 to 0.15%. . The invention according to claim 5 is characterized in that, after the cold heading, a quenching treatment is performed under a reduced-pressure nitrogen atmosphere, and a tempering treatment is performed under atmospheric pressure after the nitrogen cooling. The present invention relates to a rivet manufacturing method.

According to a sixth aspect of the present invention, the quenching conditions are as follows: nitrogen pressure: less than 0.1 atm;
6. The driving rivet according to claim 5, wherein the temperature is 50 [deg.] C., the time is 5 to 15 minutes, and the tempering conditions are atmospheric pressure: 1 atm, temperature: 200 to 240 [deg.] C., time: 2 to 3 hours. And a method for producing the same. The invention according to claim 7 relates to a method for manufacturing a driving rivet according to claim 5 or 6, wherein an immobilization process is performed after the quenching / tempering process.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A driving rivet according to the present invention and a method for manufacturing the same will be described below with reference to the drawings. As shown in FIG. 1, the driving rivet (1) according to the present invention includes a head (2) and a leg (3) extending below the head (2). A central hole (31) is formed from the tip of the leg (3) to the middle part, and is formed into a hollow cylindrical shape, and this portion functions as a caulking portion at the time of caulking. FIG. 2 is a diagram showing a state in which two driven members (4) and (5) are caulked and fastened using the driving rivet (1) according to the present invention,
The two members (4) and (5) are fastened by penetrating the leg (3) through the members (4) and (5) and curling the leg (3). However, the driving rivet according to the present invention is characterized by its material and manufacturing method, and the shape is not limited to the illustrated example, and the shape of the head, the diameter and length of the legs, As for the depth of the center hole and the like, it is possible to appropriately adopt various shapes of driving rivets conventionally used.

[0008] The driving rivet according to the present invention is characterized in that iron (Fe), which is a main component, contains C: 0.1 to
0.2%, Ni: 1.0 to 2.5%, Cr: 12.0 to
14.0%, Mo: 1.8 to 2.3%, N: 0.05 to
It is obtained by cold forging a wire made of stainless steel containing 0.15%. Of the elements blended as these essential components, nickel (Ni) improves corrosion resistance, chromium (Cr) improves corrosion resistance and increases toughness, and molybdenum (Mo) improves cold workability. Nitrogen (N) plays a role in increasing hardness and corrosion resistance. In addition to the above essential components, manganese (Mn) and silicon (Si) are appropriately blended within a range not exceeding 1.0%.

The stainless steel having the above composition is SUS
It has corrosion resistance superior to that of SUS 304, drawability and forgeability equal to or higher than SUS 304, a martensite structure, and extremely high quench hardening properties.

The driving rivet according to the present invention is manufactured using a martensitic stainless steel having the above composition as a material. The manufacturing method will be described below with reference to the flowchart of FIG. First, a martensitic stainless steel wire having the above composition is drawn and then formed into a shape as a driving rivet by cold heading. Then, the obtained driving rivet is quenched under a nitrogen atmosphere, and after being cooled by nitrogen, a tempering treatment is performed under an atmospheric pressure atmosphere (air atmosphere).

The conditions of the quenching / tempering treatment are as follows: quenching treatment conditions: nitrogen pressure: less than 0.1 atm, temperature:
1,050-1150 ° C., time: 5-15 minutes, tempering conditions: atmospheric pressure: 1 atm, temperature: 200-2
40 ° C., time: 2-3 hours. Here, the quenching treatment is performed in a nitrogen reduced pressure atmosphere of less than 0.1 atm in order to prevent decomposition and outflow of chromium (Cr).
And to the 1,050 to 1,150 ° C. × 5 to 15 minutes quenching conditions, preventing as much as possible of the surface nitriding, in order to obtain a higher hardness H _RC 53. The nitrogen pressure is preferably 0.05a
tm or less. Further, the tempering condition is set to 200 to 24.
The reason why the temperature is 0 ° C. × 2 to 3 hours is to make the rivet more tough and to make the hardness _HRC 49 or more.

As specific condition values, quenching treatment is performed at 1150 ° C. × 10 minutes in a nitrogen atmosphere of 0.05 atm.
The tempering process can be performed under the condition of 220 ° C. × 3 hours under the atmospheric pressure, and the driving rivet processed under this condition has a hardness of Hv540.

After the above-mentioned quenching and tempering, barrel polishing is performed to smooth the surface, and then passivation is performed. As a method of the passivation treatment, a method of dipping the rivet after barrel polishing in a concentrated nitric acid solution for about several minutes can be exemplified, but it is not particularly limited to this method. Since the driving rivet according to the present invention forms an oxide film on the surface by performing the passivation treatment as described above, it has extremely excellent corrosion resistance without performing plating treatment as in a conventional rivet. Become. Therefore, there is no danger of hydrogen embrittlement, and the plating cost can be reduced.

[0014]

EXAMPLES The effects of the present invention will be clarified by showing examples and comparative examples of driving rivets according to the present invention. However, the present invention is not limited at all by the following examples. (Manufacture of Example Rivets) A martensitic stainless steel containing the components shown in Table 1 in iron (Fe) as a main component was used as a material, and the final passivation treatment was omitted from the processing steps shown in FIG. Driven rivets were manufactured by the process. The quenching treatment was performed at 1150 ° C. for 10 minutes under a nitrogen atmosphere of 0.05 atm.
The test was performed under the conditions of 0 ° C. × 3 hours.

[Table 1]

(Manufacture of Comparative Example Rivets) Iron (Fe) as a main component contains 0.32% to 0.38% of C and 0.6% of Mn.
Using a wire made of S35C material containing 0 to 0.90% and Si: 0.10 to 0.35%, a driving rivet having the same shape as that of the example was manufactured by the working process shown in FIG.

(Comparative Test) The driving rivets of the example and the comparative example were compared with respect to allowable plate thickness, hardness, corrosion resistance, cold headability, fastening strength, and toughness. Table 2 shows the results. The shaft diameters of the driving rivets of the example and the comparative example are both φ4 mm.

[Table 2]

The allowable plate thickness is evaluated based on the thickness of a member to be fastened (plate material of SS400), and the hardness is measured by a Vickers hardness tester at the center position of the surface of the leg portion of the rivet (the position indicated by a horizontal arrow in FIG. 1) ) Was measured. The corrosion resistance was evaluated by a salt spray test (JIS Z 2371), and the cold forging property was evaluated by the ease of cold forging. The fastening strength of the two fastened members (SS400, thickness 1.6 mm × 2
The tensile strength and shear strength for separating
The toughness was measured by measuring the curl diameter (R dimension in FIG. 2) at which no crack was generated during swaging.

From the results shown in Table 2, it can be seen that the driving rivet according to the present invention has a wider range of allowable caulking thickness and higher fastening strength (tensile strength and shear strength) than those of the comparative example. This is because the setting rivet according to the present invention has a high toughness and can have a large curl diameter, thereby widening the range of the allowable plate thickness and increasing the fastening strength (tensile strength and shear strength). It can be said that. The driving rivet according to the present invention is also excellent in corrosion resistance, and the passivation treatment can further improve the corrosion resistance.

[0019]

As described above, according to the driving rivet and the method for manufacturing the same according to the present invention, C: 0.1 to 0.1%.
0.2%, Mn: 1.0% or less, Si: 1.0% or less,
Ni: 1.0 to 2.5%, Cr: 12.0 to 14.0
%, Mo: 1.8 to 2.3%, N: 0.05 to 0.15
% Is manufactured by cold forging a wire rod made of an alloy steel containing 0.1% by weight, so that a driven rivet excellent in corrosion resistance, strength and toughness can be obtained.

After the cold heading, a quenching process under a reduced pressure atmosphere of nitrogen and a tempering process under an atmospheric pressure are performed to obtain S35C, SCM435, and SCM440.
And strength (proof strength) equal to or higher than carbon steel or alloy steel such as
It is possible to obtain a driven rivet having corrosion resistance equal to or higher than that of S304 and significantly higher toughness than these materials. Furthermore, by performing a passivation process after the quenching / tempering process, the corrosion resistance can be further improved. In addition, since there is no need to perform a plating process, there is no danger of hydrogen embrittlement and plating costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a driving rivet according to the present invention.

FIG. 2 is a view showing a state where two fastening members are caulked and fastened using the driving rivet according to the present invention.

FIG. 3 is a flowchart showing a method for manufacturing a driving rivet according to the present invention.

FIG. 4 is a flowchart illustrating a method for manufacturing a driving rivet according to a comparative example.

[Explanation of symbols]

 1 Driving rivet 2 Head 3 Leg

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 38/44 C22C 38/44 C23C 22/06 C23C 22/06 F16B 19/08 F16B 19/08 Z F term (Reference) 3J036 AA04 BA02 EA03 4E087 AA10 BA02 BA17 CA11 CA22 CB03 DB03 DB11 DB14 EC11 EC17 EC33 EC37 EC50 HA53 HA54 4K026 AA04 AA21 AA24 BA08 BB08 CA16 CA32 DA03 EA03 EA17 4K042 AA25 DA01 DA02 DA06 DC06

Claims (7)

[Claims] 1. A driving rivet comprising a head and a hollow cylindrical leg extending below the head, wherein C:
0.1-0.2%, Mn: 1.0% or less, Si: 1.0
%, Ni: 1.0 to 2.5%, Cr: 12.0 to 1
4.0%, Mo: 1.8 to 2.3%, N: 0.05 to
A driving rivet obtained by cold forging a wire made of an alloy steel containing 0.15%. 2. The driving rivet according to claim 1, wherein a quenching process under a reduced-pressure nitrogen atmosphere and a tempering process under an atmospheric pressure are performed after the cold heading. 3. The driving rivet according to claim 2, wherein an immobilization process is performed after the quenching / tempering process. 4. A method for manufacturing a driving rivet comprising a head and a hollow cylindrical leg extending below the head, wherein C: 0.1 to 0.2%, Mn: 1. 0.0% or less, S
i: 1.0% or less, Ni: 1.0 to 2.5%, Cr: 1
2.0-14.0%, Mo: 1.8-2.3%, N:
A method for manufacturing a driving rivet, wherein a rivet having a desired shape is obtained by cold forging a wire rod made of an alloy steel containing 0.05 to 0.15%. 5. The manufacturing of a driven rivet according to claim 4, wherein after the cold heading, a quenching treatment is performed under a reduced pressure atmosphere of nitrogen, and a tempering treatment is performed under atmospheric pressure after cooling with nitrogen. Method. 6. The quenching conditions are as follows: nitrogen pressure: 0.1.
Less than 1 atm, temperature: 1050 to 1150 ° C, time: 5
１５15 minutes, and the tempering condition is the atmospheric pressure: 1 at
6. The method for producing a driving rivet according to claim 5, wherein the temperature is 200 to 240 [deg.] C. and the time is 2 to 3 hours. 7. The method for manufacturing a driving rivet according to claim 5, wherein an immobilization process is performed after the quenching / tempering process.