WO2018135111A1

WO2018135111A1 - Needle wire

Info

Publication number: WO2018135111A1
Application number: PCT/JP2017/040755
Authority: WO
Inventors: 智弘山川
Original assignee: トクセン工業株式会社
Priority date: 2017-01-17
Filing date: 2017-11-13
Publication date: 2018-07-26
Also published as: JP6467441B2; JP2018115353A; CN109844155A; CN109844155B

Abstract

Needle wire (2) is formed from steel that comprises 0.95 mass% to 1.03 mass% of C, 0.15 mass% to 0.35 mass% of Si, 0.60 mass% to 0.80 mass% of Mn, 0.35 mass% to 0.45 mass% or Cr, 0.01 mass% to 0.05 mass% of Mo, 0.10 mass% or less of Ni, and 0.026 mass% or less of P, the balance being Fe and unavoidable impurities. Said wire (2) contains multiple carbide particles in the metal structure thereof. The average particle diameter of said carbides is 0.10 µm to 1.0 µm. The area ratio of said carbides is 10% to 30%. The S content in the steel is 0.003% or less. The Vickers hardness of the wire (2) is 200 to 300.

Description

Needle wire

The present invention relates to various needles such as knitted needles, felt needles, sewing needles, fishing hooks, and lines that can be processed into parts of these needles.

針 Needles are used for various purposes. A typical material for the needle is metal. Various proposals regarding the needle material have been made.

JP-A-4-88149 discloses a needle that is applied to a textile machine. This needle is formed from carbon steel having a predetermined composition. As examples of needles, sewing needles, knitted needles and felt needles are disclosed.

Japanese Patent Laid-Open No. 5-320824 discloses a line for a fishing hook. This line is formed from carbon steel having a predetermined composition.

A general knitted needle has a main part and a latch. The latch is pivotally attached to the main portion and can swing with respect to the main portion. A loop formed by the main portion and the latch holds the yarn. Knitting can be manufactured by an automatic knitting machine having the knit needle.

In this knitted needle, the main part is formed by plastic working (punching, bending, etc.) on the plate. On the other hand, the latch is formed by plastic working on the wire from the viewpoint of manufacturing cost. This wire is obtained by drawing or rolling. The latch is attached to the main part. Thereafter, the assembly of the main part and the latch is quenched and tempered to obtain a knitted needle.

Japanese Patent Laid-Open No. 4-88149 JP-A-5-320824

The material of the main part is suitable for punching. On the other hand, the material of the latch is suitable for wire drawing. The material of the main part is different from the material of the latch. Therefore, quenching conditions suitable for the main part are not suitable for latches. On the other hand, the quenching conditions suitable for the latch are not suitable for the main part. In a knitted needle obtained by quenching and tempering an assembly of a main part and a latch, either the main part or the latch has insufficient hardness. When this knitted needle is used repeatedly, wear proceeds at an early stage in either the main portion or the latch. In a knitted needle that has undergone wear, a meshing failure occurs between the main portion and the latch. Knitted needles that have become worn must be replaced. The durability of this knitted needle is insufficient.

An object of the present invention is to provide a wire from which a needle having excellent durability can be obtained.

The wire for a needle according to the present invention is 0.95 mass% or more and 1.03 mass% or less C, 0.15 mass% or more and 0.35 mass% or less Si, 0.60 mass% or more and 0.80 mass% or less. % Mn, 0.35 mass% or more and 0.45 mass% or less Cr, 0.01 mass% or more and 0.05 mass% or less Mo, 0.10 mass% or less Ni and 0.026 mass% or less And the balance is formed from steel which is Fe and inevitable impurities. This line contains carbide particles in its metallographic structure. The average particle size of the carbide is 0.10 μm or more and 1.0 μm or less. The area ratio of carbide is 10% or more and 30% or less.

Preferably, the S content in the steel is 0.003% or less.

Preferably, the Vickers hardness of the wire is 200 or more and 300 or less.

¡A suitable application for this line is the latch of knitted needles.

The method for manufacturing a needle wire according to the present invention includes:
A step of preparing a bus bar and a step of repeatedly applying heat treatment and plastic working to the bus bar to lengthen and reduce the diameter of the bus bar. This line contains carbide particles in its metallographic structure. The average particle size of the carbide is 0.10 μm or more and 1.0 μm or less. The area ratio of this carbide is 10% or more and 30% or less.

Preferably, the manufacturing method comprises:
The method further includes a step of annealing the elongated and thinned bus bar to obtain a spheroidized structure.

In the needle wire according to the present invention, the composition and structure are appropriate. The needle obtained from this line is excellent in durability.

FIG. 1 is a perspective view showing a part of a needle line according to an embodiment of the present invention. FIG. 2 is a front view of a portion of a knitted needle having a latch obtained from the line of FIG. FIG. 3 is a photomicrograph showing the metallographic structure of the line of FIG. FIG. 4 is a histogram showing the relationship between the carbide particle size and the number of particles in the metal structure of FIG.

Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

The needle wire 2 shown in FIG. 1 is made of steel. In this embodiment, this line 2 is the material of the latch of the knitted needle. The line 2 is cut to a predetermined length, and plastic processing is performed on the line 2 to obtain a latch.

FIG. 2 shows a part of the knitted needle 6 having the latch 4. The knitted needle 6 has a main portion 8 and a shaft 10 in addition to the latch 4. The latch 4 is attached to the main portion 8 by a shaft 10. As indicated by an arrow in FIG. 2, the latch 4 can swing with respect to the main portion 8 about the shaft 10. In FIG. 2, the fallen latch 4 is indicated by a solid line 2, and the raised latch 4 is indicated by a virtual line. When the latch 4 falls, a loop 12 is formed by the latch 4 and the main portion 8. The loop 12 holds a yarn for knitting. The latch 4 may swing by means other than the shaft 10.

In the manufacturing method of the knitted needle 6, the plate is punched and the plate is bent to obtain the main portion 8. On the other hand, as described above, the latch 4 is obtained from the line 2. The latch 4 is attached to the main portion 8. Thereafter, the assembly of the main portion 8 and the latch 4 is quenched and tempered.

The composition of the steel of this wire 2 is as follows.
C: 0.95 mass% or more and 1.03 mass% or less Si: 0.15 mass% or more and 0.35 mass% or less Mn: 0.60 mass% or more and 0.80 mass% or less Cr: 0.35 mass% or more 0.45 mass% or less Mo: 0.01 mass% or more and 0.05 mass% or less Ni: 0.10 mass% or less P: 0.026 mass% or less Remaining: Fe and inevitable impurities

C is an interstitial solid solution element. The latch 4 including an appropriate amount of C has a high hardness. C contributes to the strength of the latch 4. Further, C generates carbides in the tissue. This carbide contributes to the wear resistance of the latch 4. From these viewpoints, the amount of C is preferably 0.95% by mass or more, particularly preferably 0.97% by mass or more. From the viewpoint of the cold workability of the wire 2, this amount is preferably 1.03% by mass or less, and particularly preferably 1.01% by mass or less.

Si functions as a deoxidizer during refining. The latch 4 containing an appropriate amount of Si has a high hardness. Si contributes to the strength of the latch 4. From these viewpoints, the amount of Si is preferably 0.15% by mass or more, particularly preferably 0.20% by mass or more. From the viewpoint of the cold workability of the wire 2, this amount is preferably 0.35% by mass or less, particularly preferably 0.30% by mass or less.

Mn functions as a deoxidizer during ingot melting. Further, Mn suppresses the adverse effect of S, which is an impurity. From these viewpoints, the amount of Mn is preferably 0.60% by mass or more, and particularly preferably 0.65% by mass or more. From the viewpoint of the workability of the wire 2, this amount is preferably 0.80% by mass or less, and particularly preferably 0.75% by mass or less.

The latch 4 containing Cr is excellent in corrosion resistance. Cr combines with C to form a carbide. This carbide contributes to the wear resistance of the latch 4. In this respect, the amount of Cr is preferably 0.35% by mass or more, and particularly preferably 0.37% by mass or more. From the viewpoint of the cold workability of the wire 2 and the material cost of the knitted needle 6, this amount is preferably 0.45% by mass or less, particularly preferably 0.43% by mass or less.

As described above, the latch 4 is obtained through quenching and tempering. The latch 4 containing Mo has a sufficient hardness after tempering. The latch 4 is excellent in strength. Mo combines with C to form a carbide. This carbide contributes to the wear resistance of the latch 4. From these viewpoints, the amount of Mo is preferably 0.01% by mass or more, and particularly preferably 0.02% by mass or more. From the viewpoint of the cold workability of the wire 2, this amount is preferably 0.05% by mass or less, particularly preferably 0.04% by mass or less.

Ni increases the hardenability of steel. The latch 4 containing Ni is excellent in toughness. In this respect, the amount of Ni is preferably 0.01% by mass or more, and particularly preferably 0.02% by mass or more. Ni is expensive. From the viewpoint of the material cost of the knitted needle 6, the amount of Ni is preferably 0.10% by mass or less, and particularly preferably 0.07% by mass or less.

A typical impurity is P. P segregates at the grain boundaries. P inhibits the cold workability of the wire 2. P decreases the strength of the latch 4. From these viewpoints, the smaller the amount of P, the better. Specifically, this amount is preferably 0.026% by mass or less, particularly preferably 0.010% by mass or less. Ideally, the amount of P is zero.

Another typical impurity is S. S inhibits the cold workability of the wire 2. S combines with Mn or the like to form inclusions. This inclusion reduces the strength of the latch 4. From this viewpoint, the smaller the amount of S, the better. Specifically, this amount is preferably 0.003% by mass or less, and particularly preferably 0.001% by mass or less. Ideally, the amount of S is zero.

This line 2 includes a large number of carbide particles in its metal structure. These carbide particles have an average particle size of 0.10 μm or more and 1.0 μm or less.

In the line 2 having an average particle diameter of 0.10 μm or more, the contact area between the carbide and the matrix is not excessive. Therefore, the amount of C dissolved in the matrix at the time of quenching and tempering of the knitted needle 6 is not excessive. Therefore, the hardness of the latch 4 is not too high. In this respect, the average particle size is particularly preferably 0.11 μm or more.

In the line 2 where the average particle diameter is 1.0 μm or less, the contact area between the carbide and the matrix is not too small. Therefore, the amount of C dissolved in the matrix at the time of quenching and tempering of the knitted needle 6 is not too small. Therefore, the hardness of the latch 4 is not too low. In this respect, the average particle size is more preferably equal to or less than 0.6 μm, and particularly preferably equal to or less than 0.42 μm.

As described above, the latch 4 obtained from the wire 2 in which the average particle diameter of the carbide particles is 0.10 μm or more and 1.0 μm or less has an appropriate hardness. In the knitted needle 6 having the latch 4, the difference between the hardness of the latch 4 and the hardness of the main portion 8 can be reduced. With this knitted needle 6, uneven wear is unlikely to occur. This knitted needle 6 is excellent in durability.

In this line 2, the area ratio of carbide particles in the metal structure is 10% or more and 30% or less.

In the line 2 where the area ratio is 10% or more, the amount of C dissolved in the matrix when the knitted needle 6 is quenched and tempered is not too small. Therefore, the hardness of the latch 4 is not too low. In this respect, the area ratio is more preferably 15% or more, and particularly preferably 17% or more.

In the line 2 where the area ratio is 30% or less, the amount of C dissolved in the matrix at the time of quenching and tempering of the knitted needle 6 is not excessive. Therefore, the hardness of the latch 4 is not too high. In this respect, the area ratio is more preferably equal to or less than 25%, and particularly preferably equal to or less than 22%.

As described above, the latch 4 obtained from the line 2 having an area ratio of 10% or more and 30% or less has an appropriate hardness. In the knitted needle 6 having the latch 4, the difference between the hardness of the latch 4 and the hardness of the main portion 8 can be reduced. With this knitted needle 6, uneven wear is unlikely to occur. This knitted needle 6 is excellent in durability.

Image analysis software “Image J” is used to measure the average particle size and area ratio of carbides. In the measurement, a cross section along the radial direction of the line 2 is taken with a scanning electron microscope, and an SEM photograph with a magnification of 5000 times is obtained. An example of this photograph is shown in FIG. The image file of this photograph is binarized by the image analysis software, and the region of carbide particles and the other region are color-coded. The area of each carbide particle is calculated. A circle having the same area as this area is assumed, and the diameter of this circle is the diameter of this particle. The diameter and the number of carbides having a diameter of 0.05 μm or more are histogrammed. An example of a histogram is shown in FIG. The reason for excluding carbides with a diameter less than 0.05 μm from the count is:
(1) Carbides having a diameter of less than 0.05 μm are extremely small, and therefore do not have a significant effect on the area ratio and the characteristics of the wire 2.
And (2) It is difficult to detect a carbide having a diameter of less than 0.05 μm.
There are two points.

平均 Based on this histogram, the average particle size of the carbide is calculated. Further, the ratio of the total area of carbides having a diameter of 0.05 μm or more to the total area of the photograph in FIG. 3 is calculated as the area ratio.

In the example shown in FIGS. 3 and 4, the number of carbide particles is 480, the maximum carbide particle diameter is 2.49 μm, the average particle diameter of the carbide particles is 0.42 μm, and the area ratio is 16. 5%.

The Vickers hardness of the wire 2 is preferably 200 or more and 300 or less. The latch 4 having an appropriate hardness can be obtained by quenching and tempering the wire 2 having a hardness within this range. In the knitted needle 6 having the latch 4, the difference between the hardness of the latch 4 and the hardness of the main portion 8 can be reduced. With this knitted needle 6, uneven wear is unlikely to occur. This knitted needle 6 is excellent in durability. Moreover, plastic processing of the line 2 to the latch 4 is easy. From these viewpoints, the hardness is particularly preferably not less than 210 and not more than 250.

Vickers hardness is measured according to the provisions of “JIS Z 2244”. The measurement is made with a hardness meter “MVK-G1” manufactured by Akashi Seisakusho. The load at the time of measurement is 200 gf.

In the production of this wire 2, an ingot is first obtained by melting. The ingot is hot-rolled to obtain a bus bar. The bus bar is repeatedly subjected to heat treatment and plastic working. A typical heat treatment is patenting. A pearlite structure is obtained by patenting. Typical plastic working includes cold drawing and cold rolling. Cold wire drawing is preferred. By repeating the heat treatment and the plastic working, the bus bar is elongated and the diameter is reduced. This bus bar is annealed. The structure is spheroidized by annealing, and a line 2 is obtained. After annealing, plastic processing may be further performed to obtain the wire 2. A typical diameter of the wire 2 is 0.1 mm or greater and 1.0 mm or less.

The annealing temperature is preferably 630 ° C. or higher and 850 ° C. or lower. A spheroidized structure can be obtained by annealing at a temperature of 630 ° C. or higher. In other words, it is possible to obtain a structure in which distortion caused by plastic working is removed by annealing at a temperature of 630 ° C. or higher. The hardness of the latch 4 obtained from this line 2 is not excessive. In this respect, the annealing temperature is more preferably 640 ° C. or higher, and particularly preferably 660 ° C. or higher. The annealing with a temperature of 850 ° C. or lower suppresses the formation of a pearlite structure. The hardness of the latch 4 obtained from this line 2 is not too small. In this respect, the annealing temperature is preferably 830 ° C. or lower, and particularly preferably 810 ° C. or lower.

During annealing, the bus bar is held at the above temperature for a predetermined time. The holding time is preferably 2.0 hours or more and 24 hours or less. In annealing in which the holding time is 2.0 hours or more, an appropriate temperature can be adopted. From this viewpoint, the holding time is preferably 3.0 hours or more, particularly preferably 3.5 hours or more. In annealing where the holding time is 24 hours or less, the energy cost is low. From this viewpoint, the holding time is particularly preferably 20 hours or less.

Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be interpreted in a limited manner based on the description of the examples.

[Example 1]
An ingot was obtained from the molten metal prepared with the components. The ingot was hot-rolled to obtain a bus bar. The diameter of this bus bar was 5.5 mm. The bus bar was repeatedly subjected to patenting and cold drawing. By these cold wire drawing, the bus bar was elongated and reduced in diameter. The bus bar was annealed to obtain a latch line. In this annealing, the temperature was 670 ° C. and the holding time was 4.0 hours. A spheroidized structure was obtained by annealing. The composition of this line was as follows:
C: 0.97 mass%
Si: 0.24 mass%
Mn: 0.69% by mass
Cr: 0.40 mass%
Mo: 0.03 mass%
Ni: 0.02 mass%
P: 0.01% by mass
S: 0.002 mass%
Remainder: Fe and inevitable impurities The diameter of this line was 0.4 mm. In this line, the average particle size of the carbide having a particle size of 0.05 μm or more was 0.11 μm, and the area ratio was 17.3%. The Vickers hardness of this line measured at a load of 200 gf was 240.

[Examples 2 and 3 and Comparative Examples 1 and 2]
The wires of Examples 2 and 3 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except that the conditions for patenting, cold drawing and annealing were changed.

[Production of knitted needles]
Latches were formed from the lines of each example and each comparative example. After the latch was attached to the main part, the latch and the main part were quenched and tempered to obtain a knitted needle. In this knitted needle, the hardness of the latch and the hardness of the main part were measured, and the difference was calculated. The absolute value of this difference is shown in Table 1 below.

As shown in Table 1, the hardness of the latch obtained from the line according to each example is close to the hardness of the main part. From this evaluation result, the superiority of the present invention is clear.

Various needles can be manufactured from the wire according to the present invention. Various needle parts can be made from the lines according to the invention.

2 ... Line 4 ... Latch 6 ... Knitting needle 8 ... Main part 10 ... Axis

Claims

0.95 mass% or more and 1.03 mass% or less C, 0.15 mass% or more and 0.35 mass% or less Si, 0.60 mass% or more and 0.80 mass% or less Mn, 0.35 mass% 0.45% by mass or less of Cr, 0.01% by mass or more and 0.05% by mass or less of Mo, 0.10% by mass or less of Ni, and 0.026% by mass or less of P, with the balance being Fe and Made of steel, an inevitable impurity,
Contains many carbide particles in its metal structure,
The carbide has an average particle size of 0.10 μm or more and 1.0 μm or less,
A needle wire having an area ratio of the carbide of 10% or more and 30% or less.
The wire according to claim 1, wherein the S content in the steel is 0.003% or less.
The wire according to claim 1 or 2, wherein the Vickers hardness is 200 or more and 300 or less.
The wire according to any one of claims 1 to 3, wherein the use is a latch of a knitted needle.
A method of manufacturing a wire for a needle, including a step of preparing a busbar and a step of repeatedly applying heat treatment and plastic working to the busbar to lengthen and narrow the busbar,
The line contains carbide particles in its metal structure,
The carbide has an average particle size of 0.10 μm or more and 1.0 μm or less,
The manufacturing method whose area ratio of the said carbide | carbonized_material is 10% or more and 30% or less.
The manufacturing method according to claim 5, further comprising a step of annealing the elongated and thinned bus bar to obtain a spheroidized structure.