JPH0474840A - Printed wire and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print wire for a dot printer and a method for manufacturing the same.

[Prior Art] Print wires for dot printers are required to have abrasion resistance, strong toughness, and corrosion resistance against printing ink.

As alloy materials for print wires that meet such required characteristics, molybdenum, tungsten, WC, and WC-Co cemented carbide, which has particularly excellent wear resistance, are often used. Print wires made of such materials can withstand shock during printing, allowing for higher printing speeds and clearer printing.

5 Invention or Problem Solving Section 8] However, with the need for faster data processing, and as a result of replacing the conventionally mainstream alphabets or kana, it is now possible to print kanji with complex strokes more clearly. There are also strong demands. In order to meet this demand, it is necessary to use a large number of printed wires, and a corresponding number of actuation mechanisms are required. When a formed print wire is used, the entire print head becomes larger and weighs more, so a problem arises in that the demand for higher printing speed cannot be met. In addition to the clarity of printing, ribbon inks are becoming more diverse in order to achieve compatibility with printing paper and subtle differences in fonts unique to each company, and standards for wire corrosion resistance are also becoming stricter. .

However, in terms of the weight and corrosion resistance mentioned above,
W, WC, Mo materials, etc. are unsuitable for printed wire materials. Under these circumstances, the development of a lightweight and impact-resistant printed wire has been awaited. Carbide precipitation hardening type Co alloy (DCo
CrA, B...according to JIS 2B251).

This carbide precipitation hardening type Co alloy is a material with high hardness and excellent Young's modulus, and has a structure in which carbides are precipitated in the Co-Cr alloy matrix, making it extremely hard.
It is also known for its excellent wear characteristics.

Conventionally, cast materials of DCoCrA and B were difficult to plastically work, and therefore wire rods could not be obtained. However, it has been found that this carbide precipitation-hardening Co alloy can be cold-worked, even cold-drawn, if the metal structure is made finer by methods such as rapid cooling and solidification, although the degree of workability is lower than that of ordinary metals. are doing. However, even with such materials, it is generally difficult to form a wire of less than 1 inch. Also, in terms of properties, DCCoCrA and B had the disadvantage that the required hardness could not be obtained without plastic working.

However, cold drawing is performed with a drop rate of around 10%, and after 1 to 2 bath drawing, annealing (anil) treatment (110%
1 minute/av) was required in the temperature range of 0 to 1150°C, and the manufacturing process was complicated. Further, although an improvement (improvement in hardness) can be achieved by ordinary cold working, it is still insufficient and it is necessary to further increase both hardness and strength.

Therefore, the first technical object of the present invention is to provide an alloy material and a method for manufacturing a printed wire that can reduce the weight.

A second technical object of the present invention is to provide a printed wire using an alloy material with extremely good corrosion resistance and a method for manufacturing the same.

The third technical problem of the present invention is to improve bending properties at least
An object of the present invention is to provide a printed wire using a carbide precipitation hardening type Co alloy material that is superior to the O alloy, and a method for manufacturing the same.

The fourth technical problem of the present invention is that the Young's modulus reaches 23,000, which is about the same as that of high speed steel, and the hardness is Hv, W, M.
An object of the present invention is to provide a printed wire using a carbide precipitation hardening type Co alloy material that is superior to the O alloy, and a method for manufacturing the same.

[Means for solving the problems] The present invention provides 25 to 35 wt% Cr, 3 to 10 wt% W,
In a hardening type Co alloy for carbide folding in which the balance of 0.6 to 1.5 wt% C is Co and unavoidable impurities, the size of the precipitated carbide is 5 μm or less and the surface hardness is HV 70.
The printed wire is characterized by having a hardness of HV of 0 to 800 and a hardness of the center part of HV of 600 to 650.

Further, the present invention provides 25 to 35 wt% Cr, 3 to 1 Q
An alloy ingot consisting of wt%W, 0.6 to 1.5wt%C1 with the balance being Co and unavoidable impurities, with a cooling rate of 102℃/sec or less during solidification, is finally hot-processed. A method for producing a print wire, characterized in that the print wire is produced by drawing and then age hardening.

Furthermore, in the method for manufacturing the printed wire of the present invention, the hot wire drawing process is performed at a processing temperature of 800 to 100%.
A method for manufacturing a printed wire characterized by a temperature of 0° C. and a processing rate of 15% or more.

The present invention provides the method for manufacturing a printed wire, in which the aging treatment is performed at a temperature of 550 to 650°C for 10 to 90°C.
A method for manufacturing a printed wire characterized in that the process is performed for 0 minutes.

This aging treatment cannot be carried out simply because the wire diameter is small.
It may be carried out at a high temperature of 50°C or higher, preferably 650 to 800°C, for a short time such as within 1 minute. This does not necessarily provide sufficient hardness, but it can increase the hardness in a short time.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

Preparation of samples〉 The materials shown in Table 1 are solidified by the melting method to a diameter of 2
It was prepared as an ingot with a diameter of 0 to 30 mm. The cooling rate during this solidification is 102° C./sec or less. Thereafter, this ingot was subjected to a swaging method, and then a diameter of 3I
All wires were hot wire-drawn using die wire drawing from IIIllφ. (At this time, the processing rate for each die is approximately 15~
259Q, and finished to a diameter of 3 mm.Then, using a carbide die, hot wire drawing was performed to finish the wire to a diameter of 1.5 mm. ) Especially 1. After the diameter was 1.5 mm, processing was performed under the conditions shown in Table 3. (The processing rate is approximately 15-2
It was 59o. ) After the wire drawing was completed, the wire was cut into a length of about 50 mm after being straight-lined according to the specifications. The aging treatment was performed at 600°C for 60 minutes.

The density, tensile strength, Young's modulus, and hardness of the obtained wire were measured. The results are shown in Table 3.

In the present invention, the target level of the specific gravity of the alloy material is set to 9 or less, which is conventionally considered desirable (Japanese Patent Application Laid-Open No. 1983-1989-1).
(See Publication No. 67169).

To prevent alloy decarburization, draw at high temperatures and shorten the time of exposure to high temperatures. Furthermore, in order to increase the work hardening before aging to increase the hardness compared to cold drawn wire, it is possible to obtain a wire with excellent performance as a printed wire by drawing at a high temperature and subsequent aging treatment. As mentioned above, the carbide precipitation hardening type Co alloy is
1 by drawing while heating to 800°C.
A drop rate of 0 to 25% can be obtained, and running annealing is now possible without line bowing (annealing is 850%).
~1000℃). In particular, if the diameter is 1.51φ or less, cold drawing is undesirable, but the processing temperature is 400 to 900℃.
, speed 1~50m/min, annealing temperature 800~1000
By drawing the wire at a temperature of 30 seconds or less at ℃, it is now possible to easily process it into thin wires of about 0.2 mm diameter, which is required for printed wires.

However, aging treatment is necessary, 550℃~650℃,
Hardness can be maintained by aging treatment for 30 to 90 minutes. There is no aging hardening at temperatures below 550°C, and
When the temperature exceeds ℃, the age hardening becomes smaller again. Furthermore,
Even if the temperature is raised, the same effect can be expected if the processing time is significantly reduced, but from the viewpoint of stability and reproducibility,
Aging treatment at ℃ for about 60 minutes is desirable. Through this aging treatment, the alloys according to the examples of the present invention shown in Table 1 have an Hv of 630 to 790 at the surface and an HV of 600 to 790 at the center.
650 is secured.

The hard surface not only improves bending strength, but also
In addition, during printing, the amount of wear on the surface area where wear is most severe is reduced, and the low hardness of the center area contributes to increasing the toughness of the wire.

Note that a wire rod of 0.2φI was obtained by repeatedly cold drawing and annealing an alloy material having the same composition as in the examples of the present invention, and by making a prototype of a dot pin. However, because this prototype material had been annealed many times, the surface layer was severely decarburized, and although the hardness was 600 to 670 Hv due to aging treatment, which is higher than W and Mo, it was still insufficient. The properties were poor and the expected effect could not be obtained as a printed wire.

Bending characteristics against load> FIG. 1 is a diagram showing the bending characteristics against load of the alloys shown in Table 3. As comparative examples, conventional alloy materials other than the alloy materials according to the examples of the present invention listed in Table 3 are also listed.

In FIG. 1, the alloy according to the embodiment of the present invention is M o
It can be seen that its yield strength is greater than that of the material.

Abrasion Resistance Test> Next, an abrasion resistance test was conducted to test the abrasion resistance of the printed wire according to the present invention.

The steps are (1) setting, (2) polishing, (3)
It is a measurement. The explanation will be given below in order.

(1) Settings FIGS. 2(a), (b), (c), and (d) are diagrams sequentially showing the settings of the abrasion resistance test method for the dot wire 20 according to the embodiment of the present invention.

FIG. 2(a) shows a bundle 21, 21. of aluminum vibrators each having an inner diameter of 5 mm and a length of 60 mm. Insert the test dot wire as shown in Figure 2(b) into the
As shown, wrap both ends with #60 sacid paper 22.
A vinyl chloride case 24 is provided through the vinyl chloride case 2- and the carbide plates 23, 23-, and as shown in FIG. 2(d), packing tape is wound between the vinyl chloride cases 24 to cover the gap. , completed 46 pots.

(2) Polishing FIGS. 3(a) and (b) are similar to FIGS. 2(a) and (b).

FIG. 6 is a diagram showing a method of abrasion resistance test of the pot 26 set in (c) and (d).

As shown in FIG. 3(a), the pot 26 includes a pot 2
6. Vibrations are applied to the pot 26 in a circular orbit 32 with one point on the outside as the fulcrum 31, and as shown in FIG. A rotational motion is applied around an axis. Furthermore, Figure 3 (a
) and (b), in addition to the 1200 rotation/rotation speed movement, vibrations in the front-rear, left-right, and up-down directions are added. (3) Measurement of wear resistance After the above vibrations are applied, the following measurements are performed. First, the dot wire 20 taken out from the pot is immersed in benzene and subjected to ultrasonic cleaning for 15 minutes. Weight loss measurements are then performed using an analytical balance. Furthermore, the image is magnified 100 times using a projector and the R value is measured.

FIG. 4 is a diagram showing the results of the wear test of the alloys shown in Table 3 conducted as described above.

As shown in FIG. 4, the R measurement value of the alloy wire according to the example of the present invention is represented by a curve 41, and the initial wear amount (within 5 minutes) is higher than that of W and Mo shown by a curve 421 and a curve 44. In the area where the wear time exceeds 5 minutes, the amount of wear is shown by curves 42, 43, and 44.45.
F), Mo, and a super hardening alloy (WC-Co) were found to be almost the same.

Corrosion Resistance Test> Next, a corrosion resistance test for alloy wire rods according to examples of the present invention and alloy wire rods according to comparative examples will be explained.

There are various methods for evaluating corrosion resistance, but the materials used for ink ribbons used in printers vary widely, and each ink material must be evaluated to confirm its corrosion resistance performance. The alloy wire rods shown in Table 3 were compared using a polarization test which is said to provide a comparative relationship with the corrosion of metal materials. The method is as follows.

Immerse the wire in a 1% sulfuric acid solution and use the potentiodynamic method to determine -〇,
Observe the flow of electricity (current density) and the reactivity due to the generation of bubbles when gradually changing from 7V (based on the saturated calomel electrode potential) to the (+) side, and examine the relationship between the potential and current density. It is shown in Figure 5. In general, with the saturated calomel electrode potential (V vs S, C, E) as a reference, it is better to have a low current density at least on the (+) side and little change even when the potential increases (small slope). has been done. As is clear from FIG. 5, the alloy of the example of the present invention was found to be the most superior compared to W, Mo, and high speed steel. In addition, regarding the brazing property that cannot be avoided as a printed wire,
Even with BAg-4, sufficient bonding was possible. Furthermore, if the high temperature resistance is to be further improved, the oxide layer may be removed by electrolysis or treatment with an acid such as a mineral acid, or the surface may be polished by centerless or the like and then brazed.

Table 1 [Effects of the Invention] As explained above, according to the present invention, a lightweight printed wire with a density of 9 or less can be obtained.

Further, according to the present invention, a printed wire with extremely good corrosion resistance can be obtained.

Furthermore, according to the present invention, a printed wire is obtained whose bending properties are at least better than those of Mo alloys.

Further, according to the present invention, the Young's modulus reaches 23,000,
It is about the same level as high speed steel, and can be used as a good printed wire.

Further, according to the present invention, the hardness of the surface is 700 to 80 Hv.
0. A printed wire with a center of 600-650 is obtained, which is superior to the W, Mo alloy.

Figure 3 (a) and (b) are the same as Figure 2 (a) and (b).

(c) and (d) are diagrams showing the method of conducting an abrasion test on the pot set up; Figure 5 is 1
The wire was immersed in a sulfuric acid solution of -0,7% by potentiodynamic method.
Observe the flow of electricity (current density) and the reactivity due to the generation of bubbles when gradually changing from V (based on the saturated calomel electrode potential) to the (+) side, and show the relationship between the potential and current density. It is a diagram.

In the figure, 20...dot wire, 21...aluminum pipe, 26...pot, 31...fulcrum, 32...circular orbit.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the bending characteristics against loads of the alloys shown in Table 3, and FIGS. 2(a), (b), and (c). (d) is a diagram showing in order the settings of the wear resistance test method for the dot pin 20 according to the embodiment of the present invention, Figure 3: Displacement [mm] Figure 2 (d) (C) Figure 3 (b)

Claims (1)

[Claims] 1, 25 to 35 wt% Cr, 3 to 10 wt% W, 0.6
~1.5wt%C Carbide precipitation hardening type C with the balance being Co
o alloy, the size of the precipitated carbide is 5 μm or less, the surface hardness is HV 700-800, and the center hardness is H
A printed wire characterized in that V is 600 to 650. 2, 25-35wt%Cr, 3-10wt%W, 0.6
~1.5 wt% C, the balance being Co and unavoidable impurities, the cooling rate during solidification was set to 10^2℃/
A method for producing a printed wire, characterized in that the printed wire is produced by finally subjecting the wire to a hot wire drawing process and aging hardening the wire to a wire having a wire width of less than sec. 3. In the method for manufacturing a printed wire according to the second aspect, the hot wire drawing process is performed at a processing temperature of 800 to 10
A method for manufacturing a printed wire, characterized in that the temperature is 00°C and the processing rate is 15% or more. 4. In the method for manufacturing a printed wire according to claim 3, the aging treatment is performed at a temperature range of 550 to 650°C;
A method for manufacturing a printed wire, characterized in that the process is performed for 10 to 90 minutes.