JPH0323088A - Method of high damping steel sheet - Google Patents

Abstract

PURPOSE:To continuously obtain a non-resin type high damping steel sheet having an excellent high damping characteristic in a simple process by applying pulsative current with a conductive roll between two steel sheets on which electrically conductive powder is interposed at a prescribed distribution, and joining both steel sheets through electrically conductive powder. CONSTITUTION:Electrically conductive powder 3 is distributed on a steel sheet 1a on one side at a prescribed concentration, then, the other steel sheet 1b is lapped over it. As pulse current is applied by the conductive roll 4 to the lapped steel sheets 1a, 1b, they are rolled down to continuously manufacture a high damping steel sheet. Besides, the steel sheets 1a, 1b are moved on a horizontal guide plate and the guide plate serves as a ground plate. Consequently, the steel sheets 1a, 1b receive pulse current between the conductive roll 4 and the guide plate. Usually, as electrically conductive powder 3 is distributed on the steel sheet 1a, the steel sheets 1a, 1b are welded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a non-resin damping steel plate. (Conventional technology) In recent years, the introduction of vibration-damping steel plates has been considered in automatic inverters and Uba electrical appliances to prevent noise and vibration. At present, the vibration control 111fjl, which occupies the mainstream of development, is tfi1+&1a, ib as shown in Figure 3(a).
It is a grease sandwich type with a thin resin film 2 sandwiched in between, and its practical use has begun in some areas. The damping principle is that the resin film 2 undergoes shear deformation during vibration and converts vibrational energy into thermal energy.

This resin sandwich type vibration damping steel plate has excellent vibration damping properties, but since its properties are controlled by the physical properties (viscoelasticity) of the resin film 2, it is highly temperature dependent, and the resin must be changed depending on the usage environment temperature. There is an unavoidable problem. In addition,
In the case of resin molds, there are problems with heat resistance, which limits the environment in which they can be used and results in a lack of weldability. 1: A damping steel temporary force developed against the background of problems such as
For example, there is a powder composite damping steel plate disclosed in ``Iron and Steel Lecture Collection'' 81-31500. As shown in FIG. 3(b), this damping steel plate is composed of steel plates la, lb
This is a non-resin damping steel plate with conductive powder 3 such as copper sandwiched therebetween, and the steel plates 1a, 1b and the conductive powder 3 are integrated by diffusion bonding.

The damping principle of this damping rope plate that does not use resin is that the free interface other than the powder joint absorbs vibration energy through wear, and its damping properties are substantially the same as those of the resin sand-inoch type damping rope plate. remains the same. Furthermore, since it is a non-resin type, it naturally has low temperature dependence and is excellent in heat resistance and weldability.

(Problems to be Solved by the Invention) However, in the conventional powder composite vibration damping steel plate, conductive powder 3 is sandwiched in a predetermined distribution between the temporary 1a and lb, which is cut out to a predetermined size, and then the conductive powder 3 is processed. It is manufactured using the bassochi method in which it is inserted into a heating furnace in a compressed state.Therefore, the manufacturing cost is extremely high compared to the resin sandwich type damping steel sheet, for which a continuous manufacturing method has already been developed. This was developed in view of this situation, and it is possible to continuously manufacture non-resin type vibration damping steel plates in a simple process, and also to provide excellent vibration damping characteristics to the manufactured non-resin type vibration damping plates. The purpose of the present invention is to provide a method for manufacturing a non-resin damping steel plate.

[Means to solve the problem]

In the manufacturing method of the present invention, conductive powder is interposed between steel plates in a predetermined distribution, and a pulsed current is passed between the steel plates using a current-carrying roll, thereby joining the steel plates through the conductive powder therebetween. Another characteristic is that
Rolling is performed before a pulsed current is passed through a current-carrying roll.

The first important point of the manufacturing method of the present invention is that a current-carrying roll is used to join the steel plate and the conductive powder therebetween by Joule heat. As a result, the current flowing between the steel plates is concentrated on the conductive powder, and the steel plate and the conductive powder are joined even with a small amount of current. Further, since an energizing roll is used for this energization, joining is performed continuously while moving the steel plates, and non-resin-type vibration damping steel plates are continuously manufactured.

The second important point of the manufacturing method of the present invention is that pulse current is applied. When joining M-plates using Joule heat, the joint surfaces are generally kept flat and clean. t
The situation in which conductive powder is interposed between the +g plates is essentially different from the general welding situation, and as a result, current concentration occurs in the conductive powder as described above, increasing the IT flow effect. On the other hand, excessive current concentration occurs in the conductive powder,
Continuous energization will melt and scatter the conductive powder.

Furthermore, if the amount of current is reduced to such an extent that the conductive powder does not melt or scatter, the conductive powder and the rope will not be satisfactorily joined. Pulse energization eliminates these obstacles all at once, and even in the special situation where conductive powder is present between the steel plates, it is possible to appropriately heat and bond only the bonding interface between the steel plate and the conductive powder (see Figure 2). ), stable Joule thermal bonding between the two becomes possible. [Function] The manufacturing method of the present invention will be explained in more detail below with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the present invention. After distributing the conductive powder 3 at a predetermined density on one of the IIL plates 1a, the other tA temporary 1b is placed on top of it. By rolling down the stacked steel plates 1a and 1b while applying a pulse current with the current-carrying roll 4, the vibration-damping steel plates 5
is produced continuously. In addition, steel Fj. la and lb move on horizontal temporary guides, and the four sides of the guide have ground plates stacked on top of each other. Therefore, the steel sheet receives a pulsed current between the roll 4 and the guide plate. Usually, the conductive powder 3 is distributed on the steel plate 1a while the steel plate 1a. Join 1b.

In the manufacturing method of the present invention, the pulse current application time mainly depends on the size of the conductive powder and the material of the conductive powder, and the smaller the conductive powder, the shorter the current application time needs to be. For example, if the average particle size of the conductive powder is 100 μm or less, the current application time is preferably 1 ms or less, and if it is 100 to 1000 μm, the current application time is preferably several ms or less. Additionally, if the material resistance of the conductive powder is high, it is necessary to shorten the energization time. Therefore, depending on the particle size and material of the conductive powder, the conditions for the energization time are set so that the conductive powder does not melt or fly apart. The pause time between energizations is mainly adjusted based on the line speed, and the faster the line speed, the shorter the pause time is to ensure that the conductive powder is bonded between the steel plates. In order to carry out the method of the present invention efficiently and effectively, -IC
Typically, capacitor discharge is used, and the current conduction time at that time is determined by the capacitor capacity C, the circuit resistance R, and the circuit self-inductance L, so the discharge circuit is designed to obtain the necessary current conduction time. Ru. The rolling force of the energizing roll cannot be limited because it changes depending on the material, particle size, etc. of the conductive powder, as well as the energizing time mentioned above. Therefore, this rolling is done to prevent the conductive powder interposed between the steel plates from being crushed by the rolling of the energized rolls.
Also, adjust the rolling force appropriately to avoid scattering. There are no particular regulations regarding the steel plate as long as it can conduct electricity, such as low alloy steel or clad f! A: It is possible to use high-alloy steel plates, etc. Furthermore, T1, Cu, A. A conductive metal plate of 1st grade can also be used. In addition, surface-treated steel sheets such as Zn-plated FL4 temporary are also applicable as long as they can conduct electricity. Regarding conductive powder, usually iron powder, Ni powder, Ca powder,
AI! ．． Powder, Zn powder, and stainless steel powder are used, but any type of powder other than metal may be used as long as it is made of a material that can conduct electricity.

Regarding the shape of the conductive powder, it is desirable for the shape to be relatively uniform, such as spherical or cylindrical, from the viewpoint of bonding quality control.
It can also be applied to irregular shapes.

The important factor in the vibration damping unit manufactured by the manufacturing method of the present invention is the bonding area a per conductive powder 3.
(see Fig. 2), and the ratio b (joint area ratio) of the total joint area a to the steel sheet surface area.

The joint area a is the rope plate 1a. It is related to the bonding strength of 1b, and if it is large, there is no problem, but if it is less than 0.05a*", there is a risk of peeling during manufacturing. Therefore, if the bonding surface ma is 0.0
It is desirable to select the size of the conductive powder 3 to be 5III1" or more.

The bonding area ratio b is related to both vibration damping properties and bondability. From the viewpoint of damping properties, it is better for the bonding area ratio b to be small, but if it is extremely small, a satisfactory bonding strength cannot be obtained. From this point of view, it is desirable that the bonding area ratio b be in the range of 0.5 to 30%. Therefore, the distribution of the conductive powder 3 is usually selected so that this range is satisfied.

In order for two steel plates to be effectively joined by conductive powder, as many powder particles as possible must be kept in electrical connection between the two steel plates. To do this, there are two methods: adjusting the particle size of the conductive powder to a constant value, or applying a load to the rope before passing it through an energized roll to force the conductive powder and steel plate to deform. There is a way to make contact with Rolling with rolls is the simplest method for applying a load to m-plates. In addition,
The rolling conditions at this time cannot be limited because they depend on the material of the conductive powder. Therefore, the rolling conditions should be adjusted appropriately depending on the type of conductive powder used. [Example] Next, an example of the present invention will be explained. A spherical conductive powder made of iron was distributed between two cold-rolled steel plates with a thickness of 1 mm and a temporary width of 500 mm, and the conductive powder was passed between the cold-rolled steel plates using the bearer shown in Figure 1. By passing a pulsed current through the cold-rolled steel plates, the cold-rolled steel plates were continuously bonded to each other via conductive powder to create a damping steel plate. For comparison, similar bonding was performed using continuous energization. Separately, rolling was performed before applying pulsed current, and then pulsed current was applied to manufacture damping steel plates. A test piece with a width of 20 mm and a length of 220 mm was cut out from the produced damping rope plate, and the vibration energy loss coefficient was measured.

The results are shown in Table 1 along with the bondability of the m-plate and the bonding conditions. As is clear from Table 1, the manufacturing method of the present invention can continuously and stably manufacture high-performance non-resin-type vibration damping steel sheets using conductive powder.

〔Effect of the invention〕

The manufacturing method of the present invention can continuously manufacture powder-incorporated non-resin-type vibration damping steel sheets with high properties, which could conventionally only be manufactured in a batch manner, and can greatly contribute to reducing manufacturing costs.

[Brief explanation of drawings]

Figure 1 shows one embodiment of the present invention! FIG. 2 is a cross-sectional view showing the state of bonding between the steel plate and the powder, and FIG. 3(a)
C) is a perspective view showing the structure of a damping steel plate. la, lb: wire plate, 3: conductive powder. 4: Electric roll,
5: Vibration damping rope plate. Figure 3 (Q) (b)

Claims (2)

[Claims] (1) Conductive powder is interposed between steel plates in a predetermined distribution, and a pulsed current is passed between the steel plates using a current-carrying roll, thereby joining the steel plates through the conductive powder therebetween. A method for manufacturing vibration-damping steel plates. (2) After interposing conductive powder between steel plates in a predetermined distribution, the steel plates are rolled, and then a pulsed current is passed between the steel plates with an energizing roll, so that the conductive powder is interposed between the steel plates. A method for producing a damping steel plate, characterized by joining.