JPH0358832A - Composite damping steel plate excellent in spot weldability - Google Patents

Abstract

PURPOSE:To enhance joint strength and to stabilize spot weldability by adding a metal filler having specific hardness, electric resistivity and heat conductivity to a resin layer in an amount of 0.1 - 10.0vol.%. CONSTITUTION:A desired composite damping steel plate is formed by laminating two steel plates through a resin layer having damping properties. At this time, 0.1 - 10.0vol.% of a metal filler having hardness of 100 - 400muHv, electric resistivity rho of 3muOMEGA.cm or more and heat conductivity k of 0.3cal/ deg.C.cm.sec or less is added to the resin layer. By this method, a composite damping steel plate having high joint strength and excellent in stable spot weldability can be obtained.

Description

[Detailed Description of the Invention] Industrial Application Fields> The present invention provides a metal filler-containing tree 311 between two steel plates.
It relates to a composite #il containing metal filler made by sandwiching and crimping N, and in particular to a composite type vibration damping plate with improved weldability due to the filler. Conventional technology〉 Composite steel plate containing metal filler can be electrically welded
Temporarily an automatic military component. It is widely used in civil engineering construction components, electrical product components, etc., and various improvement technologies have been proposed. In particular, various metals have been proposed for fillers. In particular, JP-A-63-122534 attempts to improve welding stability by specifying the hardness of the filler. Also, JP-A-62-151332. In JP-A No. 62-288028, the shape of the filler is specified to improve weldability. Japanese Patent Publication No. 62-297
Publication No. 430 attempts to improve weldability by specifying the amount of filler. However, both of these technologies focus on improving conductivity, and the examination of the nugget diameter obtained as a result of welding and the physical properties of the filler used is
This was rarely done, and stable properties of spot weldability were not obtained. Problems to be Solved by the Invention The present invention was made to solve the above-mentioned conventional problems, and its purpose is to improve the appropriate physical properties (hardness, electrical resistivity, thermal conductivity, ) By selecting a filler having the following properties, an object of the present invention is to provide a wcwJ plate having improved weld joint strength and stable spot weldability.

Means for Solving the Problems> The present invention provides a composite vibration damping hollow plate made by laminating two steel plates with a resin layer having vibration damping properties interposed therebetween, in which the resin layer has a hardness of 10 (1). -400μHv, electrical resistivity ρ
3 μΩ・cm or more, thermal conductivity k 0.3 cal/'C-cm-s
A metal filler having characteristics below ec is used in the range of 06l to 10.
This is a composite damping steel plate with excellent spot weldability, characterized by the addition of 0 vol%.

<Operation> The present invention will be explained in detail below. To manufacture the composite damping steel plate that is the subject of the present invention, first, one of the two steel plates is coated with metal filler BFJN on one side, and a metal filler is formed on one side of the other steel plate. Either form a resin layer containing no filler, or form a resin layer containing metal filler on both sides, or
A film with a metal filler sandwiched between them is pasted together using a roll or press. In that case, in order to provide conductivity, the ratio of the particle size of the filler to the resin J1 is preferably 1.2 or more. However, in the case of bonding, pressure is applied, so if the filler is soft, the amount of deformation of the filler will be large, and the filler will become buried in the resin and lose its conductivity, resulting in defective spot welding. Moreover, if the filler is too hard, unevenness of the filler will appear on the surface of the skin steel plate when bonding, resulting in poor appearance. Therefore, the filler needs to have a certain degree of hardness. For this reason, the hardness of the filler was defined as 100 to 400 μHv in terms of micro-Vickers hardness. Figure 1 is a graph showing the relationship between metal filler hardness, spot welding success rate, and appearance. Electrical resistivity and thermal conductivity were studied from the point of view of the basic characteristics of resistance welding, in which metals are fused by self-heating due to the flow of current and the resistance.

A high electrical resistivity of the filler means that it generates a large amount of heat when compared at the same current density, and the lower the thermal conductivity, the smaller the amount of heat escaping to the electrode. That amount of heat can be used effectively.

This point can be understood through the following simulation. That is, FIG. 2 shows the results of simulating various metal fillers and using numerical calculations to determine the temperature distribution in the axial direction during spot welding.

The case with Ni+Fe as a filler is shown by the solid line above, and it can be clearly seen that the temperature is rising. On the other hand, in the case of Cu (not shown by the dotted line below), there is no temperature rise
It can be seen that the melting point has not been reached.

Therefore, with reference to the above scenario, electrical resistivity and thermal conductivity were defined as follows. Electrical resistivity ρ
3 μΩ・cm or more, thermal conductivity k 0.3 cal/”C-cm・s
ec or less The amount of the filler used in the present invention to be incorporated into the resin is preferably in the range of 0.1 to 10 vol%, preferably in the range of 0.5 to 3 vol%. The reason is that the filler content is too low. This results in poor appearance such as dust, and too much filler content leads to a decrease in shear density strength. This relationship is shown in FIG. In addition, the shape of the filler is
It should be as spherical as possible. The type of filler is preferably cupro, monel, hastelloy. Inconel etc. is good. More preferably, the metal filler has corrosion resistance.

The steel sheets used in the present invention are cold-rolled steel sheets and chromate-treated steel sheets.
Zinc-treated steel sheet. It may be a phosphoric acid treated steel plate, a stainless steel plate, etc. Also, the thickness of the plate can be any thickness as long as it can be bonded together by just one inch. Further, the resin used in the present invention is polyethylene. These are thermoplastic resins such as polybrolylene, thermoplastic polyester, and vinyl chloride, or thermosetting resins such as epoxy polyurethane, acrylic, and thermosetting polyester. These resins can be used alone or by mixing a thermoplastic resin and a thermosetting resin to form a mixed resin that provides stable hardness over a wider temperature range than when each resin is used alone. Examples of the present invention will be shown below, but the present invention is not limited thereto.

<Examples> Examples 1 to 11 and Comparative Example 1 The metal fillers shown in Table 1 were used. It should be noted that the corrosion potential E corr of any filler is nobler than the tentative corrosion potential Esteel and has corrosion resistance.

Using this metal filler, we created a composite damping steel plate. The average particle size of the metal filler is approximately 6.
5μ, and the amount blended into the resin was 0.5νo1%.

The synthetic resin used was polyester citrus. The steel plate has a thickness of 0. A 4 mm cold rolled steel plate was degreased and used.

The lamination and crimping method was as follows. Do you use polyester resin in a solvent (toluene, xylene, methylethynoleketone) in advance? After melting, apply the resin to one side of one steel plate using a Rohno recorder to the specified resin W- (50μ), and then sprinkle the above metal filler on the coated surface so that it is evenly distributed, and then put it in an oven. The solvent was vaporized. In the same way, polyester resin was applied to one side of the other steel plate so as to form a predetermined resin layer, and the solvent was evaporated in an oven for 11 seconds.
Layer the resin-coated surfaces of the two above-mentioned sinus plates and heat to 180 ml.
C. for 1 minute at a pressure of 25 kgf/cJ to obtain a composite damping steel plate containing a metal filler.

Spot welding was performed on the obtained steel plate.

The conditions are welding of composite damping steel plates, and the dimple diameter is 8.
R ball. The applied force was 170 kgr, the current was 8k, and the energization time was 8 cycles.

The joint strength of the welded contacts was measured. Measure by pulling! ! *This was carried out using a machine at a pulling speed of 50 mm/min. The test results are shown in Table 2. Examples 1-1l of the present invention
shows good results.

Effects of the Invention> As explained above, according to the present invention, the hardness of the filler. By selecting the electrical resistivity and thermal conductivity within a specific range, it is possible to obtain a composite damping steel plate that has high joint strength and provides stable spot weldability.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between metal filler hardness, spot welding success rate, and appearance condition, and FIG.
6uΩ・cm, k =0.24cal/℃ - c
When using m・58C metal filler and ρ-1.7
μΩ・cn+. k -0.93cal/℃-cm-
Figure 3 is a graph obtained by simulation calculation of the temperature distribution in the welding axis direction for a vibration-damping steel plate using a metal filler of This is a graph showing the relationship between

Claims (1)

[Scope of Claims] A composite vibration-damping steel plate formed by laminating two steel plates with a resin layer having vibration-damping properties interposed therebetween, in which the resin layer has a hardness of 100 to 400 μHv and an electrical resistivity of ρ3 μΩ·cm or more. , A composite damping steel plate with excellent spot weldability, characterized in that 0.1 to 10.0 vol% of a metal filler having a thermal conductivity of k0.3 cal/°C.cm.sec or less is added.