JPS5941513B2 - Method of manufacturing vibration-proofing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a vibration isolating material that has a large damping capacity and can be mass-produced.

General industrial machinery, transportation equipment such as aircraft, railway vehicles, and automobiles, and general household equipment include some large castings, forgings,
With the exception of small non-ferrous metals, most of them are made of iron-based carbon steel plates or stainless steel strips.

In recent years, steel plates, which are structural members, have become thinner in order to reduce costs, save resources, and conserve energy, and as a result, noise from vibrations from the steel plates itself has increased, worsening the working environment and affecting other equipment due to the vibrations. The negative effects of this are becoming a major problem. Suppressing the vibrations and noise generated by already manufactured equipment has many technical and cost problems, so we are trying to reduce the noise and vibration generated by equipment and members of mechanical structures. The possibility of applying materials with high damping capacity, such as lead alloys, Mn--Cu alloys, or composite materials, such as resin-coated steel plates, has been studied for some time, and some of them have been put into practical use.

However, a manufacturing method has not yet been developed that allows these vibration-isolating materials with high damping ability to be easily produced in large quantities and processed and applied as structural members. Under these circumstances, the inventors of the present invention have been conducting research to provide a manufacturing method for vibration-proofing materials that can be mass-produced at a relatively low cost. We focused on the point that it is said that it is sufficient to form minute irregularities on the surface of the member or a large number of minute defects inside.

On the other hand, it is also known that intergranular corrosion occurs when austenitic stainless steel is subjected to sensitizing heat treatment and corrosive action by acid.The present invention was completed by linking this intergranular corrosion phenomenon with the formation of internal micro defects. This is what I did. That is, the present invention consists of a structure in which microscopic voids are generated at grain boundaries by heat treatment and chemical corrosion of the surface layer of the component, and then various resin films are attached and coated. The steel plate has countless fine cavities within its surface layer, which prevents vibrations, and has excellent absorption of vibrational sound waves caused by slight vibrations.Furthermore, a resin film is formed on the outermost surface, which prevents sound waves from entering the outside. to prevent leakage,
Furthermore, it is clear that it provides functions such as anticorrosion, heat insulation, and decoration.

The sensitizing heat treatment, which is one of the features of the present invention, and the intergranular corrosion treatment, which is a subsequent process, are related to each other, and the conditions differ depending on the material, thickness, time, and depth of the sensitized layer of the steel, but the sensitization Chemical heat treatment was performed at 680-820°C for 12-10 minutes, and intergranular corrosion was performed at CUSO45H2O8O-1201/1. S
It is suitable to carry out the corrosion using a solution having a composition of H2SO48O to 120ml/l and a corrosion time of 8 to 22 minutes.

Although a grain boundary corrosion layer can be obtained outside this range, the practical effect is weak. In addition, SUS3L of austenitic stainless steel
Since carbide-stabilizing elements are added to steels such as No. 6 and SUS32l, sensitization is unlikely to occur. Therefore, a carburizing treatment is performed in advance to increase the carbon concentration on the surface of the steel material. The carburizing conditions are 900-930℃, H234Ol), COl4%, CH
4l2.4%, CO2O. Use stainless steel whose outermost layer has been carburized by carburizing it for 5 to 10 minutes under conditions of 400t) and N2 remaining. When applying a resin film to the surface of a steel material subjected to sensitized intergranular corrosion, which is another feature of the present invention, various resin films such as phenol-based, epoxy-based, and fluorocarbon-based resins can be used. Depending on the purpose, it is used in a colorless and transparent state or in a colored state, and as a coating method, a pasting method such as heat-pressure pasting or mechanical fixation (if thick) is used.

With this film coating, the vibrations generated by the steel plate or the noise emitted from the material itself, which is emitted into the atmosphere without being attenuated by the intergranular corrosion surface layer, is reflected back to the steel plate, and some of the noise generated by the material itself is reflected back to the steel plate. This has the effect of allowing it to be absorbed. The present invention will be explained in more detail with reference to FIG.

FIG. 1 is a flow sheet showing the process of continuously imparting the vibration-proofing function of the present invention to a coiled thin plate.

The band-shaped austenitic stainless steel wound around the uncoiler 1 is degreased with alkali in a degreasing tank 2, spray-cleaned in a water washing tank 3, and then dried in a hot air dryer 4 to complete the pretreatment. Thereafter, the continuous strip is passed through a coil end cutting machine, a welding machine, etc. (not shown), and introduced into a sensitizing heat treatment furnace 6 at a constant speed while adjusting the speed using a loop car 5, and the surface layer is carburized to reduce carbon content. The extremely surface layer of the steel plate is made sensitized by using a steel that increases the carbon content and easily generates carbides, or by high-frequency heating, and then the coil is cooled by a cold air cooler 7. Note that from the sensitizing heat treatment furnace 6 to the cold air cooler 7, the sensitization heat treatment is performed in an inert gas atmosphere such as Ar or N2 to prevent oxidation in the atmosphere. The sensitized strip is introduced into the grain boundary corrosion tank 8, and the grain boundaries, which have become extremely susceptible to corrosion due to the segregation of carbides and other substances precipitated at the grain boundaries of the crystals during the sensitization heat treatment, are treated under optimal conditions. cause corrosion. The intergranularly corroded band plate is immediately washed with water in the washer 9 and dried in the dryer 1.
Dry with hot air at 0. Thereafter, the level is corrected using a roller leveler 11, and then a gelled or thermoplastic resin film 14 is pressed onto the sensitized surface of the coil, on one side or both sides depending on the application, using a pressure roll 13, and then placed in a curing furnace 15. A curing process is performed to increase adhesion. Subsequently, after being cooled with cold air by the cooler 16, it is wound up into a recoiler 18 via a loop car 17 and a cutting machine (not shown). Example 1 C0.062(!), Crl8.37%, Ni8.8l
(f) 680mm austenitic stainless steel plate with a thickness of 1.0mm. After sensitizing heat treatment for 12 minutes, CU
SO4・5H20100g/1. ．． H2SO4lOOm
As a result of grain boundary beak eating for 8 minutes in a boiling aqueous solution of l/l,
A grain boundary corrosion area of 25 to 30 μm was confirmed on one side, and a thin film of phenolic resin was further attached, and the vibration damping properties were measured in comparison with those not treated at all.

As a result, it was possible to increase the logarithmic attenuation rate by about 700 to 800 times compared to the untreated material. Example 2 Example 1
Using the same material as in Example 1, sensitization treatment was performed at 680°C for 4 minutes, and intergranular corrosion was performed for 12 minutes with the same composition as in Example 1 to form an intergranular corrosion layer of about 50μ on one side. As a result of measuring the mechanical properties and rotary bending fatigue properties of the treated material, as shown in Figures 2 and 3, the treated material had a depth of 50 μm.
(100μ on both sides), there is almost no difference in both mechanical properties and fatigue limit compared to the untreated material.

However, when the depth of the treated layer exceeded 100 μm (200 μm on both sides), that is, more than 10% of the thickness of the material, the above characteristics tended to gradually deteriorate. Note that the treatment depth O is the value obtained by performing only the sensitization treatment. Example 3 C0.06(!), Crl8.5OOl), Ni8.7
2%, coil thickness 1.0m71L austenitic stainless steel strip plate (width 250m0) was used as a test material, and a pilot plant equipment for the process shown in Fig. 1 was manufactured.
As a result of experiments with various sensitization treatment conditions and intergranular corrosion conditions, as shown in Table 1, the depth of the intergranular corrosion layer formed varied depending on the sensitization temperature, time, and intergranular corrosion time. It turned out that it was possible.

Furthermore, similar results were confirmed for other steel types, ie, other steel types B and C in Table 1, from the pilot plant test results. From this table, it can be seen that for steel materials with a thickness of 1.5 mm or less, 2 to 2
It can be seen that an intergranular corrosion layer of 0 to 50μ is formed.

Example 4C0.065%, Crl8.62(f), N
i8.79%, board thickness 32mm, board width 910mm, length 1
After sensitizing an 820 mm austenitic stainless steel plate, intergranular corrosion layers were formed on both surfaces to a depth of 100 μm, and a fluorocarbon film with a thickness of about 0.05 mm was attached to the surfaces.

After that, in order to measure the damping characteristics from this steel plate, trial 1 was conducted.
A test piece was taken and the vibration damping characteristics were measured using the untreated material as a comparative material. As a result, the logarithmic damping rate could be increased to about 500 to 700 times compared to the untreated material.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing the method of the present invention, and FIGS. 2 and 3 are graphs comparing the characteristics of steel materials treated according to the present invention and untreated materials.

Claims (1)

[Claims] 1. A method for producing a vibration-proof material, which comprises sensitizing the surface of an austenitic stainless steel material, subjecting it to intergranular corrosion, and then coating the surface with a resin film.