JPS601934B2 - Manufacturing method of damping steel plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a damping steel plate having extremely high vibration damping ability.

In recent years, various measures have been considered to prevent vibration pollution and noise pollution in transportation facilities, machine factories, etc., and one of the preventive measures is to use materials with high vibration damping properties in vibration-generating parts and noise-generating parts. It is being used.

Conventionally, high Cr steel and flake graphite cast iron have been known as vibration damping materials that generally have a high vibration damping capacity, but the former materials are not only expensive, but also have a low vibration damping ability due to cold working. Due to problems such as deterioration of the material, its use is limited to special fields, and the latter material is almost impossible to process.
This also has problems such as limited use.

Therefore, a pure iron-based vibration damping steel plate with improved vibration damping ability by increasing the grain size was proposed as an inexpensive and versatile damping material. Low strain amplitude castles, such as 10-3 or less, do not exhibit high vibration damping properties, and have problems such as the vibration damping ability tends to decrease due to cold working. A vibration-damping steel plate has also been proposed in which micro-porosity is created at the interface between the inclusions and the pond iron through a combination of short-time sintering and cold working, which improves the vibration damping ability. However, this material does not have a very high vibration damping ability, is susceptible to aging, and has the problems of extremely poor workability due to its high cleanliness.

From the above-mentioned viewpoints, the inventors of the present invention have conducted research to obtain a vibration damping steel plate that has high vibration damping ability and does not suffer from deterioration in vibration damping capacity due to plastic working or aging treatment. {a) The sound and vibration damping performance of a steel plate is determined by the internal friction of the steel plate Q-1
(However, Q-1 is expressed as a nose.

6: Logarithmic damping rate), and the magnitude of Q-1 corresponds to the amount of energy lost per one cycle of strain amplitude, and the larger Q-1, the more vibration The rate of converting energy into heat inside the steel plate increases, and as a result, the vibration damping effect is improved.

(b} In general, if the total solid carbon and solid solute nitrogen in steel are reduced to facilitate domain wall movement, it will have a high vibration damping ability due to magneto-mechanical static hysteresis loss, but internal friction due to this domain wall movement is highly susceptible to the effects of strain and internal stress. ``Therefore, even a small amount of cold working will significantly reduce the vibration damping ability. If there is almost no vibration, vibration damping can be achieved by subjecting it to cold working consisting of one or both of cross-rolling and cold stretching to give it plastic deformation with an elongation rate of 1.7 to 20%. ability to improve significantly.

(d- In order to extremely reduce the amount of interstitial solid solution atoms of C and N in steel, T, which is a strong carbonitride forming element, is required.
It is preferable to contain i, Nb, and Zr in an amount greater than the stoichiometric amount that forms a compound with C and N, and the presence of this excess carbonitride-forming element causes the intrusion type solidification of C and N to occur for the first time. Extremely low amount of soluble elements (0.1 p.p.m
．． = 1 x 10-5% by weight or less), and as a result, it is possible to suppress the aging deterioration of the vibration damping capacity increased by the lining processing. In this case, for example, if only the cheapest Ti is used as a carbonitride-forming element, it is sufficient to contain more Ti than Cchin+Ntaku, since the vibration damping ability deteriorates over time.

{e- The details of the vibration damping mechanism of such a damping steel plate are unknown, but the vibration damping is caused by the resonance phenomenon of string vibration of mobile dislocations introduced by cold working, and it is believed that the It is estimated that when dislocations are fixed by penetrating solid solution elements, string vibrations are inhibited and the damping capacity is significantly reduced.

[f} If one or both of S and Pb is further added to steel, which has been designed to improve vibration damping ability by reducing interstitial solid solution elements and introducing mobile dislocations, the vibration damping ability will be further improved. Improved vibration damping ability.

(g) The vibration damping ability of such a damping steel plate is not easily affected by the structure, etc., as long as the above-mentioned state of interstitial solubility elements and the introduction of an appropriate amount of dislocations by cold working are satisfied. It is possible to similarly improve the vibration damping capacity of both hot-rolled steel sheets and sintered anchor rolled steel sheets.

The findings shown in sections a to (g) above were obtained.

Therefore, this invention was made based on the above knowledge, and C: 0.002 to 0.080%, Mn: 0.0%.
3-3.00%, sol. AI: 0.50% or less, N:
Contains 0.001 to 0.020%, and further contains Ti:1.
0% or less, Nb: 1.0% or less, and Zr: 1.0%
Containing one or more of the following,
The total amount is:
)N≦ki)〉048 12, and further S: 0.02 to 0.25% and Pb: 0
．． A composition containing one or both of the vibration damping ability improving elements of 02 to 0.3%, with the remainder consisting essentially of Fe and unavoidable impurities (wt%, below %). % by weight)) is subjected to cold working consisting of either cold rolling or cold stretching, or both, to obtain an elongation rate of 1. This method is characterized by producing a vibration damping steel plate having an extremely high vibration damping ability by applying plastic deformation of 7 to 20%.

Next, in the method of the present invention, the reason why the composition and amount of deformation of the steel sheet are limited as described above will be explained.

(a) If the C content is less than 0.002%, it will be difficult to melt steel using a top-blown converter, bottom-blown converter, or vacuum degassing treatment, while if the C content exceeds 0.080%, If so, it becomes necessary to contain large amounts of Ti, Nb, and Zr, resulting in high costs.
It was set at 0.080%.

[b} The MnMn component has the effect of preventing hot embrittlement of steel sheets, so it is included depending on the manufacturing conditions, but even if its content is less than 0.03% or exceeds 3.00%, Since melting in a converter becomes difficult, its content is reduced to 0.
．． 03 to 3.00%.

'c} sol. The mountain AI components include Tj, Nb, Ta, and Zr without any influence on the vibration damping of the steel plate.
It has the effect of improving the content yield of sol. If the AI content exceeds 0.50%, it will have a negative effect on the workability of the steel sheet, so the content should be reduced to 0.
．． It was set at 50% or less.

[dI N The lower the N content, the better; however, reducing the content to less than 0.001% requires high costs for copper melting, while containing more than 0.020% increases Ti, Nb ，
The content of Ta and Zr has to be increased, which not only increases the cost but also deteriorates the workability of the steel sheet, so the content should be increased to 0.001 to 0.020%.
It was determined that

[e- Ti, Nb, and Zr These components all combine strongly with C and N to form TIC, TIN, and Nb.
By forming C, Z, and carbonitrides such as ZrN, it is possible to create a state in which there are almost no interstitial solid solution atoms of C and N in the steel, and in combination with cold working in the subsequent process, the vibration damping ability of the steel sheet is improved. Because it has the effect of improving the stoichiometric amount of each to form a compound with C and N, that is, the total amount is It must contain an amount that satisfies the following.

However, if each of Ti, Nb, and Zr exceeds 1%, the workability of the steel sheet will deteriorate and the cost will increase. : 1% or less, Nb: 1% or less, and Zr: 1% or less. 'f) Vibration damping ability improving element S of 0.02% or more and Pb of 0.02% or more have the effect of further improving the vibration damping properties of the steel plate, so they must be actively included. The S:0.
If the content exceeds 25% and Pb:0.3%, it will cause a significant deterioration in workability.
The upper limits of these components were set to the values mentioned above.

(g) Amount of plastic deformation In hot-rolled steel sheets and cold-rolled steel sheets, the dislocation density is generally low, or even if dislocations exist, they are mostly immobilized by C and N atoms.

In the present invention, a hot-rolled steel sheet or an annealed cold-rolled steel sheet of this type is subjected to cold working to generate movable dislocations, that is, dislocations that can sufficiently cause resonant vibrations of the strings and contribute to vibration damping. This can be done by rolling, cold stretching, or a combination of both, but in reality, skin-pass rolling, tension leveler, roller leveler, and stretcher are used. This may be implemented by any one of the following, or a combination thereof. In this case, a method using press forming may be considered, but since the amount of strain in press forming varies depending on the location, it cannot necessarily guarantee high vibration damping ability. If the amount of elongation is less than 17%, it will not be possible to secure enough dislocations to guarantee high vibration damping, while on the other hand, even if plastic deformation exceeding 20% of elongation is applied, the amount of dislocations will be insufficient. If the number of dislocations becomes too large, entanglement will occur between dislocations, which will not only prevent further improvement in vibration damping ability but also reduce workability. The above cold working may be performed continuously after hot rolling or after dulling.
In this case, the processing temperature is suitably in the range of 250 to 150 qo. Next, the method of the present invention will be specifically explained using examples.

Example 1 In a vacuum furnace, each steel having the composition shown in Table 1 was melted and made into a steel ingot with dimensions of 20 mm thick x 20 mm wide x 40 mm long. Cast this steel plate to 950~1
Hot forged at a temperature of 250 o'clock, thickness 50 side x width 2
A slab with dimensions of 0 yards x 80 yards in length was prepared, and then the slab was heated and held in a heating furnace at a temperature of 125,000 for 1 hour, and then immediately subjected to the conditions of a final finishing concentration of 890°C and a finishing plate thickness of 3. Hot-rolled steel sheets were produced by hot rolling the steel sheets at a temperature of 100 ℃, followed by rapid cooling to a temperature of 65,000 ℃ or less, and then rolling.

Next, a part of the hot-rolled steel sheet was pickled, subjected to cross-rolling at an elongation rate of 8.0%, and then subjected to accelerated aging treatment at a temperature of 50 qo for 3 days. For the remaining hot rolled steel sheets, 1. After cold rolling to rib thickness, 700q
Moth anchor held at a temperature of 5 hours, and subsequently 8.0%
After cross-rolling at an elongation rate of , accelerated aging treatment was performed at a temperature of 50 do for 3 days. The steel plate obtained as a result, and the ship's dimensions shown above for comparison.

[Kushiyuki ten-room base (vertical length of ten rice ants; dimension sealed) ・From the as-annealed steel plate of Ichikan and Seiseki, thickness 1.0 willow x width 1 length x length 120 sides An internal friction test piece having the dimensions was cut out, and the magnitude of internal friction Q-1 was measured using a capacitance-driven testing machine at a temperature of 23:00 and a frequency of about 340 Hz.

Note that the maximum strain amplitude in this case was in the range of 0.1 to 1 x 10-5. The measurement results are also shown in Table 1.
As shown in Table 1, the Ti equivalent is 0 or more, that is, the component composition satisfies the component composition formula in this invention,
It is clear that the cold-rolled steel sheet with an elongation rate of 8% has extremely high internal friction, that is, extremely excellent vibration damping ability. On the other hand, a cold-rolled steel sheet that has been dulled before cold rolling with an elongation rate of 8% exhibits only low internal friction, regardless of the Ti equivalent. Example 2 After pickling, the hot-rolled steel sheet of sample number 6 in Example 1 was subjected to cold rolling with the elongation rate varied in the range of 0.2 to 40%, and subsequently heated to a temperature of 5000°C. An accelerated aging treatment was performed for 3 days.

The magnitude of internal friction of the steel plate obtained as a result Q-1 and J
The elongation in the L direction was measured using an IS5 tensile test piece, and the measurement results are shown in FIG.

As shown in the figure, it is clear that when the cold rolling elongation rate is in the range of 1.7 to 20%, large internal friction and high elongation, that is, high vibration damping and excellent workability are ensured. Example 3 The annealed cold-rolled steel sheets of sample numbers 20 (comparative steel) and 6 (invention steel) in Example 1 were subjected to cross-rolling at an elongation rate of 8.0%, and then immediately heated to 50°C. Aging treatments were performed for various lengths of time in an oil bath, and the magnitude of internal friction was measured.

The measurement results are shown in FIG. As shown in the figure, the internal friction of the steel of the present invention is hardly affected by the aging time, whereas the internal friction of the comparison steel with a negative Ti equivalent decreases significantly as the aging time increases. I know what will happen.

As described above, according to the method of the present invention, it is possible to produce a damping steel plate at a low cost, which has an extremely high vibration damping ability and whose vibration damping ability does not deteriorate even after plastic working or aging treatment. When this vibration-damping steel plate is used in various machines and devices, it exhibits extremely excellent vibration-damping properties and other industrially useful effects.

[Brief explanation of the drawing]

Figure 1 is a curve diagram showing the relationship between cold rolling elongation rate, internal friction, and elongation in a steel plate, and Figure 2 is a curve diagram showing the relationship between aging time and internal friction magnitude. . Hair l figure 2

Claims (1)

[Claims] 1% by weight, C: 0.002-0.0080%, Mn
0.03-3.00%, sol. Contains Al: 0.50% or less, N: 0.001 to 0.020%, and further contains Ti.
: 1.0% or less, Nb: 1.0% or less, and Zr: 1
．． Contains one or more of the following:
(Nb(%))/(93)+(Zr(%))/(91)
-(C(%))/(12)-(N(%))/(14)>
0, and also S: 0.02-0.25% and P
b: Contains one or two of 0.02 to 0.3%, with the remainder consisting of Fe and unavoidable impurities. A method for producing a damping steel plate, characterized in that plastic deformation with an elongation rate of 1.7 to 20% is imparted by performing cold working consisting of one or both of cold stretching.