JPS5843450B2 - Manufacturing method of vibration damping thin steel plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a damping thin steel plate that has high vibration damping ability in a relatively low strain amplitude region (treble range) and has good workability.

In recent years, vibration and noise pollution caused by transportation systems, machine factories, etc. have become a problem, and there are demands from various quarters to reduce these vibrations and noises. Various countermeasures have been considered, such as designing to prevent resonance from occurring, but the actual noise sources and vibrations involved are complex, and it is difficult to eliminate them.

Therefore, attention has been focused on preventing vibration generation by using a material with high vibration damping ability in the noise generating portion.

Conventionally, Mn-Cu alloy and high chromium steel are known as such allocation materials and are commercially available.
Mn-Cu alloys have the drawbacks of low Young's modulus and high manufacturing costs, and high chromium steels also have high manufacturing costs and their vibration damping ability is significantly reduced by cold working. However, the actual situation is that its use is limited.

In addition to these materials, there are also materials that exhibit high vibration damping ability.
There is flake graphite cast iron, which is a material that is almost impossible to work with and therefore has even more limited uses.

On the other hand, for these reasons, a vibration damping steel plate has been proposed that is made of an inexpensive i-pure iron material and has improved vibration damping ability by increasing its crystal grain size. It is difficult to obtain a high vibration damping ability in a region where the strain amplitude is relatively low, such as below, and the vibration damping ability tends to decrease due to cold working.

In addition, by making the iron-based material contain a large amount of inclusions such as oxides,
A method was also proposed to improve the vibration damping ability by creating micropores at the interface between the inclusions and the base metal by a combination of short-time annealing and cold working. There were problems in that the heat resistance was not high, and aging easily occurred, and workability was extremely poor due to the large number of inclusions.

Furthermore, in high S content steel and high Pb content steel, T
Vibration damping ability is improved by adding carbonitride-forming elements such as i, Ta, N'oa, and Zr, which fixes C and N, allowing an appropriate amount of sulfide and PB to exist in the cleaned steel. It has also been proposed to obtain a material with a high vibration damping ability by obtaining a distributed steel plate with a high vibration damping capacity, or by decarburizing and annealing the thin steel plate using high S-containing steel or high Pb-containing steel. Such materials have not been satisfactory in terms of manufacturing costs.

From the above-mentioned viewpoints, the present inventors have found that the manufacturing cost is low, general press forming is possible, the elongation is, for example, 30 or more, and the minimum bending radius is It (where t is the material's When the maximum strain amplitude is 10', the internal friction Q-
1 (where δ Q 1 = -, δ is the logarithmic damping rate, and the larger Q-1 is, the greater the rate of converting vibration energy into heat inside the material, which can improve the vibration damping effect. ) is 3
In order to produce a steel plate with a vibration damping capacity of 10-3 or higher, especially in the low strain amplitude range, we conducted various studies focusing on relatively inexpensive ordinary carbon-containing steel.
” We obtained the findings shown in c.

(a) Blocked Fe5 of ordinary carbon-containing steel
If the existence of C is effectively utilized and an appropriate amount of AI is added, N in the steel will precipitate as A7N during high temperature coiling during hot rolling, and C will precipitate as Fe5C, so it will substantially improve the steel. The solid solute C and solid solute N in the solution become extremely low, and
Since the C and N atoms precipitated in this way are difficult to re-dissolve even after cold rolling and annealing, there is little decrease in damping ability, that is, internal friction Q-1, due to aging after cold working.

(b) In this way, if the presence of the MnS phase is ensured in the steel while the presence of solute C and N in the steel is kept extremely low, internal friction Q1 can be significantly improved by cold working. It is possible to obtain an excellent allocating material that can be used in a variety of ways and that does not deteriorate with aging.

(e) This damping ability is caused by the resonance of dislocation lines introduced into the steel by cold working due to vibration, and the presence of MnS affects the dispersion of these dislocation lines, It helps make resonance more effective.

This invention was made based on the above knowledge, and in weight percent, C: 0.03 to 0.30%, Si: 1.4
0% or less, Mn: 0.14-1.50%, S: 0
．． 035-0.150% (However, Mn/S>4) So4
AA: 0.02-0.20%, N: 0.010
% or less (however, 5ol-A6/N>2), and if necessary, B: 0.010 or less, Cu: 0
．． 20% or less, Cr: 1.0% or less, P: 0.20'%
Contains one or more of the following, and the rest is F
Steel having a composition consisting of eh and unavoidable impurities,
Final finishing temperature = 800℃ or higher, winding temperature = 700-76
After hot rolling at 0°C to remove scale, cold rolling at an elongation rate of 20.5 to 50, or alternatively, cold rolling at an elongation rate of over 50. After rolling, annealing at 450 to 850°C, further elongation: 0
．． A vibration damping thin steel plate having high vibration damping ability and good workability can be manufactured at low cost by temper rolling at 5 to 50 mm or by either method. It is.

Next, regarding the method for manufacturing a vibration damping steel plate of the present invention, the amount of each component of the steel, final finishing temperature of hot rolling, coiling temperature, elongation rate during cold rolling, annealing temperature, and time of temper rolling. The reasons for limiting the growth rates of each as described above will be explained.

a) In order to form lumpy Fe5C in C steel in combination with the hot rolling coiling temperature, thereby significantly reducing solid solution C and increasing internal friction Ql, 0.03% (or less) is required. The amount of C component (indicating the component composition ratio is expressed as weight) or more is required, and if the amount is less than 0.03%, lump-like Fe5C cannot be formed.

Therefore, the higher the amount of C component, the better, but if the amount is 0.
If it exceeds 30%, workability deteriorates, so the upper limit was set at 0.30%.

b) Si The Si component has the effect of facilitating the formation of lumpy Fe5C, but if the amount added exceeds 1.40%, the workability decreases, so the upper limit is set at 1.40%. did.

It goes without saying that adding the Si component brings about better results, but even without the addition of this component, a damping steel plate having high vibration damping ability can be obtained.

c) Mn The Mn component is required to be 0.14% or more in order to prevent hot embrittlement caused by S, and for this reason as well, the ratio of Mn to S must be greater than 4.

Moreover, if the content is less than 0.14φ, cold workability will deteriorate.

On the other hand, if the Mn component amount exceeds 1.50 yen, processability deteriorates, so the content was set at 0.14 to 1.50%.

In this range, the lower the Mn content, the better the internal friction Q1.

d) S The S component is important for forming MnS, but if its content is less than 0.035φ, the amount of MnS produced is too small and the damping effect is small.

On the other hand, if the content exceeds 0.150%, processability will decrease, so the content of the S component should be adjusted to 0.035 to 0.150%.
It was set as φ.

e) Mn/S As mentioned above, if the ratio of Mn to S content is 4 or less, red brittleness occurs during hot rolling and cracks occur at the edges of the steel plate, so the value of Mn/S is set to 4. Yoshi also became a dog.

f) So4Al SoA, Al has the effect of fixing N in combination with the hot rolling winding conditions, and for this purpose at least 0
．． 02φ or more is necessary, and a larger amount is preferable from the standpoint of stability in producing a damping steel plate, but if the amount exceeds 0.20%, workability decreases, so the upper limit was set at 0.20φ.

g) N The smaller the N component, the better.

If the content exceeds 0.010%, workability will be significantly reduced, so the upper limit was set at 0.010%.

h) SoA, Al/N In order to fix N in steel as A7N, the ratio of the content of SoA and AA to N must be greater than 2, and if the value of the ratio is less than 2, the steel plate The internal friction Q-1 after cold working and aging becomes lower.

For example, in the case of rimmed steel, even if the hot rolling conditions of the present invention were adopted, the internal friction Q-1 was low and not much different from that of a general steel sheet.

i) B# Cut Crs p Addition of these components is preferable for improving strength, improving corrosion resistance, or stabilizing steel sheet production.

However, it cannot be denied that the cost will generally increase to some extent.

However, if the amount of B added exceeds 0.010%, cracking during melting tends to occur, and if the amount of Cu added exceeds 0.20%, so-called hexagonal cracking tends to occur, which may damage the surface texture of the steel sheet. If the amount of Cr added exceeds 1.0%, the pickling properties and chemical conversion properties of the steel sheet will decrease.

If the amount of P added exceeds 0.20%, brittle fracture is likely to occur.

Therefore, the upper limits of the component amounts of Bs Cu, Crs b and P are set to 0.010%, 0.20% and 1, respectively.
．． 0% and 0.20 yen.

j) Hot rolling final finishing temperature If hot rolling is performed at a finishing temperature of less than 800°C, abnormal grain growth tends to occur during high-temperature coiling and the surface texture of the steel sheet deteriorates, so the upper limit of the temperature was set at 800°C. .

k) Coiling temperature The coiling temperature during hot rolling is such that the Fe5C in the steel becomes lumpy,
In order to localize C, the temperature must be 700°C or higher,
If this temperature is less than 700° C., Fe5C will be dispersed and the effect of fixing C will be reduced.

On the other hand, if this temperature exceeds 760℃, Fe5C
The coiling temperature was limited to 700 to 760 φ, since this tends to reduce the ability to fix carbon and cause loss due to oxidation of iron and deformation of the coil.

l) Elongation rate during cold rolling In the case of thin steel sheets, the internal friction Q is reduced by rolling at 0.5% or more.
-1 is significantly improved.

The higher the elongation rate, the higher the internal friction Q-1, but 50
If rolling exceeds %, the workability will be significantly reduced.
When not annealing, the elongation rate during cold rolling is 0.5 to 5.
It was limited to 0φ.

m) Annealing temperature If cold rolling is performed with an elongation rate exceeding 50%, annealing is required.

Generally, from the viewpoint of internal friction Q-''1, the lower the annealing temperature, the better, but from the viewpoint of workability, the higher the annealing temperature.

Taking these points into consideration, it is found that strain relief annealing or recrystallization annealing at a temperature of 450°C or higher improves workability considerably compared to the cold-worked state, and that annealing at a temperature of over 850°C improves workability considerably. In view of the fact that the bulk Fe5C is melted and the distribution effect of the steel plate is lost, it was determined that an annealing temperature of 450 to 850°C is appropriate to ensure the production of the desired damping steel plate. The annealing temperature was limited to a certain value.

n) It is necessary to introduce dislocation lines by cold rolling with an elongation rate of 0.5% or more in temper rolling to enhance the damping effect.

As the elongation rate increases, the density of dislocation lines increases, and the internal friction Q-1 improves.

However, if the elongation rate exceeds 50%, the length of the dislocation lines becomes short, the damping effect becomes weak, and the workability decreases, so the elongation rate was set to 0.5 to 50.

The reason why scale is removed after hot rolling is that a beautiful steel plate surface is generally required.
It may be omitted if there is no problem with the surface properties of the steel sheet.

Next, the present invention will be explained using Examples and in comparison with Comparative Examples.

Example 1 1. Steel with the composition shown in Table 1 was melted in a converter and 230m
After forming the slab into a 3.21 ftm thick slab, it was heated in a heating furnace at 1200°C for 1 hour, and then heated into a 3.21 ftm thick hot rolled coil at a final finishing temperature of 840 to 860°C and a coiling temperature of 620 to 780°C. It was extended.

Then, after pickling, it was cold rolled at an elongation rate of 1.0%.

A test piece with a thickness of 1.0 mm, a width of 1Q mm, and a length of 120 mm was cut from the steel plate manufactured in this way, and after being left at room temperature for one month, the internal friction was measured using a transverse vibration type internal friction measuring device. Friction Ql was measured.

The frequency at this time was about 280 Hz, and the maximum strain amplitude on the plate surface was about 10''.

The measurement results are shown in FIG.

As is clear from FIG. 1, the internal friction Q1 of sample A30 steel sheet of the present invention becomes significantly large when the coiling temperature is between 700 and 760°C.

In addition, in the comparison steel sheet of sample A2 with a low amount of S, the internal friction Q-1 increases in the same coiling temperature range as the steel sheet of sample A3 due to the addition of AA, but this level is lower than that of sample A3. It is significantly smaller than the steel sheet of the present invention.

Furthermore, the internal friction Q-1 of the comparative steel sheet of sample A1 to which AA is not added shows a small value at any coiling temperature.

From this result as well, it is clear that the damping steel plate manufactured by the method of the present invention has excellent vibration damping ability.

Example 2 Hot-rolled coils of each sample shown in Example 1 with a winding temperature of 740°C were pickled and cold-rolled to a thickness of LO mm with an elongation rate of about 300φ, and then each of them was subjected to the following annealing treatment. Each was applied.

(a) Continuous annealing that combines recrystallization annealing at 700°C for 30 seconds and overaging treatment at 400°C for 6 minutes.

(b) Box annealing at 650°C for 5 hours.

Next, give these growth rates of 0.2 Yu, 1.5 Yu, A.
After the temper rolling, the specimens were left at room temperature for one month.

Then, specimens with thickness: i, o, width: 10 mm, length: 120 mm were cut out from these, and the internal friction Q-1 was measured.

The measurement results are shown in Table 2. From the results shown in Table 2, it is clear that Sample A 3' manufactured by the method of the present invention, with an elongation rate of 1.5 mm and a diameter of 5 mm, has an extremely excellent vibration damping ability. I understand that.

Example 3 1. Steel with the components shown in Table 3 was vacuum melted, and the thickness was 20.
After forming a slab with a width of 2001 rLm, it was heated in a heating furnace at 1180°C for 30 minutes, then final finish rolled at about 880°C, air cooled, and then gradually cooled from 730°C.

As a result, a hot-rolled sheet with a thickness of 3.2 mm and equivalent to 730° C. winding was obtained.

After pickling the obtained hot-rolled sheets, some of them were cold-rolled at an elongation rate of 2.0 yen and left at room temperature for one month to evaluate internal friction Q-''1, elongation, and bendability. We investigated each.

The remaining part was cold rolled with a thickness of 1.0 and an elongation of about 300%, then box annealed at 730°C for 1 hour, and after cooling, temper rolled with an elongation of 2.0. After being left at room temperature for one month, internal friction Q1, elongation, and bendability were investigated.

The internal friction Q-1 was measured using the same method as in Example 1, and the elongation was measured by taking a JI No. 85 test piece in the direction perpendicular to the rolling direction and measuring the elongation after tensile breakage (gauge length: 59 m).
The bendability was evaluated based on the minimum bending radius without cracking when bent in the direction perpendicular to rolling.

The results are shown in Table 4.

The results shown in Table 4 also show that the steel plate manufactured according to the method of the present invention has an elongation of 30% or more, a minimum bending radius of 1.0 or less, and an internal friction Q-1 of 3.0% or more. □XI
It can be seen that the workability and vibration damping ability are significantly superior even when compared with comparative steel sheets.

As described above, according to the present invention, it is possible to stably produce a distributed thin steel sheet with high vibration damping ability and good workability at low cost, and to reduce the noise and vibration of machines, equipment, etc. This brings about industrially useful effects, such as making it possible to take effective measures to reduce emissions.

[Brief explanation of the drawing]

Figure 1 shows that the coiling temperature during hot rolling is the internal friction Q of the steel plate.
It is a diagram showing the influence on -1.

Claims (1)

[Claims] 1. Weight φ, C: 0.03 to 0.30, Si: 1.
40% or less, Mn: 0.14-1.50%, S: 0
．． 035-0.150% (However, Mn/S>4),
Sol, Al: 0.02-0.20%, N: 0.0
10% or less (however, 5oljAl/N>2), Fe and unavoidable impurities: the remainder, final finishing temperature: 800 ° C. or higher, coiling temperature near 00 to 7
After hot rolling at 60°C and removing scale,
A method for producing a damping thin steel sheet, characterized by cold rolling under the conditions of elongation rate = 0.5 to 50%. 2 Heavy weight, C: 0.03 to 0.30 yen, Si: 1
．． 40% or less, Mn: 0.14-1.50%, S:
0.035-0.150% (However, Mn/S>4)
, Sol, AA: 0.02-0.20%, N:
0.010% or less (Sol, AA/N > 2)
, furthermore, B: 0.010% or less, Cu: 0
．． A steel containing one or more of the following: 20% or less, Cr: 1.0% or less, P: 0.20% or less, and has a composition consisting of Feb and unavoidable impurities: the remainder,
Final finishing temperature: SOO℃ or higher, winding temperature near 00-76
A method for producing a damping thin steel sheet, which comprises hot rolling at 0° C. to remove scale, and then cold rolling at an elongation of 0.5 to 50 yen. 3 By weight, C: 0.03-0.30, Si: 1.
40% or less, Mn: 0.14-1.50%, S: 0
．． 035~0.150% (however, Mn/S>4), So
l, Al: 0.02-0.20%, N: 0.01
0% or less (however, 5o4Al/N>2), Fek and unavoidable impurities: the remainder,
Final finishing temperature 2800℃ or higher, winding temperature near 00-76
After hot rolling at 0°C to remove scale, cold rolling at an elongation of more than 50 stripes, and then annealing at an annealing temperature of 450 to 850°C. death,
A method for producing a damping thin steel sheet, further comprising temper rolling at an elongation rate of 0.5 to 50%. 4 Heavy weight, C: 0.03 to 0.30 yen, Si: 1.
40% or less, Mn: 0.14-1.50%, S:
0.035-0.150% (However, Mn/S>4), 5
oljAl: 0.02-0.20%, N: 0.01
0'% or less (however, 5o4Al/N>2), furthermore, B: 0.010% or less, Cu: 0.20% or less, Cr: 1.0% or less, P: 0.20% A steel containing one or more of the following and having a composition consisting of Fe and the remainder of unavoidable impurities is prepared under the following conditions: final finishing temperature: SOO℃ or higher, coiling temperature near 00 to 760℃ After hot rolling and removing scale, elongation rate: 5
Cold rolled under the conditions of a value exceeding 0%, then annealed at an annealing temperature of 450 to 850°C, and further,
A method for producing a vibration-damping thin steel sheet, characterized by skin pass rolling at an elongation rate of 0.5 to 50.