JP2746812B2 - Damping steel sheet for roll forming and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping steel sheet for roll forming capable of obtaining various roll-formed products having good shape and dimensional accuracy and no peeling, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a general rolled product of a steel sheet,
For example, building materials such as a roof plate, a wall plate, and a deck plate formed by roll-forming colored tin and galvanized steel sheets, and home electric appliances such as a refrigerator body formed by roll-forming pre-painted steel sheets are well known. Since roll-formed products using these surface-treated steel sheets are thin and wide products, various problems are likely to occur during the forming. For example, "Plasticity and processing" vol.20, (1979)
225, P933 and "Plasticity and Processing", vol. 23, (1982) 259, P779, describe the occurrence and countermeasures such as pocket waves, edge waves, and waist breaks as defective phenomena in roll forming.

[0003] The pocket wave is a phenomenon in which a plastic shrinkage in the longitudinal direction remains in a flange portion or a corner portion formed by roll forming, and a surplus length escapes to generate loose irregularities in a central flat portion. It is effective to make the yield point of the material sufficiently high so that all deformation during molding is within elastic deformation, and it is said that it is difficult to occur when the yield elongation is large. Regarding the influence of the leveler, it is possible to increase the flatness of the base material, but on the contrary, the yield point is greatly reduced, so that pocket waves are likely to occur, which is considered to be negative.

[0004] Hip breaks are generated around the corners when the flange is raised, and it is said that a material having a higher yield elongation is more likely to appear. As a countermeasure, it is most effective to reduce the yield elongation by applying a leveler or the like. ing. The edge wave is a phenomenon in which an outer flat portion of a steel sheet roll-formed into a mountain cross section expands and contracts and undulates. As a countermeasure, it is preferable to increase the yield point of the material.

On the other hand, recently, as a material of a roll forming plate such as a shutter material, a roof plate, a deck plate and the like, an attempt has been made to use a damping steel plate instead of the above-mentioned general steel plate. Vibration-damping steel sheets made of two steel sheets as original sheets and laminated in a sandwich by bonding the original sheets together with an adhesive cause shear deformation of the viscoelastic adhesive when bending vibration is applied, converting vibration energy into thermal energy Therefore, it has a great vibration and soundproof effect. The shutter material roll-formed from this damping steel plate has less noise when opening and closing,
Roofing can reduce the sound of rain, and if used on the deck plate of a gymnasium, can significantly reduce the impact sound of the floor.

The roll formability of the damping steel sheet having such advantages is described in, for example, "Plasticity and Working" vol. 30, (1989).
347, P1618 states that shape defects such as bending of a flange and peeling are likely to occur during molding. Flange bending is caused by the shear force generated in the process of generation and elimination of the longitudinal deviation of the front and back steel sheets seen during roll forming and the compressive shear force generated by bending of the sheet. Prevention of longitudinal displacement of the steel sheet, use of a steel material having a low yield point, and the like are effective.

[0007] The peeling phenomenon occurs when both the longitudinal displacement and the displacement in the width direction act on the front and back steel sheets, resulting in a weakened adhesive force. It is effective to be.

[0008]

However, in order to improve the roll formability of the damping steel sheet, when a steel sheet having a low yield point is simply used as the original sheet, the bending is improved but the pocket wave and the edge wave are opposite. Easily occur.
In order to suppress the occurrence of the pocket wave, it is conceivable to use a steel plate having a large yield elongation, but in this case, the flange is likely to break. If the yield elongation is reduced by using a leveler as a countermeasure against the buckling, a pocket wave is likely to occur.

On the other hand, the higher the yield point of the steel sheet, the smaller the occurrence of pocket waves and edge waves during roll forming, but on the other hand, the larger the springback, so that the end of the roll-formed damping steel sheet is likely to be peeled off. . The present invention is intended to solve such contradictory and contradictory problems, and it is difficult to bend or peel off and to obtain a roll formed product having good dimensional and shape precision, which is a vibration control for roll forming. It is an object to provide a steel sheet and a method for manufacturing the same.

[0010]

Means for Solving the Problems A first invention of the present invention for solving the above-mentioned problems relates to a damping steel sheet for roll forming in which two steel sheets are bonded with an adhesive, and in a width direction of roll forming. It is characterized in that the yield ratio in the (C direction) is 90% or more and the yield elongation is 5% or more. The steel plate may be a hot-dip galvanized plate.

The adhesive may be a thermosetting polyester resin. The steel sheet may contain 50 to 200 ppm of nitrogen (N) in the composition of the steel sheet. The second invention of the present invention relates to a method for producing a damping steel sheet for roll forming in which two steel sheets are used as original sheets, and the original sheets are laminated with an adhesive, and the steel sheets are annealed after cold rolling. Is passed through a tension leveler without passing through a temper rolling step, and is subjected to shape correction by applying tension and repeated bending to obtain the original sheet.

[0012]

The inventors of the present invention have conducted intensive studies on vibration-damping steel sheets having good roll formability, for unknown reasons. As long as the yield ratio (YR) in the direction (YR) is 90% or more and the yield elongation (YEl) satisfies the condition of 5% or more, the characteristic value in the longitudinal direction (hereinafter referred to as L direction) is not specified, The present invention has been found to be able to effectively prevent the occurrence of pocket waves and edge waves during roll forming, and to prevent defects in size, shape, and adhesion from occurring in roll-formed products.

Here, when the yield ratio in the C direction is less than 90%, pocket waves and edge waves occur. If the yield elongation in the C direction is less than 5%, the springback of the roll forming is too large, and the dimensional and shape accuracy of the product is poor. Also, peeling is likely to occur at the end of the molded product. In manufacturing the damping steel sheet for roll forming of the present invention, the following conditions must be satisfied in order to secure the mechanical properties in the C direction of the damping steel sheet within the above range.

In producing the original sheet for damping steel sheet of the present invention, the steel sheet annealed after cold rolling is not subjected to temper rolling, but is subjected to tension and repeated bending only by a tension leveler. Apply shape correction. When temper rolling is performed in the production of a master sheet, the yield point and the yield elongation in the L direction and the C direction decrease below desirable limits. On the other hand, when the shape was corrected using only the tension leveler, the yield point and the yield elongation in the C direction were small, and the yield ratio was 90% or more and 5%.
Experiments have revealed that a yield elongation of at least 10% can be obtained.

The original sheet serving as the skin material of the damping steel sheet of the present invention is not limited to a cold-rolled steel sheet or a surface-treated steel sheet. But,
For example, it is desired to cope with a material used in applications where a complicated bending process is repeatedly performed, such as a damping steel plate for a shutter material, since the end portion is easily peeled off during the bending process.
In that case, an alloyed hot-dip galvanized steel sheet is particularly preferable.
The reason for this is that the alloyed hot-dip galvanized steel sheet has a large surface roughness when not temper-rolled, and particularly has a large PPI (peak per inch) value of 400. This is because an extremely large adhesive force can be secured as a result of promoting the adhesive effect. By the way, when the temper rolling is performed, the value of PPI is halved to 200, and accordingly, the anchoring action of the adhesive is sharply reduced.
From this point, it can be said that one of the conditions in the present invention is that temper rolling is not performed during the production of the original sheet.

The base material of the damping steel sheet of the present invention has a nitrogen [N] content in its chemical composition of 50 to 200 ppm (0.0050 ppm).
~ 0.0200 wt%). When the base plate of the damping steel sheet is bonded with an adhesive, it receives a heat history of 180 to 200 ° C., and when a large amount of N is contained as much as 50 ppm or more, aging due to the heat causes the obtained damping steel sheet to This is because the yield point becomes high, and the yield ratio of 90% or more and the yield elongation of 5% or more are easily achieved. An amount of N exceeding 200 ppm causes a problem in brittleness.

As a prior art relating to a low-carbon cold-rolled steel sheet for can making in which the amount of N is controlled, Japanese Patent Application Laid-Open No. 58-27930 is disclosed.
JP-A-58-27931, JP-A-58-2176
There is No. 59. For these, materials whose N content is increased and the yield point is increased by utilizing the aging are used, but in each case, temper rolling of 1-2% is performed for adjusting the surface roughness and correcting the shape. This is different from the case of the present invention which is provided for practical use and does not perform temper rolling.

As the adhesive used in the present invention, a thermoplastic resin adhesive or a thermosetting resin adhesive generally used for a damping steel sheet can be used. It was previously proposed as a resin composition for vibration-damping steel sheets (Japanese Unexamined Patent Publication No.
4-48813), and a thermosetting polyester resin is preferable. It is composed of a saturated copolymerized polyester having a weight average molecular weight of 5,000 or more and a softening point of 50 ° C. or more and 150 ° C. or less and a polyvalent isocyanate compound as a cross-linking agent. It is excellent and has excellent adhesive performance required during molding, and also has extremely high performance in adhesive stability and durability at high temperatures after molding. By using this in the adhesive of the present invention, a vibration-damping steel sheet for roll forming having high damping properties and adhesive strength and having no end surface peeling can be easily obtained.

[0019]

Embodiments of the present invention will be described below. The present embodiment is particularly adjusted to a chemical composition having a large N content, and for the steel sheet as the original sheet of the present invention manufactured using only the tension leveler without performing temper rolling, particularly, the carbon content and the nitrogen content. A steel sheet of a comparative example manufactured by performing different tempering and temper rolling was prepared, and the mechanical properties, adhesive strength, and various vibration dampings in the L and C directions were prepared for the damped steel sheet manufactured using the steel sheet as a skin material. This is a comparative study of roll formability of a steel sheet.

Table 1 shows the chemical compositions of the original plates of the present invention and the comparative product.

[0021]

[Table 1]

As is clear from the table, a difference is particularly observed in the N content between the product of the present invention and Comparative Product 1 and Comparative Product 2. Each steel material having the composition shown in Table 1 was hot-rolled as usual, pickled and then cold-rolled to produce three types of wide-width steel sheets having a thickness of 0.3 mm. These steel sheets were sent to a hot-dip galvanizing line to produce hot-dip galvanized steel sheets to be used as base sheets for damping steel sheets. In the original plate manufacturing process, the product of the present invention was subjected to shape correction using only a tension leveler, and was not subjected to skin pass by a temper rolling mill. On the other hand, comparative products 1,
For Comparative Product 2, a 1.5% skin pass by a temper rolling mill and a tension leveler were used in combination. Subsequently, three types of damping steel plates were manufactured using these three types of steel plates as original plates by a damping steel plate manufacturing line. As the adhesive for the damping steel sheet, a thermosetting polyester resin to which Ni particles for imparting conductivity were added was used, and the resin coating thickness was 25 μm.

Table 2 shows the measurement results of the mechanical properties and the adhesion strength of the damping steel sheet of the present invention obtained in this way and the damping steel sheets of Comparative Product 1 and Comparative Product 2.

[0024]

[Table 2]

As is clear from Table 2, the temper-rolled Comparative Example 1 has a yield ratio YR in the C direction of 100% and a yield elongation YEl of 10%, which are almost the same as those of the present invention. The peak of hot-dip galvanizing collapsed by temper rolling, and the PPI value was reduced by half, and the adhesive strength was accordingly reduced. Further, in Comparative Example 2 which was also temper-rolled, the yield point YP was reduced, and the yield ratio YR was 81%.
%, And the yield elongation YEl is 3%, all of which are reduced. Furthermore, similarly to Comparative Example 1, it was recognized that the PPI value was halved and the adhesive strength was reduced.

Next, the vibration-damping steel sheet of the present invention and the comparative article 1,
Roofing is roll-formed using the damping steel sheet of Comparative Product 2, and the quality of each obtained roll-formed product is checked by examining pocket waves, the presence or absence of edge waves and the dimensional accuracy, the presence or absence of edge peeling, etc. Was evaluated. Table 3 shows the results.

[0027]

[Table 3]

From Table 3, it is clear that the vibration-damping steel sheet of the present invention has a satisfactory result in any of the items and has extremely excellent quality.

[0029]

As described above, according to the present invention,
The steel sheet annealed after the cold rolling is passed through a tension leveler without passing through a temper rolling step, and the steel sheet whose shape has been corrected is used as an original sheet. The yield ratio in the width direction (C direction) of roll forming is 90. and yield elongation at least% was assumed to achieve 5% or more roll forming damping steel plate. Therefore, the roll forming of the damping steel plate, which has been difficult in the past, becomes easy, and as a result, the vibration damping and soundproofing properties are high, the bending and the peeling are hard to occur, and the dimensions and the shape accuracy are good.
This has the effect that roll-formed products such as roofs, walls, and curtain rails can be easily obtained.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 31/12 B32B 31/12 F16F 15/02 F16F 15/02 Q (56) References JP-B-61-44065 (JP, B2 (58) Field surveyed (Int.Cl. ⁶ , DB name) B32B 31/06 B21D 5/08 B32B 7/12 B32B 15/08 B32B 27/36 B32B 31/12 F16F 15/02

Claims (5)

(57) [Claims] 1. A damping steel sheet for roll forming comprising two steel sheets bonded together with an adhesive, wherein the yield ratio in the width direction (C direction) of roll forming is 90% or more and the yield elongation is 5%.
% Of a damping steel sheet for roll forming. 2. The damping steel sheet for roll forming according to claim 1, wherein said steel sheet is a hot-dip galvanized sheet. 3. The damping steel sheet for roll forming according to claim 1, wherein the adhesive is a thermosetting polyester resin. 4. The steel sheet according to claim 1, wherein said steel sheet contains nitrogen (N) in an amount of 5%.
The damping steel sheet for roll forming according to any one of claims 1 to 3, wherein the steel sheet contains 0 to 200 ppm. 5. A method for producing a damping steel sheet for roll forming in which two steel sheets are used as original sheets, and the original sheets are laminated by bonding with an adhesive, the steel sheet annealed after cold rolling is subjected to a temper rolling step. A method for producing a damping steel sheet for roll forming, comprising a step of passing a tension leveler without passing through a tension leveler and applying a tension and repeated bending to perform shape correction to obtain the original sheet.