JPH11245329A - Surface layer pre-anticorrosion coating steel material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and inexpensively improve a flaw resistance at the time of executing by giving anticorrosion properties to a steel material used in the sea, on the sea, river or the like by an organic coating before executing. SOLUTION: The surface layer pre-anticorrosion steel material comprises grooves of 1 mm or more of a residual film thickness at 0.2 mm or more from a surface layer one to 100 per 100 mm horizontally and vertically from its organic-coated surface on its surface and a carbon steel material having a thickness of 0.3 to 2 mm for covering. The carbon steel is fixedly covered by a sticky material. No damage occurs at the time of executing even by a using method similar to a general steel material in the case of using the organic- coated steel material before executing by the above-mentioned method. And, use of a mixture of a pre-anticorrosion steel material and the general steel material is facilitated from both designing and executing. Further, a construction period is shortened to reduce a total investment. Moreover, after the execution, a beautiful surface of the organic coating can be easily recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel material used in the sea, on the sea, in a river, etc., which is provided with an anticorrosion property by an organic coating prior to the work, but easily and inexpensively improves the scratch resistance during the work. Further, after the application, the aesthetic appearance of the organic coating is developed.

[0002]

2. Description of the Related Art Steel materials, which are inexpensive and highly reliable and support the structure of various types of social capital materials, are used in many environments, including on land, in the sea, and on the sea. Among them, the use of a steel material pre-corrosion-protected by an organic coating to impart simple and long-term corrosion protection mainly in the sea and above the sea has been increasing. However, since the coating layer providing the anticorrosion property is a soft organic substance, care must be taken not to damage it during construction. The method is already established and documented. However, if it is possible to greatly improve the corrosion resistance in addition to the corrosion resistance and to perform the same work as general uncoated steel, it is designed to use a mixture of pre-corrosion resistant steel and general steel・ Easy construction can be achieved, and the construction period can be shortened, so that the total investment can be reduced.

Hitherto, to prevent this problem, there have been proposed a method of covering with a detachable protective cover as disclosed in, for example, JP-A-1-299918, and JP-A-8-25556. For example, there is a method of coating stainless steel or titanium as disclosed in US Pat.

[0004]

However, in the former, an expensive protective cover must be attached and removed before and after the construction, and in the latter, an expensive material is used in order to impart corrosion resistance after the construction. So,
These are not always sufficient as simple and inexpensive methods.

[0005] As described above, the conventional means of providing the steel material with corrosion resistance by applying an organic coating before the application of the steel material and providing the steel with scratch resistance during the application is insufficient in terms of a simple and inexpensive method. . An object of the present invention is to solve the above-mentioned drawbacks of the existing protection methods, to greatly improve the scratch resistance during construction, easily and inexpensively, and to easily secure the aesthetics of the organic coating after construction. It is to provide steel materials.

[0006]

SUMMARY OF THE INVENTION The present invention for achieving the above object has been completed, and its gist is as follows. That is, a groove having a depth of 0.2 mm or more from the surface layer and a residual film thickness of 1 mm or more was formed in the organic coating on the steel material.
A surface protective pre-corrosion resistant steel material comprising a carbon steel material having a density of 1 or more and 100 or less per 00 mm in one or more directions, and a 0.3 to 2 mm carbon steel material bonded and coated on the organic coating with a bonding agent. Further, the bonding agent for bonding the organic coating and the carbon steel material is an adhesive, and the surface protection pre-corrosion protection steel material is characterized in that it is an adhesive.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below. The present inventors have provided a surface protective material on an organic material coating, and have conducted various investigations on the relationship between the thickness, hardness and scratching phenomenon. As a result, it was confirmed that, in a state where the surface layer was a continuous body and was in full contact with the organic coating layer, the higher the hardness of the surface layer and the thicker the thickness, the more the scratch resistance was improved. In the prior art, this function is provided by a removable cover or a highly corrosion-resistant metal.

Therefore, the present inventors have separated the function of scratch resistance and the function of corrosion protection, that is, organically coated carbon steel which has no corrosion resistance but is very inexpensive and has excellent scratch resistance as a surface protective material. We have found that it adheres to the surface of steel. First, the thickness of the carbon steel material to be coated is 0.3 to 2 mm. If the thickness of the carbon steel material is too small, the effect of scratch resistance cannot be obtained, so the thickness is set to 0.3 mm or more. On the other hand, as the thickness increases, the scratch resistance improves, but the joining workability of the organic-coated steel material to the organic-coated surface is reduced.
And

Next, a detailed investigation was made on the method of applying the organic anticorrosion-coated steel material on site. As a force causing damage during the application, the force acting on the coating surface in the vertical direction and the force acting on the coating in the shearing direction were simultaneously observed. It turned out to be powerful. Therefore, as a result of investigation and research on the relationship between the steel material to be bonded on the organic coating, the fixing means of the organic coated steel material, and the force acting in the shear direction, it was found that a groove with a certain density was provided in the organic coating, and It has been found that even if there is no change in the adhesive force to the resin, the resistance to the peeling force in the shear direction can be increased.

In the present invention, the depth from the surface layer is 0.2 mm
The above-mentioned grooves having a residual film thickness of 1 mm or more are provided in one or more directions at a density of 1 or more and 100 or less per 100 mm. The reason why the depth from the surface layer is 0.2 mm or more is that when the depth of the groove is less than this, the resistance to the peeling force in the shear direction is not significantly improved. The reason why the depth of the groove is set to 1 mm or more in remaining film thickness is that if it is less than this, long-term durability cannot be secured. Groove density of 10
The reason why the number is one or more per 0 mm is that below this, the improvement in resistance to the peeling force in the shear direction is not remarkable. The reason why the density of the grooves is set to 100 or less is that the resistance of the peeling force to the force in the shearing direction is almost saturated at about 80, and that the higher the density of the grooves is, the more regular the grooves are formed, and the more the grooves are formed, which do not adversely affect the appearance. This is because the degree of difficulty increases.

[0011] Even if grooves are formed in the organic coating layer in this manner, the durability does not decrease as long as it falls within the scope of the present invention. That is, as described above, in order to ensure corrosion resistance under the film, the remaining film thickness is 1 mm or more. Further, the adhesion of the organic coating to the base steel material is rather improved because the residual stress is reduced by the groove forming treatment. Now, in order to greatly improve the scratch resistance at the time of initial construction while simply ensuring the long-term durability of the organic coating, the above-described method may be used by using an appropriate bonding agent. As the bonding agent, an adhesive and a pressure-sensitive adhesive can be used. However, it is desirable to use an adhesive in order to obtain a good aesthetic surface of the organic coating after application. The reason for this is that the use of the adhesive makes it possible to easily peel off the upper steel sheet without damaging the organic coating surface by giving a vertical peeling force after the application.

[0012]

EXAMPLES The present invention will be described below more specifically based on examples. Three test materials were prepared, each having a different thickness of carbon steel and a different coating fixing method (Table 1). As a base material of the test material, a polyethylene-coated steel material and a polyurethane-coated steel material were used. The size of the test material is 300 width x 500 length
X The thickness was 10 mm. FIG. 1 is a plan view of the test material, and FIG. 2 is a cross-sectional view thereof. AST for these two test materials
Using the MG-14 method, a carbon ball of 30 kg was dropped and collided three times from a height of 1 m, and the carbon steel material of the coating was peeled off from one of the test materials, and the appearance of the damage was observed. Table 1 shows the results. Further, the other one after the drop weight test was exposed for 6 months under the corrosion test conditions shown in Table 2, and then observed. The above results are all shown in Table 1. Further, the remaining one was rubbed off with a coated surface facing down from a 45-degree slide made of a plate material having a width of 1,000 and a length of 10,000, and the area where the coated steel material was displaced to expose the organic coated surface was measured. . The results are also shown in Table 1.

[0013]

[Table 1]

[0014]

[Table 2]

This corrosion test is rather severe.
After 6 months, all the carbon steel was corroded and peeled off. The vertical scratch resistance and corrosion resistance will be described. Comparative Example No. 1
In the case of no carbon steel, Comparative Example No. No. 2 is the case where the thickness of the carbon steel does not reach the present invention. In this severe damage evaluation test, Both 1 and 2 produce scars that reach under the coating,
Both are undergoing corrosion. On the other hand, N
o. Nos. 6 to 15 and carbon steel thicknesses within the range of the present invention. 3-5
No scratch was found in the drop test and no corrosion was found under the coating after the corrosion test, indicating extremely excellent corrosion resistance.

Next, the exposed area of the organic coating after the slip test for examining the scratch resistance in the shear direction will be described. No. of the comparative example. In the case of 3 to 5, the depth of the groove or the density of the groove is out of the range of the present invention, and the exposed area of the organic coating after the slip test is large. In particular, the exposed area tends to increase as the groove becomes shallower and the density of the groove becomes lower. On the other hand, in the example of the present invention, 6 to 15, it can be seen that both the scratch resistance in the vertical direction and the exposure of the organic coating in the sliding direction were small and very excellent results were obtained.

[0017]

According to the present invention, the depth from the surface layer is 0.2
A groove having a thickness of 1 mm or more and a residual film thickness of 1 mm or more is provided in one or more directions at a density of 1 or more and 100 or less per 100 mm, and a 0.3-2 mm carbon steel material is coated on the organic coating surface with a bonding agent. By doing so, even in the same usage as general steel, it does not cause damage during construction, it is possible to use a mixture of pre-corrosion resistant steel and general steel, and it becomes easier from both design and construction perspectives, The construction period can be shortened and the total investment can be reduced. In addition, the beautiful surface of the organic coating can be easily recovered after the application by peeling off the coated steel material.

[Brief description of the drawings]

FIG. 1 is a plan view showing groove formation in a test material.

FIG. 2 is a cross-sectional view showing groove formation in a test material.

[Explanation of symbols]

 l: groove depth from surface layer L: remaining film thickness

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Masahiro Yamamoto 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division

Claims (2)

[Claims] 1. An organic coating on a steel material having a depth of 0.
A groove having a thickness of 2 mm or more and a residual film thickness of 1 mm or more
A surface protective pre-corrosion-resistant steel material comprising a carbon steel material having a density of 1 or more and 100 or less per 00 mm in one or more directions, and a 0.3 to 2 mm carbon steel material bonded and coated on the organic coating with a bonding agent. 2. The steel material according to claim 1, wherein the bonding agent for bonding the organic coating and the carbon steel material is an adhesive.