JPH0414190B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention protects the friction welding surfaces of steel materials to be friction welded using high-strength bolts or the like from adhesion of surface treatment agents such as rust-preventing paints, and at the same time The present invention relates to a method for forming a friction joint surface of a steel material that can efficiently generate red rust all over the friction joint surface.

[Prior art]

In modern steel construction sites, joints are almost always joined using the so-called high-strength bolt friction welding method, which uses high-strength bolts to tighten the joints and transmit stress through the frictional force generated between the joints. It is used.

When joining joint members using high-strength bolts, the condition of the friction joint surface greatly affects the slip strength of the joint, and Ministry of Construction Notification No. 1309, etc. requires that the slip coefficient value (apparent friction coefficient value) is
The calculated value is expected to be 0.45 or higher, and to achieve this, the friction joint surface of the steel must be sufficiently rusted with a layer of red rust such as iron oxide.

However, the condition of the friction joint surfaces of steel materials found at actual construction sites for small and medium-sized buildings is in a worrying state, such as the bare surface still shining from a grinder, or the surface treatment agent such as rust-preventing paint adhering to it. There are quite a few things.

In addition, when assembling steel frames using the high-strength bolt welding method, conventionally, the steel materials are generally cut and welded into a predetermined size and shape in a factory, etc., and the joint surfaces of the steel materials to be joined using the high-strength bolt friction welding method described above are covered. Using a grinder or the like, the surface skin of mill scale and the like is peeled off and removed to expose the bare surface of the steel material on the friction joint surface. Next, an adhesive tape such as a wide packaging tape is applied to the friction bonding surface, and the exposed bonding surface is covered with the adhesive tape. Next, a surface treatment agent such as an undercoat for rust prevention is applied to the surface of other steel materials. At that time, the friction bonding surface is protected from adhesion of surface treatment agents such as paint with adhesive tape covering the friction bonding surface. Next, the packaging tape is peeled off from the friction bonded surface when the surface treatment agent applied to the surface of the steel material has dried. Then, the friction joint surfaces of steel materials are exposed to air containing a lot of moisture, and salt water, weak acid water, etc. are applied to the friction joint surfaces to form a red rust layer on the friction joint surfaces of the steel materials. .

However, adhesive tape such as packaging tape has a strong adhesive force and is difficult to remove from the joint surface of steel materials, especially if the tape is left attached to the joint surface of steel materials for a long time. If this happens, the adhesive strength of the adhesive tape has increased,
It was extremely difficult to remove the tape.

Therefore, in actual field work, the adhesive tape is removed from the friction bonding surface of the steel material as early as possible, before the primer coating, etc. of the steel material has sufficiently dried.

As a result, when removing the adhesive tape from the friction bonding surface, the friction bonding surface of the steel material may be contaminated with surface treatment agents such as undercoat that has not yet dried and is applied to the surface of the steel material. In many cases, a portion of the primer coating on the surface of the steel material is peeled off by hands or clothing, and each time it occurs, it is necessary to wipe off the paint adhering to the friction joint surface or repaint the surface of the steel material. and so on. Therefore, the above-described conventional method for forming a friction joint surface requires a great deal of labor and time, and requires skill.

Furthermore, in the conventional method of forming a friction bonding surface, when a surface treatment agent such as an undercoat paint is applied to the surface of the steel material in a factory and the surface treatment agent is dried, the friction bonding surface of the steel material is coated as described above. It's completely covered with adhesive tape and sealed off from the air. and,
During that time, no red rust occurs on the friction-joint surface. Afterwards, when the adhesive tape is peeled off from the friction-joint surface of the steel material and the friction-joint surface is exposed to air containing moisture, the friction-joint surface is exposed for the first time. This causes red rust to occur.

Therefore, in the conventional method of forming a friction joint surface,
There is a lot of time wasted when forming a red rust layer on the friction bonding surface of steel materials. It took a long time to allow the red rust layer to develop sufficiently naturally so that the rust value was 0.45 or more.

Further, in order to shorten the time for forming a red rust layer, applying salt water or weak acid water to the friction joint surfaces of steel materials one by one to promote the formation of red rust requires a great deal of labor and is troublesome. At the same time, even if salt water or the like is applied to the friction joint surfaces of steel materials to generate a red rust layer on the joint surfaces, it will take a considerable amount of time for the red rust layer to sufficiently develop on the joint surfaces. However, this was inconvenient when construction work was to be completed in a hurry. For this reason, at small and medium-sized construction sites, steel materials are joined using friction bonding surfaces that are still exposed to the surface of the grinder or coated with surface treatment agents, as mentioned above. This caused problems with the structural mechanics of the building.

[Summary of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to simultaneously apply a surface treatment agent such as a rust preventive paint to the surface of a steel material and dry the surface treatment agent. Red rust can be efficiently grown all over the friction joint surface covered with a sheet to prevent it from adhering in a short period of time, and the surface treatment agent such as paint on the surface of the steel material can be dried for a long time. It is an object of the present invention to provide a method for forming a friction bonding surface of a steel material, which allows the sheet to be peeled off from the friction bonding surface of the steel material very easily even after a lapse of time.

In order to achieve the above object, the method for forming a friction bonding surface according to the present invention involves peeling off and removing the skin of the friction bonding surface of the steel material, such as mill scale, to expose the steel surface on the friction bonding surface of the steel material. After that, the friction joint surface of the steel material is covered with a porous sheet through which air and water vapor can pass, and a red rust inducing agent and a solvent are used to promote the formation of red rust on the bare surface of the steel material between the sheet and the friction joint surface. The sheet is attached to the friction bonding surface of the steel material using the adhesive in the above aqueous solution with an aqueous solution mixed with an evaporative water-soluble adhesive, and then the friction bonding is covered with the sheet. A surface treatment agent such as anti-rust paint is applied to the surface of the steel material other than the surface, and the surface treatment agent is dried. At the same time, air and water vapor are distributed through the sheet, and the friction bonding surface of the steel material covered with the sheet is The process is characterized by forming a red rust layer on the bare surface and then peeling off the sheet from the friction bonding surface of the steel material.

In the method for forming a friction bonding surface of the present invention, a sheet is coated with an adhesive and a red rust inducing agent that generates adhesive force only when wetted with water, or It is preferable to use a sheet to which either an adhesive or a red rust inducing agent is attached, which only becomes adhesive when wet with water.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

1 to 4 show the state in which a friction joint surface is formed at a joint of steel materials using the forming method of the present invention.

In the figure, 10 is a porous sheet made of paper, cloth, synthetic resin, etc., which has a large number of extremely fine holes 10a on its surface through which an appropriate amount of air and water vapor can pass. On the back side of the sheet 10 is a solvent evaporation type water-soluble adhesive 12 made of a natural polymer such as starch or a synthetic polymer such as melamine resin or urea resin that generates adhesive force only when it gets wet with water.
Then, a red rust inducing agent 16 made of an oxidizing agent such as salt or acetic acid, which promotes the generation of red rust made of iron oxide, etc., is applied to the exposed surface of the steel material 14 and allowed to dry.

In the figure, this sheet 10 is used to form a friction bonding surface 18 at the joint portion of the steel material 14 in the following manner.

As shown in FIG. 1, the frictional joint surface 18 of the steel material is subjected to a grinder or the like to peel off and remove the skin made of mill scale or the like from the joint surface. and,
The bare surface of the steel material 14 is exposed on the friction joint surface 18 of the steel material.

Next, the back surface of the sheet 10 to which the adhesive 12 and red rust inducing agent 16 have been adhered is sufficiently wetted with water, and the sheet 10 is placed over the frictional joint surface 18 of the steel material.
Then, with an aqueous solution containing the adhesive 12 and red rust inducing agent 16 interposed between the sheet 10 and the friction bonding surface 18, the adhesive 12 on the back side of the sheet is wetted with water to generate adhesive force. using sheet 1
0 is adhered to the friction joint surface 18 of the steel material. The friction bonding surface 18 is covered with a sheet 10 to protect the friction bonding surface 18 from adhesion of a surface treatment agent such as paint.

Next, a surface treatment agent such as an undercoat for rust prevention is applied to the other surfaces of the steel material 14 except for the friction joint surface 18. The steel material 14 is then left as it is until the surface treatment agent such as paint dries.

At that time, the friction bonding surface 1 of the sheet 10 and the steel material
Water 20 and a red rust inducing agent 16 are interposed between the sheet 10 and the sheet 10, and an appropriate amount of air is supplied from the atmosphere to the back side of the sheet 10 through a large number of small holes 10a on the surface of the sheet 10. By evaporating an appropriate amount of moisture into the atmosphere from the back side,
Favorable environmental conditions are created to generate red rust on the friction joint surface 18 covered with the sheet 10. and,
Apply a surface treatment agent such as paint to the surface of the steel material 14, or apply the surface treatment agent such as paint to the surface of the steel material 14 until the surface treatment agent such as the paint dries.
While the steel material is left to stand, a red rust layer 22 is efficiently and quickly sufficiently rusted on the bare surface of the friction joint surface 18 of the steel material covered with the sheet 10.

Thereafter, while waiting for the time when the surface treatment agent such as paint applied to the surface of the steel material 14 has sufficiently dried and the red rust layer 22 has sufficiently formed on the friction joint surface 18,
The sheet 10 is peeled off from the friction joint surface 18.

In that case, as shown in FIG.
The back surface is raised to the upper end surface of the red rust layer 22 which is made up of small particles formed on the surface of the friction bonding surface 18, and the water interposed between the sheet 10 and the friction bonding surface 18 evaporates. Even if the adhesive force of the adhesive 12 that adheres the back surface of the sheet 10 to the friction bonding surface 18 increases, some of the small particles at the top of the red rust layer 22 on the surface of the friction bonding surface 18 are attached to the back surface of the sheet 10. In this state, the sheet 10 can be peeled off extremely easily from the middle part of the red rust layer 22 formed on the frictional joint surface 18 without applying any force.

The method for forming the frictional joint surface shown in FIGS. 1 to 4 consists of the steps described above.

In the above-mentioned forming method, the back side of the sheet 10 is coated with either a solvent evaporation type water-soluble adhesive 12 or a red rust inducing agent, which generates adhesive force only when it gets wet with water, and then the adhesive is dried. Then, when the sheet 10 is applied to the friction bonding surface 18 of the steel material with the bare surface exposed, the other red rust inducing agent 16 that is not attached to the back surface of the sheet 10 or the friction bonding surface 18 is attached to the back surface of the sheet 10. Alternatively, the sheet 10 is sufficiently wetted with an aqueous solution containing a solvent evaporation type adhesive 12, and the sheet 10 is adhered to the friction bonding surface 18 using the adhesive 12 attached to the back surface or the adhesive 12 mixed in the aqueous solution. It's okay. Water 20 and a red rust inducing agent 16 are interposed between the sheet 10 and the friction joint surface 18 covered with the sheet 10, and a red rust layer is formed on the friction joint surface 18 covered with the sheet 10 as described above. The red rust layer 22 may be efficiently and sufficiently rusted on the bare surface of the friction joint surface 18 by creating favorable environmental conditions in which the rust layer 22 will rust.

In some cases, the back side of the sheet 10 may be left without being coated with anything, and the sheet 10 may be placed on the friction bonding surface 18.
When adhering to the surface, the back surface of the sheet 10 or the friction bonding surface 18 of the steel material is thoroughly wetted with an aqueous solution containing a solvent evaporation type water-soluble adhesive 12 and a red rust inducing agent 16, and the adhesive in the aqueous solution is wetted. Sheet 1 using
0 may be applied to the friction joint surface 18 of the steel material. Water 20 and a red rust inducing agent 16 are interposed between the sheet 10 and the friction joint surface 18 of the steel material to which the sheet 10 is adhered, thereby forming a red rust layer 22 on the friction joint surface 18 to which the sheet 10 is adhered. It is also possible to sufficiently rust the efficient material.

In addition, the sheet 10 may be a long sheet rolled into a wide roll, pulled out to a predetermined length and cut into a predetermined length, or cut to fit the area of the friction bonding surface of a steel material such as a shaped steel of a certain standard. It's good to use something.

Furthermore, in summer when water evaporates easily,
The sheet 10 is thick or has small holes 10a on the sheet surface so that moisture can remain on the friction joint surface 18 until the red rust layer 22 is sufficiently formed on the friction joint surface 18. It's good. vice versa,
Sheet 10 is recommended in the harsh winter months when water is difficult to evaporate.
It is better to use a thin sheet or a sheet with relatively large small holes 10a on the surface of the sheet, as this will quickly evaporate excess water from the friction bonding surface 18 and increase the adhesive force of the adhesive 12. This is convenient because the sheet 10 can be prevented from peeling off from the friction bonding surface 18 of the steel material when applying a surface treatment agent to the surface or drying the treatment agent.

〔Effect of the invention〕

As described above, according to the method for forming a friction bonding surface of the present invention, the friction bonding surface of a steel material is covered with a sheet,
It is possible to protect the friction joint surface from adhesion of a surface treatment agent such as a rust preventive paint, and at the same time, it is possible to efficiently generate red rust all over the friction joint surface covered with the sheet. That is, while applying a surface treatment agent such as a rust preventive paint to the surface of the steel material and drying the treatment agent, red rust can be generated on the friction joint surface of the steel material at the same time. In addition, a friction joint surface can be efficiently formed in a short time by sufficiently developing a red rust layer having a slip coefficient of 0.45 or more on the friction joint surface of the steel material.

In addition, after applying a surface treatment agent such as primer paint to the steel surface and thoroughly drying the surface treatment agent, red rust caused by gathering small particles can be found on the friction joint surface area where the sheet is attached. layers are formed,
Since the back side of the sheet is floating on the top surface of the red rust layer, the moisture interposed between the sheet and the friction bonding surface evaporates, causing the adhesive that adheres the sheet to the friction bonding surface. Even if the adhesive strength of
With a part of the upper layer of the red rust layer attached to the back side of the sheet attached to the friction bonding surface, the red rust layer can be peeled off from the middle part with great ease without applying any force.

In addition, the sheet attached to the friction bonding surface of the steel material is
It is best to remove the surface treatment agent such as the undercoat paint on the steel surface after it has dried sufficiently, so when peeling off the sheet, make sure to remove part of the surface treatment agent such as the undercoat paint that has not yet dried on the steel surface. There is no chance of dripping or adhesion of surface treatment agents such as primer paint to the friction joint surfaces of steel materials.

Furthermore, since a water-soluble adhesive is used for the adhesive, when the sheet is attached to the friction joint surface of the sheet and the steel material with water interposed between them, The adhesive applied to the back of the sheet easily dissolves into the intervening water.
The adhesive does not block the porous backside of the sheet and inhibit the flow of air and water vapor through the sheet.

At the same time, since a solvent evaporation type adhesive is used for the adhesive, as the moisture interposed between the sheet and the frictional joint surface of the steel material evaporates into the atmosphere, the adhesive strength of the adhesive gradually decreases. In addition, when applying a surface treatment agent such as an undercoat to the surface of a steel material, or when drying the surface treatment agent, moisture between the sheet and the frictional joint surface of the steel material evaporates into the atmosphere. Even if the adhesive is removed, the adhesive strength of the adhesive will weaken and the sheet will not peel off from the friction bonding surface.

In addition, a sheet may be coated with an adhesive and a red rust inducing agent that produces adhesive force only when it gets wet with water, or an adhesive that produces adhesive force only when it gets wet with water is used on the back side of the sheet. In the method of forming a friction joint surface of the present invention, which uses a sheet to which one of a rust inducing agent and a red rust inducing agent is attached,
Bonding between the sheet and the friction bonding surface can be achieved by simply wetting the back side of the sheet or the friction bonding surface of the steel material with water, or simply by wetting the back surface of the sheet or the friction bonding surface of the steel material with an aqueous solution containing a red rust inducing agent or adhesive. The sheet can be applied to the friction bonding surface in the presence of an aqueous solution containing the agent and the red rust inducing agent.

At the same time, the adhesive attached to the back of the sheet does not develop adhesive strength unless it gets wet with water.
When handling the sheets, the overlapped sheets do not become irremovably bonded to each other by the adhesive attached to the back surface of the sheets, making it easier to handle them.

Further, the method for forming a friction bonding surface of the present invention has advantages such as being simple and easy to use.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the area around the friction bonding surface of a steel material exposed by grinding, etc., and FIGS. 2 and 3 are views of the present invention with a sheet attached to the friction bonding surface of the steel material. A front view and a plan view showing the steps of the method for forming a friction bonding surface, and FIG. 4 is an enlarged view of a partial fracture around the friction bonding surface of a steel material with a red rust layer formed using the method for forming a friction bonding surface of the present invention. It is a front view. 10...Sheet, 12...Adhesive, 14...Steel material, 16...Red rust inducing agent, 18...Friction bonding surface,
20...Water, 22...Red rust layer.

Claims (1)

[Claims] 1. After peeling and removing the skin of the friction joint surface of the steel material to expose the bare surface of the steel material on the friction joint surface of the steel material, the friction joint surface of the steel material is made into a porous material through which air and water vapor can pass. At the same time, an aqueous solution containing a red rust inducing agent and a solvent evaporation type water-soluble adhesive is interposed between the sheet and the friction joint surface. , the sheet is applied to the friction bonding surface of the steel material using the adhesive in the above aqueous solution, and then a surface treatment agent is applied to the surface of the steel material other than the friction bonding surface covered by the sheet to treat the surface. At the same time as drying the agent, air and water vapor are allowed to circulate through the sheet to form a red rust layer on the bare surface of the friction bonding surface of the steel material to which the sheet is attached, and then the sheet is peeled off from the friction bonding surface of the steel material. Features: A method for forming friction bonding surfaces on steel materials. 2. A method for forming a friction joint surface of a steel material according to claim 1, using a sheet having an adhesive and a red rust inducing agent attached to the back surface of the sheet, which generates adhesive force only when wet with water. 3. A method for forming a friction joint surface of a steel material according to claim 1, using a sheet having either an adhesive or a red rust inducing agent attached to the back surface of the sheet, which produces adhesive force only when wet with water.