JPH066233B2 - Assembling method of clad steel material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a material assembling method for producing a clad steel containing a Cu-based metal (pure Cu and Cu alloy) as a composite material.

<Prior art and its problems> In recent years, for example, in the fields of seawater desalination equipment and other seawater equipment, chemical industry acid-corrosion-resistant equipment, petroleum refining equipment, etc.
Carbon steel is a base material that is stable in supply and is very advantageous in terms of formability, weldability, cost, etc., and pure Cu or Cu alloy with excellent corrosion resistance (hereinafter collectively referred to as Cu-based metal) The number of cases in which Cu-based metal clad steel with clad steel is applied is increasing remarkably.

By the way, since rolling compression bonding method is advantageous for mass production of clad material from the viewpoint of workability and cost, various rolling compression bonding methods have been devised according to the metal material to be combined. The following method has been adopted when mass-producing such a clad steel material made of a hardly weldable metal material and carbon steel.

That is, as shown in FIG. 2, first, a Cu-based metal-bonding material is superposed on a carbon steel base material, and the Cu-based metal-bonding material having poor weldability is formed from an easily weldable metal (generally carbon steel). After assembling a clad steel material by covering the dummy material and a spacer formed by welding the four sides of their mating surfaces, and then heating and rolling this clad steel material and crimping the carbon steel base material and the Cu-based metal mating material. This is a method of cutting into a desired size and removing the dummy material and the spacer to produce a product. Then, in assembling the clad steel material, it was taken into consideration that both the Cu-based metal-bonding material and the dummy material are used in the same black skin in order to improve the peelability of the dummy material after the rolling and pressure bonding step.

However, with this method, the peelability of the dummy material is relatively good, but the problem is that sufficient bonding of the surface to be originally bonded (clad bonding surface) is likely to be impaired by the black skin oxide layer. However, if the black skin is removed because of this, the problem that the bonding of the clad bonding surface will be good but the dummy material will not come off was difficult.

On the other hand, Japanese Patent Application Laid-Open No. 59-30515 discloses, "In order to facilitate separation of the clad materials which do not require joining after the pressure bonding treatment, an inorganic binder such as water glass, soda glass powder or chromite is used as a separating agent. "It is good to use", and Japanese Patent Application Laid-Open No. 62-97781 discloses that "alumina, silica, a black scale of mild steel, between a clad material and a dummy material (encapsulated metal), during annealing. It is easy to remove the dummy material after the pressure-bonding treatment by interposing a release agent such as the annealing separation material. However, when trying to apply these methods, a) it is necessary to mix the release agent with the separating agent at the time of application, so that there are individual differences in the effect.b) The prepared release agent or separating agent has a certain thickness. It is necessary to apply and dry, but there will be variations in the effect due to individual differences in the application thickness during application work.c) It is difficult to judge when the applied release agent or release agent is completely dried. I could not ignore the problems such as "," and so on, and I could not say that it was a fully satisfactory method.

Therefore, an object of the present invention is to easily and surely separate the "portion not requiring joining" after the crimping operation.
Moreover, the purpose was to establish a method for assembling the clad steel material that could be stably performed without being affected by individual differences among workers.

<Means for Solving the Problems> Then, the present inventor has obtained the following findings as a result of repeated studies while repeating many experiments to achieve the above object.

That is, for example, a titanium foil is inserted and adhered between a carbon-containing member such as carbon steel and another metal member (may be a different metal member or the same kind of metal member), and then heated or pressure-bonded to them. When the treatment is performed, Ti of the titanium foil and C in the carbon-containing member cause a chemical reaction of Ti + C → TiC to cause an extremely brittle tissue layer of titanium carbide (TiC) at the interface between the carbon-containing member and another metal member. To form. Therefore, even if the carbon-containing member and the other metal member are materials that are easily bonded to each other, the titanium carbide is fragile and fragile in the tissue layer formed at the boundary surface thereof, so that both members can be separated very easily ( Can be peeled off).

In other words, Fig. 3 shows that 0.30 m is provided between the carbon steel (C: 0.01 to 0.30%) perforated material and the carbon steel (C: 0.01 to 0.30%) dummy material.
It is a graph showing the "change in peel strength depending on the heating temperature" when the m-thickness titanium foil is interposed and heated to various temperatures and pressure-bonded.
It can be seen that when the temperature exceeds 00 ° C, the peel strength changes extremely, and when the temperature exceeds 850 ° C, almost no peel strength value is exhibited. This indicates that a chemical reaction of Ti + C → TiC abruptly progresses by heating at 800 ° C. or higher, and an extremely brittle TiC texture layer is formed at the interface.

Therefore, the present inventor has paid attention to the above facts, “Cu-based metal clad steel material in which carbon steel is a base material and Cu-based metal is a combined material”
Based on the idea that titanium foil would be an effective release material even during the production of, the experiment of heating and rolling by inserting titanium foil between Cu-based metal and carbon steel dummy material was conducted. However, in this case, not only can the titanium foil not be expected to have an effect as a release material, but the titanium foil promotes the fusion between the Cu-based metal and the carbon steel dummy material and makes it difficult to remove the dummy material afterwards. The result was.

This is because when Cu-based metal and Ti come into direct contact with each other, a compound with a low melting point (melting point of about 900 ° C) such as TiCu or Ti ₂ Cu ₇ is formed and melts during heating / rolling to Cu-based metal and dummy material. It was thought that this was due to the fusion of

For this reason, in order to prevent direct contact between the Cu-based metal and the titanium foil, the carbon steel foil and the titanium foil are superposed and the Cu-based metal and the carbon-steel dummy material are positioned so that the carbon steel foil side is in contact with the Cu-based metal. Experiments were performed in which the heating and rolling were performed by interposing between them. As a result, in this case, although the Cu-based metal and the carbon steel foil are partly joined, the reaction between the Cu-based metal and the titanium foil does not occur, and “the interface between the titanium foil and the carbon steel foil” and “ At the interface between the titanium foil and the carbon steel dummy material, a fragile layer is sufficiently formed by the reaction of Ti + C → TiC, and the Cu-based metal and the carbon steel dummy material are subsequently used to form the fragile layer that progresses from both surfaces of the titanium foil. It has become clear that peeling from and becomes extremely easy. Moreover, it was also confirmed that the carbon steel foil bonded to the Cu-based metal surface can be easily removed by simple care of the Cu-based metal surface after separating the dummy material.

The present invention has been made on the basis of the above-mentioned findings and the like. “When assembling a clad steel material in manufacturing a clad steel material using carbon steel as a base material and Cu-based metal as a composite material, FIG. As shown in Fig. 3, the Cu-based metal composite material is covered with a dummy material made of an easily weldable metal (for example, steel), and the carbon steel foil and titanium (titanium alloy) are placed between the Cu-based metal composite material and the dummy material. (Including) and carbon steel foil so that the carbon steel foil is on the side of the Cu-based metal-bonding material, and then welding and assembling, the assembly efficiency of the clad steel material is significantly improved and The feature is that the dummy material can be separated (peeled) after the clad bonding work easily and stably without being affected by individual differences. "

In other words, the present invention, when the titanium foil is inserted between the “dummy material that is a separation-requiring member of the clad steel material” and the mating material, and the heating and pressure bonding work is performed, Ti, which is the component of the titanium foil, and Ti Chemical reaction (Ti in contact with C in the dummy material such as steel)
+ C → TiC) and forms a very brittle and fragile texture layer of titanium carbide with the dummy material. ”At the same time, when the laminated material is Cu-based metal, , Cu-based metals originally have a low melting point (pure Cu: 1083
(° C, Cu alloy: approx. 1000 ° C) It tends to react with Ti, which is a component of the titanium foil, to form a compound with a lower melting point and firmly bond with the dummy material. And prevent it by cutting the direct contact between Cu-based metal and titanium foil,
The reaction of “Ti + C → TiC” is positively promoted from the carbon steel foil side as well, so that the peeling of the dummy material after the pressure-bonding treatment is made more reliable.

For example, a carbon steel dummy material is used to weld the four joining surfaces of the clad steel material assembled as shown in Fig. 1, and this is heated and rolled to crimp the base material steel and the Cu-based metal bonding material. Then, the fusion of the dummy material and the Cu-based metal-bonding material during this treatment is prevented by the carbon steel foil, and the titanium foil and C in the dummy material, and the C in the titanium foil and carbon steel foil. Reacts with each other, and the titanium carbide texture layer is rapidly formed from both sides of the titanium foil. Therefore,
As a result of the fragile layer intervening at the interface between the Cu-based metal laminating material and the dummy material, the titanium carbide fragile layer can be applied by applying a force to cut the obtained clad material to the desired size and then peel off the dummy material. However, the dummy material is easily destroyed and the dummy material is easily peeled off. As described above, the carbon steel foil attached to the surface of the Cu-based metal bonding material can be easily removed without any particular trouble by simply taking care of the surface of the Cu-based metal bonding material.

Here, the steel type of the base material steel is not particularly limited, and as for the composite material, pure Cu or various Cu alloys such as cupro-nickel, naval brass, aluminum brass, etc. can be sufficiently effective. It goes without saying that it will be done. Carbon steel is generally applied as the material of the dummy material and the spacer, but the kind is not limited as long as it is a material that can be easily welded.

In addition, the thickness of the titanium foil or carbon steel foil to be used is 0.10 to 1.00 mm in consideration of securing peelability and the foil manufacturing cost.
More preferably, it is 0.30 to 1.00 mm.

In addition, FIG. 4 shows the relationship between the thickness of the inserted titanium foil and the peel strength of both carbon steels in a joining member obtained by inserting a titanium foil between carbon steels and heating and pressurizing it to 1000 ° C. Fig. 4 is a graph showing that the titanium foil
It can be confirmed that a practical peeling effect can be secured if the thickness is 0.10 mm or more. Further, since the titanium foil is coiled in each thickness size, there is no change in thickness, and therefore there is no concept that the effect of releasability changes depending on the site or work unit. Moreover, when assembling the clad steel material, it can be used by freely cutting it into a desired size, so that the work is simple, and there is almost no difference in the effect of individual skill among workers depending on their skill level.

Further, FIG. 5 shows an example of assembling the Cu-based metal clad steel material according to the present invention, and FIG. 5 (a) is for facilitating the separation of the dummy material and the product part. (b) is one embodiment of the present invention for facilitating the separation of the products when simultaneously producing a plurality of Cu-based metal clad steel materials, but is not particularly caught by this, work mode, etc. Accordingly, a titanium foil may be inserted at an appropriate place to facilitate the separation of the desired member.

Next, the effects of the present invention will be described more specifically by way of examples.

<Example> First, the following carbon steel base material, pure Cu laminated material, carbon steel dummy material, carbon steel spacer, titanium foil and carbon steel foil were prepared.

Carbon steel base material C content: 0.03% by weight, dimensions: 100 mm thickness x 2200 mm width x 4000 mm length.

Pure Cu laminated material Dimensions: 30mm thickness x 2160mm width x 3960mm length.

Carbon steel dummy material C content: 0.10% by weight, dimensions: 30mm thickness x 2200mm width x 4000mm length.

Carbon steel spacer C content: 0.10% by weight, dimensions: 30mm thickness x 2200mm width x 4000mm length.

Titanium foil material: JIS Class 1 equivalent, thickness: 0.30 mm.

Carbon steel foil C content: 0.13% by weight, thickness: 0.30 mm.

Next, after assembling these as shown in FIG. 6, four circumferences of the combined material were hermetically welded to produce a Cu clad steel material.

The clad rolling is carried out at a rolling ratio of 5 after soaking the clad steel material assembled as described above at 980 ° C. for 5 hours,
For the obtained Cu-clad steel materials, "joint state of the product", "separability of dummy material" and "degree of indentation flaw after dummy material separation" were investigated.

These results are also shown in FIG. 6 together with “Comprehensive evaluation”.

As is clear from the results shown in Fig. 6, in the conventional method, the joint state (strength) of the clad product was poor, and the peeling (separation) from the dummy material was not good, and indentation flaws occurred on the entire surface of the product. On the other hand, according to the method of the present invention, it is confirmed that the dummy material can be peeled off very easily, indentation on the surface does not occur, and a clad product having a good bonding state can be stably obtained.

<Summary of Effects> As described above, according to the present invention, a high-quality Cu-based metal-clad steel product with a good joining state and no surface indentation is subject to individual differences and skill levels of workers. It is possible to obtain a very useful effect in the industry such that it is possible to stably manufacture without producing.

[Brief description of drawings]

FIG. 1 is a conceptual diagram illustrating an example of an assembling method of a Cu-based metal clad steel material according to the present invention. FIG. 2 is a conceptual diagram illustrating an example of a conventional method of assembling a Cu-based metal clad steel material. Fig. 3 shows the "heating temperature" when a 0.30 mm thick titanium foil was interposed between a carbon steel perforated material and a carbon steel dummy material and these were heated to various temperatures and crimped. 5 is a graph showing the change in peel strength due to FIG. 4 shows that a titanium foil is inserted between carbon steel and
It is the graph which showed the relationship between the insertion titanium foil thickness and the peeling strength of carbon steel-carbon steel in the joining member obtained by heating and pressurizing this at 1000 degreeC. FIG. 5 shows one mode of assembling the Cu-based metal clad steel material according to the present invention, and FIGS. 5 (a) and 5 (b) are different modes. FIG. 6 shows an embodiment of the present invention in comparison with a conventional example.

Claims (1)

[Claims] 1. When assembling a clad steel material having a carbon steel as a base material and a Cu-based metal as a bonding material, the Cu-based metal bonding material is covered with a dummy material made of an easily weldable metal, and the Cu-based material is also used. Characteristically, the carbon steel foil and the titanium foil are interposed between the metal laminating material and the dummy material such that the carbon steel foil is on the Cu-based metal laminating material side, and then welded and assembled.
Method of assembling Cu-based metal clad steel material.