JPH03142080A - Method for assembling clad steel blank material - Google Patents

Abstract

PURPOSE:To obtain the clad steel which is free from surface flaws in a good joined state by interposing titanium foil in the contact surface of a carbon-contg. member to be separated after joining of a clad at the time of assembling the clad steel blank material. CONSTITUTION:The titanium foil is interposed between the required separating members of the clad steel blank material and the clad steel blank material is assembled. The four circumferences of the joint surfaces are welded and the base metal steel and the cladding metal steel are press welded by heating and welding. The titanium foil and the C in a dummy material react during this treatment and a titanium carbide structure layer is formed at the boundary face between the cladding metal and the dummy material. The titanium carbide structure layer is an extremely brittle layer and, therefore, if the resulted clad material is cut to a desired size and if the force to pull and peel the dummy material is applied to the dummy material, this layer is easily broken down and the dummy material is separated. The steel kinds of the base metal steel are not particularly limited and the cladding metal may be any of various steels, Cu, Cu alloy, Ti and Ti alloy. Carbon steels are generally used for the dummy material and spacers and the thickness of the titanium foil is specified to 0.1 to 1.0mm in terms of both of the peelability and the cost of titanium.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a material assembly method for producing clad steel.

<Prior art and its problems> In recent years, carbon steel (C content: 0.01 to 0
．． 30% by weight) as a base material and clad with a dissimilar metal such as high carbon steel (C content: 0.80 to 1.55% by weight), Cu or Cu alloy, or Ti or Ti alloy to form the dissimilar metal. High carbon steel-carbon steel, Cu-carbon steel, and Cu-based alloy-carbon steel, which also have the following characteristics.

Demand for clad steel materials such as Ti-carbon steel is rapidly increasing. For example, parts that require toughness, sharpness, and wear resistance, such as cooking knives and plows for agricultural equipment, are now commonly manufactured using clad steel materials made of carbon steel and high carbon steel. It is.

By the way, in mass production of cladding materials, it is advantageous to adopt the rolling crimping method from the viewpoint of workability and cost, so various rolling crimping methods have been devised according to the metal materials to be combined. When mass producing clad steel materials made of carbon steel and difficult-to-weld metal materials such as carbon steel, the following method has been adopted.

That is, as shown in FIG. 2, first, a high carbon steel laminated material is superimposed on a carbon steel base material, and the difficult-to-weld high carbon steel laminated material is covered with a dummy member and a spacer made of an easily weldable metal. The clad steel material is assembled by welding the four circumferences of their mating surfaces, and then this clad steel material is heated and heated.
In this method, a carbon steel base material and a high carbon steel composite material are rolled and crimped together, then cut into desired dimensions, and the final member and spacer portion are removed to produce a finished product. When assembling the clad steel material, consideration was given to using both the high carbon steel laminated material and the dummy material in their black skin form in order to improve the peelability of the dummy material after the rolling bonding process.

However, although the peelability of the dummy material is relatively good with this method, there is a problem in that sufficient bonding of the surfaces that should originally be bonded (clad bonding surfaces) tends to be impaired by the oxidized layer, which is a black crust. However, if the black scale was removed, the clad bonding surface would be bonded well, but the roof member would not be able to peel off. Of course, the above problem can be alleviated by removing only the black scale on the surface to be joined and leaving the other surface as it is, but in order to remove the black scale on only one side of the material, This required a great deal of effort and was not a method that could be adopted from an industrial perspective.

On the other hand, JP-A-59-30515 states, ``In order to facilitate the separation of clad materials that do not require bonding after pressure bonding, an inorganic binder such as water glass, soda glass powder, or chromite is used as a separating agent. In addition, in JP-A-62-97781, there is a statement that ``It is recommended to use alumina, silica, black scale of mild steel between the cladding material and the dummy material (encapsulated metal), In each case, there are descriptions such as ``If a release agent such as an annealing separation material is used, the dummy material can be easily removed after the pressure bonding process.'' However, in order to apply these methods, a) it is necessary to prepare a stripping agent or separating agent when applying them;
Therefore, the effectiveness will vary from person to person b) It is necessary to apply the prepared release agent or separation agent to a certain thickness and dry it, but the effectiveness will inevitably vary from person to person in the thickness of the application during the application process. Variations occur.

C) It is difficult to determine when the applied release agent or separation agent has completed drying.

These problems could not be ignored, and the method could not be said to be fully satisfactory.

Therefore, an object of the present invention is to easily and reliably separate "parts that do not require joining" after crimping work.
Moreover, the aim was to establish a method for assembling clad steel materials that could be performed stably without being affected by individual differences among workers.

Means for Solving the Problems> Therefore, the present inventors have repeatedly conducted numerous experiments and conducted research in order to achieve the above object, and have found that ``for example, carbon-containing members such as carbon steel and high carbon steel, etc. When titanium foil is inserted between other metal members (which may be different metal members or the same metal members) and is brought into close contact with them and then subjected to heat and pressure bonding, the Ti and carbon atoms in the titanium foil are The carbon in the carbon-containing member causes a chemical reaction of Ti C=Ti C to form an extremely brittle structural layer of titanium carbide (TiC) at the interface between the carbon-containing member and other metal members. Even if the containing component and other metal components are made of materials that are easy to bond to each other, it is extremely easy to separate (peel) the two components due to the brittle and easily broken tissue layer of titanium carbide that forms at the interface. We were able to obtain the knowledge that "it is possible."

Figure 3 shows that there is a gap between a perforated material made of high carbon steel (C: 0.80-1.55%) and a dummy material made of carbon steel (C: 0.01-0.30%). This is a graph showing "changes in peel strength depending on heating temperature" when these were heated and pressure bonded to various temperatures with a 30m5 thick titanium foil interposed.
It can also be seen from FIG. 3 that when the heating temperature exceeds 800° C., the peel strength changes drastically, and when the heating temperature exceeds 850° C., the peel strength hardly shows any value. This is 8
When heated above 00℃, the chemical reaction Ti+C→TiC rapidly progresses, resulting in extremely brittle TiC at the interface.
This shows that a tissue layer is formed.

The present invention has been made based on the above-mentioned findings, etc. ``When assembling clad steel materials in the production of clad steel, as illustrated in FIG. By interposing the titanium foil in contact with the carbon-containing member (dummy material or laminated material in the example shown in Fig. 1) at the contact interface of the dummy material (in the example shown in the figure), the assembly efficiency of the clamped steel material is significantly improved. It is characterized by the ability to stably ensure the ease of separating (peeling) the separation member after clad bonding work, without being affected by individual differences between workers. .

In other words, the present invention provides the following advantages: ``If titanium foil is inserted between the heating members of the clad steel material, Ti, which is a component of the titanium foil, and steel, etc. that come into contact with it during heating and crimping work, material, dummy material, etc.) through a chemical reaction (Tj + C
-Tj C) and generates a very brittle and easily broken tissue layer of titanium carbide between the heating members. For example, if the four circumferences of the mating surfaces of clad steel materials assembled as shown in Figure 1 using carbon steel dummy materials are welded, and then heated and rolled to bond the base steel and the mating materials together, this During processing, the titanium foil and C in the dummy material react, forming a titanium carbide structure layer at the interface between the laminated material and the dummy material, and the resulting cladding material is cut into desired dimensions. If a force is applied to peel off the dummy material from the dummy material, the titanium carbide structure layer is a very brittle layer, so it is easily destroyed and the dummy material is easily peeled off.

Here, the steel type of the base steel is not particularly limited, and the mating material can also be various steels, Cu, and Cu alloys.

It may be made of either Ti or Ti alloy. In other words, the present invention is applicable not only to the production of high carbon steel-carbon steel clad steel materials, but also to the direct production of composite materials and base materials, such as combinations of Cu-carbon tlJ, Cu-based alloy-carbon steel, and Ti-carbon steel. Similar effects can be obtained by applying it to assembly methods that cannot be welded. Carbon steel is generally used as the material for the dummy material and spacer, but there are no restrictions on the type of material as long as it is easily welded.

In addition, the thickness of the titanium foil to be used is 0.10 to 1.0 mm from the viewpoint of both ensuring removability and titanium foil manufacturing cost. OOm■, more preferably 0.30 to 1. It is better to set it as OOm.

Figure 4 shows that titanium foil is inserted between high carbon steel and carbon steel.
This is a graph showing the relationship between the thickness of the interposed titanium foil and the peel strength of high carbon steel-carbon steel in a bonded member obtained by heating and pressurizing this to too degrees Celsius. Titanium foil is 0. It can be confirmed that a practical peeling effect can be ensured if it is equal to or higher than ioam. Since the titanium foil is coiled in various thickness sizes, there is no variation in thickness, so there is no need to worry about variations in releasability depending on the location or unit of work. Moreover, when assembling the clad steel material, the work is simple because it can be cut to any desired size for use, and there is almost no difference in effectiveness due to individual differences or skill levels of workers.

In addition, FIG. 5 shows an example of assembling the clad steel material according to the present invention. This is one embodiment of the present invention for facilitating the separation of products when manufacturing clad steel materials at the same time. A foil may be inserted to facilitate separation of desired members.

Next, the effects of the present invention will be explained in more detail with reference to Examples.

<Example> First, the following carbon steel base material and high carbon steel composite material.

Carbon steel dummy materials, carbon steel spacers, and titanium foil were prepared.

Charcoal 8 Dandansha C content 70.03%.

Dimensions: 150mm thick x 2000mm wide x 4000m
m length.

The progress of sucking all the time C content: 70.95% by weight.

Dimensions: 20mm thick x 1960mm wide x 3960+n length.

Carbon E Demanisha C content: 0.13% by weight.

Dimensions: 30mm thick x 2000m wide x 400ONm long.

庶E”mu adventure 22 jo 2 C content: 0.13% by weight.

Dimensions: 20mm thickness x 2000u + width x 4000mm length.

titanium foil Material: Equivalent to JIS Class 1.

Thickness: 0.30mm.

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

Clad rolling was carried out at a rolling ratio of 1:2 after soaking the clad steel material assembled as described above at 1200°C for 5 hours. The ``separability'' and ``degree of indentation flaws after separation of the dummy material'' were investigated.

These results are also shown in FIG. 6 along with the "overall evaluation."

As is clear from the results shown in Figure 6, in the conventional method, the bonding condition B (strength) of the clad product was poor, and the peelability (separation) of the dummy material was not good, and the entire surface of the product was Whereas indentation defects may occur, according to the method of the present invention, the dummy material can be peeled off very easily, no indentation defects occur on the surface, and the bonded state is good, making it possible to stably obtain a rad product. This can be confirmed.

Summary of Effects> As explained above, according to the present invention, a clad steel material that can obtain a high-quality clamped steel product with a good welding state and no surface indentation flaws, etc. Industrially, extremely useful effects can be obtained, such as making it possible to assemble efficiently under extremely simple and stable work that is not affected by skill or skill level.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram illustrating an example of a method for assembling clad steel materials according to the present invention. FIG. 2 is a conceptual diagram illustrating an example of a conventional method for assembling clad steel materials. Figure 3 shows the results when titanium foil with a thickness of 0.3 (in) is interposed between a perforated material made of high carbon steel and a dummy material made of carbon steel, and when these are heated to various temperatures and crimped. Fig. 4 is a graph showing "changes in peel strength due to heating temperature" of .
It is a graph showing the relationship between the thickness of the interposed titanium foil and the high carbon steel-carbon steel peel strength in a joining member obtained by heating and pressurizing this to 1000°C. FIG. 5 shows the state of parts of the clad steel material assembly according to the present invention, and FIG. 5(a) and FIG. The example is shown in comparison with the conventional example.

Claims (1)

[Claims] A method for assembling clad steel materials, which comprises interposing a titanium foil in contact with a carbon-containing member at the abutting interface of members that need to be separated after clad joining.