KR20100028388A - Method of manufacturing titanium-aluminum-stainless steel clad plate - Google Patents

Abstract

PURPOSE: A manufacturing method of a titanium-aluminum-stainless steel clad plate is provided to secure favorable adhesion and drawability through various combinations of secondary heating temperature and time for a titanium plate, an aluminium plate, and a stainless steel plate. CONSTITUTION: A manufacturing method of a titanium-aluminum-stainless steel clad plate comprises the steps of: washing a titanium plate, an aluminium plate, and a stainless steel plate(10), laminating the titanium plate, the aluminium plate, and the stainless steel plate successively and heating the laminate at 315~325°C for 25~30 minutes first(20), laminating the titanium plate, the aluminium plate, and the stainless steel plate and rolling and bonding at a reduction ratio of 25~30%(30), and heating the bonded clad plate at 300~330°C for 45~55 minutes secondly(40).

Description

Method for manufacturing titanium-aluminum-stainless steel clad plate {Method of manufacturing titanium-aluminum-stainless steel clad plate}

The present invention relates to a method for producing a titanium-aluminum-stainless steel clad plate, and more particularly, to a method for manufacturing a titanium-aluminum-stainless steel clad plate, which can provide a clad plate with improved bond strength and drawability compared to the conventional art. It is about.

Clad is defined as a laminated composite material in which the surfaces of two or more metal materials are joined by metal bonding. These clads are economically advantageous because they can maximize the performance of materials and save expensive materials by using various combinations of appropriate materials. Therefore, the combination of materials is gradually diversified and the field of application is expanding. .

Among the claddings, the most widely used materials for home appliances are stainless steel-aluminum clads, which are used in combination with the advantages of stainless steel and aluminum, and have low specific gravity and high thermal conductivity of aluminum and excellent corrosion resistance of stainless steel. And workability. For this reason, it is used for general household cooking containers, electronic cooking utensils, etc., and it is applied also to some construction materials, heat exchanger materials used for a plant, a motor vehicle, a ship, etc.

Since clads can be used for a variety of purposes, they are likely to replace existing single materials in their respective fields. The replacement of such materials is occurring very rapidly in kitchen containers, and existing single materials such as stainless steel or aluminum are rapidly being replaced by stainless steel-aluminum or stainless steel-aluminum-stainless steel cladding.

In addition, in recent years, the use of less dangerous and environmentally friendly induction heating device instead of using gas as a heat source has gradually increased, and thus, an austenitic stainless steel-aluminum-ferrite which can evenly conduct heat and conduct heat to a suitable material. The use of stainless steel clads is increasing. In order to heat by induction heating method, magnetism must be present in the material. In the case of double plates, the outside is made of ferritic stainless steel, and the inside that is in contact with food is coated with resin on aluminum. The inside is made of ferritic stainless steel, the middle is aluminum, and the inside is made of austenitic stainless steel.

In addition, recently, in order to fully utilize induction heating characteristics, carbon steel having excellent magnetic properties is used, such as stainless steel-aluminum-carbon steel-aluminum-stainless steel clad or aluminum-carbon steel-aluminum clad.

In addition, a clad plate using titanium plate, which has higher specific strength and lighter weight than stainless steel plate, has excellent workability and formability. Looking at the conventional titanium clad plate as follows.

Japanese Laid-Open Patent Publication No. 2002-35959 discloses titanium cladding materials which are laminated and rolled on titanium and stainless steel heated to 150 to 270 ° C. on both sides of aluminum heated to 370 to 430 ° C., followed by diffusion annealing at a temperature of 350 to 430 ° C. Since a method of manufacturing a material is disclosed, this method requires a plurality of heating furnaces to heat the material to be laminated at different temperatures, thereby increasing the capital investment cost and increasing productivity by performing a separate diffusion annealing after rolling. This has the disadvantage of falling.

Japanese Patent Application Laid-Open No. 63-207483 discloses a method of cleaning and diffusing a surface of activated titanium and aluminum by heating at a pressure of 0.3 kgf / mm ² or more under a vacuum atmosphere of 550 ° C. or higher, but the method is simple. Since the joining is performed by pressure diffusion annealing, the joining surface can be separated during the drawing process of the joined cladding plate, and additional equipment for making the inside of the furnace into a vacuum atmosphere for mass production or to manufacture a large cladding plate There is a problem that the cost is excessively increased.

In addition, the clad plate produced according to the prior art including the above-mentioned Japanese patent still has insufficient bonding strength and drawability.

The present invention is to solve the above-mentioned conventional problems, an object of the present invention is to provide a method for producing a titanium-aluminum-stainless steel clad plate which can provide a clad plate with improved bonding strength and drawability compared to the prior art will be.

In order to achieve the above object, the present invention comprises the steps of washing the titanium plate, aluminum plate and stainless steel plate; A primary heating step of sequentially stacking a titanium plate, an aluminum plate, and a stainless steel plate and heating at 315 to 325 ° C. for 25 to 30 minutes; Stacking a titanium plate, an aluminum plate, and a stainless steel sheet and rolling them at a reduction ratio of 25 to 30% to bond them; And it provides a method for producing a titanium-aluminum-stainless steel clad plate comprising a secondary heating step of heating the bonded clad plate at 300 ~ 330 ° C for 45 to 55 minutes.

The washing step may be to immerse the plate in an alkaline solution.

The primary heating step may be to heat the titanium plate, aluminum plate and stainless steel plate at 320 ℃ for 27 minutes.

The secondary heating step may be to heat the bonded clad plate at 315 ° C. for 50 minutes.

According to the method for producing a titanium-aluminum-stainless steel clad plate according to the present invention, it is produced by the method according to the present invention by specifying a combination of process steps and the process conditions of each step, that is, heating temperature and time and a reduction ratio. The titanium-aluminum-stainless steel cladding plate has the advantage that the bonding strength and the drawability are remarkably improved as compared with the prior art.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 is a flowchart illustrating a procedure of a method of manufacturing a titanium-aluminum-stainless steel clad plate according to an embodiment of the present invention.

Referring to Figure 1, the manufacturing method of the titanium-aluminum-stainless steel cladding plate according to an embodiment of the present invention, the washing step 10, the primary heating step 20, the rolling bonding step 30 and the secondary A heating step 40.

First, the washing step 10 is performed. In the washing step 10, the titanium plate, aluminum plate and stainless steel plate are washed. The washing step may be to immerse the plate in an alkaline solution.

In addition, the washing of the plate may be carried out by pickling, for example, in the case of titanium plate, the scale can be removed by immersion in nitric acid or sulfuric acid solution for a certain time, in the case of aluminum immersed in sodium hydroxide solution and then petroleum What is necessary is just to wash | clean with ether solution. On the other hand, since the stainless steel sheet is not sensitive to surface oxidation, it does not need to be treated separately and may be carried out only by cleaning the surface.

Next, the primary heating step 20 is performed. In the primary heating step 20 according to the present invention, the titanium plate, the aluminum plate, and the stainless steel plate are sequentially stacked and heated at 315 to 325 ° C. for 25 to 30 minutes.

The present inventors have confirmed that not only the primary heating temperature but also the heating time are the main variables in order to improve the bonding strength and the drawability of the final manufactured clad plate, and the optimum conditions are the temperature of 315-325 ° C. and the time of 25-30 minutes. Confirmed.

When the primary heating temperature is less than 315 ° C., sufficient bonding strength and drawability cannot be obtained, and even when the primary heating temperature is above 325 ° C., sufficient bonding strength and drawability cannot be obtained.

Not only the heating temperature but also the heating time is a major variable, and sufficient joint strength could not be obtained even when the primary heating time was less than 25 minutes and more than 30 minutes.

Most preferably, the primary heating step is heated at 320 ° C. for 27 minutes.

On the other hand, when the titanium plate is heated to the same temperature together with the aluminum plate and the stainless steel plate compared to the case of not heating the titanium plate was able to obtain better bonding strength and drawing properties.

Next, the rolling bonding step 30 is performed. Rolling bonding step 30 according to the present invention is characterized in that the titanium plate, aluminum plate and stainless steel plate by sequentially laminating by rolling at a reduction ratio of 25 to 30%.

If the reduction ratio is less than 25%, sufficient bonding strength cannot be obtained, and if the reduction ratio is more than 30%, the sheet may be severely deformed and work hardening may occur.

Next, the secondary heating step 40 is performed. Secondary heating step 40 according to the invention is characterized in that for heating the bonded clad plate at 300 ~ 330 ℃ for 45 ~ 55 minutes.

In the case of performing the secondary heating step 40, the bonding strength and the drawing property were remarkably excellent compared to the case in which the secondary heating step 40 was not performed.

When the heating temperature of the clad plate is less than 300 ℃, the bonding strength and drawability was relatively inferior, and even when the heating temperature of the clad plate was higher than 330 ℃, the bonding strength and drawability were relatively inferior.

In addition, even when the heating time of the clad plate was less than 45 minutes and more than 55 minutes, sufficient bonding strength and drawability could not be obtained compared with the case of 45 to 55 minutes.

In the step of heating the bonded clad plate, it is most preferable to heat the bonded clad plate at 315 ° C. for 50 minutes.

Hereinafter, the effects of the present invention are compared in more detail through the Examples.

Experimental Example  1: with primary heating temperature and time Clad  compare

The titanium plate, aluminum plate and stainless steel plate were washed, and the titanium plate, aluminum plate and stainless steel plate were laminated and heated at various temperatures and times. In addition, a titanium plate, an aluminum plate, and a stainless steel plate were rolled to each other at a reduction ratio of 27%, and the bonded clad plate was heated at 315 ° C. for 50 minutes to prepare a titanium-aluminum-stainless steel clad plate.

In the above experiments were carried out by various combinations of the primary heating temperature and time of the titanium plate, aluminum plate and stainless steel plate, and the results of the bonding strength and drawing properties are shown in Table 1.

As can be seen in Table 1, the primary heating temperature and time of the titanium plate, the aluminum plate and the stainless steel plate is preferably 25 to 30 minutes at 315 to 325 ° C, and most preferably at 27 ° C for 320 minutes.

TABLE 1

305 ℃ 310 ℃ 315 ℃ 320 ℃ 325 ℃ 330 ℃ 400 ℃ 500 ℃ 10 minutes ×× ×× × × △ △ △ △ 15 minutes ×× × △ △ △ △ △ △ 20 minutes ×× △ △ △ △ △ △ × 25 minutes × △ ○ ○ ○ △ △ × 27 minutes × △ ○ ◎ ○ △ × ×× 30 minutes × △ ○ ○ ○ × × ×× 35 minutes × △ △ △ △ ×× ×× ××

Note) ◎: Very good, ○: Good, △: Normal, ×: Poor, ××: Very poor

Experimental Example  2: depending on whether or not titanium is heated in the primary heating stage Clad  compare

The titanium plate, aluminum plate, and stainless steel plate were washed, and the titanium plate, aluminum plate, and stainless steel plate were laminated and heated at 320 ° C. for 27 minutes. In addition, a titanium plate, an aluminum plate, and a stainless steel plate were rolled to each other at a reduction ratio of 27%, and the bonded clad plate was heated at 315 ° C. for 50 minutes to prepare a titanium-aluminum-stainless steel clad plate (Example One).

Meanwhile, the titanium plate, the aluminum plate, and the stainless steel plate were washed, and the aluminum plate and the stainless steel plate were laminated and heated at 320 ° C. for 27 minutes. In addition, a titanium plate, an aluminum plate, and a stainless steel sheet were rolled to each other at a reduction ratio of 27%, and the bonded clad plate was heated at 315 ° C. for 50 minutes to prepare a titanium-aluminum-stainless steel clad plate (Comparative Example). One).

The resulting bond strengths and drawability are shown in Table 2.

As can be seen from Table 2, when titanium is not heated like other aluminum and stainless steel in the primary heating, it has an adverse effect on the bonding strength and drawing properties.

TABLE 2

Example 1 Comparative Example 1 Bond strength / drawing property ◎ △

Note) ◎: Very good, ○: Good, △: Normal, ×: Poor, ××: Very poor

Experimental Example  3: with or without secondary heating step, and with heating temperature and time Clad  compare

The titanium plate, aluminum plate, and stainless steel plate were washed, and the titanium plate, aluminum plate, and stainless steel plate were laminated and heated at 320 ° C. for 27 minutes. In addition, a titanium plate, an aluminum plate, and a stainless steel plate were rolled to each other at a reduction ratio of 27%, and the bonded clad plate was heated at various temperatures and times to prepare a titanium-aluminum-stainless steel clad plate.

The experiment was carried out by various combinations of the secondary heating temperature and time of the titanium plate, aluminum plate and stainless steel plate, and the results of the bonding strength and drawing properties are shown in Table 3.

As can be seen from Table 3, the heating temperature and time of the bonded clad plate is preferably 45 to 55 minutes at 300 ~ 330 ℃, 50 minutes at 315 ℃ is most preferred.

On the other hand, in the absence of the cladding plate heating step, the result of the defect (×) in the bonding strength and the drawing property was obtained.

TABLE 3

270 ℃ 285 ℃ 300 ℃ 315 ℃ 330 ℃ 345 ℃ 360 ℃ 30 minutes ×× × × △ △ △ △ 40 minutes × × △ △ △ △ △ 45 minutes × △ ○ ○ ○ △ △ 50 minutes △ ○ ◎ ◎ ◎ ○ △ 55 minutes △ △ ○ ○ ○ △ × 60 minutes △ △ △ △ △ × × 70 minutes △ △ △ △ × × ××

Note) ◎: Very good, ○: Good, △: Normal, ×: Poor, ××: Very poor

Experimental Example  4: Examples and Comparative Example  Compare Effect

The titanium plate, aluminum plate, and stainless steel plate were washed, and the titanium plate, aluminum plate, and stainless steel plate were laminated and heated at 320 ° C. for 27 minutes. In addition, a titanium plate, an aluminum plate, and a stainless steel plate were rolled to each other at a reduction ratio of 27%, and the bonded clad plate was heated at 315 ° C. for 50 minutes to prepare a titanium-aluminum-stainless steel clad plate (Example One).

On the other hand, the titanium plate, aluminum plate and stainless steel plate were washed, and the surface to be bonded was roughened through papering. In addition, an aluminum plate and a stainless steel sheet were laminated and heated at 400 ° C. for 10 minutes, and the titanium plate, aluminum plate, and stainless steel plate were rolled at 25% reduction rate and joined to prepare a titanium-aluminum-stainless steel clad plate ( Comparative Example 2).

Bonding strength and drawability of Example 1 and Comparative Example 2 were confirmed.

In Example 1, the bonding strength of the titanium plate and the aluminum plate and the bonding strength of the aluminum plate and the stainless steel plate were 200 N / cm and 230 N / cm, respectively, and the drawing property was very good.

In Comparative Example 2, the bonding strength of the titanium plate and the aluminum plate and the bonding strength of the aluminum plate and the stainless steel plate were 187 N / cm and 200 N / cm, respectively, and the drawing properties were normal.

From the above results it can be seen that the method according to the invention is much superior to the method of Comparative Example 2.

Although the present invention has been described with reference to the embodiments, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a flowchart illustrating a procedure of a method of manufacturing a titanium-aluminum-stainless steel clad plate according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

10: washing step 20: primary heating step

30: rolling bonding step 40: secondary heating step

Claims (4)

Washing the titanium plate, the aluminum plate and the stainless steel plate; A primary heating step of sequentially stacking a titanium plate, an aluminum plate, and a stainless steel plate and heating at 315 to 325 ° C. for 25 to 30 minutes; Stacking a titanium plate, an aluminum plate, and a stainless steel sheet and rolling them at a reduction ratio of 25 to 30% to bond them; And Method of producing a titanium-aluminum-stainless steel clad plate comprising the secondary heating step of heating the bonded clad plate at 300 ~ 330 ℃ for 45 to 55 minutes. The method of claim 1, The washing step is a method for producing a titanium-aluminum-stainless steel clad plate, characterized in that the plate is immersed in an alkaline solution. The method of claim 1, The primary heating step is a method for producing a titanium-aluminum-stainless steel clad plate, characterized in that for heating the titanium plate, aluminum plate and stainless steel sheet at 320 ℃ for 27 minutes. The method of claim 1, The secondary heating step is a method for producing a titanium-aluminum-stainless steel clad plate, characterized in that for heating the bonded clad plate at 315 ℃ for 50 minutes.

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