JPS6076269A - Production of clad material by cast-in method - Google Patents

Abstract

PURPOSE:To reduce the cost of a clad material and to manufacture easily a multilayer clad material consisting of different kinds of steels by casting in a billet which is preliminarily clad as a core material. CONSTITUTION:A metallic plate 4 corresponding to a core material 1 in the prior art and a metal 5 of a carbon steel or the like which is the same or different from said metallic plate are preliminarily clad to manufacture a core material 10. A hook 6 is attached to the top end of the material 10 and is suspended into a casting mold. If the molten metal having the same compsn. as the compsn. of the plate 5 on one side is poured into the mold, the molten metal and the plate 5 solidify into one body. A release agent 7 is preliminarily coated on the plate 4 and the solidified metal layer on the coated side is stripped after hot rolling or the like, by which two layers of the clad steel plates are obtd. It is possible to change the thickness of the material 10 or to change the ratio of the thickness between the plates 4 and 5 and therefore even if the costly metallic plate is made thin, the erosion and deformation of the core material during pouring are prevented and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cladding material by placing a core material in a mold using a holding means such as a bow, and then casting the core material.

As shown in Fig. 1, in the conventional manufacturing method of cladding material using the casting method, a solid core material 1 made of stainless steel, carbon steel, or Ni steel, that is, a core material 1 made of a single plate, is placed in a mold 2. A widely known method is to obtain a siflad material by suspending the core material 1 within the core material 1, and pouring molten steel 3 such as carbon steel around the core material 1 and solidifying it. The steel ingot of the clad material obtained by this method is usually made into a steel billet by blooming rolling, and the surface of the clad steel billet is further treated depending on the clad material to be finally obtained as a product. This process involves peeling off one side of carbon steel, etc. that has been poured around the core material and solidifying it (hereinafter referred to as the coating material), or dividing the clad steel piece in the thickness direction. After that, it is hot rolled and plate rolled into products such as clad copper strips and clad steel plates that have a variety of properties such as corrosion resistance and mechanical properties.

However, in the conventional method as described above, if you want to vary the cladding ratio, or if you want to reduce the cladding ratio (thus reducing the thickness of the core material relative to the thickness of the dressing material), the following method is used: There was a problem. In other words, if you want to change the cladding ratio in various ways, you can prepare core materials of various thicknesses accordingly, and either hold the core materials of different thicknesses suspended in the mold and cast them, or use the core materials suspended in the mold. By changing the distance between the surface of the material and the inner wall of the mold, or by suspending multiple core materials at intervals within the mold and casting the core materials at the same time, the distance between each core material can be changed. will be manufactured by changing. One of the purposes of manufacturing clad steel is to reduce the amount of expensive special metals used.
Therefore, even in the manufacturing method of cladding materials using the casting method, it is desirable to reduce the thickness of the core material, which often contains special metals, to reduce the cladding ratio.
If the thickness of the core material is made small, the core material is likely to be eroded and deformed when the core material is held suspended in the mold and molten steel is poured around the core material, making it difficult to stabilize the cladding ratio. Do not damage the product, as this will result in a decrease in the yield of good products.
There was a limit to the reduction in the thickness of the core material in the casting method. In addition, when changing the distance between the core material surface and the inner wall surface of the mold or the distance between multiple core materials in order to change the cladding ratio, increasing these distances in order to reduce the cladding ratio will reduce the amount of coating material. There is a problem in which the yield of good products decreases due to the shrinkage of the head of the steel ingot during solidification shrinkage that occurs after hot water is poured.This problem can be solved by using heat insulators for the riser, but this also tends to have its limits. In reality, it is difficult to manufacture a cladding material with a low cladding ratio beyond a certain level.

This invention has been made in view of the above circumstances, and it is possible to easily change the cladding ratio in a method of manufacturing cladding material by the casting method, and to reduce the cladding ratio without causing the above-mentioned problems. The purpose of the present invention is to provide a method for obtaining the results.

That is, the present invention provides a method for producing a clad material by placing a core material in a mold and casting the core material, in which a 2-node steel piece that has been clad in two or more layers in advance is used as the core material. , which is characterized in that the core material is further covered with a coating material.

The method for manufacturing a cladding material according to the present invention will be explained in detail below with reference to the drawings from FIG. 2 onwards.

FIG. 2 shows a first example of the implementation status of the method of the present invention, in which the core material 1O is made of a metal selected from stainless steel, nickel steel, carbon steel, etc. It is composed of a two-layer clad steel plate made by pre-cladding a plate 4, that is, a metal plate 4 corresponding to the core material 1 in the conventional example, and a metal plate 5 made of the same or different kind of metal as the metal plate 4, such as carbon steel. ing. When actually carrying out the method of the present invention using such a core material 10, the hanger 6 is attached to the upper end of the core material 10 by, for example, welding.
It is suspended from this hanging arm 6 in a mold (not shown). At this time, it is usually desirable to apply a release agent 7 such as MgO to the surface of the metal plate 4, and by doing so, after pouring the molten metal and performing casting and rolling. The metal coating on the surface of the metal plate 4 can be easily peeled off. On the surface of the first metal plate 5 side, an antioxidant such as a hydrocarbon-based paint is applied to prevent the oxidation of the molten metal to be poured, so that the molten metal to be poured is tightly integrated with the metal plate 5. It is desirable to apply 8.

If molten metal having the same composition as the metal plate 5 on one side is poured around the core material 10 made of a clad steel piece suspended in the mold as described above, the molten metal will be integrated with the metal plate 5. It solidifies in a solidified state, yielding a two-layer cladding material.

At this stage, the molten metal is solidified on the side of the metal plate 4 as well, but by peeling off the solidified metal layer on the side of the metal plate 4 after hot rolling, etc.
It becomes a layered steel plate.

In the above method, the thickness of the core material 10 made of a two-layer clad steel piece is changed, or the ratio of the thicknesses of the metal plates 4 and 5 constituting the core material 10 is changed, and the core material 10 is suspended in a mold. The cladding ratio can be easily changed by changing the core material lo by one degree. Even if it is desired to reduce the cladding ratio in the final product by reducing the thickness of the metal plate 4, which corresponds to the core material 1 in the conventional example, which often contains particularly expensive special metals, the overall thickness of the core material 1o is small. Since there is no need to do this, the core material 10 is
In particular, the metal plate 4 is prevented from being eroded and deformed. In addition, since the metal plate 5 is attached in advance to the metal plate 4 corresponding to the core material 1 in the conventional example, even if it is desired to reduce the cranoid ratio by changing the suspension device of the core material 10, the core material lO
The distance between the surface on the metal plate 5 side and the opposing inner wall surface of the mold does not need to be very large, and therefore, unlike the conventional method, the problem of reduced yield due to shrinkage during solidification and shrinkage occurs. There is little risk.

In the above description, the molten metal to be poured is of the same composition as the metal plate 5. 75S1 In some cases, molten metal of a different thread composition from either of the metal plates 4 and 5 may be poured. You can also ask about layered rad kidnappings.

Further, although a two-layer clad steel piece is used as the core material 10 in the above-mentioned flJ, depending on the case Q, a multi-layer clad copper piece having three or more layers may be used. Therefore, a cladding material having an arbitrary number of layers can be obtained by combining these materials.

Figure 3 shows the current state of implementation of the method of this invention; in this case, stainless steel 171, nickel steel, carbon steel, etc. Each of the two gold 14 plates 4A and 4B (these correspond to the core material 1 in the conventional example) is preliminarily coated with a metal plate 5A made of a different or similar material such as carbon,
Two clad steel slab core materials 10 clad with 5B
A.1. Using OB, these cores 1ftlOA,
10B'e, metal & 4 A r 4 B are overlapped with a release agent 7 in between so as to face each other, and the periphery is temporarily fixed by welding etc., and a hanger 6 is attached, and the hanger 6 is inserted into the mold using the hanger 6. ) to let the shell hang down.

In addition, at this time, the $ (11 side,
That is, it is preferable to apply the above-mentioned mild antioxidant 8 to the surfaces of the metal plates 5A and 5B.

Two cladding sheets and four pieces of core material 1 stacked as described above
After suspending 0A and IOB in the mold, a target metal having the same composition as the outer metal plates 5A and 5B is poured around them, and the molten metal R'A is made into metal steam plates 5A and 5B.

After coagulating in a state integrated with 5B and blooming the obtained morning-finished lump according to necessity, the above-mentioned peeled FJ (ill
Dividing into two from the plane where 7 is inserted QThus, 2
Two layered cladding materials are obtained. In this case as well, the cladding ratio can be easily changed as in the example shown in FIG.

That is, the cladding ratio can be changed by changing the cladding ratio of each core material 10A and IOB, the thickness of each core material, or the position of the core material suspended in the mold 75]. In particular, it is easy to reduce the cladding ratio for the reason mentioned above. Also 2 7 & core material 1 made of clad steel piece
0A, core material 10A, which is made by casting melted metal with a completely different composition from IOB.

By using a 3-layer clad steel piece as 10B, it becomes possible to manufacture different steel types and multi-layer clad materials, and to create sophisticated designs. Furthermore, depending on the case, the core material 10A.

By making the Afl compositions of the metals 0i4A and 4B on opposite sides of the lOB different, it is possible to obtain different cladding materials at the same time.

FIG. 4 shows a third example of the situation in which the method of the present invention is implemented; in this case, a metal plate 4A and a metal plate 5A are used.
14 pieces of cladding core material 10A formed by cladding in advance;
Metal plate 4B and gold! A clad steel piece core material 10B formed by cladding the A plate 5B in advance is made to face each other by stirring the gap, and the core material 10A thereof.

10B are connected by the inter-core distance adjustment plate 9, a hanging handle (not shown) is attached, and the core materials are suspended in the mold in the same manner as described above. At this time, a release agent 7 is applied to the surfaces close to the inner wall of the mold, that is, the surfaces of the metal plates 4A and 4B, and the surfaces that face each other at a distance, that is, the metal plates 5A and 5B are coated with a release agent 7.
Antioxidant 8 is applied to the surface.

Here, the metal plates 4A and 4B are of the same type and composition, and the metal plates 5A and 5B are of the same type and composition, and the metal plates 5A and 5B are of the same type and composition, S, Q, or different from the metal plates 4A and 4B. By injecting and solidifying molten metal having the same composition as , and peeling and removing the solidified metal on the front side of the metal plates 4A and 4B after blooming, etc., both the front and back sides are made to have the same composition.
With the A configuration, a 3J low-clad material can be obtained in which the central portion is made of the same or different compositions or different metals.

In the reli shown in FIG. 4, by adjusting the length of the inter-core distance A, which is an integer 9, the distance between the core members 10A and IOH can be adjusted, and thereby the cladding ratio can be adjusted.

Also, of course, the core material 10A, the thickness of the JOB, the metal @ Saka 4A constituting the core material 10A, and the IOB are similar to the examples of FIG. 2 and FIG. 3 described above.

It is also possible to easily change the cladding ratio by changing the ratio of the thicknesses of the metal plates 4B and the metal plates 5A and 5B.

In addition, in the above explanation, the core material 10A, the IOB metal plate 4A,
Although the metal plates 4B are of the same composition, depending on the case, they may have the same or different compositions, and furthermore, the molten metal to be poured may be of a different steel type from the metal plates 5A and 5B. By combining these, it is possible to manufacture multi-layer cladding materials of different steel types.

Next, examples of this invention will be described.

The mold is for casting an 18 ton steel ingot, specifically, the head section is 802 x 1200 FIm and the bottom section is 92 x 1.
The clad material was cast according to the method of the ingot invention with a mold height of 236 mm and a mold height of 2800 mm.

The obtained cast clad clad steel ingot was subjected to blooming rolling.
The desired clad steel slab is obtained by preparing the surface of the steel slab, peeling off the surface layer of the steel slab, or dividing it in the thickness direction, and then hot rolling it to a thickness of 2 to 6 mm.
It was processed into 8 to 12 mm copper strips or 8 to 12 steel plates by plate rolling.

It was confirmed that the cladding ratio of each clad steel plate or clad steel strip obtained as described above was always stable, and the yield of non-defective products was also confirmed to be extremely good.

The cladding evaluation of each cladding material according to Examples 1 to 4 is also shown in Table 1. Here, the cladding evaluation was determined using the inclusion area ratio at the interface as an index. That is, the inclusion area ratio at the cladding interface was determined. The determination was made based on the fact that it is known that the shear strength is satisfied if the area ratio is 2 hits or less.As a result, as shown by the ◎ mark in Table 1, the cladding obtained in each of Examples 1 to 4 All materials have an inclusion area ratio of 0 to 0.
01%, which was found to be extremely excellent.

On the other hand, for comparison, a cladding material was manufactured according to Example 1 in Table 1 using a conventional solid core material. That is, a single plate core material (thickness: 30mm) made of SUS 304 steel was placed in a mold at a position 1QQtli away from the mold head wall and 1101m away from the mold bottom wall, and carbon steel was poured into the mold as the molten metal. I poured hot water. The obtained clad steel ingot was bloomed and rolled into a clad steel billet.

The crust ratio and other properties of this conventional clad chain piece were examined, but the clad ratio was not stable and it was determined to be a defective product. This is due to the core material being melted and deformed due to the heat effect of the poured molten metal.

2. The present inventors investigated the thermal influence of the molten metal being poured and found that in order to prevent the thermal influence, in the method of this invention, the core material 10 or xoA, 1o
It has been found that it is desirable to have a Bi thickness of 50 mm or more. However, since the thickness of the entire core material only needs to be 5 Q nIjn or more, the thickness of each metal plate constituting the core material can be made much thinner.

As is clear from the above explanation, according to the method of the present invention, cladding becomes unstable due to erosion and deformation of the material, or defects due to shrinkage due to solidification shrinkage are not caused.
It is possible to make the clad steel strip and shunt clad ratio much smaller than before, thus reducing the amount of alloy steel that contains expensive special metals, contributing to cost reduction and resource conservation. Various effects can be obtained, such as making it easier to manufacture different steel types and multilayer cladding materials.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view for explaining a conventional casting method for manufacturing cladding material, and FIG. 2 is a vertical cross-sectional view showing a first example of a situation in which the method for manufacturing cladding material of the present invention is carried out. Fig. 3 is a longitudinal cross-sectional view showing a second example of a situation in which the cladding material manufacturing method of the present invention is carried out, and Fig. 4 shows a third example of a situation in which the cladding material manufacturing method of the invention is carried out. FIG. 4.4A, 4B: 5, 5A, 5B...metal plate, 10,
IOA, IOB...core material. Applicant Kawasaki Steel Co., Ltd. Agent Patent Attorney Takehito Toyota (and 1 other person) 1st Third Cause

Claims (1)

[Claims] A method for manufacturing a shiflad material by placing a core material in a mold and casting the core material, the method comprising using a clad steel piece that has been clad in advance as the core material. Method of manufacturing cladding material.