JPH11347709A - Production of two layer clad stainless steel plate by casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of a two layer clad stainless steel plate excellent in the detachability between both core materials and the stickiness between the core material and a coating material based on a casting method. SOLUTION: Peryphery of polymerized surfaces of the core materials 1, 2 after polimerizing two descaled stainless steel plates 1, 2 via release agent 3, is welded. Further, the erosion preventive plate 4 of a low carbon steel is welded to the stainless steel plates 1, 2 so as to cover the welded portion. Then, after coating polymeric organic material on the whole exposed surface, the core materials 1, 2 are supported at the center in the mold 10 with a hanging tool 11, and the molten steel as the coating material is cast from a sprue 12 to make a clad steel ingot. After applying bloom-rolling and thick plate rolling, the non-clad part is removed and two pieces of the core materials 1, 2 are detached to obtain the two layer clad stainless steel plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a two-layer stainless steel clad steel sheet by a casting method, and more particularly, to a method of peeling a stainless steel clad steel sheet obtained by a casting method into a two-layer stainless steel clad steel sheet. The present invention relates to a method for producing a two-layer stainless steel clad steel sheet having excellent properties and adhesion between a core material and a clothing material with a high yield.

[0002]

2. Description of the Related Art First, a method for manufacturing a two-layer clad steel sheet by a conventional general casting method will be described with reference to FIGS. As shown in FIGS. 6 and 7, two core members 102, which are superimposed on a central portion in a mold 100 via a release agent 101, welded around, and coated with an antioxidant such as an epoxy resin on the surface. , 103 are supported by hanging tools 104, and
5, the molten steel for the batter is injected by the lower casting method, and
03 is cast with the clothing material 106 to obtain the clad steel ingot 107 shown in FIG. Next, the clad steel ingot 107 is slab-rolled into a slab, and after cutting and removing the non-clad portion of the slab, the cores 102 and 103 are separated and subjected to a hot rolling step. The two-layer clad steel sheet 108 shown in FIG.

[0003]

Conventionally, the core members 102, 1
When stainless steel is used as 03, it is common to use carbon steel, usually low carbon steel or medium carbon steel, as a garment. However, according to this conventional method, since the melting point of the stainless steel of the core members 102 and 103 is lower than that of the carbon steel of the coating material molten steel, the separation by the molten steel entering the separation surface of the core members 102 and 103 is performed. There was a problem of difficulty.

On the other hand, carbon steel having a high melting point is
Attempts have been made to use stainless steel as the garment, but to reduce the ratio of stainless steel to the product plate thickness, the thickness of the cores 102 and 103 must be increased. There was a problem that the gap between the materials 102 and 103 and the inner surface of the mold could not be sufficiently secured, and the run-up was damaged at the time of casting, resulting in product defects.

[0005] Due to these problems, the casting method has an advantage that it is suitable for mass production.
It has been difficult to use this casting method for manufacturing a two-layer clad steel sheet using stainless steel as a core material. The present invention has been made in view of such circumstances, and prevents melting and difficulties in peeling, it is possible to obtain a good product,
An object of the present invention is to provide a method for producing a two-layer clad steel sheet by a casting method using stainless steel as a core material.

[0006]

In order to prevent molten steel from entering the exfoliated surface of the stainless steel plate as the core material, that is, the superposed surface, the present inventors have developed a method of welding around the superposed surface of the stainless steel plate. It has been found that it is preferable to cover the part with a low carbon steel sheet and then cast a garment.

The present invention has been made based on such knowledge, and the method for producing a two-layer stainless steel clad steel sheet by the casting method according to the first aspect of the present invention is directed to a method of manufacturing a two-layer stainless steel sheet having a descaled core material. The steel sheet is polymerized via a release agent, and the periphery of the superposed surface is welded.The erosion prevention plate of low carbon steel is fixed to the stainless steel sheet so as to cover the welded portion, and the antioxidant is applied to all exposed surfaces. After applying a high-molecular organic material, place this core material in the center of the mold and cast the molten steel into the clad steel ingot, perform slab rolling and plate rolling, and remove the non-clad part. And two cores are peeled off to obtain a two-layer stainless steel clad steel sheet.

[0008] Further, according to the casting method described in claim 2,
The manufacturing method of the layered stainless steel clad steel sheet is such that two stainless steel sheets as the descaled core material are polymerized via a release agent and welded around the overlapped surface, so as to cover the end face where the welded portion is located. After polymerizing the erosion prevention plate of low carbon steel and descaling the polymerized surface, welding the erosion prevention plate to the stainless steel plate, descale the outer surfaces of the stainless steel plate and the erosion prevention plate, and perform an antioxidant After applying the high-molecular organic material, place the core material in the center of the mold, cast the coating material molten steel into a clad steel ingot, perform slab rolling, plate rolling, and remove the non-clad part. The present invention is characterized in that two core materials are peeled off to obtain a two-layer stainless steel clad steel plate.

Further, the method for producing a two-layer stainless steel clad steel sheet by a casting method according to claim 3 is characterized in that in each of the above production methods, low carbon steel having the same composition as the erosion prevention plate is used as the molten steel for the clothing material. Features.

[0010]

Embodiments of the present invention will be described below. First, two stainless steels, for example, SUS316, are used as the cores 1 and 2, and they are heat-treated in advance, and then descaled except for the polymerized surfaces that are in contact with each other. Then, the two scaled cores 1 and 2
Are applied to each other by applying a release agent 3 to each other, and the entire circumference of the overlapped surface is welded.

Next, the end face where the welded portions of the welded core materials 1 and 2 are located is adjusted to a carbon content of 0.001 to 0.003% by weight.
The steel plate 4 is coated with four iron plates 4 (only two steel plates are shown), which are 10 to 15 mm-thick descaled low-carbon steel erosion prevention plates, and the overlapped portions are descaled and then welded. Then, after descaling the outer surfaces of the iron plates 4 and the core members 1 and 2, a high molecular organic substance such as an epoxy resin is applied as an antioxidant thereto. In addition, high molecular organic substances such as this epoxy resin,
It is preferable to apply the coating so as to form a film thickness of 50 μm or more.

Subsequently, as shown in FIG. 1, the core members 1 and 2 are supported at the central portion in the mold 10 by the hanging members 11. In addition, the hanging leg 11 has its fixed leg 11a welded to the upper surface of the iron plate 4a.

Subsequently, molten steel to be the batter 5 is injected from the gate 12 at a pouring speed of 0.1 to 1.5 m / min by a lower casting method.
As shown in FIG. 2, core materials 1 and 2 are cast with a batter 5 to form a clad steel ingot 6. Here, low-carbon steel or medium-carbon steel may be used as the molten steel to be the clothing material 5, but low-carbon steel having the same composition as the iron plate 4 is preferable.

At the time of casting, the iron plate 4 melts from the outer surface in contact with the molten steel. However, since the temperature of the portion in contact with the cores 1 and 2 is lower than the molten steel, the welded portions of the cores 1 and 2 melt. As a result, molten steel does not enter the overlapping surfaces of the cores 1 and 2.

Further, the clad steel ingot 6 is slab-rolled by a known method to form a slab 7 shown in FIG. 3, and subsequently, the slab 7 is subjected to a thick plate rolling by the same known method. The total reduction ratio in these rolling steps is preferably in the range of 6 to 20. Next, the applied portion of the core material 1 and the release material 3 is inspected by ultrasonic flaw detection, the surrounding non-clad portion is gas-cut and cut and removed, and then the two core materials 1 and 2 are peeled off. The steel plate surface was polished to obtain a two-layer stainless clad steel plate 8 as a thick plate product shown in FIG.

Next, a preferred embodiment will be described. Example 1 Applications Steel pipe for chemical plant piping Core component C / 0.07%, Si / 0.80%, Mn / 1.8%, P /
0.02%, S / 0.09% Ni / 12.12%, Cr / 17.0% Clothing component C / 0.15%, Si / 0.34%, Mn / 1.20%, P /
0.02%, S / 0.02% Core material thickness ratio 5% Mold inner surface average width 1000mm Core material thickness 126mm Core material to mold inner surface distance 510mm

Example 2 Applications Steel pipe for chemical plant piping Core material components C / 0.06%, Si / 0.76%, Mn / 1.9%, P /
0.02%, S / 0.10% Ni / 12.86%, Cr / 16.5% Clothing material components C / 0.13%, Si / 0.32%, Mn / 1.16%, P /
0.018%, S / 0.018% Core material thickness ratio 7% Mold inner surface average width 1200mm Core material thickness 140mm Core material to mold inner surface interval 510mm

The two-layer stainless steel clad steel sheet 8 obtained in each example was compared with a two-layer stainless steel clad steel sheet manufactured by the conventional rolling method using the stainless steel sheet and the clothing material of the same components as in Example 1. As shown in FIG. 5, the double-layer stainless-clad steel sheet 8 of each embodiment is made of a conventional two-layer stainless steel clad steel sheet.
Since the inclusion area of the inclusions on the superposed surface was smaller than that of the single-layer stainless steel clad steel plate, it was confirmed that the adhesion was excellent. Further, the heat treatment characteristics and mechanical properties of the double-layer stainless steel clad steel sheet 8 obtained in each example were not inferior to those of the conventional double-layer stainless steel clad steel sheet.

[0019]

As described above, according to the present invention,
A two-layer stainless steel clad steel sheet with a stainless steel core as the core material can be obtained at a high yield by the casting method, and the manufactured two-layer stainless steel clad steel sheet has excellent adhesion on the superposed surface and also has a high heat treatment property and mechanical properties. Is also good.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a manufacturing process of a clad steel ingot according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a manufactured clad steel ingot.

FIG. 3 is a schematic sectional view showing a slab obtained by rolling.

FIG. 4 is a schematic cross-sectional view showing a two-layer clad steel sheet obtained by cutting and removing a non-clad portion and peeling a core material.

FIG. 5 is a diagram showing a comparison of the adhesiveness of a boundary portion between each embodiment of the present invention and a conventional rolling method.

FIG. 6 is a schematic cross-sectional view showing a manufacturing process of a clad steel ingot in a conventional casting method.

FIG. 7 is a plan view of the same.

FIG. 8 is a schematic cross-sectional view showing a manufactured clad steel ingot.

FIG. 9 is a schematic cross-sectional view showing a two-layer clad steel sheet obtained by cutting and removing a non-clad portion and peeling a core material.

[Description of Signs] 1, 2 core material 3 release agent 4 iron plate 5 clothing material 6 clad steel ingot 7 slab 8 two-layer clad steel plate 10 mold 11 hanging tool 12 gate

Claims (3)

[Claims] 1. A stainless steel plate as a core material, which has been descaled, is polymerized via a release agent, and the periphery of the superposed surface is welded to form a low carbon steel erosion prevention plate so as to cover the welded portion. After fixing to the stainless steel plate and applying a polymer organic substance to the entire exposed surface, this core material is arranged in the center of the mold, and then the molten steel is cast into a clad steel ingot, and then slab-rolled, thickened. After performing the sheet rolling, the non-clad portion is removed and 2
A method for producing a double-layer stainless steel clad steel sheet by a casting method, wherein a core material is peeled off to obtain a double-layer stainless steel clad steel sheet. 2. De-scaled two stainless steel sheets as a core material are polymerized via a release agent and welded around a superposed surface, and the low-carbon steel is coated so as to cover an end surface where the welded portion is located. After polymerizing the erosion prevention plate and descaling the polymerized surface,
After welding the erosion prevention plate to the stainless steel plate, descaling the outer surfaces of the stainless steel plate and the erosion prevention plate and applying a high molecular weight organic material, disposing the core material in the center of the mold, Is cast into a clad steel ingot, subjected to slab rolling and plate rolling, and after removing the non-clad portion, 2
A method for producing a double-layer stainless steel clad steel sheet by a casting method, wherein a core material is peeled off to obtain a double-layer stainless steel clad steel sheet. 3. The method for producing a two-layer stainless clad steel plate by a casting method according to claim 1, wherein low-carbon steel having the same composition as the erosion prevention plate is used as the molten steel for the garment material.