JPS58141881A - Production of 2 layered clad steel plate - Google Patents

Abstract

PURPOSE:To obtain a titled steel plate having <=50% thickness ratio of a core material and high adhesion in a method of stripping and rolling the steel ingot obtd. by embedding a core material of high carbon steel or the like with cladding materials of low carbon steel by embedding the cladding material on the side of the core material coated with a stripping agent thinly. CONSTITUTION:In the stage of disposing a core material 2 in a mold 1 by means of a suspension means 3, said material is so set as to produce a difference in the enclosing thicknesses of cladding materials 6 to be formed on both sides of the material 2 in the thickness direction of the ingot. Molten metal for the cladding material is charged into the mold from the bottom through a sprue 4. The steel ingot consisting of the material 2 and the cladding materials 6a, 6b on the thick and thin sides on both sides thereof is thus obtained. A stripping agent 5 which is mixed liquid of MgO and water is coated on the surface of the material 2 to face the material 6b before ingot making. The resulted clad steel ingot is bloomed after soaking to a slab. The respective side corner parts 7 on four sides formed of the material 6b are cut off by scarfing or the like from said slab. Since the parts 2a are exposed slightly by the cutting, the material 6b is stripped easily from the material 2 and after the stripping, the material is subjected to hot rolling.

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing 8-layer clad steel sheets, and in particular, the present invention relates to a method for manufacturing 8-layer clad steel sheets, and in particular, when a clad steel ingot obtained by the casting method is subjected to peeling and rolling processes to form a 2-layer clad steel sheet, its peelability and core We propose a method that is easy to manufacture with high yield and has excellent adhesion between materials and coatings. Figure 1 shows the pattern of a general ingot-forming method for casting clad steel. To explain the gist of this prior art, a core material 8.2' made of two stacked layers with a layering agent 5 sandwiched in the center of the casting M1 is supported in the air via a hanger 8, and the mold Molten steel flows from sprue 4 into l.

[Introduced using the sub-injection method,
The core materials 2, 2' are cast with a coating material to obtain a clad steel ingot. Thereafter, this clad steel ingot was bloomed into a slab, the non-clad part tty+ was dropped off, and the space between the core materials 2 and 2' was separated from the peeling agent 5 portion, and the slab was subjected to a hot rolling process. In the above-mentioned conventional technology, the core materials 2 and 2' contain high carbon and agglomerates! When using I, low carbon steel is usually used as the coating material (molten steel for casting). However, when casting with this combination, the core material is 2.2
Since the melting point of the high carbon steel ' is lower than that of the low carbon steel that becomes the molten coating material, the 1# steel invades the peeling surface, making it difficult to peel. In response to this, there have been attempts to use low carbon steel with a high melting point as the core material 3, s' and high carbon steel as the coating material, but in order to reduce the thickness ratio of high carbon steel in the product plate thickness, The low carbon steel core material2. Because the thickness of s' had to be removed in a hurry, there was not enough space between the core material 2.2' surface and 1lIlrIB in the mold, and the hot water level during ingot making was marked, resulting in product defects. . In this sense, it has been impossible to manufacture a three-layer clad steel sheet in which the ratio of high carbon to the product sheet thickness is SS% or less. In addition, in the above-mentioned conventional technology, when performing the peeling work, the four shoulders of the steel slab are cut with e-gas, but this work requires a rapid heat load, so in the case of high carbon steel, which is highly sensitive to heat, The drawbacks of stress cracking and transformation stress cracking were also pointed out. In addition to the above-mentioned example, there is a 4% conventional technique in which the J core material is densely layered on one of the inner bell surfaces of the mold, and the coating material is applied only to that part. When #liA is heated in a soaking furnace, the heating atmosphere gas enters the interface between the core material and the coating material, oxidizing the interface and causing poor adhesion of the rolled material, which is a major drawback. The present invention is based on the method of casting the above-mentioned low melting point metal as a core material with a coating material of a high melting point metal.
The present invention relates to a method aimed at overcoming the above-mentioned drawbacks of I-building techniques. The feature is that one side of the core material: that is, the thickness of the coating material placed on the area where the peeling has been formed is cast so that it becomes thin, and later the thin coating material is added to the core material. The purpose is to create a two-layer clad board with better separation and no defects. Below is the configuration of the *ar-1 core material. This will be explained along with the description of a preferred embodiment in which sea bream is used and low carbon fII is used as the coating material. FIG. 8 shows the state of forming a clad steel ingot based on the method of the present invention. The feature of this ingot-forming method is that when the core material 8 is placed in the mold 1 via a hanger 8, 1IL of the coating material 6 is generated on both sides of the core material in the thickness direction of the slab.
The point is to set it so that there is a difference in WJ thickness (Ta and Tb), and then pour it through a sprue using molten steel as a coating material. As a result of this am, the coating materials located on both sides of the core material 3 have uneven thickness, consisting of the thick coating material 6a and the thin coating material 6b. For the above-mentioned agglomeration, first, the surface of the core snow facing the thin-walled side covering material 6b is coated with MgO (a mixture of MgO and water), as a preferred example, by applying the delamination st value. put. In addition, in order to form the thin side covering material 6b by hitting the jl mass, the distance [Tb] between the core material 2 and the # wall inner surface must be at least 20 cm at the closest point, and 80 to 10 m.
111 (steel ingot 11) is good. This option requires more than sOs processing when manufacturing slabs from steel ingots, but the thickness of the above-mentioned thin side coating material -b! If it is less than O■, it will be less than 1G- at the stage of blooming rolling, so cracking will occur during rolling, so this is rtj! It is decided based on the meaning of the term. Others, Tb: ! If the temperature is less than 0 days, the rise of the molten metal will be poor, resulting in poor water circulation. However, Tb is 11
If 9. is too large, this part will be cut off, resulting in a decrease in yield. The core material 2 mentioned above is made of high carbon steel or alloy with an O/ of 0.451 or more, and the coating material 6 is made of O/Q of 0.451 or more. OS
The following low carbon steel is used. In this case, it is suitable for use in cutlery, agricultural engineering, etc., and materials for such uses require a material that can be hardened by hardening and has excellent impact resistance. Therefore, the method of the present invention is advantageous. Note that during ingot formation, there is a risk that the cut S may fall off the surface of the core material 8, so it is desirable to cover it with a metal mesh or the like to prevent this. The clad steel ingot thus obtained is soaked and rolled into slabs, and as shown in FIG. scrape off by. By scraping off the corner 1, the core corner 2a is slightly exposed. Therefore, the thin side clothing material abt-core material 2 causes swelling in the product. The treatment of the present invention after agglomeration, such as core material 2

[Since it can be heated in a state where it is completely surrounded by the dressing material 6, it is effective in preventing poor adhesion at the bonding interface (between the core material and the thick side dressing material). Finally, the above-mentioned corner treatment-G=<ll1f: The completed slab in the state shown in the 1mm diagram is subjected to hot circle rolling to obtain a two-layer clad steel plate. Examples according to the present invention are shown below. 6 Example 1 Application: V-chair for kitchen knife 4.6amtx90Gssv
XJI000mJ core material component 1%) Olo, 85%
5i10.8"Mn10.45%p/Q, 0gG%8
10.005% Clothing material weight (9G) Olo, 04% 8110.0
10% Mn10.08011P10.0111 Regret S1
0.004% Core material thickness ratio aS%c to black plate thickness ratio) Mold inner surface average width 704■ Core material thickness 1QQsa Core material to mold inner surface 1m (Tb) 81mm Example 8 Application, size For sickles 2.8awmtx8 !10s1
11Ivx8000■! Core material component (regret) C/1.
00%8170.18%In10.861P10.01
9≦S10.014%Mi, 10. st%0r10.8
0% Clothing ingredients (1) Olo, 04% f9110.0
10% Mn10.62%F10.008%870.0
08% Core material thickness ratio 10% (relative to product plate thickness) Mold inner surface average width 704■ Core material thickness 7- Core material to casting hole inner surface distance (Tb) 40 ■Example 8 Application, size For sickles 1.51111t× TeQQsw
ayxQ core material component C%) Olo, 50% 8110.1
7% Mn10.75%P10. OHm 810.00
6≦ Clothing ingredients (%) Olo, 05%8110.009
%Mn10.0δ1 attack P10.010% 810.00
6% Core material thickness ratio sri% (relative to product sheet thickness) Mold inner surface average width 704- Core material thickness] 80 ■ Core material to mold inner surface distance 60 ■ The 8-layer clad steel sheet obtained in each of the above examples was Compared to products manufactured by the method, as shown in Figure 1, this product has excellent adhesion because it has a smaller surface area for inclusions at the interface, and is also superior to conventional products in terms of heat treatment characteristics and mechanical properties. It was completely comparable.

[Brief explanation of drawings]

11th i! (A) of I, (Dakamo is a cross-sectional view clarifying the ingot making technology for clad steel ingots based on the conventional method, and (A) of Fig. 2)
b), (- is based on the method of the present invention (Cross section clarifying the ingot making technology of clad steel ingots - Figure 11M5 is a perspective view of the steel ingot with the corners treated with solvent, Figure 4 is the slab of the present invention) FIG. 1 is a diagram showing a comparison of adhesion between the conventional method and the method of the present invention. 1...Casting tube 2...Core material!a...Core material angle N 8... Hanging sound... Tobiyuguchi b.
... is (Rearing 6... Plate material 6a... Thick side coating material 6b... Thin side coating material 1... Corner part.

Claims (1)

[Scope of Claims] L Clad steel that corresponds to a product in which a core material made of high carbon or the like is cast with a coating material made of low carbon steel, and the thickness ratio of the core material to the product plate thickness is 50% or less. In the method of obtaining a two-layer clad steel plate by forming a lump and rolling the same, the above-mentioned core material is coated with a layering agent, and then the core material is rolled. The coating material surrounding L is placed in a mold so that the thickness is thinner on the side where the foil is applied, and the steel is cast into uneven thickness to form a steel ingot, which is then bloomed and rolled into a slab. A bale with each corner of 4Ni formed by the thin side coating material shaved off,
A method for producing a two-layer steel plate, characterized in that the thin-walled coating material is hot-rolled after being peeled from the core material.