JPH0117809B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a blade for a push-cutting device that advances a pair of V-shaped blades from a direction perpendicular to both surfaces of a metal material to cut the metal material. [Prior art] When cutting various metal materials such as cast steel slabs obtained by continuous casting and aluminum molded materials by shearing, a pair of rectangular blades with their tips offset above and below the material to be cut are sheared. Conventionally, cutting devices have been commonly used that cut the material by moving the material in a direction perpendicular to the material to be cut. however,
In such a cutting device, a cutting burr that recoils toward the cut surface side is often generated at the cut ends of both cut materials separated by cutting, so when this is rolled in a rolling machine, the surface longitudinal direction of the rolled product is There was a drawback that sludge defects were formed in the direction, and these sludge defects lowered the yield of the product. Therefore, we created a V-shaped blade to replace the conventional rectangular blade.
A push-cutting device has been proposed and used, which advances the blade from both sides of the material to push it into the material to cut the material. According to this type of cutting device, the material to be cut is torn off and cut by the horizontal component force due to the wedge action of the V-shaped blade at the final stage of cutting, so that the cut end is formed into a tapered shape and the cutting edge is tapered. Since burrs are generated in the center of the thickness of the plate, even if the plate is rolled using a rolling mill, the product is less likely to have flaws due to cutting burrs, and the yield of the product can be improved. However, even with the conventional V-shaped cutter used in this type of cutting device, continuous casting slabs are used to cool the inside and outside of the cutter in order to maintain heat resistance and prevent cracks on the cutter surface and internal cracks. There are many problems when cutting under severe thermal conditions, so heat-resistant steel has traditionally been used as the material for cutlery, or cutlery with a core made of this material built up on the surface. However, I was not able to expect satisfactory results. In other words, Fig. 1a is a photographic reproduction of the front of the built-up part of a conventional V-shaped blade built up with nickel alloy steel, Fig. 1b is a photo of the cut surface, and Fig. 1c is a photocopy of Fig. 1b. This is a micrograph magnified 100 times. In Fig. 1a, hair cracks 1 are observed on the surface of the knife within a range of 15 mm from the tip of the knife. Furthermore, in FIGS. 1b and 1c, microscopic cracks are observed on the surface. These hair cracks 1 are heat cracks that occur due to thermal cycles and stress loads due to heating and cooling of the cutter during cutting of a continuously cast slab as the material to be cut, and these cracks gradually progress to breakage of the cutter. Not only is this possible, but there is also the drawback that cutting under high heat can cause the tip of the blade to melt. [Summary of the Invention] The present invention has been developed in view of the above points, and it solves the problem of cracks by welding and overlaying a special austenitic nickel alloy containing 19 to 21% Ni on the V-shaped surface of the tip. The present invention provides a cutter for a push cutting device which is designed to reduce the amount of damage and improve durability. Embodiments of the present invention will be described in detail below with reference to the drawings. [Example] Figures 2 to 4 a, b, and c show examples of the blade for a push-cutting device according to the present invention, and Figure 2 shows a side surface near the tip of the blade of a push-cutting device in which this is implemented. Figure 3 is a perspective view of the cutlery, Figure 4 a, b, c
are photographic reproductions corresponding to FIGS. 1a, b, and c, respectively. In the figure, a continuously cast slab 11 as a material to be cut has a temperature of, for example, 700 DEG to 800 DEG C. on the outer surface and 1000 DEG to 1200 DEG C. on the inner surface. An upper blade 12 and a lower blade 13 are respectively disposed above and below the slab 11, and the tips of the upper blade 12 and the lower blade 13 are each shaped like a V-shape. It is formed. Then, when the upper blade 12 and the lower blade 13 are simultaneously advanced in a direction orthogonal to the slab 11 using a hydraulic cylinder (not shown), the blade edge is pushed into the slab 11, and the horizontal direction of the wedge action of the blades 12, 13 at the final stage of this pushing. The slab 11 is cut by tearing by force. Upper blade 12 used in such a push cutting device
and the lower blade 13 are constructed as follows. That is, the base materials 12a and 13a of the blades 12 and 13 are made of, for example, SNCM steel and formed into a V-shape, and the V-shaped surface at the tip is welded with an austenitic special high nickel alloy having the composition shown in the following table. Overlay 1
2b and 13b are applied, respectively.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a cutter for a push cutting device, crack resistance is improved by welding and overlaying a special austenitic nickel alloy containing 19 to 21% Ni on the V-shaped surface at the tip of the cutting edge. , the abrasion resistance is improved and the durability of cutlery is greatly improved, and this effect is particularly noticeable in cutlery that is repeatedly subjected to heating and cooling.

[Brief explanation of drawings]

Figure 1a is a photographic reproduction of the front of the internal buildup of a conventional V-shaped blade built up with nickel alloy steel, Figure 1b is a photograph of the same cut surface, and Figure 1c is 100 times larger than Figure 1b. Micrographs enlarged in Figures 2 to 4a,
b and c show an embodiment of the blade for a push-cutting device according to the present invention, FIG. Figure a is a photographic reproduction of the front of the overlay of the blade, Figure 4b is a photograph of the cut surface of the overlay of the blade, and Figure 4c is a micrograph of Figure 4b magnified 100 times. 11...Slab, 12...Upper blade, 13...Lower blade, 12a, 13a...Base material, 12b, 13b...
...meat.

Claims (1)

[Claims] 1. Forming the tip surface of the blade into a V-shape,
Ni 19-21 is applied to the V-shaped surface at the tip of this V-shaped blade.
A cutter for a push-cutting device characterized by being overlaid with a special austenitic nickel alloy containing %.