JPH01273603A - Cutting method for steel billet - Google Patents

Abstract

PURPOSE:To reduce the formation of a saw cut burr by cutting by a hot saw after forming a groove on the surface of the cutting final part running along the cut line of a cast billet. CONSTITUTION:A groove 3 is provided on a billet 1 by actuating a driving device 7 after fixing the billet 1 subjected to blooming and making a notcher 6a collided with a cast billet 1. The notcher 6a is then retreated by actuating the driving device 7, a hot saw 2 is advanced and cutting is started from the opposite side of the groove. When the hot saw 2 reaches the cutting final part 5 where the groove is provided in advance with the progress of cutting, the billet 1 is cut off and the cutting is completed. In this case, the billet 1 for rolling having no defect on the cut sectional face is obtd. without forming any saw cut burr on the cutting final part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of cutting a slab of steel such as a bloomed billet using a hot saw.

[Prior Art] A billet or other steel billet hot-rolled in a blooming process is sequentially cut into lengths that match product dimensions. The steel pieces such as billets, which are the rolled material, are cut by a method such as saw cutting, gas cutting, or shearing. Among these, saw cutting is performed by the method shown in FIG. FIG. 9 is an explanatory diagram of a conventional saw cutting method, and is a diagram showing a state after cutting a billet, which is a steel billet. In this figure, it is formed by blooming and has a surface temperature of 700 to 900.
℃ billet 1 is fixed by a device not shown and then cut by a hot saw 2 equipped with a forward and backward movement mechanism.

[Problems to be Solved by the Invention] However, in conventional saw cutting, there is a problem in that saw burrs, which are defects in the cut section, are generated.

FIG. 10 is a diagram showing the state of generation of saw burrs. 1st
In Figure 0, the saw burr 10 is generated only at a specific location in one direction of the cross section of the billet 1.

Once cut, the billet is sent to a rolling process, but if there is a saw burr on the billet, this will have an adverse effect on the rolling process and also pose a safety problem during transportation and other handling. For this reason, the saw burrs are removed using a grinder or the like, but this removal work requires a lot of effort.

This sawing burr is caused by: (1) If the teeth of the hot saw become poorly sharp, the final part of the cut will not be cut, and the thinner uncut part will be pushed and bent.

(2) The billet to be cut is still hot, and a portion of the final cut portion is softened by the rH friction between the hot saw and the billet during cutting, and this softened steel is pressed and bent by the hot saw.

It is generated due to causes such as.

The present invention aims to solve the above-mentioned problems and provide a method for cutting steel pieces in which sawing burrs are not generated.6 "Means for Solving the Problems" A method of cutting a bloomed and rolled steel billet with a hot saw according to the present invention, wherein a groove is formed on the surface of the final cut portion along the cutting line of the steel billet during cutting, and the steel billet is cut with the hot saw. Features.

[Operation] This will be explained with reference to the drawings. FIGS. 2 and 3 are diagrams showing the positions of grooves formed in a billet, which is a steel piece. FIG. 2 is a front view of the vicinity of the cut portion of the billet, and the groove 3 is formed along the cutting line 4 on one or two sides of the billet 1. FIG. 3 is a side view, and the groove 3 is
It is formed at the final part reached by the hot saw along the cutting line of the billet, that is, the cut@final part 5.

If cutting is performed after forming the groove 3 in the final cut portion 5, the final cut portion 5 will be in the same state as if it had been cut in advance, and no sawing burrs will be generated.

The width of the groove should be the same as the thickness of the hot saw, or slightly wider. The width of the groove needs to be equal to or greater than the thickness of the hot saw; however, if it is too wide, the effect will not be achieved.

Also, the depth of the groove varies depending on the thickness of the hot saw, but 1
~5 openings is sufficient.

[Example] Hereinafter, embodiments of the present invention will be explained.9 Fig. 1 is a diagram showing an example of the steel billet cutting method according to the present invention, and is a diagram schematically showing a side view of a steel billet cutting state. be. In FIG. 1, 1 is a square billet which is a steel piece manufactured by blooming, 2 is a hot saw, 6a is a notch, and 7 is a driving device. The hot saw 2 is rotated by a motor and has a mechanism for advancing toward the billet 1 and retreating. The notch 6a is provided to form a groove on the surface of the billet 1 by colliding with the billet 1, and the notch 6a is disposed facing the corner of the billet 1, and the hydraulic cylinder,
It is reciprocated by a drive device such as an air cylinder. Moreover, the shape of the notch container 6a, which is also equipped with a device (not shown) for fixing the billet 1 during cutting, is such that the side surface is located between the two sides of the billet 1.
It is L-shaped so that it touches the sides. 4 and 5 are diagrams in which the notch shows the shape of the vessel, FIG. 4 is a front view, and FIG. 5 is a sectional view taken along the line A-A in FIG. 4. As shown in FIGS. 4 and 5, a protrusion 8a that is continuous in a direction perpendicular to the longitudinal direction of the billet 1 is provided on the surface facing the billet 1. Figure 5 is an enlarged sectional view of the area around the protrusion, Figures 4 and 5 are diagrams showing the shape of the vessel, Figure 4 is a front view, and Figure 5 is A-A in Figure 4. FIG. As shown in FIGS. 4 and 5, a protrusion 8a that is continuous in a direction perpendicular to the longitudinal direction of the billet 1 is provided on the surface facing the billet 1. FIG. 5 is an enlarged sectional view of the vicinity of the protrusion 1, and is an explanatory diagram of the size of the protrusion. The width β of the protrusion 8a is equal to or slightly wider than the thickness of the hot saw. In addition, the protrusion 8
The height h of a is about 1 to 5 degrees.

Further, the notch 6a is accurately installed so that the protrusion 8a is located at the cutting line of the billet.

When cutting a billet with such equipment, after fixing the billet 1 which has been bloomed and rolled, the drive bag W7 is activated, and the cutter 6a collides with the steel piece 1 to form a groove in the billet 1. Next, actuate the drive device 7 to open the notch 6a.
, move the hot saw 2 forward, and start cutting from the opposite side of the groove.

As the cutting progresses, when the hot saw 2 reaches the final section of the cut, which has been set in advance, the billet 1 is separated and the cutting is completed. At this time, no sawing burrs are generated at the final cut portion, and a rolling billet with no defects in the cut cross section is obtained.

FIG. 6 is a sectional view showing another embodiment of the shape of the protrusion. In FIG. 6, the protrusion 8b shown in FIG.fa1 has a rectangular cross section, and the protrusion 8C shown in FIG. 6(b) has a mountain-shaped cross section. The protrusion 8d in the figure (C) has a recessed portion in the center so that two grooves can be formed in the steel piece. The shape of such protrusions is appropriately selected depending on the size of the steel piece, the thickness of the hot saw, etc.

FIG. 7 is a diagram showing a method of forming a groove on only one side of a steel piece. In this method, a notch 6b is provided at a position facing one side of the fillet 1, which is a steel piece, and is employed when cutting relatively small size sliding pieces.

FIG. 8 is a diagram showing a method of forming grooves in a round piece of steel. In this method, a cutout having a protrusion having the same curvature as the round billet 1-9 is provided with a cutter 6c.

[Effects of the Invention] The method of cutting a steel billet according to the present invention is a method in which a groove is formed on the surface of the final cut portion along the cutting line of the steel billet, and then the cut is performed using a hot saw. The state is the same as if it had been cut, and the generation of saw burrs is significantly reduced. Therefore, the work required to remove saw burrs is greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the steel billet cutting method according to the present invention, FIGS. 2 and 3 are diagrams showing the positions of the holes formed in the steel billet, and FIGS. 4 and 5 are diagrams showing the notches. Figure 6 is a cross-sectional view showing another example of the shape of the protrusion, Figure 7 (3 is a diagram showing a method of forming grooves only on one side of the steel piece, Figure 8 is a diagram showing the shape of the vessel), The figure shows a method for forming a round steel piece with a clear shape, Figure 9 is an explanatory diagram of the conventional saw cutting method, and Figure 10
The figure shows the state in which sawing burrs are generated. 1... Square billet, 2... Hot saw, 3... Groove, 4...
... Cutting line, 5... Cutting final part, 6a, 6b, 6c.
...Notches are vessels, 8a, 8b, 8c, 8d - protrusions, 9...round billet, 10...sawn burrs.

Claims (1)

[Claims] A method of cutting a bloomed and rolled steel billet with a hot saw, characterized in that, during cutting, a groove is formed on the surface of the final cut portion of the steel billet along the cutting line, and the steel billet is cut with the hot saw. How to cut a piece of steel.