JPS6021106A - Edger rolling method of plate material - Google Patents

Abstract

PURPOSE:To prevent floating-up of a rolling material during cross rolling and to improve the dimensional accuracy of the width in the stage of rolling the rolling material while adjusting the width thereof with a cross rolling stand by working preliminarily the width in the end edge parts on both lower sides of the rolling material smaller than the upper side end edges. CONSTITUTION:Corner parts C1 are machined off at a thickness (h) and width W at the side edges on both lower sides of a rolling material S such as a steel slab or the like in the stage of cross rolling said material S with a cross rolling stand having a pair of vertical rolls. Or stepped parts C2 are formed at the thickness (h) and the width W or tapered surfaces C3 are preliminarily formed at the width W and an angle theta. In either case the material S is preliminarily worked to have WT>WB between the upper width WT and lower width WB of said material. If such material S is cross-rolled with a pair of vertical rolls, the floating-up on one side of the material S is eliminated and is cross-rolled to the steel plate having excellent dimensional accuracy of the width.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rough rolling process such as thick plate rolling or hot strip rolling, or an edger rolling method in blooming rolling or the like.

For example, in the rough rolling of hot strip rolling mentioned above, the rolled material is rolled to a thickness that can be rolled in the subsequent continuous finishing mill, and width adjustment rolling is performed to obtain a predetermined product. , this Q-width adjustment'' rolling, that is,
In edge rolling, when width adjustment rolling is performed using a vertical scale breaker (VSB) or a pair of cylindrical vertical rolls as an edger, if a rolling edge is provided to the rolled material, the rolling edge in contact with the vertical rolls One side of the material often lifts up, making it impossible to apply sufficient medium pressure, resulting in a decrease in width dimension accuracy, and
A stepped portion is formed on the side end face of the floating rolled material, resulting in a decrease in perpendicularity, which in turn leads to a decrease in yield. In particular, when the above-mentioned phenomenon of multiple uplifts on one side of the rolled material occurs, the uplifts occur in multiple directions alternately on the work side and drive side in each pass during the medium reduction pass, and the rolled material becomes more and more This promotes a decrease in the width dimension accuracy and deterioration of the side end surface shape. These phenomena also appear in the thick plate rolling process or edger rolling in the blooming process.

For this reason, various edger rolling methods have been proposed in the past. For example, a typical edger rolling method uses a tapered roll whose diameter expands upward as a vertical roll. (Japanese Unexamined Patent Application Publication No. 116259/1982)
There are methods that generate a pressing force on the rolled material during rolling to prevent buckling or lifting, but they cannot completely prevent lifting, and there are also The inclination of the vertical rolls in the width direction reduces the perpendicularity of the side end surfaces of the rolled material.

In addition, a method has been proposed in which a presser roll is attached to press the central part of the rolled material, but although it can be assumed to be effective in preventing buckling and lifting, the rolling equipment is complicated and
This makes maintenance difficult, and if the rolled material is warped, the rolled material will collide with the presser roll, not only causing damage to the equipment but also impeding smooth operation.

Furthermore, it has been proposed to use caliber rolls as vertical rolls (Japanese Patent Publication No. 55-7322
(No. Publication), this is originally intended to reduce the rolled material by a large width to reduce biting defects and slippage, and to prevent the lifting phenomenon when the plate thickness becomes thinner than the caliber dimension. It has the drawback that it cannot be prevented, and it must be said that the conventional edge rolling methods are extremely insufficient in solving the buckling phenomenon and the lifting phenomenon, especially the lifting on one side. Regarding the phenomenon,
The current situation is that no concrete solution can be found.

Therefore, the inventors of the present invention conducted various analyzes on the floating phenomenon on one side of the rolled material during edger rolling, and conducted repeated experiments using a plasticine model using an experimental rolling mill. As a result of various analyses, the phenomenon that one side of the rolled material rises during rolling material is caused by (1) non-uniformity of shape at the side edge of the rolled material, 12) inclination of the rolled material in the width direction of the roller table that conveys the rolled material. Horizontal inclination (3) It was found that the inclination of the vertical roll of the edger was the main cause.

Among the above-mentioned factors, the phenomenon of one side of the rolled material lifting up due to factors (2) and (3) can be resolved by improving the rolling equipment.
For problems caused by the shape of the rolled material, it is necessary to fully understand the behavior of the rolled material caused by the shape of the side edges during rolling.

Now, as shown in Figure 1, (1) the rectangularity of the cross-sectional shape of the Al rolled material (slab) is deformed, and the bulge formed by the thickness adjustment rolling (horizontal pass) is unbalanced. In some cases, the corners and parts of (C1 rolled material) are symmetrically deformed (rolled), but when these types of rolled material are edge rolled, the plasticity of the rolled material is reduced by medium rolling. Material flows as a result of deformation, but regardless of the shape of the rolled material, the part A in the figure, which protrudes outward, is larger than the part B, regardless of the shape of the rolled material. ,
The reaction of the material flow applied to the rolled material from the vertical rolls is not thicker on the A part, and the reaction of the material flow on the A and B parts acts as a couple to rotate the rolled material.
Rotation of the rolled material in the direction of the arrow in the figure, in other words, lifting of one side of the rolled material occurs.

The present invention has been made based on the above-mentioned findings, and is characterized by an edger for rolling a rolled material to a required width using a width reduction stand having a pair of vertical rolls.
In rolling, the rolled material to be width-adjusted rolled by the vertical rolls is processed in advance so that the width of both lower side edges thereof is smaller than that of the upper side edges, and then rolled. It exists in

That is, 1. The present invention is based on the above-mentioned material flow phenomenon in edger rolling, and the cross-sectional shape of the rolled material is adjusted before applying smooth rolling so as to actively give the flow amount of the material on the upper and lower surfaces of the rolled material. The basic idea is to perform pre-processing to prevent warping, and to explain it in more detail below as shown in the diagram, the cause of the lifting phenomenon on one side of the rolled material is greatly influenced by the flow of the material, and this The material flow depends on the shape of the side edges of the rolled material, and the force generated as a reaction to this material flow is used as a restraining force against lifting of the rolled material. From this point of view, the shape of the side edges of the rolled material is changed, as shown in FIG. 2 for an example, to actively cause a change in material flow between the upper and lower sides of the rolled material. That is, as shown in FIG. 2(a), the lower side edges of the rolled material S are thickened, and the corner portions are removed at the width W, or as shown in +1), the thickness is increased. , a step C2 with a width W is formed, or a tapered surface Cs with an appropriate width W and an angle θ is formed as shown in (C), so that the lower side of the so-called rolled material S is formed. Chamfer parts C are formed on both side edges, and the rolled material is vertically shaped so that the upper width dimension WT and lower width dimension WB of the rolled material satisfy the relationship W T > W E in any case. Prior to applying the applied pressure reduction using rolls, the cross-sectional shape of the rolled material S is preformed. Various methods can be considered for chamfering this rolled material S. For example, in the case of using a gas bath agent, press forming, cutting, or rolling, etc. You just have to choose the method.

Now, to give an example of the case where chamfering is performed by rolling, FIG. A caliber 2 is formed, and the upper side of this caliber 2 is a side wall 3 in a horizontal plane parallel to the pass line that restrains the upper surface of the rolled material S, and the lower side is a side wall 3 in a horizontal plane that is parallel to the pass line that restrains the upper surface of the rolled material S.
In contrast, the chamfer part C is formed with an inclined side wall 4 that forms a shadow, and the chamfer part is formed by rolling down the rolled material S from both sides with this vertical roll 1.
In addition, what is shown in FIG. 3 (bl) is a case in which the chamfer portion C is formed between a pair of upper and lower rolling rolls, and the chamfer portion C is formed between a smooth cylindrical upper roll 5 and a step with inclined surfaces 7 formed on both sides. The chamfered portion C of the rolled material S is formed between a pair of rolls of the attached roll 7.

As shown in FIG. 4, when the rolled material S having the chamfered portion C formed in advance is subjected to pressure reduction using a pair of left and right vertical rolls 10, the upper and lower corner portions of the rolled material S are At this stage, the material flow state changes and the formation of the upper dogbone I becomes larger than the lower dogbone. As a result of the load acting as a force that presses the rolled material S against the transport roller table, floating of the rolled material S can be suppressed and prevented. When the applied pressure reduction by the vertical rolls 10 is followed by the thickness adjustment reduction by the horizontal rolls, a double bulge l is formed at the side edge of the resulting rolled material S' as shown in FIG. Because there is a difference in the amount of dog bores 1 and 1 formed under the application pressure reduction in the previous stage, the upper bulge 2 protrudes greatly outward in the bulge seal.As a result, the rolled material S As a result, the side edges of the rolled material S' are uneven, and even when the rolled material S' is further subjected to the flat reduction shown in FIG. 6, the material flow of the rolled material as shown in FIG. A similar movement occurs, thereby preventing the rolled material S' from floating. The same process will be repeated in the following edger rolling. However, in order to more reliably prevent the rolled material S from lifting up, a chamfer section is actively applied to the lower side edges of the rolled material prior to the application smoothing by the vertical rolls at each stage. By performing the molding process by the means illustrated in FIGS. 3 and 4, it is possible to perform stable pressure adjustment.

As is clear from the above explanation, one edger according to the present invention
According to the rolling method, chamfering is previously applied to the lower side edges of the rolled material to be rolled to adjust the width by vertical rolls. Because of this, it is possible to sufficiently apply the application pressure reduction, improve the width accuracy, and minimize the cut-off portion of the edge after rolling, which has the effect of improving product yield, etc. It makes a great contribution to industry.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the cross-sectional shape of a rolled material, FIG. 2 is a cross-sectional view showing the cross-sectional shape of the rolled material applied to the present invention, FIG. 3 is an explanatory diagram showing an example of forming processing, and FIGS. FIG. 6 is a schematic explanatory diagram showing the deformation process of a rolled material in edger rolling according to the present invention. In the figure, 1.10 is a vertical roll, 2 is a caliber, 4 is an inclined side wall, S is a rolled material, and C is a part of a chamfer. Patent applicant Yoshinobu Kaji, patent attorney representing Kobe Steel, Ltd. l Fig, 2 Fig, 3 (a) 1 Fig, 3 (b) 6':)t

Claims (1)

[Claims] Regarding the edge rolling of a plate material in which a rolled material is rolled to a required width by a width reduction stand having a pair of vertical rolls, the rolled material to be width-adjusted by the vertical rolls is preliminarily rolled. ,
A method for edge rolling a plate material, which comprises processing the lower side edges so that the width thereof is smaller than the upper side edges, and then rolling the plate material.