KR20020038998A - Method and apparatus for measuring the thickness of scale in hot rolling process - Google Patents

Abstract

PURPOSE: A device and a method for measuring the thickness of an oxidation film in hot rolling are provided to clarify generation conditions of surface defects by correctly measuring the oxidation film during a process of hot finish rolling, so that effects of a cooling system and an oxidation film removing device are correctly evaluated and the quality of hot rolling products are improved. CONSTITUTION: An oxidation film(D) grown on a surface of a rolled material(S) is removed by spraying high-pressure water from a header(32) of a scale removing device(31). However, the oxidation film is grown again after being removed. A progress of the rolled material is suspended at a position to measure the thickness of the oxidation film, at the same time, a fusion glass(G) is loaded to prevent the growth of the oxidation film on the surface of the rolled material. In a fusion glass loading device(41), the fusion glass is heated by a heater and immersed in a U-shaped instrument. If a pressure gas is applied, the fusion glass is loaded on the rolled material from a loading hole with a pressure of a fusion glass gas.

Description

METHOD AND APPARATUS FOR MEASURING THE THICKNESS OF SCALE IN HOT ROLLING PROCESS}

The present invention relates to a method and apparatus for measuring the thickness of the oxide film on the surface of a rolled material (hot steel sheet) in the steel sheet manufacturing process, such as filament rolling line, continuous casting line of the hot rolling equipment, more specifically, Improved hot spots by accurately measuring the thickness of the oxide film by preventing growth, thereby clarifying the conditions of occurrence of product surface defects of the hot rolled steel sheet, and accurately evaluating the performance effect of the oxide film removing device installed at the entrance of the finishing mill. The present invention relates to an oxide film thickness measuring method and apparatus in rolling.

6 is a view showing an example of a hot rolling apparatus according to the prior art, in which a plurality of finishing mills 11 to 17 are arranged along the direction of rolling, and each of the finishing mills 11 to ( 17, the finishing rolling mill group 10 which has the work rolls 21-27 of up-down symmetry, respectively is comprised. Then, the rolling material S is rolled from the entrance side in the advancing direction (from the left side to the right side in the figure) between the filament rolling group 10 and proceeds.

At the front end of the first rolling mill 11, an oxide film removing device 31 for removing the surface oxide film of the roughly rolled rolling material S is disposed, and the header 32 of the oxide film removing device 31 is disposed. The high pressure water is injected from the surface oxide film (Scale) of the rolled material (S) is removed.

In addition, although not shown in FIG. 6, in some hot rolling mills, a cooling device (not shown) or an oxide film for suppressing the growth of an oxide film during hot rolling is placed on the inlet side of the finishing mills 12 to 17. FIG. An apparatus for removing an oxide film (not shown) and the like is disposed to provide a means for reducing the thickness of the oxide film on the surface of the steel sheet which affects product quality.

On the other hand, in the hot rolling as described above, although the thickness of the oxide film grown during the rolling process is an important factor that is closely related to the product quality of the hot rolled steel sheet, it is difficult to measure the oxide film between the finishing mills during rolling. After winding up to the winding device (not shown) of a process, ie, the thickness of the oxide film after completion | finish of rolling has been performed. For this reason, during the rolling process, the thickness of the oxide film could not be measured. Accordingly, the condition of occurrence of surface defects due to the thickness of the oxide film was unclear. Accordingly, the cooling device or the oxide film removing device that suppressed the growth of the oxide film was quantitative. There was such a problem that phosphorus evaluation was impossible.

The present invention has been made to solve the above-mentioned conventional problems, and its object is to clarify the occurrence conditions of surface defects by accurately measuring the oxide film during the hot finishing rolling process, thereby evaluating the effect of the cooling device and the oxide film removing device. It is to provide a method and apparatus for measuring the thickness of the anodized film in hot rolling to precisely improve the quality of the hot rolled product accordingly.

1 is a configuration diagram showing an example in which the molten glass dropping apparatus of the present invention is arranged on the inlet side of a first sand mill;

FIG. 2 is a partially enlarged view showing the vicinity of the molten glass dropping apparatus in the finishing rolling apparatus shown in FIG. 1; FIG.

Figure 3 a), b), c) is a detailed view showing an example of the configuration of the molten glass dropping apparatus according to the present invention;

4 is a configuration diagram showing an example in which a molten glass dropping device is placed on the mouth side of a first rolling mill according to a second embodiment of the present invention;

FIG. 5 is a configuration diagram showing an example in which a molten glass dropping device is placed on the mouth side of a first sand mill according to a third embodiment of the present invention; FIG.

6 is a block diagram showing a general hot-phase rolling apparatus according to the prior art.

Explanation of symbols on the main parts of the drawings

11-17 ..... finishing mill 21-27 ..... work roll

31 ..... descaler 32 ..... header

41 ..... loading device 42 ..... container

43 ..... dripping 44 ..... molten glass

45 ..... Pressurized gas 46 ..... Heater

47,52 ..... Cylindrical container 48 ..... Opening and closing door

54 ..... Chiller

According to a first embodiment of the present invention to achieve the above object,

A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entrance side of the rolling mill to the exit side. The molten glass is added dropwise to the upper surface of the rolled material, prevented the growth of the oxide film of the rolled material by the dropped molten glass, and measuring the thickness of the oxide film from the end face of the rolled material at the position By providing an oxide film thickness measurement method in hot rolling.

And the present invention,

In a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entry side to the exiting direction to the rolling mill group, melting to drop molten glass onto the surface of the rolled material in an upward direction of the rolling material conveying path. Equipped with a glass dropping device, stopping the rolling mill and dropping the molten glass on the upper surface of the rolled material by the molten glass dropping device, prevent the growth of the oxide film of the rolled material by the dropped molten glass at the position The thickness of the oxide film is measured from the end surface of the rolled material of the present invention.

Further, according to the second embodiment of the present invention,

A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entrance side of the rolling mill to the exiting direction. The molten glass dropping apparatus which has a molten glass dropping apparatus which drips molten glass, The molten glass is dripped on the upper surface of the rolling material by a molten glass dropping apparatus during conveying a rolled material, The oxide film of the part which molten glass dripped after the said rolled material was wound up to coil shape. The thickness of the oxide film is measured, and the thickness of the oxide film at the position where the molten glass is dropped from the measured oxide film thickness is obtained.

And, according to the third embodiment of the present invention,

A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entry side to the exit side of the rolling mill group. A molten glass dropping device is provided on the upstream side and the downstream side of the film removing device, and the molten glass is dropped on the upper surface of the rolling material by the molten glass dropping device, and the oxide film thickness of the portion where the molten glass is dropped is measured and cooled. By providing a method for measuring the thickness of the oxide film in hot rolling, characterized in that the effect of the device or the oxide film removing device can be measured.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

First, Embodiment 1 of the present invention will be described in more detail with reference to Figs. The same members as those in FIG. 6 described in the prior art are denoted by the same reference numerals, and redundant description thereof will be omitted.

In this Example 1, a molten glass dropping device 41 is disposed on the inlet side of the first finishing mill 11 to drop molten glass on the surface of the rolled material S, and growth of the oxide film in the molten glass portion dropped is performed. It is configured to prevent the oxide film thickness at that time.

In FIG. 1, the rolling material S is conveyed while rolling between each rolling mill of the 1st seventh rolling mill 11-7th rolling mill 17 from the entrance side to the exit side.

And the molten glass dripping apparatus 41 is arrange | positioned at the entrance side of the 1st spiral rolling mill 11, and it is made possible to drop molten glass from the upper surface of the rolling material S to the upper surface of the rolling material S. FIG.

In FIG. 2, the oxide film D, which has grown on the surface of the rolled material S, is removed by spraying high pressure water from the header 32 of the descaling device 31, but after the removal, the oxide film D is oxidized again. The film D grows. In the present invention, the progress of the rolling material S is stopped at the position where the thickness of the oxide film is to be measured, and the molten glass G is dropped to prevent the growth of the oxide film on the surface of the rolling material S. .

An example of the configuration of the molten glass dropping device 41 is the same as that shown in FIG. 3. In FIG. 3A, the molten glass 44 is heated and contained in the U-shaped container 42 by the heater 46. . When the pressurized gas 45 is blown, the molten glass 44 can be dropped onto the rolling material S from the dropping port 43 by the pressing pressure of the molten glass gas.

In addition, in FIG. 3B, the molten glass 44 is heated and contained in the cylindrical container 47 by the heater 46. As shown in FIG. Thus, the molten glass 44 can be dropped in the downward direction by opening and closing the shutter of the lower opening and closing port 48.

In addition, in Fig. 3C, the finely divided glass is contained in the cylindrical container 49, and the finely divided glass 51 is dropped down by opening and closing the opening and closing plate of the lower opening / closing opening 50 to be melted by the heat of the rolling material S. It is supposed to be.

The container shape of the molten glass dropping device 41 is not limited to FIGS. 3 (a) to 3 (c), and other containers may be used as long as molten glass or finely divided glass can be dropped.

As described above, the molten glass dropping device 41 is disposed at a position where the thickness of the oxide film is to be measured so that the molten glass is dropped (or dropped) downward from the molten glass dropping device 41 to prevent the growth of the oxide film. Consists of.

Example 1 of the present invention configured as described above is to measure the oxide film thickness by the molten glass dropping device 41, which is the molten glass when the rough-rolled rolled material (S) is conveyed from the left side to the right side of the figure Although the molten glass is dripped from the dripping apparatus 41 to the surface of the rolling material S, the timing of this dripping takes place simultaneously with the conveyance stop of the rolling material S, and the dropping glass G is added to the specific part of the oxide film D. Covered.

In this case, the oxide film D in the portion covered by the dropping glass G is blocked from contact with air, so that the oxide film does not grow. Since the rolling mill group 10 is urgently stopped in this state, as shown in FIG. 2, the oxide film thickness d1 can be measured correctly from the cross section of the rolling material S. As shown in FIG.

Moreover, the effect of the scale removal apparatus 31 can be quantitatively evaluated by arrange | positioning the molten glass dripping apparatus 41 immediately after the scale removal apparatus 31, and measuring the thickness of an oxide film by the above-mentioned method.

In addition, in Example 1 mentioned above, the case where the molten glass dripping apparatus 41 was installed in the inlet side of the 1st rolling mill 11 and the thickness d1 of an oxide film was measured was described, but other finishing rolling process The molten glass dropping device 41 may be provided at any position of and the oxide film thickness at that position can be accurately measured.

Hereinafter, a second embodiment of the present invention will be described in more detail.

4 is a configuration diagram for explaining a method for measuring an oxide film thickness according to Example 2 of the present invention.

In the second embodiment of the present invention, the same members as in the first embodiment are denoted by the same reference numerals, and redundant description thereof will be omitted.

In Example 1, the rolling material in the rolling process was stopped and the molten glass was dropped to measure the thickness of the oxide film at the time. In the second embodiment, the molten glass was dropped to transport the rolled material, and the rolled material was wound up. By measuring the thickness of the oxide film later, the thickness of the oxide film at the position where the molten glass was dropped is obtained. The rest of the configuration is the same as in Example 1.

In FIG. 4, molten glass is dripped from the molten glass dripping apparatus 41 on the upper surface of the rolling material S being conveyed to the inlet side of the finishing mill 11, and the said rolling material S is in the state with a finishing mill ( 11) It is rolled and conveyed to the coil 17, and wound up in coil shape. Then, the oxide film thickness d and plate | board thickness t of the part by which molten glass was dripped and rolled were measured, and the oxide film thickness in the position where molten glass was dripped is calculated | required based on the measured value.

The structure other than the above is substantially the same as that of Example 1, and description is abbreviate | omitted.

In measuring the oxide film thickness by the molten glass dropping device 41 configured as described above, as shown in Fig. 4, the rolled material S being conveyed from the molten glass dropping device 41 provided at the inlet side of the finishing mill. The molten glass is dripped on the upper surface, the dripping glass G is covered by the specific part of the oxide film D, it rolls through the rolling mills 11-17 in that state, and is wound up to coil shape.

After the rolled material S is wound into a coil, molten glass is dropped to measure the thickness t of the rolled portion and the thickness d of the oxide film D. On the other hand, at the entrance side of each finishing mill 11-17, plate thickness t1-t7 can be calculated | required from the reduction ratio of each finishing mill based on the measured plate thickness t.

Thus, oxide film thicknesses (d1) to (d7) can be obtained as follows.

d1 = dx (t1 / t), d2 = dx (t2 / t), d3 = dx (t3 / t) ... It can obtain | require by the same method below.

In this manner, the oxide film thickness d1 at the position where the molten glass is dropped and the oxide film thicknesses d2 to d7 in each finishing rolling period can be obtained.

In addition, in Example 2, the case where the molten glass dripping apparatus 41 was arrange | positioned at the entrance side of the finishing mill 11 and the oxide film thickness d1 at the position was measured was demonstrated, but other finishing rolling process The molten glass dropping device 41 may be provided at any position of and the thickness of the oxide film at that position can be obtained by the above-described method.

As described above, according to the present invention, the molten glass is dropped on the upper surface of the rolled material S being conveyed and wound up into a coil to determine the thickness of the oxide film of the corresponding portion. Can be measured.

Otherwise, the same effects and effects as in Example 1 can be obtained.

Hereinafter, a third embodiment of the present invention will be described in more detail.

5 is an explanatory view of an oxide film thickness measuring method according to Example 3. FIG.

In the third embodiment of the present invention, the same members as those of the first embodiment or the second embodiment are denoted by the same reference numerals, and redundant description thereof will be omitted.

In Example 3, in order to evaluate the effect of the cooling device installed during the rolling period, a molten glass dropping device 52 is disposed before and after the cooling device, and molten glass is dropped on the upper surface of the rolling material S from the copper device. The thickness of the oxide film is measured in the same manner as in Example 1 or Example 2, and the rest of the configuration is the same as in Example 1 or 2.

In FIG. 5, between the finishing mill 11 and the finishing mill 12, the cooling apparatus 54 of the rolling material S is arrange | positioned facing up and down. The molten glass dropping device 52 and the molten glass dropping device 53 are provided in the upper side P1 of the cooling device 54, and the downstream side P2, respectively, and the molten glass is dripped on the upper surface of the rolling material S.

The configuration other than the above is almost the same as that of the first embodiment or the second embodiment, and description thereof is omitted.

As described above, molten glass is dropped on the upper surface of the rolled material S from the molten glass dropping devices 52 and 53 disposed on the upstream side P1 and the downstream side P2 of the cooling device 54, so that the oxide film (D) Dropping glass (G) is covered in specific areas to prevent the growth of oxide film.

Then, as in Example 1 or Example 2, the thickness of the oxide film was measured, and as shown in FIG. 5, the cooling device 54 was determined from the difference between the oxide film thickness dP1 on the upstream side P1 and the oxide film thickness dP2 on the downstream side. The cooling effect can be assessed quantitatively. In addition, in Example 3, although the cooling apparatus 54 was arrange | positioned between the finishing mills 11-12, the case where the oxide film thickness was measured in the upstream and downstream sides was demonstrated, By installing a cooling device or an oxide film removing device at an arbitrary position and measuring the oxide film at that location, the effect of installing a cooling device or an oxide film removing device can be evaluated.

In other respects, the same effects and effects as in Example 1 or 2 are obtained.

According to the first embodiment of the present invention as described above, the thickness of the oxide film can be accurately measured by dropping the molten glass on the rolling material S by the molten glass dropping device 41 to prevent the growth of the oxide film. have. In addition, since the thickness of the oxide film can be accurately measured, it is possible to clarify the conditions of occurrence of product surface defects of the hot-rolled steel sheet. And, it is possible to accurately evaluate the performance effect of the oxide film removing device installed at the entrance of the finishing mill.

In addition, according to the second embodiment of the present invention, in addition to the effect of the first embodiment, the molten glass is dropped on the upper surface of the rolled material S during conveying and wound up in a coil shape, and then the thickness of the oxide film of the corresponding portion. Since it is possible to measure the thickness of the oxide film without stopping the rolling process.

In addition, according to the third embodiment of the present invention, a cooling device or an oxide film removing device is installed at an arbitrary position of the finishing rolling process and the oxide film is measured at that position. The effect of the case can be evaluated accurately and quantitatively.

Claims (5)

A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entrance side of the rolling mill to the exit side. The molten glass is added dropwise to the upper surface of the rolled material, prevented the growth of the oxide film of the rolled material by the dropped molten glass, and measuring the thickness of the oxide film from the end face of the rolled material at the position Method of measuring thickness of oxide film in hot rolling. In a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entry side to the exiting direction to the rolling mill group, melting to drop molten glass onto the surface of the rolled material in an upward direction of the rolling material conveying path. Equipped with a glass dropping device, stopping the rolling mill and dropping the molten glass on the upper surface of the rolled material by the molten glass dropping device, prevent the growth of the oxide film of the rolled material by the dropped molten glass at the position An oxide film thickness measuring apparatus in hot rolling, characterized in that the thickness of the oxide film is measured from the end face of the rolled material. The molten glass dropping apparatus of claim 2, wherein the molten glass is loaded into a U-shaped container by heating with a heater, and blows the pressurized gas to one side of the container, thereby dropping the molten glass at a pressing pressure of the molten glass gas. An oxide film thickness measuring apparatus in hot rolling, characterized in that it is configured to be loaded onto a rolled material. A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entrance side of the rolling mill to the exiting direction. The molten glass dropping apparatus which has a molten glass dropping apparatus which drips molten glass, The molten glass is dripped on the upper surface of the rolling material by a molten glass dropping apparatus during conveying a rolled material, The oxide film of the part which molten glass dripped after the said rolled material was wound up to coil shape. And measuring the thickness, and calculating the thickness of the oxide film at the position where the molten glass is dropped from the measured oxide film thickness. A method of measuring the thickness of the oxide film of the rolled material in a hot rolling facility in which a plurality of filament rolling mills are arranged in parallel, and the rolled material is hot rolled while being conveyed from the entry side to the exit side of the rolling mill group. A molten glass dropping device is provided on the upstream side and the downstream side of the film removing device, and the molten glass is dropped on the upper surface of the rolling material by the molten glass dropping device, and the oxide film thickness of the portion where the molten glass is dropped is measured and cooled. An oxide film thickness measuring method in hot rolling, characterized in that the effect of the device or the oxide film removing device can be measured.