JP3417301B2 - Temperature measurement method and apparatus for parallel flange rolled section steel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel flange rolling shaped steel such as rolled H-section steel or rolled channel steel manufactured by gradually reducing the thickness and width of each of the web and the flange by rolling in multiple passes. The present invention relates to a temperature measuring method and a temperature measuring device in an intermediate rolling process. Specifically, the present invention is particularly applicable to TMCP (Thermo Mechanical Contr
ol Process) A temperature measurement method for stable and efficient production of parallel-flange rolled steels, such as steel, that can obtain desired mechanical properties by controlling the material temperature during rolling to an appropriate range. And a temperature measuring device.

[0002]

2. Description of the Related Art Various structural steel materials used in the fields of construction and civil engineering include general structural rolled steel material (JIS G 3101) and structural rolled steel material for welding (JIS G 3106) hot rolled H-section steel. Widely used.

Based on these steel types, the parallel flange rolled steels (such as rolled H-shaped steel and rolled grooved steel) satisfying the mechanical properties suitable for their respective applications (in the following description,
For convenience, "rolled H-section steel" is taken as an example. ) Is traditionally
It is manufactured by performing hot rolling using a steel slab manufactured by continuous casting or slabbing as a rolling material.

FIG. 7 is an explanatory view schematically showing this hot rolling step 1. Further, FIG. 8 is an explanatory view showing an example of the cross-sectional shape of the material to be rolled in each step of the hot rolling step 1, and FIG. 8 (a) shows an example of the cross-sectional shape at the end of rough rolling. )
Shows an example of the sectional shape at the time of intermediate rolling, and FIG. 8 (c) shows an example of the sectional shape at the end of finish rolling.

As shown in FIG. 7, a steel piece such as a beam blank, a slab or a bloom is heated to a predetermined temperature by a heating furnace 2 and then is subjected to a rough rolling machine such as a breakdown mill 3 to obtain a steel sheet as shown in FIG. As shown in (1), rough rolling is performed into a rough shaped billet (beam blank) 7.

[0006] Next, this rough-shaped steel piece 7 is generally shown in FIG.
By an intermediate rolling step in which at least one or more rolling mill rows each including a rough universal mill 4 including a pair of upper and lower rolling rolls and a pair of edger mills 5 including a pair of upper and lower rolling rolls are arranged, Intermediate rolling is performed. In this intermediate rolling, multiple passes of reversible rolling are performed by the rough universal mill 4 and the edger mill 5, the web thickness, the flange thickness and the flange width are stretched to predetermined values, and the intermediate rolled material having the cross-sectional shape shown in FIG. 8 (b) is obtained. Eight.

Further, as shown in FIGS. 7 and 8 (c), the intermediate rolled material 8 has a total of 4 pairs of upper and lower pairs and left and right pairs.
Finish rolling is performed by the finishing rolling process in which the finishing universal mill 6 composed of individual rolling rolls is arranged,
The final product 9 is a rolled H-section steel. In this finish rolling, generally, the thickness adjustment (uniformization) of each of the flange and the web is generally performed in one pass, and the angle raising of the flange having an angle of about 5 degrees is performed in the intermediate rolling process. , Web and flange thickness reduction is several%
It is a degree.

Not only the rolled H-section steel shown in FIG. 8 but also the rolled channel steel 10 having the web 10a and the flanges 10b, 10b having the cross-sectional shape shown in FIG. 9 are also shown in FIGS. 7 and 8. It is manufactured by a hot rolling process 1 similar to the above.

By the way, the rolled H-section steel manufactured by hot rolling is generally used as it is without being subjected to tempering treatment such as quenching and tempering. Therefore, the rolled H-section steel is superior in terms of economy to the welded H-section steel, which is assembled by welding three long plates obtained by cutting thick steel plates into a H-shaped cross section and then assembled. Due to the effects of hot working conditions and cooling conditions, it has a disadvantage in terms of composition that requires a higher carbon equivalent than welded H-section steel, and has lower toughness and weldability compared to welded H-section steel. Easy to do.

As a pillar material for high-rise buildings,
A box column welded with a thick steel plate is used, and in order to improve the applicability of the rolled H-section steel for such applications, improvement of the toughness and weldability of the rolled H-section steel is desired.
In particular, when applied to a box column, it is necessary to increase the plate thickness of both the flange and the web.

However, in the conventional rolling method in which finish rolling is finished at a high temperature and then gradually cooled, it is unavoidable that the composition has a high carbon equivalent in order to secure strength. Therefore, rather, both toughness and weldability are deteriorated.

In order to solve such a problem, in recent years, TM
Utilizing CP (Thermo Mechanical Control Process) technology, hot rolling a steel slab containing a specified alloy element in a specified temperature range provides high strength, as well as toughness and weldability. Various methods for producing H-section steel have been disclosed. For example, JP-A-6-240350
In the gazette, a steel slab containing Mn, Al and Nb added is 1200 to 13
A method of terminating hot rolling in a temperature range of Ar ₃ transformation point or higher after heating to 50 ° C. is disclosed.

By the way, in the rolled steel standards for building structures (JIS G 3136) established in 1994, the conventional rolled steel standards for general structures (JIS G 3101) and rolled steel standards for welding (J
Unlike IS G3106), upper limit of yield point (or yield strength) and upper limit of yield ratio (yield point / tensile strength or yield strength / tensile strength) are regulated. Therefore, since the yield point and the yield ratio tend to increase when the rolling finish temperature of the steel material decreases, the temperature of the rolled material in the intermediate rolling process to the finishing rolling process of the H-section steel is set to be equal to or higher than the predetermined lower limit temperature. The need for tight control has increased.

On the other hand, the conventional rolled steel standard for general structure (JIS
G 3101) and the structural rolled steel standards for welding (JIS G 3106), rather, in order to satisfy the lower limit values of the yield point (or proof stress) and the tensile strength, rolling in the intermediate rolling process to the finish rolling process It is also necessary to control the temperature of the material below a predetermined upper limit temperature. As described above, in recent years, the requirement for temperature control of the material to be rolled in the rolling process of rolled H-section steel has become considerably stricter than in the past.

In the rolling process of rolled H-section steel, generally, a radiant energy from a material to be rolled and a wave carrying the same are applied to a thermocouple and a radiation thermometer is used to measure the temperature from a thermoelectromotive force generated. Temperature control is performed.

Specifically, a radiation thermometer is installed and installed on a gantry at one or both of the inlet side and the outlet side of each mill, and the surface temperature of the material to be rolled before and after rolling is measured and recorded. To do. A radiation thermometer measures the local surface temperature of the flange and / or the web, and the average value of these local measurements has been taken as the surface temperature.

[0017]

However, the flange surface temperature in the rolling process of rolled H-section steel is not uniform in the flange width direction. Figure 10 shows rolling H in the rolling process.
FIG. 3 is an explanatory diagram showing an example of distribution of surface temperature on a flange 11b of the shaped steel 11.

As shown in the figure, the surface temperature of the flange 11b decreases toward the both ends of the flange with a peak near the center in the flange width direction, and the temperature difference Δt ₁ between the peak temperature and the tip of the flange is Although it varies depending on the dimensions and material of the rolled H-section steel 11, it is 70 to 150 ° C. Moreover, Delta] t than the upper half and the lower half of the flange 11b _2: 20 to 30 ° C. Also the temperature is high.

Therefore, when the temperature of the rolled H-section steel is controlled, for example, when the maximum temperature in the flange width direction does not exceed a predetermined temperature control upper limit value, or when the minimum temperature in the flange width direction is set to a predetermined value. If the dimensions and materials of the rolled H-section steel are changed when controlling so that the temperature control lower limit value is not exceeded, the radiation thermometer will be installed with the installation height fixed by the pedestal as described above. However, the measurement position for the rolled H-section steel is changed, and the measurement value is different. For this reason, it was not possible to quickly and accurately measure the temperature of the rolled H-section steel in accordance with changes or changes in the dimensions and materials of the rolled H-section steel.

In Japanese Patent Laid-Open No. 5-117754, a plurality of temperature sensors are arranged in the width direction of the shaped steel flange, and a plurality of radiation thermometers are installed as needed, so that the flange width direction can be improved. A method of measuring the surface temperature at a plurality of points has been proposed. A method has also been proposed in which the temperature sensor is scanned at high speed in the flange width direction to measure the surface temperature distribution in the flange width direction. However, according to these, the cost required for the temperature measuring device increases significantly,
It cannot be implemented in reality.

In view of the problems associated with the conventional material temperature measurement for parallel flange rolled steels such as rolled H-shaped steels, the object of the present invention is to provide an existing radiation thermometer without introducing an expensive temperature measuring device. Even if the dimensions and material of the material to be rolled are changed, the rolling temperature can be optimally controlled with only a few changes, the variation in the mechanical properties of the product can be suppressed, and the nonstandard specifications can occur. It is an object of the present invention to provide a temperature measuring method and a temperature measuring device for a parallel-flange rolled shape steel which does not exist.

[0022]

SUMMARY OF THE INVENTION Here, the gist of the present invention is to dispose on the inlet side and / or the outlet side of a coarse universal mill and / or an edger mill that constitute an intermediate rolling process of a parallel flange rolling section steel. The installed height of the radiation thermometer is adjusted based on the material of the rolled material to be conveyed before measuring the temperature of the rolled material using the Is a method for measuring the temperature of a parallel-flange rolled section steel, which is characterized by measuring the surface temperature in a part of the.

From another aspect, the present invention provides a parallel flange.
Coarse universal mill that constitutes the intermediate rolling process of rolled steel
And / or entry and / or exit of the edger mill
Installation of the radiation thermometer using the radiation thermometer placed on the side
Height of the material to be rolled and / or medium
Based on the dimensions of each pass of the hot rolling process,
Adjustment before measuring the degree of
It is a temperature measurement method that measures the surface temperature in some parts.
And the installation height is determined by the following formula using the material and / or the dimension, the parallel flange
This is a method for measuring the temperature of rolled steel. h _n = f _n × g _n × B _n ··· , where h _{n is} the installation height of the radiation thermometer at the n-th pass (ta
Height from the upper surface of the bull to the radiation thermometer ) f _n : correction coefficient based on the material of the rolled material in the nth pass g _n : correction coefficient based on the dimensions of the rolled material in the nth pass B _n : the nth pass The flange width of the rolled material is shown.

The present invention also relates to a parallel flange rolling section steel.
Coarse universal mill and / or composing the intermediate rolling process
Or on the inlet and / or outlet side of the edger mill
Radiation thermometer and lifting device that raises and lowers the radiation thermometer
And the radiation thermometer is based on the material of the material being rolled.
The lifting device is controlled so that the installation height is determined by
And a vertical control device
This is a temperature measuring device for rolled steel.

From another point of view, the present invention relates to a radiation thermometer arranged on the inlet side and / or the outlet side of a rough universal mill and / or an edger mill which constitutes an intermediate rolling process of a parallel flange rolling section steel. , An elevating device for elevating and lowering the radiation thermometer, and the radiation thermometer, so that the installation height determined based on the material of the material to be transported and / or the size of each pass of the intermediate rolling process, and a lifting controller for controlling the lifting device, further installation height
Equipped with a rolling control device that calculates
E is Rukoto temperature measuring device parallel flange rolling shape steel, wherein.

In the above-mentioned temperature measuring device for parallel flange rolled steel according to the present invention, the installation height depends on the material and
/ Or be determined by the above formula using dimensions
Is desirable. Further, from another point of view, the present invention is directed to a parallel frame.
Coarse universa constituting the intermediate rolling process of Lanji rolled steel
Lumill and / or edger mill inlet and / or
Raise or lower the radiation thermometer placed on the output side or the radiation thermometer
Lifting device and radiation thermometer to be transported
Material and / or dimensions for each pass in the intermediate rolling process
Lifting device so that the installation height is determined based on
Equipped with a lifting control device to control the
And / or determined by the above formula using dimensions
Parallel flange rolling section temperature measuring device characterized by
Is.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) Hereinafter, embodiments of a temperature measuring method and a temperature measuring device for a parallel flange rolled steel according to the present invention will be described in detail with reference to the accompanying drawings. In the following description of the embodiments, the case where the parallel flange rolled steel is rolled H-shaped steel is taken as an example. Also,
In the present embodiment, the installation height of the radiation thermometer is changed for the same intermediate rolled material 30 as the rolling pass progresses.

FIG. 1 is an explanatory view schematically showing a hot rolling process 20 in which the temperature measuring device of this embodiment is installed, together with an example of the cross-sectional shape of the material to be rolled in each process. This rolling step 20 is roughly classified into a rough rolling step 22 using a breakdown mill 21 which is a double type rolling mill, an intermediate rolling step 25 including a rough universal mill 23 and an edger mill 24,
It consists of three processes, a finish rolling process 27 consisting of a finish universal mill 26.

First, the breakdown mill 21 in the rough rolling step 22 is composed of a pair of upper and lower horizontal rolls engraved with a plurality of hole dies. The continuous casting slab or continuous casting beam blank (rough shaped billet), which is the raw material, is heated to 1200 to 1300 ° C by the heating furnace 28 and then broken down.
A plurality of passes of reversible rolling (reverse rolling) is performed by 21, and the rough shaped steel slab 29 is shaped and stretched.

Next, the rough shaped steel slab 29 shaped by the breakdown mill 21 is subjected to a multi-pass tandem reverse rolling using the rough universal mill 23 and the edger mill 24 which are installed close to each other so that continuous rolling is possible. The intermediate rolled material 30 having a cross-sectional shape close to a predetermined product thickness and flange width is drawn.

The coarse universal mill 23 is provided with a pair of upper and lower horizontal rolls and a pair of left and right vertical (vertical) rolls, and the web thickness between the upper and lower horizontal rolls and the flange thickness between the vertical rolls and the horizontal rolls and the side face are determined. , Respectively, and draw. On the other hand, the edger mill 24 is composed of a pair of upper and lower horizontal rolls, and lightly presses down the flange so as to have a predetermined width and arranges the flange tip into a rectangular shape.

In the hot rolling step 20 shown in FIG. 1, 1
An intermediate rolling step 25 is constituted by a set of the coarse universal mill 23 and the edger mill 24, but two or more sets may be used. Finally, in the finish rolling step 27, the intermediate rolled material 30 is usually finished by one pass of finish rolling by the finish universal mill 26 to be finished into the final product 31. In this step, the angle of the flange of the intermediate rolled material 30 is raised, and the web and the flange are slightly reduced in thickness to obtain a rolled H-section steel 31 as a final product.

In the hot rolling process, the temperature of the material to be rolled at the time of extracting the heating furnace is usually set by arranging the temperature measuring device at the position A marked with ▲, and the temperature of the material to be rolled when extracting the heating furnace is set by the temperature measuring device at position B. By arranging the temperature of the material to be rolled at the time of rolling by arranging the temperature measuring device at the positions C and D, the surface temperature of the web and the flange of the material to be rolled at the time of intermediate rolling can be obtained by arranging the temperature measuring device at the position E. The surface temperature of the web and flange of the material to be rolled during finish rolling is measured and managed. Especially, in the intermediate rolling step 25, it is necessary to perform multipass rolling of 10% or more in the non-recrystallization temperature region of the steel having a rolling temperature of 1000 to 800 ° C, so that the mechanical properties of the product (tensile strength, yield strength, etc.) The points and impact values are most affected by rolling conditions (temperature, rolling reduction, etc.). Therefore, in the present embodiment, the temperature measuring device 32 of the present embodiment is arranged at each of the position C and the position D in FIG.

FIG. 2 shows the temperature measuring device 32 arranged at the position C.
FIG. In FIG. 2, the roller table 40
The intermediate rolled material 30 is conveyed by, and the temperature measuring device 32 is arranged beside the roller table 40. In addition,
In the figure, the shaft support of the roller table 40 is omitted for convenience of description. The temperature measuring device 32 of the present embodiment includes a radiation thermometer 33, a lifting device 34, a lifting control device 35, and a rolling control device 36. These will be sequentially described.

[Radiation Thermometer 33] In the present embodiment, the radiation thermometer 33 has a range of 0.5 to 0.5 in the light emitted from the intermediate rolled material 30.
The lens 33 allows the energy of light in the relatively narrow wavelength range of 1.2 μm
A non-contact type thermometer that measures the temperature of the flange of the intermediate rolled material 30 by collecting and measuring it in a silicon cell (not shown) incorporated by a and converting it into an electric signal was used. This thermometer is a so-called continuous light pyrometer.

In addition to the continuous light pyrometer, all of the radiated light from the intermediate rolled material 30 or energy in a considerably wide wavelength range is collected by a thermocouple by a lens or a reflecting mirror, measured, and converted into an electric signal. It is also possible to use a full radiation type thermometer. Since such a radiation thermometer is well known, further description will be omitted.

[Elevating device 34] In FIG. 2, the radiation thermometer 33
Is supported by a lifting device 34 so as to be lifted and lowered in the direction of the outlined arrow in the figure. In this embodiment, the lifting device 34 includes an electric (or hydraulic) jack 34a on a pedestal 37 installed on the floor.
Is configured and equipped. As the electric jack 34a expands and contracts, the radiation thermometer 33 moves up and down to an appropriate installation height.

[Lift Control Device 35] In the present embodiment, in order to control the operation of the lifting device 34, a rolling control device 36, which will be described later,
A lifting control device 35 connected to the above is provided. FIG. 3 is an explanatory diagram showing exchanges of control signals among the lifting device 34, the lifting control device 35, and the rolling control device 36.

As shown in FIGS. 2 and 3, the elevating control unit 35 sets the height h of the radiation thermometer 33 based on the radiation thermometer setting position command signal F input from the rolling control unit 36 described later. A signal G for controlling the electric power is output to the electric jack 34a. Then, the control signal G is continuously output until the feedback signal H from the position detector 34b (not shown in FIG. 2) attached to the electric jack 34a reaches the set height h to drive the electric jack 34a. . The adjustment of the height of the electric jack 34a by the lifting control device 35 is completed during non-rolling time such as between passes or between steel billets.

[Rolling Control Device 36] The rolling control device 36 is a control computer conventionally installed for managing the entire rolling process, and is a so-called rolling process control computer.
Rolling material information such as dimension information I and material information J for each pass of the intermediate rolled material 30 is registered in advance in the rolling control device 36.

In the present embodiment, the rolling control device 36 calculates based on the rolled material information regarding the intermediate rolled material 30 to determine the set height h of the radiation thermometer 33. Specifically, based on at least one of the dimension information I and the material information J of the intermediate rolled material 30 registered in advance, first, the installation height of the radiation thermometer 33 for each pass of the rough universal rolling is calculated by the above formula. The height h _n is calculated as h _n = f _n × g _n × B _n .

Here, the correction coefficient f _n is a correction coefficient depending on the material of the material to be rolled in the n-th pass, and the material information table J
Registered in advance. This value is 0 or more and 1 or less. The correction coefficient g _n is the dimension (web height, web height,
The correction coefficient is based on the flange width, the web thickness, and the flange thickness), and is registered in the dimension information table I in advance. This value is 0 or more and 1 or less. The target web thickness, flange thickness, flange width, etc. for each pass are registered in the dimension information table I, and the horizontal roll and vertical roll openings of the universal mill and the roll opening of the edger mill for each pass are registered. The setting values of the opening degree of each mill guide, the front and rear tilting table height, etc. are calculated from the dimension information table I and the material information J, and registered in the pass schedule table K.

Further, the value B _n means the flange width of the material to be rolled in the nth pass, and is calculated from the pass schedule table K determined according to the material information table J and the dimension information table I.

In the present embodiment, when the installation height h _n is calculated, the correction coefficients f _n and g _n are stored in advance in the memory of the rolling control device 36 as a numerical table, and the correction coefficients f _n and g _n are stored according to the material and size of the product. by using removed appropriately, eventually the set height h = h _n of the radiation thermometer 33 Te, a radiation thermometer
The set height h of 33 is calculated and calculated. Then, the radiation thermometer setting position command signal F is output to the elevation control device 35 so that the installation height of the radiation thermometer 33 is set to the set height h.

The temperature measuring device 32 of this embodiment is constructed as described above. Next, a case where the temperature of the flange of the intermediate rolled material 30 is measured by the temperature measuring device 32 will be described. FIG. 4 is an explanatory diagram showing an example of a situation in which the temperature of the flange of the intermediate rolled material 30 is measured by the temperature measuring device 32 shown in FIG.

In the multi-pass rough universal rolling of the rolled H-section steel with respect to the intermediate rolled material 30, the thickness and the flange width of each of the web and the flange of the intermediate rolled material 30 are shown in FIG. 4 as the rolling pass progresses. From the first rolling pass indicated by the broken line to the final rolling pass indicated by the solid line, it gradually decreases. Therefore, in the present embodiment, the installation height of the radiation thermometer 33 is gradually reduced between rolling passes as the rolling passes progress. As a result, according to the temperature measuring device 32 of the present embodiment, the temperature of any one point in the flange width direction (for example, the central portion 30a in the flange width direction) can be accurately measured in each rolling pass.

Depending on the size of the intermediate rolled material 30 and the pass schedule, the amount of adjustment of the installation height of the radiation thermometer 33 between the rolling passes is extremely small, so that the radiation between the rolling passes is radiated. There may be no problem in practical use without adjusting the installation height of the thermometer 33. In such a case, the installation height of the radiation thermometer 33 does not have to be changed, and for example, the installation height can be an average value of the installation height in the first rolling pass and the installation height in the final rolling pass.

As described above, according to the present embodiment, the size of the intermediate rolled material 30 can be reduced by adding the elevating device 34 and the elevating control device 35 to the existing radiation thermometer 33 without introducing an expensive temperature measuring device. Even if it changes as the rolling pass progresses,
The temperature of the rolled material 30 can be measured with high accuracy. Therefore, it is possible to optimally control the rolling temperature, thereby suppressing variations in the mechanical properties of the rolled H-section steel, which is a product, and preventing out-of-specification.

(Second Embodiment) Next, a second embodiment will be described. It should be noted that the following description of each embodiment will be given only on the portions different from the first embodiment, and the common portions will be denoted by the same reference numerals in the drawings, and redundant description will be omitted.

FIG. 5 shows two types of intermediate rolled materials 30-1 and 30- having different flange widths by the temperature measuring device 32 shown in FIG.
It is explanatory drawing which shows an example of the situation where the temperature measurement of 2 is performed. In the present embodiment, the flange temperature of the rolled H-section steel 30-1 having a relatively large flange width and the flange temperature of the rolled H-section steel 30-2 having a relatively small flange width are both measured by the same temperature measuring device 32. This is the case when measuring.

In this case, in order to accurately measure the temperature of each of the rolled H-section steels 30-1 and 30-2, for example, in the central portion 30a in the flange width direction, in each pass of rolling, the radiation thermometer 33 is used. The installation height may be changed by 1/2 of the difference between the flange widths of the rolled H-section steels 30-1 and 30-2.

As a result, the temperature of the rolled H-section steels 30-1 and 30-2 can be measured with high accuracy. Therefore, it is possible to optimally control the rolling temperatures of the two types of intermediate rolled materials having different flange widths, thereby suppressing variations in the mechanical properties of the rolled H-section steel, which is a product, and causing nonstandard specifications. Never.

(Third Embodiment) FIG. 6 is an explanatory view showing another example of the situation in which the temperature of the flange of the intermediate rolled material 30 is measured by the temperature measuring device 32 shown in FIG. In the present embodiment, for the same intermediate rolled material 30, in order to regulate the upper limit value of the rolling temperature, a region where the temperature is higher in the width direction of the flange 30b is measured, and the lower limit value of the rolling temperature is regulated. In the case of measuring a region where the temperature is lower in the width direction of the flange 30b. In this case, the installation height of the radiation thermometer 33 may be changed by 1/2 of the width of the flange 30b.

As a result, both the maximum temperature and the minimum temperature of the flange 30b can be measured for the rolled H-section steel 30, and the temperature measurement in the flange width direction can be performed with high accuracy. Therefore, it is possible to optimally control the rolling temperature, thereby suppressing variations in the mechanical properties of the rolled H-section steel, which is a product, and preventing out-of-specification.

[0055]

EXAMPLES The present invention will be described more specifically with reference to examples. While the temperature measurement device 32 shown in FIG. 2 is installed at the position C and the position D of the hot rolling step 20 shown in FIG. Thirty types of die-rolled H-section steel (tensile strength 50 kg steel: web height 612 mm, flange width 515 mm, web thickness 65 mm, flange thickness 80 mm) were manufactured.

That is, molten steel refined into a predetermined component system
(Nb and V added alloy steel) is cast into a continuous casting slab,
Next, this continuous cast slab was heated to about 1250 ° C. in a heating furnace 28, then reverse-rolled in a plurality of passes by a breakdown mill 21, and rough-rolled into a rough-shaped steel slab 29 for shaping.

After this rough steel slab 29 is allowed to stand by for a predetermined time and air-cooled to lower the temperature to about 950 ° C., reverse rolling is performed for 15 passes using the rough universal mill 23 and the edger mill 24 to a predetermined temperature. Intermediate rolling was performed on an intermediate rolled material 30 having a web thickness, a flange thickness, and a flange width. In this intermediate rolling, the web thickness and the flange thickness were reduced by the rough universal mill 23, and the flange width was reduced by the edger mill 24.

The temperature control in the intermediate rolling is carried out by controlling the rolling start temperature by the rough universal mill 23 so that the surface temperature at the central portion in the flange width direction of the intermediate rolled material 30 of each rolling pass falls within a predetermined temperature range, It was performed by adjusting the height of the radiation thermometer 33 between the passes and the rolling speed in each pass as shown in Table 1.

[0059]

[Table 1]

In Table 1, the correction coefficient f _n is a correction coefficient depending on the material of the material to be rolled in the n-th pass. For the material to be rolled this time, the temperature control point is the outer surface temperature in the flange width direction for each pass. Since the peak is in the center of the flange width, 0.5 was set for each pass. Therefore, the correction factor f _n is that the temperature control point is 1/4 above the flange width direction.
If it is a point, set it to 0.75.

The correction coefficient g _n can be changed according to the dimensions (web height, flange width, web thickness and flange width) of the rolled material in the n-th pass. It was set to 1.0 uniformly for each pass. Therefore, the correction coefficient g _n may be displaced from the temperature peak portion in the flange outer surface width direction to the lower side than the flange width direction central portion depending on the dimensions of the material to be rolled, but in this case, a numerical value smaller than 1. And

The intermediate rolled material 30 was subjected to 1-pass finish rolling using the finish universal mill 27 to obtain a final product. From these final products,
Samples in the L direction were taken from 1/4 position and 1/4 position in the thickness direction, and the mechanical properties (tensile strength, yield point and impact value) of these samples were measured.

Table 2 shows the mechanical properties of products when the above-described rolled H-section steel is manufactured by using the temperature measuring method and the temperature measuring apparatus of the present invention. In Table 2, as a comparative example, the installation height of the radiation thermometer 33 is fixed at a position half the flange width of the final rolling pass for each intermediate rolling pass, and the material to be rolled in each rolling pass is fixed. The mechanical properties of the product when the rough universal rolling start temperature, the height of the thermometer between each pass, and the rolling speed at each pass are adjusted so that the flange temperature of , Also shown.

[0064]

[Table 2]

It can be seen from Table 2 that the inventive examples have better mechanical test values and less variation than the comparative examples. Therefore, it is understood that the product performance is improved and the productivity is improved because the product performance variation is small.

That is, in this embodiment, since both the starting temperature and the ending temperature of the reverse rolling by the rough universal mill 23 and the edger mill 24 can be shifted to higher values, the material to be rolled is cooled before the intermediate rolling. It is possible to reduce the standby time and increase the intermediate rolling speed, and it is possible to improve the rolling efficiency by shortening the rolling cycle time.

Further, since there is little variation in product performance, the amount of alloying elements added for ensuring performance can be reduced within the range not exceeding the lower limit of the prescribed value, and the manufacturing cost can also be reduced. .

[0068]

[Modifications] In the description of the embodiments and examples, the case where the parallel flange rolled section steel is a rolled H section steel is taken as an example, but the present invention is not limited to this mode, and two parallel flanges are used. Can be equally applied to rolled steel having For example, rolled channel steel can be exemplified.

In the description of the embodiments and examples, the temperature measuring device according to the present invention is provided on the inlet side of the coarse universal mill.
Although the case where it is installed on the outlet side of the edger mill is taken as an example, the present invention is not limited to such an aspect, and it may be installed on the inlet side and / or the outlet side of the coarse universal mill and / or the edger mill. .

Further, in recent years, during the production of TMCP type parallel flange rolling section steel, in the intermediate rolling step, the temperature of the material to be rolled can be freely controlled to reduce the additive elements in the steel material and improve the rolling efficiency. There is a method of installing a water cooling device on the inlet side or the outlet side of the intermediate rolling mill and performing thickness reduction while cooling the material to be rolled between rolling passes. It is also possible to apply.

[0071]

As described in detail above, according to the present invention, the dimensions of the intermediate rolled material can be changed by simply changing the existing radiation thermometer without introducing an expensive temperature measuring device. Or, even if it is changed, the temperature of the material to be rolled can be measured with high accuracy. Therefore, it is possible to optimally control the rolling temperature, which suppresses variations in mechanical properties of the product, such as rolled H-section steel, parallel-flange rolled section steel , and does not cause out-of-specification.
It is possible to improve productivity and reduce manufacturing costs.
The significance of the present invention having such an effect is extremely remarkable.

[Brief description of drawings]

FIG. 1 is an explanatory diagram schematically showing a hot rolling process in which a temperature measuring device according to a first embodiment is installed, together with an example of a sectional shape of a material to be rolled in each process.

FIG. 2 is a perspective view showing the temperature measuring device according to the first embodiment.

FIG. 3 is an explanatory diagram showing exchanges of control signals among the lifting device, the lifting control device, and the rolling control device in the first embodiment.

FIG. 4 is an explanatory diagram showing an example of a situation in which the temperature of the flange of the intermediate rolled material is measured by the temperature measuring device shown in FIG.

5 is an explanatory diagram showing an example of a situation in which the temperature measurement device shown in FIG. 2 measures the temperatures of two types of intermediate rolled materials having different flange widths.

FIG. 6 is an explanatory diagram showing another example of a situation in which the temperature of the flange of the intermediate rolled material is measured by the temperature measuring device shown in FIG.

FIG. 7 is an explanatory view schematically showing a hot rolling step.

FIG. 8 is an explanatory view showing an example of the cross-sectional shape of the material to be rolled in each step of the hot rolling process, FIG. 8 (a) is an example of the cross-sectional shape at the end of rough rolling, and FIG. 8 (b) is an intermediate figure. An example of the sectional shape at the time of rolling, and FIG. 8C shows an example of the sectional shape at the end of finish rolling.

FIG. 9 is an explanatory diagram showing a cross-sectional shape of rolled channel steel.

FIG. 10 is an explanatory diagram showing an example of distribution of surface temperature on a flange of rolled H-section steel in a rolling process.

[Explanation of symbols]

30 Rolled material 32 Temperature measuring device 33 Radiation thermometer 34 Lifting device 35 Lift control device 36 Rolling controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI // C21D 9/00 102 B21B 37/00 BBG (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 1/08 B21B 37/00-37/78 B21C 51/00 G01J 5/00 C21D 9/00

Claims (6)

(57) [Claims] 1. A radiation thermometer installed on the inlet side and / or the outlet side of a rough universal mill and / or an edger mill that constitutes an intermediate rolling process of a parallel flange rolled steel, and the installation height of the radiation thermometer is used. According to the material of the rolled material to be conveyed, it is adjusted before performing the temperature measurement of the rolled material, and the surface temperature at a part of the flange of the rolled material is measured. Method for Measuring Temperature of Parallel Flange Rolled Shaped Steel. 2. An intermediate rolling process for parallel flange rolled steel
Composing coarse universal mill and / or edger
Radiation thermometers located on the inlet and / or outlet side of the mill
To determine the installation height of the radiation thermometer.
Material of rolled material and / or each part of the intermediate rolling process
The temperature of the rolled material is measured based on the dimensions of each
Adjust it before, and attach it to a part of the flange of the rolled material.
A temperature measuring method for measuring a surface temperature of a parallel flange rolling shape steel , wherein the installation height is determined by the following formula using the material and / or the dimension. . h _n = f _n × g _n × B _n where h _{n is} the installation height of the radiation thermometer at the n-th pass (height from the table top to the radiation thermometer) f _n : of the material to be rolled at the n-th pass Correction coefficient gn based on material: correction coefficient _Bn based on dimensions of rolled material of _n- th pass: flange width of rolled material of n-th pass. 3. A radiation thermometer arranged on the inlet side and / or the outlet side of a rough universal mill and / or an edger mill constituting an intermediate rolling process of a parallel flange rolled steel, and a lifting device for raising and lowering the radiation thermometer. And a radiation thermometer, which is provided with an elevating control device for controlling the elevating device so that the installation height is determined based on the material of the rolled material to be conveyed. Steel temperature measuring device. 4. An intermediate rolling process for parallel flange rolled steel
Crude Universality Sarumiru and / or edger constituting
Radiation thermometers located on the inlet and / or outlet side of the mill
An elevating device for elevating the radiation thermometer, and the radiation
The thermometer is the material of the material to be rolled and / or the
Determined based on the size of each pass of the intermediate rolling process
Elevator that controls the elevating device so that the installation height is
And a control device, further, the installation height, calculated by rolling control device temperature measuring device parallel flange rolling shape steel, characterized in that it comprises an input to the elevator control device. Wherein said installation height, said by the material and / or the following formula using the dimensions, Ru determined 請 Motomeko 4
A temperature measuring device for the parallel flange rolled shape steel described. h _n = f _n × g _n × B _n where h _{n is} the installation height of the radiation thermometer at the n-th pass (height from the table top to the radiation thermometer) f _n : of the material to be rolled at the n-th pass Correction coefficient gn based on material: correction coefficient _Bn based on dimensions of rolled material of _n- th pass: flange width of rolled material of n-th pass. 6. The intermediate rolling step of parallel flange rolling section steel
Composing coarse universal mill and / or edger
Radiation thermometers located on the inlet and / or outlet side of the mill
An elevating device for elevating the radiation thermometer, and the radiation
The thermometer is the material of the material to be rolled and / or the
Determined based on the size of each pass of the intermediate rolling process
Elevator that controls the elevating device so that the installation height is
A control device, and the installation height is the material and / or
Or be determined by the following formula using the above dimensions
A temperature measuring device for parallel flange rolled steel, characterized by. h _n = F _n × g _n × B _n However, h _n : Installation height of the radiation thermometer at the nth pass (Table
Radiation temperature from the top of the bull Height to total) f _n : Correction factor based on the material of the rolled material in the nth pass g _n : Correction factor based on the dimensions of the rolled material in the nth pass B _n : Flange width of rolled material in the nth pass Indicates.