JP2004330213A - Furnace coiler of steckel mill rolling equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality and the yield of a product by reducing the crack of a steel sheet caused by hot-rolling and also the occurrence of breakage etc. <P>SOLUTION: Reciprocative burners 17a, 17b are slantingly set to the axial direction of a mandrel 5 on both side walls 3a, 3b of a furnace body 3 corresponding to both end parts of the mandrel 5, and flames 18a, 18b from the burners are made to inject toward winding start part 4a of the steel sheet for winding round the mandrel. Gas ventilating holes 14a, 14b communicating with the inner part of this mandrel are opened on the conical wall surface part near both end parts of the hollow fusiform mandrel 5 and also a burner 15 is arranged on the furnace wall side 3a so that the flame 16 is injected toward these gas ventilating holes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a furnace coiler for a Steckel mill rolling plant, and more particularly to a furnace coiler structure for maintaining a uniform temperature of a steel strip during rolling and improving quality and yield.
[0002]
[Prior art]
[Patent Document 1]
JP-A-10-137844 [Patent Document 2]
Japanese Patent No. 3335540 [Patent Document 3]
Japanese Patent Application Laid-Open No. 8-155526
As shown in Patent Documents 1 to 3, the Steckel mill rolling equipment is provided with a furnace coiler having a built-in mandrel for winding a steel strip in a coil shape on each of an inlet side and an outlet side of a hot rolling mill. Is reciprocated between the two furnace coilers so that rolling by the hot rolling mill is repeated.
[0004]
As described in Patent Documents 1 to 3, the furnace coiler is conventionally provided with a heat source for keeping heat, so as to prevent a temperature drop of the steel strip during rolling.
[0005]
Incidentally, the furnace coiler disclosed in Patent Document 1 is provided with a burner that emits a flame in the tangential direction of the steel strip coil. ) Is likely to be lower than the temperature of the central part. Further, the furnace coiler disclosed in Patent Document 2 is provided with a burner on the furnace side wall for heating the strip from both end surfaces in the sheet width direction, but still starts winding the strip in direct contact with the mandrel. It was inevitable that the temperature of the part would be low. This is because the winding start portion is not stored in the furnace coiler on the opposite side but stays outside in the pass before and after the winding, and the temperature is remarkably lowered in the configuration of the equipment of the Steckel mill rolling equipment. For this reason, in particular, heat-resistant steel, inconel superalloy, high-carbon stainless steel, and the like are inferior in hot workability and cause work cracking, which has a disadvantage of lowering product quality and yield.
[0006]
In Patent Document 3, an opening is formed in the outer peripheral surface of the mandrel, and a fin is provided in the opening to protrude outward. By rotating the mandrel, high-temperature combustion gas in the furnace is guided into the mandrel. To prevent the temperature of the end portion of the steel strip from dropping during rolling, but when the mandrel stops rotating, almost no high-temperature combustion gas is introduced. Insufficient, for this reason, especially in heat-resistant steel, inconel superalloy, high-carbon stainless steel, etc., the hot workability is inferior, and there is a drawback that the start end and the rear end of the strip are broken. .
[0007]
[Problems to be solved by the invention]
Therefore, the present invention is intended to improve the quality and yield of a steel strip by enabling a required portion to be heated positively and keeping the temperature of a steel strip wound around a mandrel always uniform. There is [0008]
[Means for Solving the Problems]
Therefore, in the furnace coiler of the Steckel mill rolling equipment according to the present invention, burners are set on each side wall of the furnace body corresponding to both ends of the mandrel at an angle to the axial direction of the mandrel. It is characterized in that it is sprayed toward the winding start of the steel strip wound around the mandrel.
For this reason, it is possible to eliminate temperature unevenness of the strip in the sheet width direction.
[0009]
Further, in the furnace coiler of the Steckel mill rolling equipment according to the present invention, a vent hole communicating with the inside of the mandrel is opened in a conical wall portion near both ends of a hollow spindle type mandrel, and a flame is sprayed toward the vent hole. A burner is provided on the furnace wall so that
For this reason, the flame and the combustion gas of the burner penetrate the inside of the mandrel, and the mandrel can always be heated to a necessary and sufficient temperature.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view schematically showing the configuration of the Steckel mill rolling equipment. Reference numeral 1 denotes a hot rolling mill, and 2 denotes a furnace coiler provided on the inlet side and the outlet side of the hot rolling mill. The furnace coiler 2 has a built-in mandrel 5 for winding a steel strip 4 in a coil shape in a furnace body 3 as shown in the vertical sectional view of FIG. Then, the high-temperature strip 4 extracted from the heating furnace is carried in by the transport roller 6 and reciprocated between the two furnace coils, so that hot rolling is repeated and processed to a required thickness. Reference numerals 7a and 7b are provided on the transport roller 6 and at the entrance of the furnace coiler 2, and guide arms for guiding the end of the steel strip 4 to the engaging holes 9 of the mandrel 5, and 8a and 8b are guide rollers. Reference numeral 10 denotes an electric heater provided on the peripheral surface of the furnace body for heating the atmosphere in the furnace body 3, and reference numeral 11 denotes a flue.
[0011]
The mandrel 5 is of a hollow spindle type made of heat-resistant cast steel. A support shaft 12 through which cooling water circulates is inserted through the center of the mandrel 5, and both ends are rotatably supported by bearings 13 provided outside the furnace. As shown in FIG. 3, slit-shaped ventilation holes 14a and 14b communicating with the inside of the mandrel are opened in the conical wall portions near both ends of the mandrel 5, and a flame is injected toward the ventilation holes. A burner 15 is provided obliquely on one side wall 3a of the furnace body 3 corresponding to both ends of the mandrel 5, and a flame 16 and a combustion gas injected from the burner toward one vent hole 14a are provided. As indicated by an arrow, the mandrel 5 passes through the inside of the mandrel 5 and is discharged from the other vent hole 14b into the furnace.
[0012]
Further, burners 17a, 17b are set on both side walls 3a, 3b of the furnace body 3 corresponding to both ends of the mandrel 5, respectively, obliquely with respect to the axial direction of the mandrel, and winding of a steel strip wound around the mandrel. The flames 18a and 18b are injected from the burner toward the beginning 4a.
[0013]
As the burner 15 and the burners 17a and 17b, it is desirable to use a high-speed burner having a high flame directivity so that the injected flame is directly injected and a target portion can be intensively heated.
[0014]
In the furnace coiler thus configured, the mandrel 5 is always heated to a necessary and sufficient temperature by the flame 16 of the burner 15, and the winding start portion 4a of the steel strip 14 is directly heated by the flames 18a, 18b of the burners 17a, 17b. Since it is sprayed and locally heated, it is possible to eliminate temperature unevenness in the plate width direction unlike the conventional heating as in the related art. For this reason, the risk of breakage of the start end and the rear end of the strip is eliminated, and even if the strip is inferior in hot workability, it is less likely to cause work cracking, thereby improving the quality and yield. The number of burners corresponding to the burners 17a and 17b can be set to one or more on each side as needed.
[0015]
By the way, when the nickel alloy strip is hot-rolled (final temperature: about 600 ° C.), heating by only the conventional electric heater 10 is about 40 ° C. at the longitudinal center of the strip in the sheet width direction, and the start and rear ends. Temperature irregularities of about 60 to 120 ° C. occurred, and machining cracks having a depth of 2 mm or more occurred about 30 m at the start end and the rear end of the steel strip. Therefore, in order to obtain a product, the part had to be trimmed. In contrast, by implementing the present invention, such excessive temperature unevenness was eliminated, and the length requiring trimming could be greatly reduced.
[0016]
Although this embodiment is an example in which the invention described in claim 1 and the invention described in claim 2 are both implemented, the desired effect can be obtained by implementing only one of the inventions. In addition, a synergistic effect is achieved by implementing the two inventions as described above.
[0017]
【The invention's effect】
As described above, according to the present invention, the portion of the furnace coiler, in which the temperature was conventionally reduced, was actively heated by the flame of the burner, and the temperature distribution of the steel strip could be made uniform. The occurrence of cracks, breakage, and the like of the steel strip due to hot rolling is reduced, and there is a remarkable effect of improving product quality and yield.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a Steckel mill rolling facility showing an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a furnace coiler of a Steckel mill rolling facility showing an embodiment of the present invention.
FIG. 3 is a sectional view taken along line AA of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hot rolling mill 2 Furnace coiler 3 Furnace body 3a, 3b Side wall 4 Steel strip 4a Winding start part 5 Mandrel 10 Electric heater 14a, 14b Vent hole 15 Burner 16 Flame 17a, 17b Burner 18a, 18b Flame

Claims (2)

Burners are respectively set obliquely to the axial direction of the mandrel on both side walls of the furnace body corresponding to both ends of the mandrel, and from the burner toward the winding start portion of the strip where the flame is wound around the mandrel. Furnace coiler of steckel mill rolling equipment characterized by being injected. A vent hole communicating with the inside of the mandrel is opened in a conical wall portion near both ends of a hollow spindle-shaped mandrel, and a burner is provided on a furnace side wall so that a flame is injected toward the vent hole. Furnace coiler of Steckel mill rolling equipment.

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