WO1985003891A1 - Method for the reduction of local temperature irregularity in steel slabs at rolling - Google Patents
Method for the reduction of local temperature irregularity in steel slabs at rolling Download PDFInfo
- Publication number
- WO1985003891A1 WO1985003891A1 PCT/SE1985/000092 SE8500092W WO8503891A1 WO 1985003891 A1 WO1985003891 A1 WO 1985003891A1 SE 8500092 W SE8500092 W SE 8500092W WO 8503891 A1 WO8503891 A1 WO 8503891A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- slab
- rolling
- temperature
- steel
- steel slab
- Prior art date
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 27
- 239000010959 steel Substances 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims description 4
- 238000005096 rolling process Methods 0.000 title description 18
- 238000010438 heat treatment Methods 0.000 claims description 19
- 238000005098 hot rolling Methods 0.000 claims description 3
- 230000001939 inductive effect Effects 0.000 claims description 2
- 238000003303 reheating Methods 0.000 abstract description 6
- 230000006698 induction Effects 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 230000000284 resting effect Effects 0.000 description 2
- 241000277301 Esociformes Species 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
- B21B45/004—Heating the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/02—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling heavy work, e.g. ingots, slabs, blooms, or billets, in which the cross-sectional form is unimportant ; Rolling combined with forging or pressing
- B21B1/026—Rolling
Definitions
- the present invention concerns a way to influence the temperature irregularity in slabs which are heated for hot-rolling i.a. to achieve a better endproduct, which is more even, has better limit gauge and material-characteristics and to balance loading pikes in the mill stand. The possibility to achieve the attained quality with more simple control equipment in the mill also is achieved. BACKGROUND TECHNIC
- the steel slab Before rolling, the steel slab is heated up to a desired temperature usually in a so called reheating furnace. For bigger slabs it is usual that the steel slab is heated from both sides at the same time. This usually is managed by resting the steel slab during the heating upon a pipe structure which mostly is water cooled. The desired temperature in the slab is reached by supplying energi from e.g. combustion of fuel to both of the over-side and the under-side of the steel slab.
- the steel slab with great accuracy can be heated up to the desired temperature level.
- a lower temperature level than in the other parts of the steel slab is present.
- the lower temperature level mostly is present as strips across the underside of the slab in the locations, where the steel slab has been in contact with the carrying pipes in the furnace.These strips causes at the succeeding hot-rolling i.a. dimension deviations, lower uniformity in quality and e.g. bad flatness if the end product is a steel strip.
- the disadvantages at the heating partly can be compensated in the following rolling mills with very exact control equipment, but can not be fully eliminated.
- the techics to get slabs with an uniform heat are that the reheating furnaces have been provided with a metallic, heat resistant material, so called travellers, between the slab and the carrying pipe structure. It is also known, during the rolling , to arrange heat equalization stations , often heat insulated and also heat storing, where the slab is stopped for temperature equalization. The result has not been satisfactory when the loss in temperature and remaining irregularities in temperature still have caused bad limit gauges in the finish rolling and a reduced capacity in the rolling mill. Not even equalization stations whith supply of heat have given satisfying results, while as well areas with colder spots as adjacent areas have been supplied with heat. Irregularities in temperature still have remained even if the cold spots have been eliminated. The different pairs of rolls in the rolling mill also have been provided with a more and more advanced control equipment. Still remaining however, irregularities in temperature in the slab constitute a considerable inconvenience in quality with the present technics of furnaces and rolling. CONCLUSION OF THE INVENTION
- the temperature equlization is made by a local heat supplying directed to the colder sections in the steel slab.
- Heating and rolling by that can be done with an encreased degree of freedom and with an improved quality as a result.
- figure 1 shows a view of a rolling mill for wide steel strips and figure 2 how a slab is in close contact with a water-cooled carrying pipe.
- figure 2 shows a view of a rolling mill for wide steel strips and figure 2 how a slab is in close contact with a water-cooled carrying pipe.
- the equalization of the temperature is brought about by delimimited heating the steel slab at a suitable occation at the rolling at the section where the steel slab has an irregularity in temperature.
- the difficulty to locate and control this heating, during the rolling or when the steel slab is moving, makes the proposed invention especially applicable if the heated slab is put in a fix position before the rolling, in that the colder sections are placed straight in front of the firmly installed heating source.
- the proposed method is, when heating of steel slabs in a so called reheating furnace, especially applicable in the position which becomes natural to the slab when pulled out from the furnace and put down upon the roller bed leading to the rolling mill.
- the local supplying of heat can be generated in many ways.
- induction heating, gas and oil burning and radiation of electrical heating can be mentioned.
- Induction heating is preferred why this can be concentrated in an easy way just to the areas which are needed to be heated without affecting surrounding sections worth mentioning.
- the induction heating also can be computer-controlled to be further precised to the right areas. It also can be freely used in the room without affecting the surrounding environment.
- Steel slabs 4 with a length of 11 m and a cross-section with a width of 1200 mm and a thichness of 220 ram as an average, is heated in a oil-fired furnace 1 up to about 1250°C.
- the maximum capacity of heating amounts to 300 ton/hour.
- the steel slab 4 is heated both from its upper and lower side with a great number of oil burners. This is brought about by resting the slab 4 upon eleven water-cooled carrying pipes 2.
- these are provided with a heat insulating material 13. Despite of that the depression of temperature in the slab 4 will be obvius and gives for the rolling unfavourable gradients 14 of temperature.
- the heated slab will be put in a fix position upon a so called roller bed 5 for further transporting to the mill.
- a heating source 6 which consists of inductors, which are placed in the roller bed 5 in that way that they are heating the slab 4 only at that side and in those places where the carrying pipes 2 in the furnace 1 have caused unfavourable gradients 14 of temperature.
- the inductors are supplied from a for the purpose especially arranged electrical interlocking post 7 and can be controlled separately.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metal Rolling (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
In order to eliminate the drawbacks from colder zones on steel slabs from water cooled carrying pipes in reheating furnaces, the steel slab is heated locally, preferably by induction heaters in a following roller bed.
Description
TITLE OF THE INVENTION
Method for the reduction of local temperature irregularity in steel slabs at rolling. TECHNICAL AREA The present invention concerns a way to influence the temperature irregularity in slabs which are heated for hot-rolling i.a. to achieve a better endproduct, which is more even, has better limit gauge and material-characteristics and to balance loading pikes in the mill stand. The possibility to achieve the attained quality with more simple control equipment in the mill also is achieved. BACKGROUND TECHNIC
Before rolling, the steel slab is heated up to a desired temperature usually in a so called reheating furnace. For bigger slabs it is usual that the steel slab is heated from both sides at the same time. This usually is managed by resting the steel slab during the heating upon a pipe structure which mostly is water cooled. The desired temperature in the slab is reached by supplying energi from e.g. combustion of fuel to both of the over-side and the under-side of the steel slab.
With the technics till now existing the steel slab with great accuracy can be heated up to the desired temperature level. But where the steel slab has been in contact with the water-cooled pipe construction, a lower temperature level than in the other parts of the steel slab is present. If e.g. a so called reheating furnace is used for heating, the lower temperature level mostly is present as strips across the underside of the slab in the locations, where the steel slab has been in contact with the carrying pipes in the furnace.These strips causes at the succeeding hot-rolling i.a. dimension deviations, lower uniformity in quality and e.g. bad flatness if the end product is a steel strip. The disadvantages at the heating partly can be compensated in the following rolling mills with very exact control equipment, but can not
be fully eliminated.
The techics to get slabs with an uniform heat are that the reheating furnaces have been provided with a metallic, heat resistant material, so called travellers, between the slab and the carrying pipe structure. It is also known, during the rolling , to arrange heat equalization stations , often heat insulated and also heat storing, where the slab is stopped for temperature equalization. The result has not been satisfactory when the loss in temperature and remaining irregularities in temperature still have caused bad limit gauges in the finish rolling and a reduced capacity in the rolling mill. Not even equalization stations whith supply of heat have given satisfying results, while as well areas with colder spots as adjacent areas have been supplied with heat. Irregularities in temperature still have remained even if the cold spots have been eliminated. The different pairs of rolls in the rolling mill also have been provided with a more and more advanced control equipment. Still remaining however, irregularities in temperature in the slab constitute a considerable inconvenience in quality with the present technics of furnaces and rolling. CONCLUSION OF THE INVENTION
With this invention colder, limited sections in a steel slab for rolling, which remain after heating in an e.g. reheating furnace, can be equalized at a desired temperature level.
The temperature equlization is made by a local heat supplying directed to the colder sections in the steel slab.
Heating and rolling by that can be done with an encreased degree of freedom and with an improved quality as a result.
The invention will be described closer in claims, in the following sector and in an example of performance and by help of figures enclosed of which figure 1 shows a view of a rolling mill for wide
steel strips and figure 2 how a slab is in close contact with a water-cooled carrying pipe. CLOSER DESCRIPTION OF THE INVENTION The equalization of the temperature is brought about by delimimited heating the steel slab at a suitable occation at the rolling at the section where the steel slab has an irregularity in temperature. The difficulty to locate and control this heating, during the rolling or when the steel slab is moving, makes the proposed invention especially applicable if the heated slab is put in a fix position before the rolling, in that the colder sections are placed straight in front of the firmly installed heating source. In this position of waiting the colder sections of the steel slab is heated from one side during a period of time necessary to get the wished increase in temperature. The proposed method is, when heating of steel slabs in a so called reheating furnace, especially applicable in the position which becomes natural to the slab when pulled out from the furnace and put down upon the roller bed leading to the rolling mill.
The local supplying of heat can be generated in many ways. As an example, induction heating, gas and oil burning and radiation of electrical heating can be mentioned. Induction heating is preferred why this can be concentrated in an easy way just to the areas which are needed to be heated without affecting surrounding sections worth mentioning. The induction heating also can be computer-controlled to be further precised to the right areas. It also can be freely used in the room without affecting the surrounding environment. EXAMPLE
Steel slabs 4, with a length of 11 m and a cross-section with a width of 1200 mm and a thichness of 220 ram as an average, is heated in a oil-fired furnace 1 up to about 1250°C. The maximum capacity of heating amounts to 300 ton/hour. In the hearth the steel slab 4
is heated both from its upper and lower side with a great number of oil burners. This is brought about by resting the slab 4 upon eleven water-cooled carrying pipes 2. In order to, if possible, avoid a too great depression of temperature in the steel slab 4 above the carrying pipes 2, these are provided with a heat insulating material 13. Despite of that the depression of temperature in the slab 4 will be obvius and gives for the rolling unfavourable gradients 14 of temperature. At the outlet-end of the furnace 1 the heated slab will be put in a fix position upon a so called roller bed 5 for further transporting to the mill. At the put dow point at the roller bed 5, the steel slab 4 is heated during a short period of time by help of a heating source 6, which consists of inductors, which are placed in the roller bed 5 in that way that they are heating the slab 4 only at that side and in those places where the carrying pipes 2 in the furnace 1 have caused unfavourable gradients 14 of temperature. The inductors are supplied from a for the purpose especially arranged electrical interlocking post 7 and can be controlled separately. By this well defined additional heat, as well as quantity as area, together with the subsequent rolling in an universal mill 9 , remaining variations in temperature in the rolled slab are to be neglected at the arrival to the finishing pairs 11.
After the inductive heating, scales on the surface of the slab will be separated in a spraying chamber 8. In universal mill 9, coiling box 10, and finishing pairs 11, the slab is rolled to a strip which after cooling is coiled to a coil in a coiling capstan 12.
Claims
1. Method for the reduction of temperature irregularity in a steel slab (4) at hot rolling, c h a r a c t e r i s e d in that the steel slab (4), after an ordinary heating, is heated by firmly mounted inductive heaters against the sections of the slab (4) where the temperature is unfavourable differing and that the slab (4) thereby is stationary at a predetermined place upon the roller bed (5) direct after the ordinary heating furnace (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE8585901132T DE3572608D1 (en) | 1984-02-29 | 1985-02-27 | Method for the reduction of local temperature irregularity in steel slabs at rolling |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8401102A SE447069B (en) | 1984-02-29 | 1984-02-29 | SET TO REDUCE LOCAL TEMPERATURE INNOVATIVES ON THE HEAT COLLECTOR |
| SE8401102-2 | 1984-02-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1985003891A1 true WO1985003891A1 (en) | 1985-09-12 |
Family
ID=20354939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/SE1985/000092 WO1985003891A1 (en) | 1984-02-29 | 1985-02-27 | Method for the reduction of local temperature irregularity in steel slabs at rolling |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0208679B1 (en) |
| AU (1) | AU3995885A (en) |
| DE (1) | DE3572608D1 (en) |
| SE (1) | SE447069B (en) |
| WO (1) | WO1985003891A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013110754A3 (en) * | 2012-01-25 | 2014-04-03 | Sms Siemag Ag | Method and plant for producing a metal strip |
| WO2019049597A1 (en) | 2017-09-11 | 2019-03-14 | 愛知製鋼株式会社 | Magneto-sensitive wire for magnetic sensor and production method therefor |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2417030A (en) * | 1943-12-22 | 1947-03-04 | Olin Ind Inc | Electric induction furnace for continuously heating metal strips |
| US2722589A (en) * | 1950-11-30 | 1955-11-01 | Ohio Crankshaft Co | Method and apparatus for uniformly heating intermittently moving metallic material |
| US3080468A (en) * | 1960-03-07 | 1963-03-05 | Lindberg Eng Co | Billet heater control and method |
| US3264856A (en) * | 1963-06-26 | 1966-08-09 | Canada Steel Co | Hot strip mill |
| US3344648A (en) * | 1963-11-19 | 1967-10-03 | United Eng Foundry Co | Method and apparatus for controlling the temperature of hot strip |
| US3471673A (en) * | 1968-02-19 | 1969-10-07 | United States Steel Corp | Apparatus for inductively heating a traveling metal slab |
| US3582598A (en) * | 1967-12-09 | 1971-06-01 | English Electric Co Ltd | Methods and apparatus for heating a body conveyor system for heating bodies by a microwave cavity |
| US3587268A (en) * | 1968-09-17 | 1971-06-28 | Francis H Bricmont | Workpiece temperature equalization in rolling of steel |
| US3596036A (en) * | 1970-03-16 | 1971-07-27 | Ajax Magnethermic Corp | Induction heater |
| US3715556A (en) * | 1970-10-05 | 1973-02-06 | Park Ohio Industries Inc | Slab heating method and apparatus |
| US4182146A (en) * | 1976-01-10 | 1980-01-08 | Hoesch Werke Aktiengesellschaft | Hot rolling mill |
| US4185183A (en) * | 1976-06-26 | 1980-01-22 | Toyo Aluminum K.K. | Induction heating apparatus with adjustable flux concentrators |
| EP0048503A2 (en) * | 1978-04-27 | 1982-03-31 | Encomech Engineering Services Limited | Heat shield arrangements for strip or billet-form material |
-
1984
- 1984-02-29 SE SE8401102A patent/SE447069B/en not_active IP Right Cessation
-
1985
- 1985-02-27 WO PCT/SE1985/000092 patent/WO1985003891A1/en not_active Application Discontinuation
- 1985-02-27 AU AU39958/85A patent/AU3995885A/en not_active Abandoned
- 1985-02-27 DE DE8585901132T patent/DE3572608D1/en not_active Expired
- 1985-02-27 EP EP19850901132 patent/EP0208679B1/en not_active Expired
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2417030A (en) * | 1943-12-22 | 1947-03-04 | Olin Ind Inc | Electric induction furnace for continuously heating metal strips |
| US2722589A (en) * | 1950-11-30 | 1955-11-01 | Ohio Crankshaft Co | Method and apparatus for uniformly heating intermittently moving metallic material |
| US3080468A (en) * | 1960-03-07 | 1963-03-05 | Lindberg Eng Co | Billet heater control and method |
| US3264856A (en) * | 1963-06-26 | 1966-08-09 | Canada Steel Co | Hot strip mill |
| US3344648A (en) * | 1963-11-19 | 1967-10-03 | United Eng Foundry Co | Method and apparatus for controlling the temperature of hot strip |
| US3582598A (en) * | 1967-12-09 | 1971-06-01 | English Electric Co Ltd | Methods and apparatus for heating a body conveyor system for heating bodies by a microwave cavity |
| US3471673A (en) * | 1968-02-19 | 1969-10-07 | United States Steel Corp | Apparatus for inductively heating a traveling metal slab |
| US3587268A (en) * | 1968-09-17 | 1971-06-28 | Francis H Bricmont | Workpiece temperature equalization in rolling of steel |
| US3596036A (en) * | 1970-03-16 | 1971-07-27 | Ajax Magnethermic Corp | Induction heater |
| US3715556A (en) * | 1970-10-05 | 1973-02-06 | Park Ohio Industries Inc | Slab heating method and apparatus |
| US4182146A (en) * | 1976-01-10 | 1980-01-08 | Hoesch Werke Aktiengesellschaft | Hot rolling mill |
| US4185183A (en) * | 1976-06-26 | 1980-01-22 | Toyo Aluminum K.K. | Induction heating apparatus with adjustable flux concentrators |
| EP0048503A2 (en) * | 1978-04-27 | 1982-03-31 | Encomech Engineering Services Limited | Heat shield arrangements for strip or billet-form material |
| EP0049000A2 (en) * | 1978-04-27 | 1982-04-07 | Encomech Engineering Services Limited | Heat shields for rolling mills |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013110754A3 (en) * | 2012-01-25 | 2014-04-03 | Sms Siemag Ag | Method and plant for producing a metal strip |
| US9242293B2 (en) | 2012-01-25 | 2016-01-26 | Sms Group Gmbh | Method and plant for producing a metal strip |
| WO2019049597A1 (en) | 2017-09-11 | 2019-03-14 | 愛知製鋼株式会社 | Magneto-sensitive wire for magnetic sensor and production method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0208679A1 (en) | 1987-01-21 |
| DE3572608D1 (en) | 1989-10-05 |
| AU3995885A (en) | 1985-09-24 |
| SE447069B (en) | 1986-10-27 |
| EP0208679B1 (en) | 1989-08-30 |
| SE8401102D0 (en) | 1984-02-29 |
| SE8401102L (en) | 1985-08-30 |
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