US3774353A - Method for partially grinding surface flows of a hot bloom and slab - Google Patents

Method for partially grinding surface flows of a hot bloom and slab Download PDF

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Publication number
US3774353A
US3774353A US00154926A US3774353DA US3774353A US 3774353 A US3774353 A US 3774353A US 00154926 A US00154926 A US 00154926A US 3774353D A US3774353D A US 3774353DA US 3774353 A US3774353 A US 3774353A
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United States
Prior art keywords
bloom
hot
flaws
grinding
flaw
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00154926A
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English (en)
Inventor
S Yasunaga
T Oniki
H Sumitomo
E Tanaka
O Araki
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Nippon Steel Corp
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Nippon Steel Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B39/00—Arrangements for moving, supporting, or positioning work, or controlling its movement, combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B39/20—Revolving, turning-over, or like manipulation of work, e.g. revolving in trio stands
    • 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
    • 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
    • B21B45/02—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 for lubricating, cooling, or cleaning
    • B21B45/0203—Cooling
    • B21B45/0209—Cooling devices, e.g. using gaseous coolants
    • B21B45/0215—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes
    • B21B45/0218—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes for strips, sheets, or plates
    • 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
    • B21B45/04—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 for de-scaling, e.g. by brushing
    • B21B45/08—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 for de-scaling, e.g. by brushing hydraulically

Definitions

  • ABSTRACT A method for partially grinding surface flaws of hot Foreign Application Priority Data steel slabs including bloom, wherein the hot bloom im- J 19 1970 J 45/53107 mediately after being hot-rolled is maintained in the une apan state most suitable for detecting surface flaws therein in the rolling line from a rolling mill to a cooling zone.
  • the surface flaws are detected and the thus detected Field 51552 323 surface flaws are removed by grinding, while the Sear 51,327, bloom is hot.
  • FIG. 2 6 Claims, 8 Drawing Figures Patented Nov. 27, 1973 FIG- 1 Scale generating state FIG. 2
  • the present invention relates to an improvement in a method for removing surface flaws in a steel bloom by grinding.
  • An object of the present invention is to provide an improved hot partial grinding method, wherein the defects of conventional methods may be eliminated to the effect that not only the finished surface of the bloom after the treatment of removing flaws is good, but also the treating efficiency is high enough formass production, the working environment is favorable, and the grinding method is particularly suitable for the treatment of ordinary steels on a large scale.
  • Another object of the present invention is to provide a method, wherein a hot bloom discharged from a rolling mill is subjected to a partial grinding in a rolling line extending from the rolling mill to a cooling zone.
  • the present invention is characterized by detecting parts having flaws in a steel bloom immediately after hot-rolled but descaled in a temperature range of from 650 to 1,000C. and grinding only the detected parts having flaws.
  • Essential requirements for the grinding of ordinary steels to remove flaws therefrom are that the operation cost is low and the working efficiency is high, and the only possible method, which may meet these requirements, is a hot partial grinding method. However, the essential point in this method is how to detect the parts in the bloom having flaws, while it is hot.
  • FIG. 1 shows relations between the bloom temperature and the scale generating state.
  • FIG. 2 shows therelationship between bloom temperature and surface flaw detectability with the naked eye.
  • FIG. 3 shows the relationship between bloom temperature and grinding efficiency.
  • FIG. 4 shows the relationship between bloom temperature and grinding ratio.
  • FIG. 5 shows the relationship between the bloom treating method and the flaw treating rate in the next step.
  • FIG. 6 shows an example of the hot grinding equipment arrangement according to the present invention.
  • FIG. 7 is a cross-sectional view on line A-A in FIG. 6.
  • FIG. 8 is an elevation schematically showing a hot surface grinding machine of the present invention.
  • FIG. I shows the generation of secondary scales when a time of about 10 minutes, which is required to grind a surface flaw of a bloom, has elapsed after the primary scales formed on the surface of the bloom at various temperatures have been removed.
  • the hot bloom flaw detection rate is also related to the bloom temperature. That is, as is shown in FIG. 2, in the temperature range of from 650 to l,000C.
  • the corner part formed by the surface and crack has such a small heat supply from the interior of the bloom, but has such a large heat dissipation that this part appears dark, whereas the bottom part of the crack appears bright, because the heat dissipation in this part is small, and the part having no flaw has a medium heat dissipation. Consequently, there are produced differences in the brightness among the above three parts.
  • the scab part appears dark, because the heat supply from the interior of the bloom to the scab part is small, but the heat dissipation from the tip of the scab part is large.
  • the part having no flaw has a medium heat dissipation, there is produced a difference in the brightness between the above two parts.
  • the temperature of the bloom exceeds 1,000C.
  • the bloom temperature is below 650C.
  • the flaw detectability is also very low just as in the case of a high bloom temperature.
  • the grinding efficiency (the amount of bloom ground per hour) rises rapidly from a temperature of about 550C, but then rather falls, if the temperature exceeds l,050C., due to the grindstone losing it resistance to heat and the teeth of the grindstone becoming clogged.
  • the grinding ratio (the amount of bloom ground per the amount of the grindstone abraded) increases in the same temperature range for the above-mentioned reason.
  • the above-mentioned transfer and water-cooling apparatus are as shown in FIG. 7 (a cross-section view on line AA of FIG. 6). That is to say, the water-cooling transfer 2 consists of a fixed skid 20, moving bar 21 and dogs 24 provided at fixed intervals on moving bar 21. The bloom A is slid on the fixed skid 20 with the moving bar 21, with the bloom abutted by dogs 24, and is stopped in a fixed position in the water-cooling apparatus, wherein it is quenched to a fixed temperature.
  • the water-cooling apparatus 3 is provided with upper and lower nozzle headers 18 and 22 on upper and lower cooling branch pipes 16 and 23 respectively.
  • the upper and lower nozzle headers are provided with upper and lower cooling nozzles 17 and 26 respectively, and they are all covered with a cover 19.
  • the bloom is quenched and descaled so that the flaw detectability of the bloom may be elevated and is then sent to a surface grinding roller table 5 through a water-cooling transfer outlet roller table 4.
  • An upper surface grinding machine 6 is arranged on roller table 5 so that the upper surface of the bloom may be partially ground.
  • FIG. 8 An example of the structure of the above-mentioned grinding machine 6 is shown in FIG. 8.
  • a grindstone 36, grindstone driving device 28 and operating chamber 27 are mounted so as to move on a grindstone base traversing beam 29. Further, grinding machine 6 is so made as to run on a running rail 32 through leg bases 33 in a direction at right angles with the moving direction of the grindstone 36.
  • 30 is a dust collecting box.
  • 31 is a dust collecting duct.
  • 37 is a driving current collecting device.
  • 37 is a hone roller table.
  • the bloom is transferred to a side grinding roller table 7, wherein any flaw on the side of the bloom is treated with a side grinding machine 8. Thereafter, the bloom A is sent to a plate rotating roller table 9 and is rotated by with a plate rotating machine 10. Thereupon, the bloom is again returned to the side grinding roller table 7 and any flaw on the new side is treated with the side grinding machine 8. The thus treated bloom is then sent to a lower surface grinding roller table 11 through the roller tables 7 and 9 and any flaw in the lower surface is partially treated with a lower surface grinding machine 12.
  • the bloom in which the treatment of flaws in the upper and lower surfaces and both sides have been finished, is conveyed to an outlet transfer receiving roller 13 and is successively moved to an outlet roller table 15 through an outlet transfer 14. Then, the bloom is sent to a cooling zone in the next step.
  • An example is shown in the following:
  • Hone 610 mm. in diameter and 75 mm. thick Grinding time (for four surfaces): minutes Grinding efficiency: 800 kg. (grinding amount)lhour 80 kg. (grinding amount)/kg. (of hone consumption) l% (9% in the case of the cold partial treatment of flaws. See FIG. 5.)
  • any flaw in a bloom can be exactly detected in a simple way by utilizing the difference in the amount of self-discharged light between the part having a flaw and the other part having no flaw, which makes it possible in accordance with the present invention to partially grind any flaws at a high temperature. Therefore, by arranging a hot grinding machine within a conventional rolling line, wherein a bloom discharged from a rolling mill is conveyed to a cooling zone, the exact treatment of flaws may be carried out with high efficiency so that the mass production of blooms having flaw free surfaces may be performed within a successive streamedline rolling operation.
  • the present invention may be said to be quite epochal as a method of treating flaws particularly in ordinary steels.
  • the present invention has great advantages in exactly removing any flaws of a bloom with a high efficiency, largely lowering the cost, economizing the required worker and assuring a favorable environment.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
  • Metal Rolling (AREA)
US00154926A 1970-06-19 1971-06-21 Method for partially grinding surface flows of a hot bloom and slab Expired - Lifetime US3774353A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45053107A JPS5036594B1 (enrdf_load_stackoverflow) 1970-06-19 1970-06-19

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US (1) US3774353A (enrdf_load_stackoverflow)
JP (1) JPS5036594B1 (enrdf_load_stackoverflow)
CA (1) CA955835A (enrdf_load_stackoverflow)
IT (1) IT942121B (enrdf_load_stackoverflow)
ZA (1) ZA714047B (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3924358A (en) * 1973-10-17 1975-12-09 British Steel Corp Machine for processing billet or bar stock
US3953943A (en) * 1975-02-27 1976-05-04 Shimadzu Seisakusho Ltd. Apparatus for automatically detecting and eliminating flaws on slabs or billets
US4074982A (en) * 1976-02-20 1978-02-21 Fried Krupp Huttenwerke Ag Process and means for grinding out faults in the surface of a work piece
US5193317A (en) * 1988-09-16 1993-03-16 Tom Nordquist Method for grinding metal and metal-alloy stock
EP1097764A3 (de) * 1999-11-04 2003-08-13 SMS Demag AG Verfahren zur Oberflächenbearbeitung eines kontinuierlich gegossenen Stahlproduktes und Einrichtung hierzu
CN103203663A (zh) * 2013-04-12 2013-07-17 山西太钢不锈钢股份有限公司 一种双相和耐热不锈钢连铸中板坯的修磨方法
CN110757256A (zh) * 2019-10-30 2020-02-07 南京钢铁股份有限公司 一种去除初轧坯原始脱碳层的方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1689512A (en) * 1921-12-19 1928-10-30 Samuel G Worton Hot rolling
US1689544A (en) * 1928-10-30 Method of kgllistg
US2158063A (en) * 1936-04-23 1939-05-16 American Foundry Equip Co Method of cleaning sheet metal and the like
US3253368A (en) * 1963-10-08 1966-05-31 Pettibone Mulliken Corp Surface conditioning grinding machine
US3474576A (en) * 1965-06-25 1969-10-28 Carborundum Co Process of conditioning metal
US3683565A (en) * 1970-11-02 1972-08-15 Johns Manville Method of treating the surface of textured cementitious sheet
US3708920A (en) * 1970-11-18 1973-01-09 Pettibone Corp Grinding machine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1689544A (en) * 1928-10-30 Method of kgllistg
US1689512A (en) * 1921-12-19 1928-10-30 Samuel G Worton Hot rolling
US2158063A (en) * 1936-04-23 1939-05-16 American Foundry Equip Co Method of cleaning sheet metal and the like
US3253368A (en) * 1963-10-08 1966-05-31 Pettibone Mulliken Corp Surface conditioning grinding machine
US3474576A (en) * 1965-06-25 1969-10-28 Carborundum Co Process of conditioning metal
US3683565A (en) * 1970-11-02 1972-08-15 Johns Manville Method of treating the surface of textured cementitious sheet
US3708920A (en) * 1970-11-18 1973-01-09 Pettibone Corp Grinding machine

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3924358A (en) * 1973-10-17 1975-12-09 British Steel Corp Machine for processing billet or bar stock
US3953943A (en) * 1975-02-27 1976-05-04 Shimadzu Seisakusho Ltd. Apparatus for automatically detecting and eliminating flaws on slabs or billets
US4074982A (en) * 1976-02-20 1978-02-21 Fried Krupp Huttenwerke Ag Process and means for grinding out faults in the surface of a work piece
US5193317A (en) * 1988-09-16 1993-03-16 Tom Nordquist Method for grinding metal and metal-alloy stock
EP1097764A3 (de) * 1999-11-04 2003-08-13 SMS Demag AG Verfahren zur Oberflächenbearbeitung eines kontinuierlich gegossenen Stahlproduktes und Einrichtung hierzu
CN103203663A (zh) * 2013-04-12 2013-07-17 山西太钢不锈钢股份有限公司 一种双相和耐热不锈钢连铸中板坯的修磨方法
CN110757256A (zh) * 2019-10-30 2020-02-07 南京钢铁股份有限公司 一种去除初轧坯原始脱碳层的方法
CN110757256B (zh) * 2019-10-30 2021-10-26 南京钢铁股份有限公司 一种去除初轧坯原始脱碳层的方法

Also Published As

Publication number Publication date
ZA714047B (en) 1972-08-30
JPS5036594B1 (enrdf_load_stackoverflow) 1975-11-26
IT942121B (it) 1973-03-20
CA955835A (en) 1974-10-08

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