EP3388160A1 - Procédé de production de poutre d'acier en h, et laminoir - Google Patents

Procédé de production de poutre d'acier en h, et laminoir Download PDF

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Publication number
EP3388160A1
EP3388160A1 EP16883696.3A EP16883696A EP3388160A1 EP 3388160 A1 EP3388160 A1 EP 3388160A1 EP 16883696 A EP16883696 A EP 16883696A EP 3388160 A1 EP3388160 A1 EP 3388160A1
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EP
European Patent Office
Prior art keywords
calibers
caliber
rolled
bending
projections
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.)
Withdrawn
Application number
EP16883696.3A
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German (de)
English (en)
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EP3388160A4 (fr
Inventor
Hiroshi Yamashita
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Nippon Steel Corp
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Nippon Steel and Sumitomo Metal Corp
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Application filed by Nippon Steel and Sumitomo Metal Corp filed Critical Nippon Steel and Sumitomo Metal Corp
Publication of EP3388160A1 publication Critical patent/EP3388160A1/fr
Publication of EP3388160A4 publication Critical patent/EP3388160A4/fr
Withdrawn legal-status Critical Current

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    • 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
    • B21B1/08—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 structural sections, i.e. work of special cross-section, e.g. angle steel
    • B21B1/088—H- or I-sections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/02—Shape or construction of rolls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2203/00—Auxiliary arrangements, devices or methods in combination with rolling mills or rolling methods
    • B21B2203/18—Rolls or rollers

Definitions

  • the present invention relates to a method for producing H-shaped steel using a slab or the like having, for example, a rectangular cross section as a material, and a rolling apparatus.
  • a material such as a slab or a bloom extracted from a heating furnace is shaped into a raw blank (a material to be rolled in a so-called dog-bone shape) by a rough rolling mill (BD). Thicknesses of a web and flanges of the raw blank are subjected to reduction by an intermediate universal rolling mill, and flanges of a material to be rolled are subjected to width reduction and forging and shaping of end surfaces by an edger rolling mill close to the intermediate universal rolling mill. Then, an H-shaped steel product is shaped by a finishing universal rolling mill.
  • BD rough rolling mill
  • Patent Document 1 1)
  • Patent Document 2 discloses a technique of forming flange-corresponding portions of H-shaped steel by creating splits on slab end surfaces, sequentially making the splits deeper, and then expanding the splits in a box caliber.
  • the rate of spread which represents the rate of a spread amount of the flange width to an edging amount
  • the rate of spread is approximately 0.8 even under a condition that the efficiency at the initial stage of edging is the highest, decreases as the spread amount of the flange width increases under a condition that edging is repeated in the same caliber, and finally becomes approximately 0.5.
  • flange-corresponding portions are shaped by edging rolling by a box caliber with a bottom surface in a flat shape, immediately on a material such as a slab provided with splits through no transition of split shapes or the like.
  • a material such as a slab provided with splits through no transition of split shapes or the like.
  • the change in shape of the material to be rolled in such shaping is decided depending on the relation between the force of a contact portion between the material to be rolled and a roll, and, the flexural rigidity of the material to be rolled, and brings about a problem of being more likely to cause shape defects in the case of producing H-shaped steel with a flange width larger than a conventional flange width.
  • an object of the present invention is to provide a method for producing H-shaped steel, capable of suppressing occurrence of shape defects in a material to be rolled by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material such as a slab using projections in acute-angle tip shapes, and sequentially bending flange portions formed by the splits, to efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width, and capable of separately shaping by the same roll H-shaped steels different in flange width in the H-shaped steel product with a large flange width, and to provide a rolling apparatus.
  • a method for producing H-shaped steel including: a rough rolling step; an intermediate rolling step; and a finish rolling step, wherein: a rolling mill that performs the rough rolling step is engraved with a plurality of calibers configured to shape a material to be rolled, the number of the plurality of calibers being seven or more; shaping in one or a plurality of passes is performed on the material to be rolled in the plurality of calibers; the plurality of calibers include a plurality of wedging calibers as calibers at a previous stage provided with projections configured to create splits vertically with respect to a width direction of the material to be rolled, and a plurality of bending calibers as calibers at a subsequent stage configured to bend flange corresponding portions of the material to be rolled formed by the wedging calibers; the wedging calibers include calibers configured to create two kinds of splits different in length; the bending calibers include ca
  • Each of the plurality of bending calibers may be provided with projections configured to bend the flange corresponding portions by pressing the projections against the flange corresponding portions formed by the wedging calibers.
  • All of the projections provided in the plurality of wedging calibers may have a tip angle of 25° or more and 40° or less.
  • the plurality of bending calibers may be provided at two stages in a configuration in which the calibers having dimensions according to the two kinds of flange corresponding portions different in length are provided with two kinds of projections different in tip angle, respectively; the projections of one of the bending calibers provided at the two stages may have a tip angle of 70° or more and 110° or less; and the projections of another of the bending calibers may have a tip angle of 130° or more and 170° or less.
  • the rough rolling step may be performed in a sizing mill and a rough rolling mill; the calibers at the previous stage of the plurality of wedging calibers and the plurality of bending calibers may be engraved on a roll of the sizing mill; and the calibers at the subsequent stage of the plurality of bending calibers may be engraved on a roll of the rough rolling mill.
  • the rough rolling step may be performed by one rough rolling mill; shaping by the calibers at the previous stage of the plurality of wedging calibers and the plurality of bending calibers may be performed in first heat by the rough rolling mill; and shaping by the calibers at the subsequent stage of the plurality of bending calibers may be performed in second heat by the rough rolling mill.
  • Materials same in thickness and different in width may be used to produce H-shaped steels same in web height and different in flange width.
  • a rolling apparatus performing a rough rolling step in production of H-shaped steel, wherein: the rolling apparatus is engraved with a plurality of calibers configured to perform shaping in one or a plurality of passes on a material to be rolled, the number of the plurality of calibers being seven or more; the plurality of calibers include a plurality of wedging calibers as calibers at a previous stage provided with projections configured to create splits vertically with respect to a width direction of the material to be rolled, and a plurality of bending calibers as calibers at a subsequent stage configured to bend flange corresponding portions of the material to be rolled formed by the wedging calibers; the wedging calibers include calibers configured to create two kinds of splits different in length; the bending calibers include calibers having dimensions according to two kinds of flange corresponding portions different in length formed in the material to be rolled in the wedging calibers; and the bending calibers have
  • Each of the plurality of bending calibers may be provided with projections configured to bend the flange corresponding portions by pressing the projections against the flange corresponding portions formed by the wedging calibers.
  • All of the projections provided in the plurality of wedging calibers may have a tip angle of 25° or more and 40° or less.
  • the plurality of bending calibers may be provided at two stages in a configuration in which the calibers having dimensions according to the two kinds of flange corresponding portions different in length are provided with two kinds of projections different in tip angle, respectively; the projections of one of the bending calibers provided at the two stages may have a tip angle of 70° or more and 110° or less; and the projections of another of the bending calibers may have a tip angle of 130° or more and 170° or less.
  • the rolling apparatus may include a sizing mill and a rough rolling mill; the calibers at the previous stage of the plurality of wedging calibers and the plurality of bending calibers may be engraved on a roll of the sizing mill; and the calibers at the subsequent stage of the plurality of bending calibers may be engraved on a roll of the rough rolling mill.
  • the present invention it becomes possible to suppress occurrence of shape defects in a material to be rolled by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material such as a slab using projections in acute-angle tip shapes, and sequentially bending flange portions formed by the splits, to efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width, and to separately shape by the same roll H-shaped steels different in flange width in the H-shaped steel product with a large flange width.
  • FIG. 1 is an explanatory view about a production line T for H-shaped steel including a rolling facility 1 according to this embodiment.
  • a heating furnace 2 a sizing mill 3, a rough rolling mill 4, an intermediate universal rolling mill 5, and a finishing universal rolling mill 8 are arranged in order from the upstream side.
  • an edger rolling mill 9 is provided close to the intermediate universal rolling mill 5.
  • a steel material in the production line T for explanation is sometimes collectively described as a "material to be rolled A" and its shape is sometimes illustrated using broken lines, oblique lines and the like in the drawings.
  • the material to be rolled A such as a slab 11 extracted from the heating furnace 2 is subjected to rough rolling in the sizing mill 3 and the rough rolling mill 4. Then, the material to be rolled A is subjected to intermediate rolling in the intermediate universal rolling mill 5. During the intermediate rolling, reduction is performed on end portions or the like (flange corresponding portions 12) of the material to be rolled by the edger rolling mill 9 as necessary.
  • an H-shaped steel raw raw blank 13 is shaped by reverse rolling in a plurality of passes through those calibers, and the H-shaped steel raw blank 13 is subjected to application of reduction in a plurality of passes using a rolling mill train composed of two rolling mills such as the intermediate universal rolling mill 5 and the edger rolling mill 9, whereby an intermediate material 14 is shaped.
  • the intermediate material 14 is subjected to finish rolling into a product shape in the finishing universal rolling mill 8, whereby an H-shaped steel product 16 is produced.
  • caliber configurations and caliber shapes engraved on the sizing mill 3 and the rough rolling mill 4 illustrated in FIG. 1 will be explained below referring to the drawings.
  • a caliber which makes the material to be rolled A shaped by those calibers, into a so-called dog-bone shaped H-shaped steel raw blank 13 is further provided, but this caliber is conventionally known one and therefore its illustration and explanation will be omitted in this description.
  • the heating furnace 2, the intermediate universal rolling mill 5, the finishing universal rolling mill 8, the edger rolling mill 9 and the like in the production line T are standard apparatuses conventionally used in production of the H-shaped steel, and their apparatus configurations and so on are already known and therefore their explanation will be omitted in this description.
  • FIG. 2 to FIG. 8 are schematic explanatory views about calibers engraved on the sizing mill 3 and the rough rolling mill 4 which perform a rough rolling step.
  • All of the first caliber to the fourth caliber explained here may be engraved, for example, on the sizing mill 3, or the first caliber to the fourth caliber may be engraved separately on the sizing mill 3 and the rough rolling mill 4.
  • the first caliber to the fourth caliber may be engraved across both the sizing mill 3 and the rough rolling mill 4, or may be engraved on one of the rolling mills.
  • shaping in one or a plurality of passes is performed in each of the calibers.
  • each of the second caliber, the third caliber, and the fourth caliber is composed of two kinds of calibers different in dimension and shape
  • the second caliber is composed of a second-first caliber and a second-second caliber
  • the third caliber is composed of a third-first caliber and a third-second caliber
  • the fourth caliber is composed of a fourth-first caliber and a fourth-second caliber.
  • FIG. 2 is a schematic explanatory view of a first caliber K1.
  • the first caliber K1 is engraved on an upper caliber roll 20 and a lower caliber roll 21 which are a pair of horizontal rolls, and the material to be rolled A is subjected to reduction and shaping in a roll gap between the upper caliber roll 20 and the lower caliber roll 21.
  • a peripheral surface of the upper caliber roll 20 namely, an upper surface of the first caliber K1
  • a projection 25 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 21 namely, a bottom surface of the first caliber K1 is formed with a projection 26 protruding toward the inside of the caliber.
  • projections 25, 26 have tapered shapes, and dimensions such as a protrusion length of the projection 25 and the projection 26 are configured to be equal to each other.
  • a height (protrusion length) of the projections 25, 26 is h1 and a tip portion angle thereof is ⁇ 1a.
  • a tip portion angle (also called a wedge angle) ⁇ 1a of the projections 25, 26 is desirably, for example, 25° or more and 40° or less.
  • the lower limit of the wedge angle is normally decided by the strength of the roll.
  • the material to be rolled A is brought into contact with the rolls (the upper caliber roll 20 and the lower caliber roll 21 in the first caliber K1), and the rolls expand due to heat receiving during the contact and contract due to cooling of the rolls when the material to be rolled A is separated from the rolls.
  • these cycles are repeated, in which if the wedge angle is too small, the heat inputted from the material to be rolled A becomes more likely to be inputted from right and left of the projections because of the small thicknesses of the projections (the projections 25, 26 in the first caliber K1), and the rolls are more likely to become higher in temperature. If the rolls become high in temperature, a thermal amplitude increases to cause a heat crack, possibly leading to a roll breakage.
  • the range of the wedge angle ⁇ 1a is 25° or more and 40° or less in the caliber configuration according to this embodiment.
  • a caliber width of the first caliber K1 is preferably substantially equal to the thickness of the material to be rolled A (namely, a slab thickness).
  • a slab thickness namely, a slab thickness
  • the widths of the caliber at the tip portion portions of the projections 25, 26 formed in the first caliber K1 is set to be the same as the slab thickness, a right-left centering property of the material to be rolled A is suitably secured.
  • a reduction amount at the projections 25, 26 (reduction amount ⁇ T at wedge tips) at the time when the projections 25, 26 are pressed against the upper and lower end portions (slab end surfaces) of the material to be rolled A to form the splits 28, 29 is made sufficiently larger than a reduction amount at the slab upper and lower end portions (reduction amount ⁇ E at slab end surfaces) and thereby forms the splits 28, 29.
  • FIG. 3 is a schematic explanatory view of a second caliber K2-1.
  • the second caliber K2-1 is engraved on an upper caliber roll 30 and a lower caliber roll 31 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 30 (namely, an upper surface of the second caliber K2-1) is formed with a projection 35 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 31 namely, a bottom surface of the second caliber K2-1
  • projection 36 protruding toward the inside of the caliber.
  • These projections 35, 36 have tapered shapes, and dimensions such as a protrusion length of the projection 35 and the projection 36 are configured to be equal to each other.
  • a tip portion angle of the projections 35, 36 is desirably a wedge angle ⁇ 1b of 25° or more and 40° or less.
  • a height (protrusion length) h2 of the projections 35, 36 is configured to be larger than the height h1 of the projections 25, 26 of the first caliber K1 so as to be h2 > h1.
  • the height h2 of the projections 35, 36 formed in the second caliber K2-1 is larger than the height h1 of the projections 25, 26 formed in the first caliber K1, and an intrusion length into the upper and lower end portions (slab end surfaces) of the material to be rolled A is also similarly larger in the second caliber K2-1.
  • An intrusion depth into the material to be rolled A of the projections 35, 36 in the second caliber K2-1 is the same as the height h2 of the projections 35, 36.
  • an intrusion depth h1' into the material to be rolled A of the projections 25, 26 in the first caliber K1 and the intrusion depth h2 into the material to be rolled A of the projections 35, 36 in the second caliber K2-1 satisfy a relation of h1' ⁇ h2.
  • angles ⁇ f formed between caliber upper surfaces 30a, 30b and caliber bottom surfaces 31a, 31b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 35, 36, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 3 .
  • the shaping in the second caliber K2-1 is performed by multi-pass, and in the multi-pass shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 30a, 30b and the caliber bottom surfaces 31a, 31b facing them in the final pass.
  • This is because if the upper and lower end portions of the material to be rolled A are made to be out of contact with the inside of the caliber in all passes in the second caliber K2-1, a shape defect such as flange corresponding portions (the later-described flange portions 100) being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • FIG. 4 is a schematic explanatory view of a second caliber K2-2.
  • the second caliber K2-2 is engraved on an upper caliber roll 40 and a lower caliber roll 41 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 40 (namely, an upper surface of the second caliber K2-2) is formed with a projection 45 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 41 namely, a bottom surface of the second caliber K2-2
  • These projections 45, 46 have tapered shapes, and dimensions such as a protrusion length of the projection 45 and the projection 46 of the second caliber K2-2 are configured to be equal to each other.
  • the shapes of the projections 45, 46 are similar shapes as the shapes of the projections 35, 36 of the aforementioned second caliber K2-1, in which a tip portion angle is similarly a wedge angle ⁇ 1b of 25° or more and 40° or less. Further, a height h2' of the projections 45, 46 is configured to be larger than the height h2 of the aforementioned projections 35, 36 (namely, h2 ⁇ h2').
  • angles ⁇ f formed between caliber upper surfaces 40a, 40b and caliber bottom surfaces 41a, 41b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 45, 46, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 4 .
  • an intrusion length of the projections 45, 46 at the time when pressed against the upper and lower end portions (slab end surfaces) of the material to be rolled A is configured to be larger than that in any of the first caliber K1 and the second caliber K2-1 as illustrated in FIG. 4 , further deeper splits 48, 49 are formed in the second caliber K2-2.
  • the shaping in the second caliber K2-2 is performed by multi-pass, and in the multi-pass shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 40a, 40b and the caliber bottom surfaces 41a, 41b facing them in the final pass.
  • This is because if the upper and lower end portions of the material to be rolled A are made to be out of contact with the inside of the caliber in all passes in the second caliber K2-2, a shape defect such as flange corresponding portions (the later-described flange portions 100) being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • the second calibers K2-1, K2-2 can be used properly as needed, and there are conceivable cases such as a case of performing shaping by passing the material to be rolled A passed through the first caliber K1 through only the second caliber K2-1 and a case of performing shaping by passing the material to be rolled A passed through the first caliber K1 through both the second caliber K2-1 and the second caliber K2-2.
  • FIG. 3 illustrates the shape of a material to be rolled in the case of shaping an H-shaped steel raw blank small in flange half-width of the flange corresponding portions (the parts corresponding to the later-described flange portions 100) by passing the material through only the second caliber K2-1
  • FIG. 3 illustrates the shape of a material to be rolled in the case of shaping an H-shaped steel raw blank small in flange half-width of the flange corresponding portions (the parts corresponding to the later-described flange portions 100) by passing the material through only the second caliber K2-1
  • FIG. 4 illustrates the shape of a material to be rolled in the case of using a material having a larger slab width than (different in material section from) that in the case illustrated in FIG. 3 and shaping an H-shaped steel raw blank large in flange half-width of the flange corresponding portions (the parts corresponding to the later-described flange portions 100) by passing the material through both the second caliber K2-1 and the second caliber K2-2.
  • Such proper use enables shaping to be performed separately in the case where the flange half-width of the flange corresponding portions (the parts corresponding to the later-described flange portions 100) shaped by forming splits in the upper and lower end portions (slab end surfaces) of the material to be rolled A is small and the case where the flange half-width is large.
  • use of the two calibers (second calibers K2-1, K2-2) enables shaping for producing two kinds of products different in flange width, as the H-shaped steel being the final product, from materials which are the same in slab thickness and different in width.
  • the slabs used as the materials are materials which are the same in thickness and different in width (slab width). Accordingly, use of the material small in slab width in the case of performing shaping by passing the material through only the second caliber K2-1 and use of the material large in slab width in the case of performing shaping by passing the material through both the second caliber K2-1 and the second caliber K2-2, enables shaping separately in the case where the flange half-width is small (see FIG. 3 ) and the case where the flange half-width is large (see FIG. 4 ).
  • first caliber K1 and the second calibers K2-1, K2-2 explained above are for forming splits in the upper and lower end portions (slab end surfaces) of the material to be rolled A, and are therefore called wedging calibers.
  • FIG. 5 is a schematic explanatory view of a third caliber K3-1.
  • the third caliber K3-1 is engraved on an upper caliber roll 50 and a lower caliber roll 51 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 50 (namely, an upper surface of the third caliber K3-1) is formed with a projection 55 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 51 namely, a bottom surface of the third caliber K3-1) is formed with a projection 56 protruding toward the inside of the caliber.
  • These projections 55, 56 have tapered shapes, and dimensions such as a protrusion length of the projection 55 and the projection 56 are configured to be equal to each other.
  • a tip portion angle ⁇ 2 of the projections 55, 56 is configured to be larger than the aforementioned angle ⁇ 1b, and an intrusion depth h3 of the projections 55, 56 into the material to be rolled A is smaller than the intrusion depth h2 of the projections 35, 36 in the second caliber K2-1 (namely, h3 ⁇ h2).
  • angles ⁇ f formed between caliber upper surfaces 50a, 50b and caliber bottom surfaces 51a, 51b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 55, 56, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 5 .
  • the splits 38, 39 formed in the second caliber K2-1 at the upper and lower end portions (slab end surfaces) of the material to be rolled A passed through the second caliber K2-1 are pressed against the projections 55, 56 and thereby become splits 58, 59.
  • a deepest portion angle (hereinafter, also called a split angle) of the splits 58, 59 becomes ⁇ 2.
  • shaping is performed so that divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 38, 39 in the second caliber K2-1 are bent outward.
  • the shaping in the third caliber K3-1 is performed by at least one pass or more, and in the shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 50a, 50b and the caliber bottom surfaces 51a, 51b facing them in the final pass.
  • a shape defect such as flange corresponding portions (the later-described flange portions 100) being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • FIG. 6 is a schematic explanatory view of a third caliber K3-2.
  • the third caliber K3-2 is engraved on an upper caliber roll 60 and a lower caliber roll 61 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 60 (namely, an upper surface of the third caliber K3-2) is formed with a projection 65 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 61 namely, a bottom surface of the third caliber K3-2
  • projections 65, 66 have tapered shapes, and dimensions such as a protrusion length of the projection 65 and the projection 66 are configured to be equal to each other.
  • the shapes of the projections 65, 66 are similar shapes as the shapes of the projections 55, 56 of the aforementioned third caliber K3-1, in which a tip portion angle is similarly a wedge angle ⁇ 2 and a height h3' of the projections 65, 66 is configured to be larger than the height h3 of the projections 55, 56 (namely, h3 ⁇ h3'). Further, angles ⁇ f formed between caliber upper surfaces 60a, 60b and caliber bottom surfaces 61a, 61b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 65, 66, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 6 .
  • the splits 48, 49 formed in the second caliber K2-2 at the upper and lower end portions (slab end surfaces) of the material to be rolled A passed through the second caliber K2-2 are pressed against the projections 65, 66 and thereby become splits 68, 69.
  • a deepest portion angle (hereinafter, also called a split angle) of the splits 68, 69 becomes ⁇ 2.
  • shaping is performed so that divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 48, 49 in the second caliber K2-2 are bent outward.
  • the shaping in the third caliber K3-2 is performed by at least one pass or more, and in the shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 60a, 60b and the caliber bottom surfaces 61a, 61b facing them in the final pass.
  • a shape defect such as flange corresponding portions (the later-described flange portions 100) being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • the third caliber K3-1 and the third caliber K3-2 explained referring to FIG. 5 and FIG. 6 are for calibers for bending outward the divided parts (the parts corresponding to the later-described flange portions 100) shaped by the splits
  • the third caliber K3-1 is for shaping the material to be rolled A shaped by using only the second caliber K2-1 as a caliber at a previous stage
  • the third caliber K3-2 is for shaping the material to be rolled A shaped by using the second caliber K2-1 and the second caliber K2-2 as calibers at a previous stage.
  • the third caliber K3-1 is used when producing a product small in flange width and the third caliber K3-2 is used when producing a product large in flange width.
  • shaping is performed so that the flange corresponding portions (the later-described flange portions 100) shaped by the third caliber K3-2 are larger in flange half-width than the flange corresponding portions (the later-described flange portions 100) shaped by the third caliber K3-1.
  • the split angle ⁇ 2 of the third calibers K3-1, K3-2 is desirably set, for example, to 70° or more and 110° or less.
  • shape defects such as deformation unbalance between right and left flange portions 80 and crush of the outside surfaces of the flange portions 80 possibly occur, and a shape defect that a middle portion of the outside surface of the flange portion 80 is formed into a material-accumulated shape in shaping the dog-bone shape in a known flat shaping caliber to cause a product flaw possibly occurs.
  • the range of the split angle ⁇ 2 is 70° or more and 110° or less in the caliber configuration according to this embodiment.
  • FIG. 7 is a schematic explanatory view of a fourth caliber K4-1.
  • the fourth caliber K4-1 is engraved on an upper caliber roll 70 and a lower caliber roll 71 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 70 (namely, an upper surface of the fourth caliber K4-1) is formed with a projection 75 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 71 namely, a bottom surface of the fourth caliber K4-1) is formed with a projection 76 protruding toward the inside of the caliber.
  • These projections 75, 76 have tapered shapes, and dimensions such as a protrusion length of the projection 75 and the projection 76 are configured to be equal to each other.
  • a tip portion angle ⁇ 3 of the projections 75, 76 is configured to be larger than the aforementioned angle ⁇ 2, and an intrusion depth h4 of the projections 75, 76 into the material to be rolled A is smaller than the intrusion depth h3 of the projections 55, 56 (namely, h4 ⁇ h3).
  • angles ⁇ f formed between caliber upper surfaces 70a, 70b and caliber bottom surfaces 71a, 71b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 75, 76, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 7 .
  • the splits 58, 59 formed in the third caliber K3-1 at the upper and lower end portions (slab end surfaces) of the material to be rolled A passed through the third caliber K3-1 are pressed against the projections 75, 76 and thereby become splits 78, 79.
  • a deepest portion angle (hereinafter, also called a split angle) of the splits 78, 79 becomes ⁇ 3.
  • shaping is performed so that divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 58, 59 in the third caliber K3-1 are bent outward.
  • the shaping in the fourth caliber K4-1 is performed by at least one pass or more, and in the shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 70a, 70b and the caliber bottom surfaces 71a, 71b facing them in the final pass.
  • a shape defect such as flange corresponding portions (the later-described flange portions 100) being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • FIG. 8 is a schematic explanatory view of a fourth caliber K4-2.
  • the fourth caliber K4-2 is engraved on an upper caliber roll 80 and a lower caliber roll 81 which are a pair of horizontal rolls.
  • a peripheral surface of the upper caliber roll 80 (namely, an upper surface of the fourth caliber K4-2) is formed with a projection 85 protruding toward the inside of the caliber.
  • a peripheral surface of the lower caliber roll 81 namely, a bottom surface of the fourth caliber K4-2) is formed with a projection 86 protruding toward the inside of the caliber.
  • These projections 85, 86 have tapered shapes, and dimensions such as a protrusion length of the projection 85 and the projection 86 are configured to be equal to each other.
  • the shapes of the projections 85, 86 are similar shapes as the shapes of the projections 75, 76 of the aforementioned fourth caliber K4-1, in which a tip portion angle is similarly a wedge angle ⁇ 3 and a height h3' of the projections 85, 86 is configured to be larger than the height h4 of the projections 75, 76 (namely, h4 ⁇ h4'). Further, angles ⁇ f formed between caliber upper surfaces 80a, 80b and caliber bottom surfaces 81a, 81b facing the upper and lower end portions (slab end surfaces) of the material to be rolled A, and, inclined surfaces of the projections 85, 86, are configured to be about 90° (almost right angle) at all of four locations illustrated in FIG. 8 .
  • the splits 68, 69 formed in the third caliber K3-2 at the upper and lower end portions (slab end surfaces) of the material to be rolled A passed through the third caliber K3-2 are pressed against the projections 85, 86 and thereby become splits 88, 89.
  • a deepest portion angle (hereinafter, also called a split angle) of the splits 88, 89 becomes ⁇ 3.
  • shaping is performed so that divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 68, 69 in the third caliber K3-2 are bent outward.
  • the parts of the upper and lower end portions of the material to be rolled A shaped in this manner are parts corresponding to flanges of a later-described H-shaped steel product and called the flange portions 100 here.
  • the shaping in the fourth caliber K4-2 is performed by at least one pass or more, and in the shaping, shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surfaces 80a, 80b and the caliber bottom surfaces 81a, 81b facing them in the final pass.
  • the upper and lower end portions of the material to be rolled A are made to be out of contact with the inside of the caliber in all passes in the fourth caliber K4-2, a shape defect such as the flange portions 100 being shaped to be laterally asymmetrical possibly occurs, bringing about a problem in terms of a material passing property.
  • the split angle ⁇ 3 of the fourth calibers K4-1, K4-2 is desirably set to an angle slightly smaller than 180° , and is desirably set to, for example, 130° or more and 170° or less. This is because if the split angle ⁇ 3 is set to 180° , spread occurs on the outside of the flange portions 100 at the time of decreasing the web thickness in the flat shaping caliber being the next step, and an overfill is likely to occur in rolling in the flat shaping caliber.
  • the split angle ⁇ 3 is suitably decided in consideration of the shape of the flat shaping caliber and the reduction amount of the web thickness.
  • both the fourth caliber K4-1 and the fourth caliber K4-2 explained referring to FIG. 7 and FIG. 8 are calibers for bending outward the divided parts (the later-described flange portions 100) shaped by the splits
  • the fourth caliber K4-1 is for shaping the material to be rolled A shaped by using the third caliber K3-1 as a caliber at a previous stage
  • the fourth caliber K4-2 is for shaping the material to be rolled A shaped by using the third caliber K3-2 as a caliber at a previous stage.
  • the fourth caliber K4-1 is used when producing a product small in flange width and the fourth caliber K4-2 is used when producing a product large in flange width.
  • shaping is performed so that the flange portions 100 shaped by the fourth caliber K4-2 are larger in flange half-width than the flange portions 100 shaped by the fourth caliber K4-1.
  • the third calibers K3-1, K3-2 and the fourth calibers K4-1 K4-2 explained above perform shaping of bending outward the divided parts (the later-described flange portions 100) formed at the upper and lower end portions (slab end surfaces) of the material to be rolled A, and are therefore called bending calibers.
  • Steps in the case of producing two kinds of H-shaped steel products different in half-width of the flange portion 100 from slab materials having the same thickness and different widths in the rolling and shaping by the first caliber K1 to the fourth calibers K4-1, K4-2 of the H-shaped steel raw blank 13 will be briefly explained. Specifically, shaping of the H-shaped steel raw blank in the case of producing a first H-shaped steel product (small-width product) having a flange half-width of L1 and a second H-shaped steel product (large-width product) having a flange half-width of L2 (> L1) will be explained.
  • first caliber K1 On the slab materials 11 extracted from the heating furnace 2, formation of the splits 28, 29 is performed on upper and lower end portions in the first caliber K1 (see FIG. 2 ). Subsequently, in the second caliber K2-1, shaping is performed to make the splits 28, 29 deeper to form the splits 38, 39.
  • the steps in the first caliber K1 and the second caliber K2-1 are performed commonly on the first H-shaped steel product and the second H-shaped steel product (see FIG. 3 ). At this time, the thicknesses of the slab materials 11 to be used are the same for both of them, but the slab width of the material corresponding to the second H-shaped steel product is larger.
  • the material to be rolled A is shaped in the third caliber K3-1, the splits 38, 39 are spread out, and the divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 58, 59 are bent outward (see FIG. 5 ). Then, the material to be rolled A shaped in the third caliber K3-1 is further shaped in the fourth caliber K4-1, in which the divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 78, 79 are further bent outward (see FIG. 7 ).
  • the flange half-width L1 of the first H-shaped steel product depends on the half-width of the flange corresponding portions shaped along with the formation of the splits 38, 39 in the second caliber K2-1.
  • the material to be rolled A shaped in the third caliber K3-2 is further shaped in the fourth caliber K4-2, in which the divided parts (the parts corresponding to the later-described flange portions 100) shaped along with the formation of the splits 88, 89 are bent outward (see FIG. 8 ).
  • the flange half-width L2 of the second H-shaped steel product depends on the half-width of the flange corresponding portions shaped along with the formation of the splits 48, 49 in the second caliber K2-2.
  • the two kinds of H-shaped steel raw blanks thus shaped have the flange half-widths L1 and L2 different from each other as explained above.
  • the widths of the H-shaped steel raw blanks the widths of the parts corresponding to the webs are almost equal. Shaping the H-shaped steel raw blanks with the above configurations enables rolling and shaping of the two kinds of H-shaped steel raw blanks at the same roll chance in the rolling and shaping in the intermediate universal rolling mill 5, the edger rolling mill 9, and the finishing universal rolling mill 8 at a subsequent stage.
  • Table 1 is a table made by summarizing shaping processes of the H-shaped steel raw blanks in the case of producing the aforementioned first H-shaped steel product (small-width product) having a flange half-width of L1 and second H-shaped steel product (large-width product) having a flange half-width of L2 (> L1).
  • caliber names G1 to G4-2 in Table 1 correspond to the first caliber K1 to the fourth caliber K4-2, the stand No.
  • 1st time and 2nd time indicates an example of rolling calibers and their order in the case where when only one rolling stand for performing rough rolling is provided, operation is performed in two separate roll chances for heating twice in order to compensate for insufficiency of a roll barrel length.
  • the numbers of 1 to 4 regarding the first H-shaped steel product (small-width product) and the numbers of 1 to 5 regarding the second H-shaped steel product (large-width product) indicate calibers through which the material is passed and the order of the calibers.
  • the first H-shaped steel product (small-width product) and the second H-shaped steel product (large-width product) are shaped separately.
  • a second caliber 2-1 (G2-1 in Table) is used for both of the products. This is for stably forming splits without causing lateral nonuniformity of the flange corresponding portions and poor material passage when further deepening the splits 28, 29 formed at the upper and lower end portions of the material to be rolled A in the first caliber K1.
  • the first caliber K1 to the fourth caliber K4-2 are used to create splits in the upper and lower end portions (slab end surfaces) of the material to be rolled A and perform processing of bending to right and left the portions separated to right and left by the splits to perform the shaping of forming the flange portions 100 as explained above, thereby enabling shaping of the H-shaped steel raw blank 13 without performing vertical reduction on the upper and lower end surfaces of the material to be rolled A (slab).
  • the slab materials which are the same in thickness and different in width are used to shape two kinds of raw blanks such as one having a small half-width of the flange portion 100 shaped using the third caliber K3-1 and the fourth caliber K4-1 and one having a large half-width of the flange portion 100 shaped using the third caliber K3-2 and the fourth caliber K4-2, and they are shaped in a so-called dog-bone shape by a known flat shaping caliber (web thinning caliber), whereby H-shaped steel raw blanks 13 different in dimension of the flange portion are shaped.
  • the two kinds of H-shaped steel raw blanks 13 with different flange widths are shaped at the same roll chance from the slab materials having the same thickness and different widths, and the rolling mill train composed of two rolling mills such as the intermediate universal rolling mill 5 and the edger rolling mill 9 illustrated in FIG. 1 is used to apply reduction in a plurality of passes on the two kinds of H-shaped steel raw blanks 13, whereby intermediate materials 14 are shaped.
  • the intermediate materials 14 are then subjected to finish rolling into product shapes in the finishing universal rolling mill 8, whereby H-shaped steel products 16 are produced.
  • rolling and shaping of greatly changing the flange half-width is not performed in an intermediate rolling step and a finish rolling step, so that two kinds of H-shaped steel products different in flange width are produced from the two kinds of H-shaped steel raw blanks 13 different in flange width.
  • shaping is performed to bring the upper and lower end portions (slab end surfaces) of the material to be rolled A into contact with the caliber upper surface and the caliber bottom surface facing them in the final pass in the second caliber K2-1 to the fourth caliber K4-2.
  • the material to be rolled A is shaped while keeping dimensions with high accuracy in a shape following the caliber shape in each caliber rolling step.
  • the raw blank corresponding to the first H-shaped steel product (small-width product) shaped using the third caliber K3-1 and the fourth caliber K4-1 and the raw blank corresponding to the second H-shaped steel product (large-width product) shaped using the third caliber K3-2 and the fourth caliber K4-2 are shaped into shapes following the respective caliber shapes.
  • the above shaping enables efficiently and stably the raw blank corresponding to the first H-shaped steel product (small-width product) and the raw blank corresponding to the second H-shaped steel product (large-width product) while suppressing a shape defect such as right and left flange corresponding portions (the later-described flange portions 100) being nonuniform in material amount.
  • the H-shaped steel products having the two kinds of flange widths produced as above the following dimensions are exemplified. Specifically, conceivable cases include the case of producing products having flange widths of 300 mm and 400 mm, and the case of producing product having flange widths of 400 mm and 500 mm, from the slab materials having the same thickness.
  • the dimension pitch of the flange width of a standard H-shaped steel product is 50 mm, and a case of separately shaping two kinds of H-shaped steel products different in flange width by 50 mm can be realized even by adjustment of a pass schedule or the like by the same caliber.
  • a case of separately shaping two kinds of H-shaped steel products different in flange width by more than 50 mm (for example, 100 mm) deformation of the material to be rolled has a problem in the intermediate rolling step or the like, requiring adjustment of the flange width from the stage of shaping the raw blank. Accordingly, in such a case, use of the method according to the above embodiment leads to production of two kinds of H-shaped steel products different in flange width by separate shaping at the same roll chance.
  • the first caliber K1 to the fourth caliber K4-2 may be engraved across both the sizing mill 3 and the rough rolling mill 4 or may be engraved on one of the rolling mills, but it is more desirable that the first caliber K1 to the third caliber K3-2 are engraved on the sizing mill 3 as a first rolling mill and the fourth calibers K4-1 and K4-2 are engraved on the rough rolling mill 4 as a second rolling mill as explained referring to Table 1.
  • shaping may be performed in first heat using a roll on which the first caliber K1 to the third caliber K3-2 are engraved, then rolls are rearranged, and shaping may be performed in second heat using a roll on which the fourth calibers K4-1 and K4-2 are engraved.
  • the present invention is applicable to a producing technique of producing H-shaped steel using a slab or the like having, for example, a rectangular cross section as a material.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Metal Rolling (AREA)
  • Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
  • Rod-Shaped Construction Members (AREA)
EP16883696.3A 2016-01-07 2016-11-17 Procédé de production de poutre d'acier en h, et laminoir Withdrawn EP3388160A4 (fr)

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JP6447286B2 (ja) * 2015-03-19 2019-01-09 新日鐵住金株式会社 Ｈ形鋼の製造方法及びｈ形鋼製品

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PH12018501323A1 (en) 2019-02-18
JP6593457B2 (ja) 2019-10-23
CN108430659A (zh) 2018-08-21
WO2017119196A1 (fr) 2017-07-13
JPWO2017119196A1 (ja) 2018-10-18
US20190009315A1 (en) 2019-01-10
KR20180097665A (ko) 2018-08-31
EP3388160A4 (fr) 2019-10-09

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