JP2009006358A - Equipment and method for manufacturing steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely suppress peaking after O formation in a process where a steel pipe is manufactured by performing C-formation, U-formation and the O-formation of a steel plate. <P>SOLUTION: Edge-part deforming mechanisms 52A, 52B for deforming the edge parts 5e, 5f of a steel plate 5 and a control section 53 for controlling the edge deforming mechanisms 52A, 52B are provided in the C-formation. The control section 53 is constituted so that strength information for every steel plate 5 is obtained and edge part forming conditions corresponding to each steel plate 5 are respectively obtained on the basis of the strength information for every steel plate 5. The edge deforming mechanisms 52A, 52B allows the edge parts 5e, 5f of each steel plate to be respectively deformed according to the edge part forming conditions corresponding to each steel plate 5. By a such constitution, the generation of peaking is surely prevented even when the strength of each steel plate 5 is different each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steel pipe manufacturing facility and a steel pipe manufacturing method.

  A UO manufacturing method is known as a typical method for manufacturing a steel pipe (see Patent Documents 1, 2, and 3). In this method, first, C forming (end bending) is performed to bend and deform both edges of a flat steel plate that is a material to be formed, and then the center portion of the material to be formed is bent and deformed so that the material to be formed is substantially U-shaped. U-shaped to form a letter, and further O-shaped to deform the material to be molded from a substantially U-shape to a substantially O-shape (substantially circular), then a butted portion (part where both edges are close to each other) ) Are welded to produce a circular welded steel pipe (UO steel pipe). The welded steel pipe is formed into a desired shape and dimension by a pipe expander. In addition, as a to-be-molded material, the thick board manufactured by rolling a slab (steel piece obtained by cut | disconnecting the slab cast in strip | belt shape in the continuous casting equipment) is used.

  In such a UO manufacturing method, it is required to suppress the peaking of the butt portion after the O molding by appropriately performing the C molding of the material to be molded. For example, if the amount of deformation at both edges of the material to be molded in C molding is too small, the butted portion protrudes outward. That is, positive peaking occurs. On the other hand, if the amount of deformation at both edges is too large, the butted portion will be recessed toward the inside. That is, minus peaking occurs. As a method for suppressing such peaking, conventionally, there is a method for obtaining edge molding conditions (such as molding force applied to the edge of the molding material) in C molding from the strength, plate thickness, etc. of the molding material. It has been proposed (see Patent Document 3).

Japanese Patent Publication No. 60-40934 JP-A-7-32049 Japanese Patent No. 3214292

  However, in the conventional steel pipe manufacturing method, there is a problem that the edge forming conditions are inappropriate because the set value of the strength of the molding material used when obtaining the edge forming conditions is different from the actual strength. It was. For example, in the case where thick plates manufactured from the slab as described above are used as the molding material, the molding materials having the same lot (that is, the thick plates obtained from the same slab) are substantially the same. The component values were estimated to have almost the same material, and the strength setting values were also the same. However, in practice, there is a large variation in strength, and it is difficult to sufficiently suppress peaking. That is, when the actual strength of the material to be molded is higher than the set value, the pressure applied to the edge of the material to be molded is insufficient, and the amount of deformation of the edge of the material to be molded is too small. Speaking was easy to occur. On the other hand, if the actual strength of the molding material is lower than the set value, the pressure applied to the edge of the molding material becomes excessive, the amount of deformation of the edge of the molding material is too large, and minus Peaking was easy to occur.

  This invention is made | formed in view of said point, and it aims at providing the steel pipe manufacturing equipment and steel pipe manufacturing method which can suppress the peaking after O shaping | molding reliably.

  In order to solve the above-described problems, according to the present invention, a steel pipe manufacturing facility for manufacturing a steel pipe by sequentially forming a steel sheet by C forming, U forming, and O forming, an edge that deforms the edge of the steel sheet in the C forming. And a control unit for controlling the edge deformation mechanism, the control unit acquires strength information of each steel plate, and based on the strength information, sets the edge forming conditions corresponding to each steel plate. Obtaining each, controlling the edge deformation mechanism according to the edge forming conditions, the edge deformation mechanism respectively deform the edge of each steel plate according to the edge forming conditions corresponding to each steel plate A steel pipe manufacturing facility is provided.

The strength information may be obtained based on the chemical composition of the steel sheet and the TMCP conditions used in the steel sheet rolling equipment. The intensity information may be obtained based on, for example, the formula (1).
TS = aX ³ + bX ² + cX
+ DY ³ + eY ² + fY
+ GZ ³ + hZ ² + iZ + j + kβ (1)
(TS: Tensile strength, X: Heating temperature, Y: Water cooling start temperature, Z: Water cooling stop temperature, β: Hardenability, a, b, c, d, e, f, g, h, i, j, k: coefficient)

  The strength information may be obtained by actually measuring the strength of the steel plate. The strength information may be obtained by a tensile test or a hardness test.

  The edge deformation mechanism includes a lower mold that contacts the lower surface side of the steel sheet and an upper mold that contacts the upper surface side of the steel sheet, and the edge portion of the steel sheet is formed by the lower mold and the upper mold. It is good also as a structure which press-molds.

  The edge deformation mechanism includes a lower roll that contacts the lower surface side of the steel plate and an upper roll that contacts the upper surface side of the steel plate, and the edge of the steel plate is rolled by the lower roll and the upper roll. It is good also as a structure to shape.

  Furthermore, according to the present invention, there is provided a steel pipe manufacturing method for manufacturing a steel pipe by sequentially performing C forming, U forming, O forming of a steel sheet, obtaining strength information of each steel plate, and based on the strength information, Steel pipe manufacturing, characterized in that each edge forming condition corresponding to each steel sheet is determined and each steel sheet is C-shaped by deforming the edge of each steel sheet according to the edge forming conditions corresponding to each steel sheet. A method is provided.

The strength information may be obtained based on the chemical composition of the steel sheet and the TMCP condition in the rolling process of the steel sheet. The intensity information may be obtained based on, for example, the formula (1).
TS = aX ³ + bX ² + cX
+ DY ³ + eY ² + fY
+ GZ ³ + hZ ² + iZ + j + kβ (1)
(TS: Tensile strength, X: Heating temperature, Y: Water cooling start temperature, Z: Water cooling stop temperature, β: Hardenability, a, b, c, d, e, f, g, h, i, j, k: coefficient)

  The strength information may be obtained by actually measuring the strength of the steel plate. The strength information may be obtained by a tensile test or a hardness test.

  The edge forming condition may include pressure information applied to the edge of the steel plate and position information with respect to the steel plate of an edge deformation mechanism that deforms the edge of the steel plate.

  In this steel pipe manufacturing method, the steel sheet may be C-formed by press forming. Further, the steel plate may be C-formed by roll forming.

  According to the present invention, by adjusting the edge forming conditions individually based on the strength of each steel plate (formable material), even if the strength of each steel plate is different from each other, the occurrence of peaking in each steel pipe is ensured. Can be prevented. Furthermore, welding defects, conveyance failures, pipe expansion cracks and the like due to peaking can be prevented.

  Embodiments according to the present invention will be described below. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 shows a rolling equipment 2 (steel production equipment) for producing a thick plate as a steel plate from a slab (for example, a steel piece obtained by cutting a slab cast in a strip shape in a continuous casting equipment), and a thick plate. The schematic of the steel pipe manufacturing equipment 3 which manufactures a steel pipe by carrying out C forming, U forming, and O forming sequentially is shown.

  As shown in FIG. 1, a rolling facility 2 includes a heating furnace 10 that heats a molding material 5 (slab), and a rough rolling mill 11 that performs rough rolling (hot rolling) the molding material 5 heated by the heating furnace 10. A finish rolling machine 12 that finish-rolls (hot-rolls) the roughly-rolled material 5, a cooling unit 13 that cools the finish-rolled material 5, and the like. The cooling unit 13 is configured to supply cooling water to the molding material 5 in a high temperature state after finish rolling, and to perform a water cooling process (water quenching) of the molding material 5. Thereby, the to-be-molded material 5 (thick board) which has a predetermined material (strength etc.) and a dimension is manufactured. Moreover, the rolling equipment 2 in this embodiment is configured to perform processing using a control cooling technique such as TMCP (Thermal Mechanical Control Process). That is, the heating temperature X in the heating furnace 10, the water cooling start temperature Y in the cooling unit 13, the water cooling stop temperature Z in the cooling unit 13, etc. are appropriately adjusted according to the TMCP conditions set individually for each molding material 5. However, it has the structure which can roll each to-be-shaped material 5. FIG.

  The steel pipe manufacturing equipment 3 performs a C molding machine 21 (C press machine) that performs C molding (C press) of the workpiece 5 (thick plate), and U molding (U press) of the C molded workpiece 5. U molding machine 22 (U press machine), O molding machine 23 (O press machine) that performs O molding (O press) of U molded material 5, and ends of O molded material 5 A welding machine 31 for welding, a pipe expanding machine 32 for expanding the molding material 5 to predetermined dimensions (inner diameter, outer diameter, wall thickness) and the like are provided. Further, although not shown, a tab plate welding machine for attaching a tab plate 38 to be described later to the material 5 (thick plate) before being carried into the C forming machine 21, and an edge for performing groove processing to be described later A mirror, a tab plate removing machine for removing a tab plate 38 to be described later from the workpiece 5 after welding by the welding machine 31, and the like are provided.

  In addition, each equipment provided in the rolling equipment 2 and the steel pipe manufacturing equipment 3 (the heating furnace 10, the roughing mill 11, the finishing mill 12, the cooling unit 13, the C molding machine 21, the U molding machine 22, and the O molding machine 23). The welding machine 31, the pipe expansion machine 32, and the like) are controlled by the main control unit 36 (business computer).

FIG. 2 shows the molding material 5 that is C-molded by the C-molding machine 21. The molding material 5 is a steel material (steel plate) having a substantially rectangular flat plate shape, and includes a planar lower surface 5a and an upper surface 5b. Two tab plates 38 are provided at both edge portions facing each other in the length direction D _L (plate length direction) of the molding material 5, that is, at the front edge portion 5 c and the rear edge portion 5 d. The tab plate 38 is provided at the left end and the right end of the front edge 5c, and at the left and right ends of the rear edge 5d, as viewed from the front edge 5c side.

Both edge portions facing each other across the central portion in the width direction D _B of the molded material 5 _(the plate width direction and the direction perpendicular to the length direction D _L), i.e., left edge 5e and right edges 5f Is provided with a groove for welding. That is, for example, as shown in FIG. 3, first groove surfaces 41 are provided on the lower surface 5a side of the left edge portion 5e and the lower surface 5a side of the right edge portion 5f, respectively, and the upper surface 5b side of the left edge portion 5e Second groove surfaces 42 are provided on the upper surface 5b side of the right edge portion 5f. The first groove surface 41, a second open tip surface 42 are respectively provided along the longitudinal direction D _L. Further, the first groove surface 41 is an inclined surface that is gradually inclined upward from the lower surface 5a toward the outside (left side at the left edge portion 5e and right side at the right edge portion 5f). The second groove surface 42 is an inclined surface that is inclined so as to gradually go downward from the upper surface 5b as it goes outward.

  Next, the configuration of the C molding machine 21 will be described. As shown in FIG. 4, the C molding machine 21 deforms the conveyance mechanism 51 that conveys the molding material 5, the left edge deformation mechanism 52A as the edge deformation mechanism that deforms the left edge 5e, and the right edge 5b. A right edge deformation mechanism 52B is provided as an edge deformation mechanism. Further, a C molding machine control unit 53 (so-called process computer) as a control unit for controlling each device (conveying mechanism 51, left edge deformation mechanism 52A, right edge deformation mechanism 52B, etc.) provided in the C molding machine 21. ).

The transport mechanism 51 includes a plurality of transport rolls 51a. Transport rolls 51a are substantially more aligned provided, also, the length direction of the transport rolls 51a (center axis direction) with respect to the conveying direction D ₁ in the conveying direction D ₁ of the the molded material 5 _(horizontal direction) It is provided in a state of being oriented in the vertical horizontal direction. That is, in a state where the molding material 5 is placed on the respective transport rolls 51a, the respective transport rolls 51a are rotated around the respective central axes, whereby the molding material 5 is kept in a substantially horizontal posture in a predetermined transport direction. and it has a configuration for conveying the D _1.

  The left edge portion deformation mechanism 52A includes a pair of dies, that is, a lower die 61 as a first contact body that comes into contact with the lower surface 5a side of the left edge portion 5e during press molding, and a press molding. An upper die 62 as a second contact body that contacts the upper surface 5b side of the left edge portion 5e is provided. Further, although not shown, a mold moving device that moves the lower mold 61 and the upper mold 62 relative to the molding material 5 on the transport mechanism 51 is provided. Further, an edge deformation mechanism control device 65 for controlling the operation of the mold moving device is provided.

Incidentally, the length in the conveying direction D ₁ of the lower die 61, the length in the transport direction D ₁ of the upper mold 62, the length of the left edge 5e (Itacho, of the molded material 5 lengthwise direction D _L The dimension is shorter than In other words, while shifting in the longitudinal direction D _L of the position of the lower die 61 and upper die 62 relative to the left edge 5e, by performing dividing the press-molding a plurality of times, thereby bending deformation across left edge 5e structure It has become.

As shown in FIG. 5, the lower mold 61 includes a concave curved surface 61a formed along a cylindrical surface. The concave curved surface 61a is formed in a concave shape toward the lower left side and gradually upward as it goes from the molding material 5 side to the left side. On the other hand, the upper mold 62 is provided above the lower mold 61 and includes a convex curved surface 62a formed along a cylindrical surface. The convex curved surface 62a is formed so as to protrude downward on the left side and gradually upward as it goes from the molding material 5 side to the left side. That is, the left edge portion 5e is bent by press molding by pressing the left edge portion 5e between the concave curved surface 61a and the convex curved surface 62a. In the example shown in FIG. 5, the portion overlapping the concave curved surface 61a and the convex curved surface 62a in a plan view, i.e., the left side surface of the molded material 5 prior to press-molding the width direction D from (end surface of the left edge 5e) _B width portion of the length L _M bent at is, along the gap between the concave curved surface 61a and the convex curved surface 62a, it is adapted to be bent and deformed into a shape gradually upward toward the left.

Further, the lower mold 61 and the upper mold 62 are moved in the vertical direction (thickness direction D _T (plate thickness of the molding material 5 supported by the transport mechanism 51) by operation of a mold moving device (not shown). direction, it is possible to close and away from each other in the direction) perpendicular to the longitudinal direction D _L and the width direction D _B. that is, when separating the lower mold 61 and upper mold 62 in the vertical direction, the transport mechanism lower die 61 and upper die 62 from the molding material 5 is supported by 51 spaced apart, moving in the conveying direction D ₁ of the molded material 5 with respect to the lower mold 61 and upper mold 62 Further, when the lower mold 61 and the upper mold 62 are brought close to each other in the vertical direction, the lower mold 61 and the upper mold 62 with respect to the molding material 5 supported by the transport mechanism 51. Comes into contact with the workpiece 5 from the lower mold 61 and the upper mold 62. Pressure (pressing pressure, bending force) is configured to be added.

Furthermore, the lower mold 61 and the upper mold 62 can be slid in a horizontal direction (width direction D _B ) orthogonal to the transport direction D ₁ by operation of a mold moving device (not shown). That is, the contact position where the concave curved surface 61a abuts against the molded material 5 which is supported by the transport mechanism 51, the contact position of the convex curved surface 62a is in contact, is configured to be adjusted in the width direction D _B ing. With this configuration, so that the bending length L _M can be adjusted to the desired value.

  The edge deformation mechanism control device 65 is electrically connected to the C molding machine control unit 53, and control information transmitted from the C molding machine control unit 53 (for example, information such as edge molding conditions described later). Accordingly, a mold moving device (not shown) is controlled. That is, a mold moving device (not shown) is operated so as to realize the received edge forming conditions.

  The right edge deformation mechanism 52B has a configuration that is substantially symmetrical to the left edge deformation mechanism 52A. The detailed description of the right edge portion deformation mechanism 52B overlaps with the left edge portion deformation mechanism 52A described above, and is therefore omitted.

  The C molding machine control unit 53 is electrically connected to the main control unit 36, and according to the control information transmitted from the main control unit 36, the edge deformation mechanism control device 65 of the left edge deformation mechanism 52A, Control information is transmitted to the edge deformation mechanism control device 65 of the right edge deformation mechanism 52B. Further, the C molding machine control unit 53 includes information on each material 5 (for example, component values of chemical components of each material 5, TMCP conditions used in the rolling process of each material 5 in the rolling equipment 2, respectively). Information, dimensions of each molding material 5, strength information of each molding material 5, and the like, and further, edge molding corresponding to each molding material 5 based on the strength information of each molding material 5 Conditions can be determined individually for each sheet.

In the present embodiment, information such as the chemical composition of each workpiece 5, TMCP conditions in the rolling equipment 2, and dimensions is stored in the main control unit 36. And, information such as the chemical composition of each molding material 5 stored in the main control unit 36 and the TMCP conditions in the rolling equipment 2 is transmitted from the main control unit 36 to the C molding machine control unit 53. It is acquired by the C molding machine control unit 53. Component values of the chemical components of each of the molding material 5, for example, the C content _{R C} (mass%) of (carbon), the content of Si (silicon) _{R Si} (% by mass), the content of Mn (manganese) R _Mn (mass%), Ni (nickel) content R _Ni (mass%), Cu (copper) content R _Cu (mass%), Cr (chromium) content R _Cr (mass%), V ( the content of vanadium) _{R V} (wt%), Mo (may be the content _{R Mo} (wt%), etc. molybdenum). In addition, the TMCP condition information may include, for example, the heating temperature X in the heating furnace 10, the water cooling start temperature Y in the cooling unit 13, the water cooling stop temperature Z in the cooling unit 13, and the like.

  Further, the C molding machine control unit 53 can calculate the hardenability β (predicted value) of each molding material 5 based on the component value of the chemical component of each molding material 5 received from the main control unit 36. Further, based on the calculated hardenability β and the TMCP condition, the strength TS (predicted value of tensile strength) for each piece of the molding material 5 can be calculated. That is, the strength TS can be obtained based on the chemical component of each molding material 5 and the TMCP condition.

The strength TS can be obtained based on, for example, the following formula (1) (strength prediction formula) and formula (2) (hardenability prediction formula). In the present embodiment, a program for calculating the strength TS using the formulas (1) and (2) is stored in the C molding machine control unit 53, and by executing this program, the strength TS Is calculated.
TS = aX ³ + bX ² + cX
+ DY ³ + eY ² + fY
+ GZ ³ + hZ ² + iZ + j + kβ (1)
(TS: Strength (tensile strength), X: Heating temperature, Y: Water cooling start temperature, Z: Water cooling stop temperature, β: Hardenability, a, b, c, d, e, f, g, h, i, j , K: coefficient)
β = f (R _C , R _Si , R _Mn , R _Ni , R _Cu , R _Cr , R _V , R _Mo ) (2)
(R _C : C content (% by mass), R _Si : Si content (% by mass), R _Mn : Mn content (% by mass), R _Ni : Ni content (% by mass), R _Cu : Cu content (% by mass), R _Cr : Cr content (% by mass), R _V : V content (% by mass), R _Mo : Mo content (% by mass)

Incidentally, the formula (2) means that the hardenability β depends on the component values (R _C , R _Si , R _Mn , R _Ni , R _Cu , R _Cr , R _V , R _Mo ) of the material 5 to be molded. is doing.

Further, the C molding machine control unit 53 is based on the calculated strength TS of the molding material 5 and the thickness of the molding material 5 transmitted from the main control unit 36 (plate thickness, dimension in the thickness direction _DT ). And has a function of calculating edge forming conditions. The edge molding conditions required by the C molding machine controller 53 include, for example, pressure information applied to the left edge 5e by the lower mold 61 and the upper mold 62 of the left edge deformation mechanism 52A, and right edge deformation. Pressure information given to the right edge 5f by the lower mold 61 and the upper mold 62 of the mechanism 52B, position information of the left edge deformation mechanism 52A with respect to the molding material 5 supported by the transport mechanism 51, and the transport mechanism 51 The position information and the like of the right edge portion deformation mechanism 52B with respect to the molding material 5 supported by the above-mentioned are included. In the present embodiment, the position information of the left edge deformation mechanism 52A with respect to the molding material 5 (right edge deformation mechanism 52B), the position information in the width direction D _B of the lower mold 61, the upper die 62 location in the width direction D _B, position information in the thickness direction D _T of the lower mold 61, the position information in the thickness direction D _T of the upper mold 62.

Incidentally, for example, a known method can be used for calculating the edge forming conditions. For example, the pressure applied to the molding material 5 from the left edge deformation mechanism 52A or the right edge deformation mechanism 52B can be obtained from the strength TS of the molding material 5 (see Patent Document 3). Further, for example, after O molding the outer diameter of the molded material 5 (tube expansion before), from such a thickness of the molded material 5 (thickness), the goal of bending length L _M of the left edge 5e or right edge 5f range can be obtained (see Patent Document 1), from the bending length L _M, it is possible to set the position information of the position information and the upper die 62 of the lower mold 61.

  Next, a steel pipe manufacturing method in the steel pipe manufacturing facility 3 configured as described above will be described. First, the main control unit 36 stores in advance information (a chemical component of each material 5, TMCP conditions used in the rolling equipment 2, dimensions, etc.) regarding a plurality of materials 5 (each steel sheet). ing. In addition, the chemical component of each to-be-molded material 5 is stored in the tundish of the continuous casting equipment in the steel making process in the steel making equipment (continuous casting equipment) before the to-be-formed material 5 (slab) is carried into the rolling equipment 2, for example. You may make it obtain | require by sampling from the molten steel etc. which are currently inspected. That is, the analysis result (component value) of the molten steel may be stored in the main control unit 36. As for the TMCP condition, when rolling is performed in the rolling facility 2, the main control unit 36 controls the rolling facility 2 (for example, a process computer that controls the heating furnace 10, a process computer that controls the roughing mill 11, and finish rolling. Control information transmitted to a process computer for controlling the machine 12, a process computer for controlling the cooling unit 13, etc. (for example, a set value of the heating temperature X in the heating furnace 10, a set value of the water cooling start temperature Y in the cooling unit 13) The set value of the water cooling stop temperature Z in the cooling unit 13) may be stored. Alternatively, the actual value of the TMCP condition from the rolling equipment 2 to the main control unit 36 (for example, the actual value of the heating temperature X in the heating furnace 10, the actual value of the water cooling start temperature Y in the cooling unit 13, and the water cooling stop in the cooling unit 13) The actual value of the temperature Z or the like) may be transmitted and stored in the main control unit 36.

  In the steel pipe manufacturing facility 3, a tab plate 38 is first attached to the material 5 by welding, and then groove processing (first groove surface 41, first groove) is performed by cutting using an edge mirror (not shown). Formation of the second groove surface 42). Thereafter, C molding (C press) is performed by the C molding machine 21.

In the C molding machine 21, the C molding machine control unit 53 firstly provides information on the first molding material 5 on which C molding is performed (the chemical composition of the first molding material 5, the first molding material 5). The TMCP conditions, the dimensions of the first molding material 5, etc.) are acquired from the main control unit 36. And by calculating based on said Formula (1), (2), intensity | strength TS ₍₁₎ of the _1st to-be-molded material 5 is calculated | required from a chemical component and TMCP conditions.

Further, the C molding machine control unit 53 determines the edge molding condition corresponding to the first molding material 5 (that is, based on the dimension of the first molding material 5, the calculated strength TS _(1), etc. Pressure information given to the left edge portion 5e of the first molding material 5, pressure information given to the right edge portion 5f of the first molding material 5, and left edge deformation of the first molding material 5 Position information of the mechanism 52A, position information of the right edge portion deformation mechanism 52B with respect to the first molding material 5, and the like) are calculated. That is, for example, the edge molding conditions are set so that the pressure applied to the left edge 5e and the right edge 5f is higher as the water cooling stop temperature Z is lower and the strength TS ₍₁₎ is higher. Thus, the edge molding conditions corresponding to the first workpiece 5 obtained in the C molding machine control unit 53 are set as the edge deformation mechanism control device 65 of the left edge deformation mechanism 52A and the edge of the right edge deformation mechanism 52B. Each is transmitted to the part deformation mechanism control device 65.

Meanwhile, first the molded material 5 is supported substantially horizontal posture by the conveying mechanism 51, it is conveyed along the conveying direction D ₁ (see FIG. 6). During transport, the lower surface 5a is directed downward, an upper surface 5b is directed upwards, the front edge portion 5c is disposed in front (out side in the conveying direction D _1), the trailing edge portion 5d is rear (conveying direction D _{1 on} the carry-in side). Further, the left edge portion 5e is disposed on the left side when viewed from the front edge portion 5c side, and the right edge portion 5f is disposed on the right side. The length direction D _L of the molded member 5 is directed in the conveying direction D _1, the width direction D _B are oriented substantially perpendicular to the conveying direction D _1.

By being conveyed along the conveying direction D ₁ Thus, the molded material 5 is inserted from the front edge portion 5c side left edge deformation mechanism 52A, the right edge deformation mechanism 52B (see FIG. 6). At this time, the lower mold 61 and the upper mold 62 of the left edge deforming mechanism 52A, and the lower mold 61 and the upper mold 62 of the right edge deforming mechanism 52B are separated from each other in the vertical direction. It is made to stand by in the position which does not contact with 5. In this state, the front end of the left edge portion 5e is inserted between the lower mold 61 and the upper mold 62 of the left edge deformation mechanism 52A, and the lower mold 61 and the upper mold of the right edge deformation mechanism 52B are inserted. Between the mold 62, the front end portion of the right edge portion 5f is inserted.

Next, the lower mold 61 and the upper mold 62 of the left edge deforming mechanism 52A and the lower mold 61 and the upper mold 62 of the right edge deforming mechanism 52B are brought close to each other in the vertical direction, so that the left edge The front edge part of the part 5e and the front edge part of the right edge part 5f are respectively between the lower mold 61 (concave surface 61a) and the upper mold 62 (convex surface 62a) of the left edge deformation mechanism 52A, and the right edge part deformation mechanism. 52 is sandwiched between a lower mold 61 and an upper mold 62 and press-molded (see FIGS. 5 and 7). That is, the front end portion (the portion of the length L _M bending from the end face of the left edge 5e) of the left edge 5e, by the pressure given by the lower die 61 and upper die 62 of the left edge deformation mechanism 52A The left edge portion deforming mechanism 52A is bent and deformed along the concave curved surface 61a and the convex curved surface 62a. That is, the shape is curved along a substantially cylindrical surface (in a substantially arc shape when viewed from the front edge portion 5c side) so as to go upward as it goes to the left side. Further, a front end portion (right edge portion 5f of the length L _M bending from the end face of) the right edge 5f, by the pressure given by the lower die 61 and upper die 62 of the right edge deformation mechanism 52B Then, it is bent and deformed along the concave curved surface 61a and the convex curved surface 62a of the right edge portion deformation mechanism 52B. That is, it becomes a shape curved along a substantially cylindrical surface so as to go upward as it goes to the right side. In this way, the front end portion of the left edge portion 5e and the front end portion of the right edge portion 5f are curved in a shape that is symmetrical to each other when viewed from the front edge portion 5c side.

  Further, when performing such press molding, the edge deformation mechanism control device 65 of the left edge deformation mechanism 52 </ b> A receives the edge molding conditions (the edge of the first molding material 5) transmitted from the C molding machine control unit 53. Based on the molding conditions), the mold moving device (not shown) of the left edge portion deformation mechanism 52A is controlled. That is, the concave curved surface 61a and the convex curved surface 62a of the left edge deforming mechanism 52A are edge portions with respect to the molding material 5 (edge molding conditions of the first molding material 5) supported by the transport mechanism 51. It is brought into contact with a predetermined position based on molding conditions. Further, the left edge 5e is pressurized with a predetermined pressure based on the edge molding conditions. Similarly, the edge deformation mechanism control device 65 of the right edge deformation mechanism 52B is based on the edge molding conditions transmitted from the C molding machine control unit 53, and the mold moving device (see FIG. (Not shown). In other words, the concave curved surface 61a and the convex curved surface 62a of the right edge deforming mechanism 52B are brought into contact with the molding material 5 supported by the transport mechanism 51 at predetermined positions based on the edge molding conditions. Further, the right edge 5f is pressurized with a predetermined pressure based on the edge molding conditions. Thus, the left edge deforming mechanism 52A and the right edge deforming mechanism 52B respectively change the front end of the left edge 5e and the front edge of the right edge 5f according to the edge forming conditions transmitted from the C molding machine controller 53. The front edge part of the left edge part 5e and the front edge part (first molded part) of the right edge part 5f are optimal under the optimum edge molding conditions based on the strength TS of the first molded material 5, etc. It is molded into a simple shape.

When the press forming of the front end portion of the left edge portion 5e and the front end portion of the right edge portion 5f is completed, the lower die 61 and the upper die 62 of the left edge portion deformation mechanism 52A, and the lower die 61 of the right edge portion deformation mechanism 52B. And the upper mold 62 are again separated from each other in the vertical direction, and are disposed at a position where they do not contact the material to be molded 5. Then, by the operation of the transport mechanism 51, the molded material 5 is conveyed along the conveying direction D ₁ (see FIG. 8). That is, the relative positions of the left edge deformation mechanism 52A and the right edge deformation mechanism 52B with respect to the molding material 5 are moved backward. Then, the portion adjacent to the rear side of the press-formed portion in the left edge portion 5e (the portion that has not yet been press-formed) is used as the next molding portion in the left edge portion deformation mechanism 52A, and the left edge portion deformation. The mechanism 52A is disposed between the lower mold 61 and the upper mold 62. Further, the portion adjacent to the rear side of the press-formed portion in the right edge portion 5e is the next molding portion in the right edge portion deforming mechanism 52B, and the lower die 61 and the upper die of the right edge portion deforming mechanism 52B. 62. In this state, the transport mechanism 51 is temporarily stopped, and the left edge portion 5e and the right edge portion 5e are respectively press-molded (see FIG. 9) in the same manner as in the above-described press molding. Also at this time, the edge deformation mechanism control device 65 of the left edge deformation mechanism 52A and the edge deformation mechanism control device 65 of the right edge deformation mechanism 52B follow the edge molding conditions of the first workpiece 5 described above. Each mold moving device (not shown) is controlled. In this way, the next part to be molded is also formed into an optimal shape under the optimal edge forming conditions based on the strength TS of the first material 5 as in the case of the first part.

As described above, the first molding material 5 is press-molded sequentially from the front edge portion 5c side to the rear edge portion 5d side based on the edge molding conditions of the first molding material 5. To go. That is, the molded portion by a left edge deformation mechanism 52A, the molded part by right edge deformation mechanism 52B is divided into a plurality of areas in each conveying direction D _1. By that all of the molded part is press-molded, (total of the length L _M bending from the end face of the left edge 5e) left edge 5e whole, the right edge portion 5f total (right edge portion 5f state the entire portion of the length L _M bending from the end face) was allowed to continuously bending deformation, i.e., a state in which C molded into the molded material 5 is applied. Each molded part is molded into an optimal shape under optimal edge molding conditions based on the strength TS of the first molded material 5 and the like, like the first molded part.

  The first molding material 5 subjected to the C molding is carried out of the C molding machine 21 in front of the left edge deformation mechanism 52A and the right edge deformation mechanism 52B. Thus, the C forming process of the first material 5 is completed.

Thereafter, the first to be molded member 5 C molding has been performed is conveyed to the U forming machine 22, the U forming machine 22, the central portion in the width direction D _B, is bent along the substantially cylindrical surface deformation (See FIG. 10). That is, it is U-shaped into a shape having a certain substantially U-shaped cross section.

  The first workpiece 5 that has been subjected to U molding is conveyed to the O molding machine 23, O molded by the O molding machine 23, and shaped into a substantially tubular shape. As shown in FIG. 11, the lower surface 5a becomes the outer peripheral surface 5a, the upper surface 5b becomes the inner peripheral surface 5b, and the left edge portion 5e and the right edge portion 5f are brought close to each other at the upper portion of the molding material 5, and the butting portion 68 Form. Here, since the left edge portion 5e and the right edge portion 5f of the first workpiece 5 are bent and deformed to an optimum shape in the C molding machine 21, they are peaked at the butting portion 68 (indicated by the one-dot chain line in FIG. 11). Or negative peaking indicated by a two-dot chain line) does not occur. That is, as shown by a solid line in FIG. 11, the material 5 is molded into a substantially circular tube with a high roundness (so that the cross-sectional shape along the radial direction is a substantially circular shape with a high roundness). Can do.

  After the O molding, the molding material 5 is conveyed from the O molding machine 23 to the welding machine 31, and the butt portion 68 is welded in the welding machine 31. When conveying the molding material 5 from the O molding machine 23 to the welding machine 31, it is possible to prevent conveyance failure due to peaking by suppressing peaking. That is, the butting portion 68 can be prevented from being caught by the transport mechanism, and the molding material 5 can be held in a stable state and smoothly transported.

In the welding process in the welding machine 31, as shown in FIG. 12, a groove (butting) is formed between the first groove surface 41 of the left edge portion 5e and the first groove surface 41 of the right edge portion 5f. Groove portion (butting portion 68) formed between the second groove surface 42 of the left edge portion 5e and the second groove surface 42 of the right edge portion 5f. the groove) of the inner peripheral surface side of and along the length D _L of the molded material 5, the filler material 71 is added (see FIG. 12). Thereby, the left edge part 5e and the right edge part 5f are joined. At this time, if peaking occurs in the material 5 to be molded, there is a possibility that welding defects due to peaking may occur. However, by suppressing peaking, such welding defects can be prevented and welding can be reliably performed. It can be carried out. The welding is started from the tab plate 38 provided on the front edge portion 5c, and is continuously performed on the first groove surface 41 and the second groove surface 42, and is provided on the rear edge portion 5d. The tab plate 38 is finished. After the welding, the tab plate 38 is removed from the molding material 5. That is, the start and end portions of the welding that are likely to become unstable are removed together with the tab plate 38.

  After the tab plate 38 is removed from the material 5, the tube 5 is expanded in the tube expansion machine 32. During peak expansion, if peaking occurs in the material 5 to be molded, there is a risk of pipe expansion cracking due to peaking. By suppressing peaking, such pipe expansion cracking can be prevented and tube expansion is ensured. Can be done. Thus, a steel pipe having a predetermined dimension can be manufactured.

  After the first molding material 5 is unloaded from the C molding machine 21, the next unprocessed molding material 5, that is, the second molding material 5 is loaded into the C molding machine 21. . Then, C molding of the second molding material 5 is performed in the same manner as the first molding material 5 described above.

In the C molding of the second workpiece 5, the C molding machine controller 53 separates the information on the second workpiece 5 (the second workpiece) separately from the information on the first workpiece 5. The chemical composition of the molding material 5, the TMCP condition of the second molding material 5, the dimensions of the second molding material 5, etc.) are acquired from the main control unit 36. And strength TS ₍₂₎ of the _2nd molding material 5 is calculated | required by the calculation based on the information regarding the 2nd molding material 5, and said Formula (1), (2). Further, the edge molding conditions corresponding to the second molding material 5 are calculated based on the dimensions of the second molding material 5 and the calculated strength TS _{(2) of the} second molding material 5. . The edge molding conditions corresponding to the second workpiece 5 are set to the edge deformation mechanism control device 65 of the left edge deformation mechanism 52A and the edge deformation mechanism control device 65 of the right edge deformation mechanism 52B. Send each one. Therefore, when performing press molding, the edge deformation mechanism control device 65 of the left edge deformation mechanism 52A and the edge deformation mechanism control device 65 of the right edge deformation mechanism 52B are transmitted from the C molding machine control unit 53. Each mold moving device (not shown) is controlled in accordance with the edge molding conditions of the second molding material 5.

Thus, also in the second molding material 5, each molding part is molded into an optimum shape under the optimum edge molding conditions based on the strength TS _{(2) of the second} molding material 5. . That is, even if the chemical composition, TMCP conditions, dimensions, hardenability β, strength TS, and the like of the second molding material 5 are different from the first molding material 5 described above, In addition, the edge molding conditions such as the pressure necessary for molding the second molding material 5 into a desired shape are newly calculated and molded according to the edge molding conditions. Accordingly, it is possible to prevent the pressure applied to the second molding material 5 from the left edge deformation mechanism 52A and the right edge deformation mechanism 52B from becoming insufficient or excessive. That is, the second molding material 5 can be appropriately bent and deformed, and peaking after the O molding can be prevented.

Similarly, when C-molding the third and subsequent n-th workpieces 5, the C-molding machine control unit 53 also provides information on each molding material 5 (chemical components of the n-th molding material 5, n-th molding material 5). The TMCP conditions of the molding material 5 and the dimensions of the n-th molding material 5 are respectively acquired from the main control unit 36, and based on these information, the edge corresponding to the n-th molding material 5 The molding conditions are obtained, and the left edge deformation mechanism 52A and the right edge deformation mechanism 52B are controlled according to the edge molding conditions. The left edge part deformation mechanism 52A and the right edge part deformation mechanism 52B correspond to the edge part molding conditions corresponding to the respective molding materials 5 (when the nth molding material 5 is molded, they correspond to the nth molding material 5). Each molding material 5 is respectively molded according to the edge molding conditions to be performed. Accordingly, each molding material 5 is molded into an optimum shape under optimum edge molding conditions based on the strength TS _(n) of each molding material 5 and the like.

  In addition, after the molding of the molding material 5 is performed, the U molding, O molding, welding, tube expansion, and the like of each molding material 5 after the second is performed in the same manner as the first molding material 5 described above. Are performed sequentially. As described above, in the second and subsequent workpieces 5 as well, it is possible to prevent peaking from occurring during O molding. In the second and subsequent molding materials 5 as well, welding defects, conveyance failures, and pipe expansion cracks due to peaking can be suitably prevented.

As described above, according to the present embodiment, the edge of the C molding is based on the strength TS (TS _(n) , n = 1, 2, 3,...) For each material 5 to be molded. Even if the strength TS of each molding material 5 is different from each other by adjusting the part molding conditions individually, each molding material 5 is appropriately used by using the edge molding conditions corresponding to each molding material 5. Can be C-shaped. For example, in the molding material 5 with the same lot (thick plates obtained from the same slab), even if the actual strength varies, one piece of the optimum edge molding condition for each molding material 5 It can obtain | require for every and can respectively carry out C shaping | molding appropriately. By appropriately performing the C molding, it is possible to reliably prevent occurrence of peaking after the O molding of each molding material 5 and to increase the roundness of each molding material 5. Furthermore, it is possible to reliably prevent welding defects, conveyance failures, and pipe expansion cracks due to peaking of the respective molding materials 5, and to reliably manufacture steel pipes having desired shape dimensions.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

For example, the shapes of the lower mold 61 and the upper mold 62 are not limited to those shown in FIG. In FIG. 5, between the lower mold 61 and upper mold 62, but the concave surface 61a showed a state in contact with the whole the molded part of the molded material 5 (entire portion of the bending length L _M), For example, as shown in FIG. 13, only a part (tip portion) of the part to be molded may be in contact. Even when such an edge deformation mechanism is used, the edge molding conditions can be suitably obtained. That is, the pressure applied to the workpiece 5 by the lower mold 61 and the upper mold 62, the position of the lower mold 61 with respect to the molding material 5, the position of the upper mold 62 with respect to the molding material 5, etc. Can be calculated.

In the above embodiments, while shifting in the conveying direction D ₁ of the molded material 5 to the edge deformation mechanism, by performing a plurality of press-molded to a sheet of the molded member 5, the left edge Although the entire portion 5e and the entire right edge portion 5f are bent and deformed, the present invention is not limited to such a configuration. That is, the length of the concave curved surface 61a and the convex curved surface 62a (the dimension in the transport direction D _1), than about the same size (or the left edge 5e or right edge 5f and the length of the left edge 5e or right edge 5f The left edge portion 5e or the right edge portion 5f may be configured to be bent and deformed collectively by one press molding.

  In the above embodiment, the left edge deformation mechanism 52A and the right edge deformation mechanism 52B sandwich the material 5 to be molded between the lower mold 61 having the concave curved surface 61a and the upper mold 62 having the convex curved surface 62a. Thus, the press molding is performed, but the edge deformation mechanism is not limited to this. For example, like the left edge part deformation mechanism 80A and the right edge part deformation mechanism 80B shown in FIG. 14, it is good also as a structure which roll-forms the to-be-shaped material 5 with a pair of roll, ie, the lower roll 81 and the upper roll 82. That is, the first contact body that contacts the lower surface 5a side and the second contact body that contacts the upper surface 5b side may each have a roll shape.

In FIG. 14, the left edge portion deformation mechanism 80 </ b> A includes a lower roll 81 and an upper roll 82. The lower roll 81 is formed so that the outer diameter gradually increases toward the outer side, and the vertical cross-sectional shape of the outer peripheral surface is a concave curved surface. The upper roll 82 is provided above the lower roll 81 and is formed so that the outer diameter gradually decreases toward the outer side, and the vertical cross-sectional shape of the outer peripheral surface becomes a convex curved surface. Further, the lower roll 81 and the upper roll 82 are rotatable about a central axis directed substantially in the horizontal direction. That is, the molding material 5 (the left edge portion 5e or the right edge portion 5f) is sandwiched between the outer circumferential surface of the lower roll 81 and the outer circumferential surface of the upper roll 82, and the molding material 5 is sandwiched between the lower roll 81 and the upper roll 82. While applying pressure to the lower roll 81 and the upper roll 82 in directions opposite to each other, the material 5 is bent and deformed along the outer peripheral surface of the lower roll 81 and the outer peripheral surface of the upper roll 82. and it is configured to deliver the conveying direction D _1. The right edge deforming mechanism 52B is substantially symmetrical with respect to the left edge deforming mechanism 52A. Even when such an edge deformation mechanism is used, the edge molding conditions can be suitably obtained in the C molding machine controller 53. That is, the pressure applied to the molding material 5 by the lower roll 81 and the upper roll 82, the position of the lower roll 81 with respect to the molding material 5, the position of the upper roll 82 with respect to the molding material 5, and the like can be suitably calculated. Is possible.

  In the above embodiment, information such as chemical components, TMCP conditions, and dimensions of each molding material 5 is stored in the main control unit 36 (upper control computer), and the hardenability β of the molding material 5, The information such as the strength TS is obtained by calculation in the C molding machine control unit 53 (subordinate control computer for the main control unit 36), but is not limited to such a form. For example, the hardenability β of each molding material 5 may be calculated by the main control unit 36. That is, the information on the hardenability β may be acquired by the C molding machine control unit 53 by being transmitted from the main control unit 36. The TMCP condition information may be directly transmitted from the cooling unit 13 to the C molding machine control unit 53. Further, the strength TS may be calculated by the main control unit 36. That is, information on the strength TS (strength information) may be acquired by the C molding machine control unit 53 by being transmitted from the main control unit 36.

  Furthermore, the calculation method of the strength of the molding material 5 is not limited to that using the formulas (1) and (2). For example, the material of the molding material 5, that is, the strength (yield strength, tensile strength, etc.) may be obtained by a calculation method using a metallurgical mathematical model or a neural network (Japanese Patent Laid-Open No. 2005-315703). See the official gazette). Even in such a case, the edge forming condition can be obtained from the calculated strength.

  Furthermore, the strength of the molding material 5 used for obtaining the edge molding conditions is not limited to the predicted value (predicted strength) obtained by calculation, but may be a past value (measured value, actually measured strength). That is, the strength information may be obtained by actually measuring the strength of the molding material 5. For example, after water cooling by the cooling unit 13 and before C forming, a part of the molding material 5 (steel plate) is sampled as a test piece, and a physical property test (a tensile tester is installed on the test piece). The actual strength value can be measured by performing a tensile test or the like. With such a method, the actual value of the strength of each material to be molded 5 may be measured, and the actual value may be transmitted to the main control unit 36 or the C molding machine control unit 53. .

  In the above embodiment, the strength of the strength information is the tensile strength. However, the strength information is not limited to this, and may be other mechanical strength such as hardness (hardness). For example, as a characteristic test to be performed on the above-described test piece (test piece collected before C forming), a hardness test using a hardness tester (for example, a Vickers hardness test) is performed. The actual value may be obtained.

  The inventors examined the peaking reduction effect of the C molding machine 21. First, it calculated | required by performing the tensile test with respect to the estimated value TS of the intensity | strength calculated | required based on Formula (1), (2) about the some to-be-molded material 5, and the test piece extract | collected from the to-be-molded material 5. The actual values of tensile strength were compared. As a result, as shown in FIG. 15, the error (accuracy) of the predicted value TS with respect to the actual value, that is, the value of the actual value−predicted value TS was about ± 30 MPa.

Further, a plurality of molding materials in the state where the edge molding conditions such as the press pressure in the C molding are the same (conditions such that the peaking amount p is 0 mm when the tensile strength of the molding material 5 is 660 MPa). 5 was subjected to C molding, U molding and O molding were performed, and the relationship between the actual value of strength (tensile strength) of each molding material 5 and the peaking amount p after O molding was examined. FIG. 16 shows the result. In addition, the peaking amount p was calculated | required on the basis of the position of the outer surface of the butt | matching part 68 when there is no peaking, as shown in FIG. That is, the distance L _p from the central portion _PO to the outer surface of the butt portion 68 in the inner space of the molding material 5, and the distance L from the central portion _PO to the outer surface of the butt portion 68 when the peaking amount p is 0 mm. A value obtained by subtracting _O (half of the outer diameter of the molding material 5) (p = L _p −L _O ) was used.

  From the result of FIG. 16, it can be seen that the peaking amount p is substantially proportional to the strength of the molding material 5. That is, it is estimated that the relationship between the strength of the molding material 5 and the peaking amount p follows a graph line indicated by a dotted line in FIG. Also, from FIG. 16, for example, when the predicted value TS of the strength of the molding material 5 is 660 MPa, on the basis of the predicted value TS, when setting the edge molding conditions such that the peaking amount p is 0 mm, If the error of the predicted value TS with respect to the actual value is about ± 30 MPa, it can be seen that the peaking amount p can be suppressed to be sufficiently small to about ± 0.9 mm. That is, when the actual strength of the molding material 5 is about 30 MPa larger than the predicted value TS (when it is about 690 MPa), the peaking amount p is about +0.9 mm, and the actual strength of the molding material 5 is When it is smaller than the predicted value TS by about 30 MPa (when it is about 630 MPa), the peaking amount p is about -0.9 mm. In other words, it can be said that the range of variation in the peaking amount p caused by the error of the predicted value TS can be suppressed to about 1.8 mm.

(Comparative example)
About the molding material with the same lot (thick plate obtained from the same slab), the water cooling stop temperature Z was varied, and the actual value of the strength (tensile strength) of the molding material 5 was measured. As a result, when the range of variation of the water cooling stop temperature Z was about 67 ° C., the range of variation of the actual value was about 120 MPa. In this case, when C molding is performed by the conventional method without using the predicted value TS (that is, the set value of the strength of the molding material used when obtaining the edge molding conditions is set for the molding material having the same lot. When the edge forming conditions are determined while keeping the same), the range of variation in the peaking amount p is considered to be about 3.6 mm from the proportional relationship shown by the graph line (dotted line) shown in FIG.

  From the above results, as in the above embodiment, by using the method of setting the edge molding condition based on the predicted value TS, the peaking is performed compared to the case of using the conventional method of setting the edge molding condition. It can be said that the variation range of the quantity p can be reduced to about 50% (1.8 mm / 3.6 mm × 100).

  The present invention can be applied to, for example, a steel pipe manufacturing facility and a steel pipe manufacturing method used when manufacturing UO steel pipes, UOE steel pipes, and the like.

It is explanatory drawing which showed the outline of the rolling equipment and the steel pipe manufacturing equipment. It is a top view of a molding material (steel plate). It is sectional drawing of a to-be-molded material (steel plate). It is a schematic perspective view of a C molding machine. It is a schematic longitudinal cross-sectional view of a left edge part deformation | transformation mechanism and a right edge part deformation | transformation mechanism. It is explanatory drawing explaining a C shaping | molding process. It is explanatory drawing explaining a C shaping | molding process. It is explanatory drawing explaining a C shaping | molding process. It is explanatory drawing explaining a C shaping | molding process. It is sectional drawing of the to-be-molded material U-shaped. It is sectional drawing of the to-be-molded material O-molded. It is sectional drawing which showed the butt | matching part after welding. It is sectional drawing which showed embodiment which makes a lower metal mold | die contact | abut only to the front-end | tip part of a to-be-molded part. It is explanatory drawing which showed C molding machine made into the structure which performs roller molding. It is the graph which compared and showed the predicted value TS and the actual value of the intensity | strength of a to-be-molded material. It is the graph which showed the relationship between the performance value of the to-be-molded material, and the peaking amount p. It is explanatory drawing explaining the peaking amount p.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Rolling equipment 3 Steel pipe manufacturing equipment 5 Molding material 5e Left edge part 5f Right edge part 13 Cooling part 21 C forming machine 22 U forming machine 23 O forming machine 36 Main control part 52A Left edge part deformation mechanism 52B Right edge part deformation mechanism 53 C molding machine controller 61 Lower mold 62 Upper mold

Claims (15)

A steel pipe manufacturing facility for manufacturing a steel pipe by sequentially forming steel sheets into C, U and O,
An edge deformation mechanism for deforming the edge of the steel sheet in the C-forming,
A control unit for controlling the edge deformation mechanism,
The control unit acquires the strength information of each steel plate, obtains the edge forming conditions corresponding to each steel plate based on the strength information, respectively, controls the edge deformation mechanism according to the edge forming conditions,
The said edge part deformation | transformation mechanism deform | transforms the edge part of each steel plate according to the edge part formation conditions corresponding to each said steel plate, respectively, The steel pipe manufacturing equipment characterized by the above-mentioned. The steel pipe manufacturing facility according to claim 1, wherein the strength information is obtained based on a chemical composition of a steel plate and a TMCP condition used in a steel plate rolling facility. The steel pipe manufacturing facility according to claim 2, wherein the strength information is obtained based on the formula (1).
TS = aX ³ + bX ² + cX
+ DY ³ + eY ² + fY
+ GZ ³ + hZ ² + iZ + j + kβ (1)
(TS: Tensile strength, X: Heating temperature, Y: Water cooling start temperature, Z: Water cooling stop temperature, β: Hardenability, a, b, c, d, e, f, g, h, i, j, k: coefficient) The steel pipe manufacturing facility according to claim 1, wherein the strength information is obtained by actually measuring the strength of a steel plate. The steel pipe manufacturing facility according to claim 4, wherein the strength information is obtained by a tensile test or a hardness test. The edge deformation mechanism includes a lower mold that contacts the lower surface side of the steel sheet and an upper mold that contacts the upper surface side of the steel sheet, and the edge portion of the steel sheet is formed by the lower mold and the upper mold. The steel pipe manufacturing equipment according to claim 1, wherein the steel pipe is press-formed. The edge deformation mechanism includes a lower roll that contacts the lower surface side of the steel sheet and an upper roll that contacts the upper surface side of the steel sheet, and rolls the edge of the steel sheet by the lower roll and the upper roll. The steel pipe manufacturing facility according to any one of claims 1 to 6, wherein A steel pipe manufacturing method for manufacturing a steel pipe by sequentially forming steel sheets into C, U, and O,
Obtain strength information for each steel plate,
Based on the strength information, obtain the edge forming conditions corresponding to each steel sheet,
A steel pipe manufacturing method, wherein each steel plate is C-shaped by deforming the edge of each steel plate according to the edge forming conditions corresponding to each steel plate. The steel pipe manufacturing method according to claim 8, wherein the strength information is obtained based on a chemical composition of the steel sheet and a TMCP condition in the rolling process of the steel sheet. The steel pipe manufacturing method according to claim 8, wherein the strength information is obtained based on the formula (1).
TS = aX ³ + bX ² + cX
+ DY ³ + eY ² + fY
+ GZ ³ + hZ ² + iZ + j + kβ (1)
(TS: Tensile strength, X: Heating temperature, Y: Water cooling start temperature, Z: Water cooling stop temperature, β: Hardenability, a, b, c, d, e, f, g, h, i, j, k: coefficient) The steel pipe manufacturing method according to claim 8, wherein the strength information is obtained by actually measuring the strength of a steel plate. The method of manufacturing a steel pipe according to claim 11, wherein the strength information is obtained by a tensile test or a hardness test. The edge forming condition includes pressure information applied to an edge of the steel plate and position information with respect to the steel plate of an edge deformation mechanism that deforms the edge of the steel plate. The steel pipe manufacturing method in any one of. The steel pipe manufacturing method according to any one of claims 8 to 13, wherein the steel plate is C-formed by press forming. The steel pipe manufacturing method according to any one of claims 8 to 13, wherein the steel plate is C-formed by roll forming.

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