RU2533614C1 - PRU WITH PILGER MILLS FOR ROLLING OF SEAMLESS HOT-ROLLED 273-630 mm-DIA PIPES - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: this pipe-rolling unit has section for store and preparation of forged billets, cast billets, ESR ingots-billets and ESR hollow ingots-billets for rolling. It comprises furnaces to heat said ingots-billets to ductility temperature. Roll table is used to delivers said forged ingots and ESR ingots-billets to helical rolling mills. Besides, it comprises plants for out-of-mill mandrel fitting, two transfer trucks to carry sleeves with mandrels to Pilger mills, two Pilger mills and other equipment. This plant is provided with section for preparation of process tools including two machines for production and control of geometrical sizes of Pilger rolls with body diameters of 975 to 1100 mm and 1125 to 1250 mm Two machines are used for surfacing of Pilger roll working parts by "30Х25Н16Г7"-grade wire. Lathe is used to produce mandrels, their diameter making 258-580 mm and while length approximates to 5.5 m.

EFFECT: higher precision of sizes, high-quality pipes and process efficiency.

6 cl

Description

The invention relates to the field of metallurgy, in particular, to tube-rolling plants with pilgrim mills for rolling seamless hot-rolled pipes for general purposes, threaded, boiler, thick-walled and special-purpose pipes with a diameter of 273 to 630 mm, comprising a section for storage and preparation of forged billets, NLZ, ESR ingot blanks and ESW hollow ingot blanks for rolling, furnaces for heating them to the ductility temperature, live rolls for transporting forged blanks heated to the ductility temperature ovok, NLZ and ingots-blanks ESR to cross-helical rolling mills, two cross-helical rolling mills for flashing them into hollow shells or blanks-blanks and rolling blanks-blanks in short-sleeve shells, installations for extra-charge charging of mandrels, two transfer trolleys for transporting sleeves with mandrels to pilgrim mills, two pilgrim mills for rolling sleeves and hollow ingots-blanks ESR in whip tubes up to 40 m long in profile rolls on a long mandrel - mandrel, hot cutting saws for removal of technological equipment ezi (pilgrim heads and seed ends), a continuous sectional furnace for heating pipes in front of the calibration mill, a mill for calibrating pipes by diameter, a slipper for transporting pipes to six-roll straightening machines, two six-roll straightening machines, a section for preliminary quality control of pipes, a processing section threaded pipes, smooth pipe processing section, boiler and special purpose pipe processing section, and can be used in the production of seamless hot-rolled smooth pipes in general on the purpose of rifled, boiler, thick-walled and special-purpose pipes with a diameter of 273 to 630 mm from carbon, alloy and difficult to deform grades of steel and alloys.

Pipe rolling plants with pilgrim mills are one of the main pipe rolling plants for the production of long, smooth, general-purpose pipes, threaded, boiler, especially thick-walled, special-purpose pipes, profile, square, conical, step, fin, etc. Known pipe rolling installation (TPU 8-16 ″ JSC ″ ChTPZ ″) for rolling pipes with a diameter of 273-550 mm, having in its composition a warehouse of ingots and billets, two methodical furnaces, a two-roll cross-helical rolling mill (piercing mill) with a drive capacity of 2750 kW, two pilgrim mills, two saws for cutting technological waste and cutting hot pipes into measured lengths, a heating feed-through furnace, a 5-stand calibration mill and two six-roll straightening machines.

A disadvantage of the known TPU 8-16 ″ is the insufficient drive power of the cross-helical rolling mill, which leads to double flashing and loss of productivity when rolling pipes with a diameter of more than 325 mm from hard-deformed steel grades and alloys and pipes with a diameter of 465-550 mm from carbon and low alloy steel grades (TI 158-Tr. TB 1-38-2007 ″ Production of seamless hot-rolled pipes for steam boilers and pipelines according to TU 14-3R-55-2001, TU 14-3-460-2003 and TU 14-3-420-2005 ″ , TI 158-Tr. TB 1-56-97 ″ Production of seamless hot-rolled pipes from steel grade 20 for oil processing industry according to TU 14-3-587-77 ″, TI 158-Tr. TB 1-51-2002 ″ Production of seamless hot-rolled pipes from steel 15X5M according to TU 14-3R-62-2002 ″ and TI 158-Tr. TB 1 -53-2007 ″ Production of seamless hot-rolled pipes from corrosion-resistant steel grades with high surface quality according to TU 14-3R-197-2001 ″).

The disadvantage of this equipment is also that it depends on the human factor at each pipe redistribution from heating to acceptance and storage of finished products, and double flashing of ingots and billets leads to double heating and, consequently, to increased metal consumption and lower pilgrim productivity installation and increase the cost of their redistribution. The heating of the sleeves for the second rolling firmware leads to uneven heating of the sleeves due to the increased length, curvature and unevenness of their tilting along the bottom of the methodological furnaces. Firmware-rolling of unevenly heated sleeves on mandrels with a diameter of 425 mm or more with a ratio D / S≥6.0 leads to their uneven cooling in the piercing mill and additional curvature, which, in turn, leads to an increased difference in pipes on the pilgrim mill and, as a result, to increased consumption of metal during redistribution (ingot-billet) - a finished pipe.

A modernized tube-rolling installation with pilgrim mills is known, including two ring furnaces for heating ingots and billets to a plasticity temperature, a horizontal press for preliminary flashing of ingots and billets into glasses, a heating furnace in front of a cross-helical rolling mill (elongator), and a cross-helical rolling mill ( elongator) for rolling cups and bottom firmware, two feeding apparatuses, two pilgrim stands for rolling sleeves into tubes in profile rolls, two hot cutting saws, p dogrevatelnuyu oven before calibration, sizing mill and roller mill proper (VY Osadchy et al., "Technology and equipment for tube production", Moscow "Intermet Engineering", 2007 p.195).

One of the main disadvantages of this composition of equipment is that the technological process of pipe production, from heating to acceptance and storage of finished products, also depends on the human factor. When flashing on a horizontal press, the lateral difference is 6.5-12.5%, and on the cross-helical mill, 2.5-4.5%. The installation of an additional furnace to heat the glasses in front of the mill elongator leads to additional waste of metal, and therefore, increased consumption of metal. For flashing ESR ingots and workpieces from hard to deform steel grades and alloys, it is necessary to install a powerful press with a complex hydraulic system, which leads to additional energy and metal consumption of the equipment.

In the pipe industry, a tube rolling installation for rolling seamless hot-rolled pipes of large and medium diameters is known, comprising two transverse helical rolling mills installed in parallel, the input side of the first transverse helical rolling mill is located at the input side of the second transverse helical rolling mill and is equipped with a transfer grill, cross-screw rolling mills have individual transport roller tables from the furnace for heating ingots and billets to the input sides of the cross-screw mills th rolling and individual transfer trolleys on their output sides to the pilger (Patent RU №2387496, Cl. V21V 21/00, Bul. №12 from 27.04.2010). The advantages of this tube-rolling installation include the production of pipes with a diameter of 325 to 550 mm in small batches without loss of productivity, the production of pipes with a diameter of 465-550 mm from carbon and alloy steel grades and pipes with a diameter of more than 325 mm from hard-deformed steel grades and alloys from one heating, increasing the flexibility of the pipe rolling installation and reducing the cost of pipe products, and the disadvantage is that it improves only the firmware and rolling process and does not extend to the improvement of the whole hnologicheskogo manufacturing of pipes from 273 to 630 mm in the TPU pilger.

The closest technical solution is the scheme of the modern technological process for the production of pipes on TPA with pilgrim mills, including: two or one ring furnace for heating ingots and billets, an apparatus for descaling, a press for flashing ingots and billets into glasses, an annular furnace for heating glasses, 2- or 3-roll cross-screw rolling mill for rolling cups and bottom flashing, installation for charging mandrels into sleeves, two pilgrim stands, two saws for cutting hot pipes into measured lengths, a unit for removing mandrels from pipes, a bath for cooling mandrels, a unit for applying grease to mandrels, a furnace for heating pipes in front of calibration or reduction mills, a calibration-reduction mill and one or two straight six-roll machines (V.Ya. Osadchiy et al. ″ Technology and equipment for pipe production ″, Moscow, ″ INTERMET ENGINEERING ″, 2007, p.196. Fig. 6.10).

The composition of the equipment of this prototype and the technological process for the production of pipes, as well as the above analogues, depends on the human factor in each pipe conversion from heating to acceptance and storage of finished products, has two extra energy-consuming and metal-intensive units, namely a press for flashing ingots and billets into glasses and an annular furnace for heating glasses, is aimed at improving the quality indicators and geometric dimensions of hot-deformed pipes, but does not solve the main problem, namely the production of pipes size of 610 and 630 mm, decrease in the coefficient of consumable metal, the possibility of production of long pipes with a diameter over 273 mm of hard steels and alloys with improved performance TPU pilger rolled tubes with a diameter of 465-630 mm and 273-426 mm pipes of small batches.

The objective of the proposed pipe rolling installation with pilgrim mills is to exclude from the equipment two energy-intensive and metal-intensive units (a press for flashing ingots and billets into glasses and an annular furnace for heating the glasses before flashing them in the cross-helical rolling mill), giving increased difference in glasses and burning metal when heated glasses. The equipment and its location in the technological process make it possible to perform rolling of seamless hot-rolled smooth general-purpose, threaded, boiler, thick-walled and special-purpose pipes with a diameter of 273 to 630 mm from ingots and billets with a diameter of 400 to 600 mm, and pipes of 465-630 mm in size from hardly deformable grades of steel and alloys from hollow ingot-blanks EShPs with a size of 630-720 mm, a decrease in the expenditure coefficient of the metal and an increase in the productivity of pipe rolling plants with pilgrim mills due tions in its composition: the computer center; A computer at each redistribution of pipes from heating ingots and billets to acceptance, storage and shipment of finished products to consumers; site for processing, preparation and control of the geometric dimensions of the technological tool; high-speed roller tables for transporting hollow ingots-blanks of ESR to pilgrim mills; two pilgrim mills with personal computers, in the stands of which rolls with a barrel diameter of 975 to 1250 mm can be installed, the upper roll of which, on a computer command, for each feed of the sleeve into the deformation zone, makes a smooth rise; installations for preliminary assembly and transshipment of rolls of the pilgrim mill by stands; two walking beam furnaces; two five-stand calibration mills; a slapper for transporting pipes up to 40 m long; site for preliminary quality control and geometric dimensions of pipes; anodic-mechanical cutting installations for removing defective pipe sections and cutting lashes into measured or multiple lengths; presses for calibrating the ends of threaded pipes; site for the manufacture of couplings, safety rings and nipples; installations in the production line of two transverse helical rolling mills, which, in addition to sequential flashing and rolling of ingots and billets, make it possible to produce pipes with a diameter of 426 to 630 mm from ingots and billets with a diameter of 600 mm and pipes from hardly deformed steel grades and alloys with a diameter of more than 325 mm per one heating, to exclude downtime of the second pilgrim mill during rolling of pipes in small batches, i.e. on the first cross-helical rolling mill, piercing ingots and billets into the sleeves of one diameter, and on the second cross-helical rolling mill into the sleeves of another diameter, for rolling pipes of different diameters on the pilgrim mills.

The technical result is achieved by the fact that the tube-rolling installation with pilgrim mills for rolling seamless hot-rolled pipes with a diameter of 273 to 630 mm contains a section for storing and preparing forged billets, continuously cast billets (NLZ), ESR ingots-blanks and ESR hollow ingots-blanks for rolling, technological units, incorporating furnaces for heating billets to plasticity temperature, a rolling table for transporting heated forged billets, billets and ingot blanks ESR to two transverse mills ntn rolling for flashing into hollow sleeves or blanks-blanks and rolling on a short mandrel of blanks-blanks into sleeves, two transfer trolleys for transporting sleeves loaded with mandrels and high-speed roller tables for transporting heated hollow ingots-blanks ESR to two pilgrim mills for rolling sleeves and hollow ESR ingots-blanks in whip tubes with diameters from 273 to 630 mm and lengths up to 40 m, installation for preliminary assembly and transshipment of pilgrim mill rolls, two furnaces with walking beams, two five-stand calibration gauges for calibrating pipes by diameter, a splitter for transporting lash pipes up to 40 m long to two six-roll straightening machines, a section for preliminary quality control and geometric dimensions of pipes, an anode-mechanical cutting section for removing defective pipe sections and cutting pipe lashes to measuring or multiple lengths, a section for the manufacture of couplings, safety rings and nipples, while the installation is equipped with a section for processing, preparing and controlling the geometric dimensions of the technological tool, including two machine for the manufacture and control of the geometric dimensions of pilgrim rolls with barrel diameters from 975 to 1100 mm and from 1125 to 1250 mm, two machines for surfacing with wire grade 30X25H16G7 of the working part of the pilgrim rolls, consisting of a striker with a central angle of 100 °, a polishing section with a central angle 70 °, a section of the angle of the longitudinal outlet with a central angle of 40 ° and a blank section adjacent to the section of the angle of the longitudinal outlet, with a central angle of 35-40 °, a lathe for the manufacture of mandrels with a diameter of 258 to 580 mm, length up to 5.5 m, milling st nock for processing the cheeks of the mandrel mandrels of the mandrels, an automatic installation for surfacing of mandrel heads, the pipe rolling unit is equipped with a computer center connected to a computer on each of the technological units, furnaces with walking beams are made with the possibility of regulating the pace of walking beams depending on the diameter and thickness of the pipe wall ensuring rotation of the pipes at each step by an angle of 90-180 °, large values of which relate to pipes of smaller diameter, a slapper for transporting lash pipes from calibration gauges The cans for the correct machines contains chains with stops and rollers for smooth rotation of the pipes during transportation, the installation is equipped with presses for calibrating the end sections of the threaded pipes, located in the flow in front of the threaded machines and having fixing devices from axial movement of the pipe, devices for moving forward short conical mandrels for distribution of the end sections of the pipes along the inner diameter, followed by returning to the initial position and calibration with ring patterns of the outer diameter of the end sections of pipes, a section for preliminary quality control and geometric dimensions of pipes is located after the correct machines and has devices for measuring diameter, wall thickness, total curvature and curvature per meter, to mark the location of defective sections on lash pipes with data being recorded in memory Computers for transferring them to the computer center and to the computer of the anode-mechanical pipe cutting installations, and the anode-mechanical cutting section is located after the preliminary quality control section and geometric of pipe sizes and includes anode-mechanical cutting devices made with the possibility of removing defective pipe sections by a computer command of the preliminary pipe inspection section and cutting lashes into measured or multiple lengths at the command of a computer center.

A comparative analysis of the inventive tube-rolling installation with the prototype shows that the tube-rolling installation is equipped with a section for processing, preparing and controlling the geometric dimensions of the technological tool, including two machines for manufacturing and controlling the geometric dimensions of pilgrim rolls with barrel diameters from 975 to 1100 mm and from 1125 to 1250 mm , two machines for surfacing with wire grade 30X25N16G7 of the working part of the pilgrim rolls, consisting of a striker with a central angle of 100 °, a polishing section with a central angle of 70 °, a part of the angle of the longitudinal outlet with a central angle of 40 ° and a blank area adjacent to the portion of the angle of the longitudinal outlet, with a central angle of 35-40 °, a lathe for manufacturing mandrels with a diameter of 258 to 580 mm, length up to 5.5 m, a milling machine for processing cheeks of mandrel mandrels of mandrels, an automatic installation for surfacing mandrel heads, moreover, the tube-rolling installation is equipped with a computer center connected to a computer on each of the technological units, furnaces with walking beams are made with the possibility of controlling the pace beams depending on the diameter and wall thickness of the pipes with ensuring the rotation of the pipes at each step by an angle of 90-180 °, large values of which relate to pipes of a smaller diameter, the slapper for transporting lashing pipes from calibration mills to the correct machines contains chains with stops and rollers for smooth rotation of the pipes during transportation, the installation is equipped with presses for calibrating the end sections of the threaded pipes located in the stream in front of the threaded machines and having fixing devices against axial movement of devices for moving forward short conical mandrels for distributing the end sections of pipes along the inner diameter with subsequent returning to the initial position and calibrating the outer diameter of the end sections of the pipes with ring patterns, the section for preliminary quality control and geometric dimensions of the pipes is located after the correct machines and has devices for measuring diameter, wall thickness, total curvature and curvature per meter, to mark the location of defective sections on pipes-pl networks with entering data into the computer memory for transferring them to the computer center and to the computer of the anodic-mechanical pipe cutting units and the anodic-mechanical cutting section is located after the section of preliminary quality control and geometric dimensions of the pipes and incorporates anodic-mechanical cutting devices with the ability to remove defective pipe sections on a command from the computer of the preliminary pipe inspection section and cutting lashes into measured or multiple lengths at the command of a computer center. Thus, the inventive pipe-rolling installation for rolling seamless hot-rolled pipes with a diameter of 273 to 630 mm meets the criterion of "inventive step".

Comparison of the claimed pipe-rolling installation not only with the prototype, but also with other technical solutions in this technical field did not reveal the signs that distinguish the claimed pipe-rolling installation from the prototype, which corresponds to the patentability ″ inventive step ″.

Since pipe rolling plants with pilgrim mills with similar equipment and a method for producing seamless hot-rolled pipes with a diameter of 273 to 630 mm on it do not exist in world practice, it is not possible to give an example of a concrete implementation for this period of time. Instead of an example of a specific implementation, the technological sequence of operations for the production of commodity and conversion pipes with a diameter of 273-630 mm is given. Hot-rolled smooth rolled general purpose, threaded, boiler, thick-walled and special-purpose pipes with a diameter of 273 to 630 mm from carbon and alloy steel grades are produced from forged, NLZ and ESH ingots-billets with a diameter of 400 to 600 mm, pipes from hardly deformed steel and alloys with a diameter of 273 to 426 mm from ingots-blanks of ESR with a diameter of from 400 to 600 mm, and pipes with a diameter of 465 to 630 mm from hollow ingots-blanks of ESR with a diameter of 630 to 720 mm in rolls with a barrel diameter of 975 to 1250 mm s polishing coefficient 2.5≤K _n ≤5.0. After the formation of a monthly program for the production of pipes, taking into account the average static expenditure coefficients of the metal, the dimensions of the forged billets, NLZ, ingots-blanks of ESR and hollow ingots-blanks of ESR are determined and their required number. Data is entered into the computer memory. To carry out the program, the required number of them is acquired by size, type and grade of steel. In accordance with the monthly program and the technological sequence of its execution, the production of the necessary technological tool is made (l.1 of the claims). The sequence of the monthly plan execution is determined, the preparation of forged blanks, NLZ, ESR ingots-blanks and ESW hollow ingots-blanks for rolling and their storage at the warehouse of ingots and blanks in the technological sequence of their rolling, the data is stored in the computer memory. Billets, ingots-blanks and hollow ingots-blanks of ESR are loaded into ring furnaces, data on the heating time of forged blanks, NLZs, ingots-blanks of ESRs and hollow ingots-blanks of ESRs are stored in the computer memory, which makes adjustments to the heating conditions. During the flashing of forged blanks, NLZ and ingot-blanks of ESR into sleeves and sleeves-blanks, when rolling sleeves into blanks, the outside diameter of forged blanks, NLZ, ingots-blanks, diameter of sleeves, diameter of sleeves-blanks and mandrels of the piercing mill are fixed, which are entered into the memory of a computer and by calculation determine the geometric dimensions of the sleeves. Commodity and conversion pipes are rolled on pilgrim mills on mandrels with a taper from 1.0 to 6.0 mm, the values of which depend on the diameter of the pipes, steel grade and alloy. Rolling lash tubes on pilgrim mills is produced in accordance with claim 1 of the claims. After the saws remove the impact of technological waste (seed ends and pilgrim heads), the whip pipes for the production of smooth general purpose and threaded pipes are heated in walking beam furnaces, calibrated in five-stand calibration mills and straightened in six-roll straightening machines. Modes of heating, calibration and editing are carried out under the control of a computer. The transportation of lash pipes from calibration mills to the correct machines is carried out using a slapper with smooth rotation (claim 3 of the claims). Inspection of the pipe-lashes is carried out on the preliminary acceptance table, and the location of the defects is recorded in the memory of the computer, which is removed by anodic-mechanical cutting, followed by cutting the pipe-lashes into measured or multiple lengths according to the marking of the computer. To increase the performance of pilgrim mills, the transshipment of rolls is carried out with stands previously assembled on a special transshipment stand.

Thus, the use of this composition of equipment will allow for the first time in world practice to produce hot-rolled smooth general-purpose, threaded, boiler, thick-walled and special-purpose pipes with a diameter of 273 to 630 mm with wall thicknesses of 6.0 to 90 mm on a pipe-rolling plant with pilgrim mills from forged billets, NLZ, ingots and blanks of ESR with a diameter of 400 to 600 mm with maximum performance, and pipes from hard to deform steel grades and alloys with a diameter of 465 to 630 mm from hollow ingots wok ESR diameter from 630 to 720 mm with high geometrical parameters, to ensure the country's demand for pipes of the mix, to produce competitive products and export them to other countries.

Claims (6)

1. Pipe rolling plant with pilgrim mills for rolling seamless hot-rolled pipes with a diameter of 273 to 630 mm, containing a section for storage and preparation of forged billets, continuously cast billets (NLZ), ESR ingots-blanks and ESW hollow ingots-blanks for rolling, technological units comprising a furnace for heating billets to a temperature of plasticity, a roller table for transporting heated forged billets, an overhead billet, and ESR ingots-blanks to two transverse helical rolling mills for piercing into hollow weights blades or blanks-blanks and rolling on a short mandrel of blanks-blanks into sleeves, two transfer carts for transporting mandrels loaded with mandrels, and high-speed live rolls for transporting heated hollow ingots-blanks ESR to two pilgrim mills for rolling cartridges and hollow ingots-blanks ESR into lash pipes with a diameter of 273 to 630 mm and lengths of up to 40 m, two furnaces with walking beams, two five-stand calibration mills for calibrating pipes by diameter, a slapper for transporting lash pipes up to 40 m long to two six-roll right for flax machines, a section for preliminary quality control and geometric dimensions of pipes, anode-mechanical cutting section for removing defective pipe sections and cutting lashes into measured or multiple lengths, a section for the manufacture of couplings, safety rings and nipples, while the installation is equipped with a section for processing, preparation and control of the geometric dimensions of the technological tool, which includes two machines for the manufacture and control of the geometric dimensions of pilgrim rolls with barrel diameters from 975 to 1 100 mm and from 1125 to 1250 mm, two machines for surfacing with a grade 30X25H16G7 wire of the working part of pilgrim rolls, consisting of a striker with a central angle of 100 °, a polishing section with a central angle of 70 °, a section of the longitudinal outlet angle with a central angle of 40 ° and an empty section adjacent to the section of the angle of longitudinal output, with a central angle of 35-40 °, a lathe for the manufacture of mandrels with a diameter of 258 to 580 mm up to 5.5 m long, a milling machine for milling cheeks of mandrel mandrels of mandrels and an automatic installation for surfacing worn mandrels O heads, the pipe-rolling plant is provided with a computer center, connected with a computer to each of the process units. 2. Installation according to claim 1, characterized in that the furnace with walking beams is made with the possibility of regulating the pace of walking of the beams depending on the diameter and wall thickness of the pipes, ensuring rotation of the pipes at each step by 90-180 °, large values of which relate to pipes smaller diameter. 3. Installation according to claim 1, characterized in that the slapper for transporting lash pipes from calibration mills to the correct machines contains chains with stops and rollers for smooth rotation of the pipes during transportation. 4. Installation according to claim 1, characterized in that it is equipped with presses for calibrating the end sections of the threaded pipes, located in the stream in front of the threaded machines and having fixing devices from the axial movement of the pipe, devices for moving forward short conical mandrels for distributing the end sections of the pipes inner diameter with subsequent return to its original position and calibration of the outer diameter of the end sections of the pipes with ring patterns. 5. Installation according to claim 1, characterized in that the section for preliminary quality control and geometric dimensions of the pipes, located after the correct machines, is equipped with devices for measuring the diameter, wall thickness, total curvature and curvature per meter, to mark the location of defective sections on lash pipes with data being entered into the memory of a computer for transferring them to a computer center and to a computer on the section of anode-mechanical pipe cutting. 6. Installation according to claim 1, characterized in that the anode-mechanical cutting section, located after the preliminary quality control section and the geometric dimensions of the pipes, incorporates anode-mechanical cutting devices configured to remove defective pipe sections by the computer command of the section preliminary control of pipes and cutting of lashes to measured or multiple lengths at the command of a computer center.