RU2550041C2 - MANUFACTURING METHOD OF SEMI-FINISHED HOT-ROLLED MECHANICALLY PROCESSED PIPES WITH SIZE OF 325×12 mm WITH INCREASED ACCURACY AS TO DIAMETER AND WALL FROM STEEL GRADES "12Х12М1БФРУ-Ш", "16Х12МВСФБР-Ш" FOR REROLLING ON "ХПТ" 450 AND "ХПТ" 250 MILLS INTO SEMI-FINISHED PIPE WORKPIECES WITH SIZE OF 202±1,2×3,5+0,3/-0,2 mm AND FURTHER SHAPING INTO HEXAGONAL PIPE WORKPIECES WITH FLAT-TO-FLAT SIZE OF 181,8±0,4×3,5+0,3/-0,2×3750+20/-0 mm AND 175±0,4×2,5+0,3/-0,2×2680+20/-0 mm FOR FAST NEUTRON REACTORS OF NEW GENERATION - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to a manufacturing method of semi-finished hot-rolled mechanically processed pipes with size of 325×12 mm with increased accuracy as to diameter and a wall from steel grades “12Х12М1БФРУ-Ш” and “16Х12МВСФБР-Ш” for their rerolling on ХПТ450 and ХПТ 250 mills into semi-finished pipes with sizes of 202±1.2×3.5+0.3/-0.2 mm and 194±1.2×2.5+0.3/-0.2 mm and further shaping into hexagonal pipe workpieces with flat-to-flat sizes of 181.8±0.4×3.5+0.3/-0.2×3750+20/-0 mm and 175±0.4×2.5+0.3/-0.2×2680+20/-0 mm for fast neutron reactors of a new generation. Hollow electroslag remelting ingots are cast from steel grade “12Х12М1БФРУ-Ш” with the size of 490×in290×2850±25 mm, and from steel grade “16Х12МВСФБР-Ш” with the size of 490×in290×3000±25 mm, which are turned and bored into hollow cakes with the size of 480×in300×2850±25 and 480×in300×3000±25 mm, heated up to the temperature of 1130-1150°C, rolled on pilger mills into semi-finished hot-deformed pipe workpieces with the size of 338×25×11200±100 and 338×25×11850±100 mm, straightened in a six-roll straightening machine, cut into two pipe workpieces with the size of 338×25×5600±50 and 338×25×5925±50 mm, bored and turned into pipe workpieces with the size of 325×12×5600±50 and 325×12×5925±50 mm with metal removal in the quantity of 6.5 mm along inner and outer surfaces.

EFFECT: reduction of a metal consumption coefficient.

5 cl, 1 tbl

Description

The invention relates to metallurgical and pipe production, and in particular to a method for the production of hollow ingots by electroslag remelting from 12Kh12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) steels, redistributed them into hollow ingots, and the production method from hollow ingots-blanks ESR on TPU 8-16 ″ with pilgrim mills of hot rolled pipe size 338 × 25 mm, machining them into steel pipe size 325 × 12 mm with a tolerance of ± 0.8% in diameter and ± 10% wall thickness , for rolling them on the mills HPT 450 and HPT 250 conversion pipes with a size of 202 ± 1.2 × 3.5 + 0.3 / -0.2 mm, 194 ± 1.2 × 2.5 + 0.37-0.2 mm and subsequent profiling into hexagonal workpieces of size turnkey 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 mm and 175 ± 0.4 × 2.5 + 0.3 / -0, 2 × 2680 + 20 / -0 mm for new generation fast-neutron reactors and can be used for casting hollow ingots from steel grade 12X12M1BFRU-Sh (EP450U-Sh) with a size of 490 × vn. 290 × 2850 ± 25 mm and hollow ingots from steel grade 16Kh12MVSFBR-Sh (EP823-Sh) with a size of 490 × vn. 290 × 3000 ± 25 mm on ESR installations, regrinding them into ingots-blanks of respectively 480 × vn. 300 × 2850 ± 25 and 480 × vn. 300 × 3000 ± 25 mm at OJSC "ZMZ" , redistribution of hollow ingots-billets of ESR into hot-rolled pig-shaped tubes of 338 × 25 mm in size on TPU 8-16 ″ with piligrim mills, machining - boring and turning into pig-iron pipes of 325 × 12 mm in size, rolling them on HPT 450 mills and HPT 250 into cold rolled cold-rolled pipes of size 202 ± 1.2 × 3.5 + 0.37-0.2 and 194 ± 1.2x × 2.5 + 0.3 / -0.2 mm for subsequent profiling into hexagonal pipes - turnkey billets of 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 mm and 175 ± 0.4 × 2.5 + 0.3 / -0.2 × 2680 + 20 / -0 mm at ChTPZ OJSC and their use at nuclear power plants incorporating new reactors fast neutrons.

In pipe-rolling production, a method is known for producing hot-rolled commodity and conversion pipes of large and medium diameters from hard-to-deform steel grades in pipe-rolling plants with pilgrim mills from EShP ingots of steel grade 10X9MFB-Sh (TU 14-134-398-2003 "Billet pipe - ingots for boiler pipes EShP ", TU 14-3R-55-2001" Seamless steel pipes for steam boilers and pipelines ", TI 158-Tr. TB1-56-2007" Production of seamless hot-rolled pipes for steam boilers and pipelines according to TU 14-3R-55- 2001 ").

The disadvantage of this method is that the pipes after rolling have a large number of defects on the inner surface in the form of captures and hot cracks, require subsequent machining - boring and turning with metal removal of 8-10 mm per side. This steel grade has a hot ductility range of 1160–900 ° C and an increased coefficient of linear expansion. If the ESR ingots-blanks are heated to a temperature of 1160 ° C, then when the ingots are pierced in the cross-helical rolling mill into the sleeves, the temperature of the metal in the deformation zone at the mandrel-inner surface of the sleeves increases by 50-70 ° C depending on the diameter of the ESR ingot. When rolling sleeves on a pilgrim mill to tubes with an outer surface temperature of 1160C ° or less, the end of rolling occurs at a temperature of 800-850 ° C depending on the diameter and wall thickness, which leads to tightening of mandrels even with a taper of 4-5 mm instead of 1, 0 according to TI 158-Tr. TB1-56-2007. The heating of the ESR ingots-blanks of this steel grade above 1160 ° C leads to overheating of the inner surface of the sleeves and the mass formation of internal captures and hot cracks. These pipes must be rejected or bored onto a smaller wall with metal removal of more than 10 mm per side, which in turn leads to increased metal consumption and an additional laborious operation - boring of pipes with defects on the inner surface.

In pipe rolling production, there is also known a method for the production of pipes from hardly deformable grades of steel and alloys with an increased coefficient of linear expansion, including heating the working part of the mandrel to an average temperature equal to or higher than the required temperature of the front end of the pipe at the moment of its descent from the mandrel T _cf. ≥T _AC where T _av.d. - average temperature of the mandrel before rolling, ° C; T _lane - the required temperature of the front end of the pipe at the moment of its descent from the mandrel, ° C, heating of the working part of the mandrel with a temperature difference along the length of the working part no more than 100 ° C, T _max -T _min <100 ° C, where T _max is the maximum working temperature parts of the mandrel in the zone of intense deformation, ° C; T _min - the minimum temperature of the working part of the mandrel, ° C (RF Patent No. 2214312, CL B21B 21/00, 10/20/2003, bull. No. 29).

The disadvantage of this method is that it is aimed at reducing the number of puffs of mandrels during rolling of pipes from hard to deform steel grades and alloys with an increased coefficient of linear expansion by heating the mandrels before rolling and during the rolling process. This method does not solve the main technological issues: roll-up of sleeves - break-in of pilgrim heads at temperatures below the lower hot plasticity interval of these grades of steel and alloys and, all the more, the technology of producing high-quality shell sleeves on the internal surface of the shell during the flashing of ingot-blanks of ESR and firmware-rolling of blanks-blanks into the sleeves in the cross-helical rolling mill of steel grades 12X12M1BFRU-Sh (EP450U-Sh) and 16X12MVSFBR-Sh (EP823-Sh).

In the pipe industry, there is also a known method for the production of hot-rolled commodity and conversion pipes of large and medium diameters from hard-to-deform steel grades and alloys in pipe rolling plants with pilgrim mills, including the casting of hollow ingots 1750-2100 mm high on electroslag remelting plants. The ingots are grinded and bored to remove scale and microcracks to a diameter of 400-620 mm with a ratio of diameter to wall thickness D / S = 3.0-4.0, large values of which correspond to ingots-sleeves of smaller diameter. Then, the ingot sleeves are heated to the temperature of plasticity and stitched-rolled in a cross-helical rolling mill into sleeves with hoods µ = 1.5-1.7, large values of which correspond to sleeves of a larger diameter. The sleeves, stitched-rolled with hoods µ = 1.5-1.6, are rolled on the pilgrim mills into conversion tubes, and the sleeves, stitched-rolled with hoods µ = 1.6-1.7, are rolled into commodity pipes (RF Patent No. 2311979. CL B21B 21/00. 12/10/2007).

The disadvantage of this method is that it only partially reduces the formation of defects on the inner surfaces of the sleeves by reducing the drawing coefficient (squeezing the sleeve blanks on the wall) in the deformation zone when flashing-rolling the sleeve blanks from corrosion-resistant hard-deformed steel grades and alloys with low temperature hot ductility interval and high coefficient of linear expansion in cross-helical rolling mills. This method does not solve the technological issues of heating ESR ingots from steel grades 12X12M1BFRU-Sh and 16X12MVSFBR-Sh, piercing and rolling conversion tubes from hard-to-form steel grades and alloys with a low temperature range of hot ductility and a high coefficient of linear expansion for rolling them on HPT 450 and CPT 250 into conversion pipes of size 202 ± 1.2 × 3.5 + 0.3 / -0.2 and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm for subsequent profiling them into hexagonal billet pipes measuring 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0.3 / -0, 2 × 2680 + 20 / -0 mm for new generation reactors I'm on fast neutrons.

In the pipe industry, a method is known for producing cold-rolled large and medium-diameter pipes from hard-deformed steel grades and alloys with increased accuracy on the wall, including rolling the welded billet in calibers with a variable radius into a cold-rolled commodity pipe with a maximum diameter with an extractor μ = 1.4-1, 7 and compression on the wall of at least 25%, while during subsequent rolls, the hood gradually increases by 0.05-0.10 to 1.7-2.0, and large values of hoods and wall compressions are accepted for steels with a high content using chromium and nickel, the conversion pipe billet is rolled into a commodity or conversion cold-rolled pipe of maximum diameter with a ratio of diameter to pipe wall thickness D / S = 40-50, which is rolled into pipes of smaller diameter during subsequent rolling with an increase in D / S ratio from 2 to 10, and the last roll is performed with the ratio D / S = 50-75.

The disadvantage of this method is that it is directed to the technology for the production of cold-rolled large and medium diameter pipes from hard-deformed steel grades and alloys with increased accuracy on the wall from welded billets and does not solve the technological and structural issues of the manufacture of machined steel tubes of 325 × 12 mm in size steels of grades 12Kh12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) with increased accuracy in diameter and wall for their subsequent redistribution at KhPT 450 and KhPT 250 mills into pipes of 202 ± 1.2 × 3.5 + 0 3 / -0.2 and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm and profiling into hexagonal pipe blanks with a turnkey size of 181.8 ± 0.4 × 3.5 + 0.37-0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0.3 / -0.2 × 2680 + 20 / -0 mm for new generation fast-neutron reactors.

There is also known a method for the production of seamless hot-rolled conversion lengthy pipes from hard-to-deform grades of steel and alloys, comprising rolling the billet sleeves into hot rolled billet tubes in a pilgrim mill in roll calibers with a difference between the inner diameter of the billet blanks and the average diameter of the mandrels equal to D _{g. ext.} -D _avg. = 10-20 mm and with extracting µ≤6,0, where µ is the extraction coefficient on the pilgrim mill; D _m.v. - inner diameter of the sleeve, mm; D _average - the diameter of the mandrel, mm. Rolling pipes on a pilgrim mill in rolls with a round gauge with an angle of lateral release on the polishing section α = 25-30 °, where α is the angle of lateral release of the rolls of the pilgrim mill on the polishing section, deg., Or rolling on a pilgrim mill in rolls with an oval caliber with the ratio B / H = 1.1-1.15, where B is the width of the caliber of the roll in the polishing section, mm; H is the height of the roll caliber, mm (RF Patent No. 2266132, class B21B 21/00, 03/27/2004. Bull. No. 9).

The disadvantage of this method, as well as the above analogues, is that it is also aimed at reducing the number of puffs of mandrels when rolling pipes from hard to deform steel grades and alloys with an increased coefficient of linear expansion due to rolling in rolls with increased ovalization and does not solve the main technological issue , rolling of shell-breaker sleeves of pilgrim heads at temperatures below the lower range of hot ductility of these grades of steel and alloys, technologies for producing high-quality internal surfaces ty of sleeves in the process of flashing ingots and flashing of blanks-blanks into sleeves in a cross-helical rolling mill.

There is also known a method for the production of prototypes of hexagonal tube blanks with a turnkey size of 181.8 × 3.5 × 3750 + 20 / -0 mm from steel grade 12X12M1BFRU-Sh (EP450U-Sh) for new generation fast-neutron reactors ( protocol No. 60/11 of 08/03/2011 and TU 1367-043-00186654-2012 (experimental batch) "Seamless cold-deformed hexagonal pipes from steel grade 12X12M1BFRU-Sh (EP450U-Sh)", including casting of ingots by electroslag remelting with a size of 485 × 1540 mm , turning of ingots into ingots-blanks with a size of 470 × 1540 mm, drilling in ingots-blanks of a central hole with a diameter ohm 100 ± 5 mm, heating to a temperature of 1180-1200 ° C, piercing in a cross-helical mill into sleeves of size 480 × ext. 315 × 2400 mm, rolling the sleeves on pilgrim mills into red hot-formed pipe billets of 344 × 31 mm in caliber 351 mm, a length of a saw by a hot-cutting saw of technological waste - pilgrim heads and seed ends, straightening pipes and machining-boring and turning into pig tubes with a size of 325 × 12 mm with a tolerance of ± 1.0% in diameter and ± 12 wall thickness, 5%, with metal removal on the outer and inner surfaces of 9.5 m m with a surface finish of R _z ≤30 μm, rolling of machined pipes of 325 × 12 mm in size at KhPT 450 KhPT 250 mills into conversion pipes of 202 × 3.5 mm in size with a tolerance of ± 0.8% in diameter and ± 10 wall thickness, 0%

The disadvantage of this method is that when redistributing ingots-blanks of ESRs of 470 × 1540 mm in size to hot-rolled mechanically processed tubes of 325 ± 3.25 × 12 ± 1.5 mm in size, even with a three-time roll on the HPT 450 and HPT 250 mills, it is impossible to obtain cold-rolled pipes measuring 202 × 3.5 mm with a tolerance of ± 1.2 mm in diameter and a wall of + 0.3 / -0.2 mm. In the production of hot-rolled chimneys with a size of 325 × 12 mm, increased waste in multiplicity is obtained. The piercing of ESR blanks in a cross-helical rolling mill at a heating temperature of 1180-1200 ° C leads to a temperature increase at the border of the mandrel with the inner surface of the sleeves to 1250-1270 ° C, which for this steel grade is fraught with overheating of the inner surface and the formation of a grid of high-level cracks, which in turn leads to marriage or an increase in metal removal during boring of hot-rolled pipes into redistributed machined pipes with a size of 325 × 12 mm.

The closest technical solution (prototype) is a method for the production of conversion pipes from low plastic steel with a boron content of 1.3-1.8%, including casting by electroslag remelting of hollow ingots of size 480-490 × ext. 270 × 2300-2500 mm, boring and turning before removing shells and traces of flux into hollow ingots-blanks of size 470-480 × ext. 280 × 2300-2500 mm with a surface purity of R _z ≤40 μm, at the ends of which, corresponding to the bottom ends of hollow ESR ingots, are made from the outer surface of the cone length L = (1.5-2.0) S, with a blunting thickness h = (5.0-6.0) S _m , where S _m - wall thickness of conversion pipes, mm; S _z - wall thickness of the hollow billets of electroslag remelting, mm; h is the wall bluntness of the hollow ingots-billets of electroslag remelting, mm, heating the billets to a temperature of 1040-1060 ° C and rolling them on a pilgrim mill in hot-rolled steel tubes measuring 290 × 12 × 22000-23000 mm on mandrels with a diameter of 264/265 mm s extractor hood µ = 10.7–11.4, a hot saw cut off technological waste — pilgrim heads and seed ends, warm dressing on a six-roll straightening machine using rolling heating temperature, and shipment of conversion pipes to workshop No. 5 for all subsequent operations on the technological process of redistributing hot-rolled pipes into turnkey hexagonal pipe billets of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm (RF Patent No. 2297893. Cl. B21B 21/00. 04/27/2007).

The disadvantage of this method of production of hexagonal tubes-blanks is that it is aimed at the production of hexagonal tubes from boron-containing steel ChS 82 turnkey size 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm, those. with a wider tolerance range for round pipes in diameter and wall thickness and does not solve the technical and technological issues of the production of 325 × 12 mm conversion tubes with increased accuracy in diameter and wall for their subsequent rolling on the HPT 450 and HPT 250 mills into 202 ± pipes 1.2 × 3.5 + 0.3 / -0.2 and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm and profiling them into hex keys with a turnkey size of 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0.3 / -0.2 × 2680 + 20 / -0 mm from hardly deformable steels of grades 12X12M1BFRU (EP450U-Sh) and 16X12MVSFBR-Sh (EP823-Sh) for fast neutron reactors.

The objective of the proposed method is to exclude from the technological process the most defect-forming operation - flashing in the mill of cross-helical rolling of ESHP ingots from 12Kh12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) steels into sleeves, reducing metal consumption, during redistribution, a hollow ingot of ESR - a hot-rolled conversion pipe - a mechanically processed conversion pipe, due to a change in the heating technology and the deformation scheme of hollow ingots-billets on a pilgrim mill in the production of hot-rolled conversion pipes, technologies for the production of machined redistributed pipes 325 × 12 mm in size with a guaranteed tolerance of ± 0.8% in diameter and ± 10.0% in wall thickness for their subsequent use in mastering the production of turn-key hexagonal billets of 181.3 ± 0 , 4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0.3 / -0.2 × 2680 + 20 / -0 mm from steels of grades 12X12M1BFRU-Sh and 16X12MVSFBR-Sh for equipping nuclear power plants with new generation fast-neutron reactors, and consequently, reduction in the cost of conversion tubes of 325 × 12 mm.

, где d - наружный диаметр передельной трубы, мм, нагрев полых слитков-заготовок ЭШП из сталей марок 12Х12М1БФРУ-Ш (ЭП450У-Ш) и 16Х12МВСФБР-Ш (ЭП823-Ш) производят по технологии: на колосники методической печи садят две углеродистые гильзы из стали марок 10 или 20 размером 480×вн.300×2500-3000 мм для настройки пилигримового стана и разогрева дорнов, затем в один ряд садят 6-8 полых слитков-заготовок при температуре в третьей зоне печи 800-900°C и выдерживают их без кантовки в течение 30-45 минут, нагревают до температуры 1130-1150°C со скоростью 3,3-3,5°C в минуту с равномерной кантовкой по два слитка-заготовки с 22-го по 7-е окно через 17-20 минут на угол, равный ≈290-300°, выдерживают при температуре 1130-1150°C в течение 30-50 минут с равномерной кантовкой с 7-го на 4-е окно через 10-15 минут, кантуют с 4-го окна на яму печи и выдают с температурой центра слитков-заготовок 1130-1150°C, посад следующих 2-х слитков-заготовок производят после кантовки с колосников первых двух слитков-заготовок, полые слитки-заготовки выдают с ямы печи на слитковую тележку, внутрь слитков-заготовок задают смазку в виде смеси поваренной соли и графита (50/50) массой 1000-1200 грамм и краном с максимальной скоростью транспортируют на входную сторону пилигримового стана, полые слитки-заготовки прокатывают на пилигримовом стане в передельные трубы на дорнах с температурой наружной поверхности 500-600°C, которая достигается за счет прокатки двух настроечных углеродистых гильз.The technical result is achieved by the fact that in the known method for the production of hot rolled machined tubes with a size of 325 × 12 mm with increased accuracy in diameter and wall of steel grades 12X12M1BFRU-Sh (EP450U-Sh), 16X12MVSFBR-Sh (EP823-Sh) for rolling them on mills KhPT 450 and KhPT 250 into conversion pipes with a size of 202 ± 1.2 × 3.5 + 0.3 / -0.2 mm, 184 ± 1.2 × 2.5 + 0.3 / -0.2 mm and subsequent profiling into hexagonal pipe blanks with a turnkey size of 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 mm and 175 ± 0.4 × 2, 5 + 0.3 / -0.2 × 2680 + 20 / -0 mm for new-generation fast neutron reactors, including about electroslag remelting of ingots with a size of 485 × 1540 mm, turning of ingots into ingots-blanks of 470 × 1540 mm in size, drilling of central hole diameters of 100 ± 5 mm in ingots, heating to ductility temperature, piercing in a helical rolling mill on a mandrel with a diameter 300 mm in sleeves with a size of 480 × 480 × in. 315 × 2400 mm with a hood µ _ave. = 1.55-1.56 and a diameter rise of δ = (2.1-2.2)%, rolling the sleeves on pilgrim mills into hot-deformed pipe billets measuring 344 × 31 mm in caliber 351 mm on mandrels with a diameter of 283/287 mm with a hood μ _n = 3,28-3,29, swaging diameter Δ = (28,3-28,4)% and feeding cartridges into a deformation zone m = 20-22 mm segment of technological wastes - pilger seed heads and ends of the hot saw cutting, straightening pipes, machining, boring and turning into pig tubes of 325 × 12 mm in size with a tolerance of ± 1.0% in diameter and ± 12.5% in the wall with 9.5 mm metal removal on the outer and inner surfaces, ingots Electroslag remelting is cast hollow from steel grade 12Kh12M1BFRU-Sh (EP450U-Sh) with a size of 490 × ext. 290 × 2850 ± 25 mm, and from steel grade 16Kh12MVSFBR-Sh (EP823-Sh) with a size of 490 × ext. 290 × 3000 ± 25 mm, which are grinded and bored into hollow ingots-blanks, respectively, of size 480 × ext. 300 × 2850 ± 25 and 480 × ext. 300 × 3000 ± 25 mm, heated to a temperature of 1130-1150 ° C, rolled on pilgrim mills using lining carbon rings into hot-deformed tailpipe blanks measuring 338 × 25 × 11200 ± 100 and 338 × 25 × 11850 ± 100 mm in caliber 340 mm on mandrels with a diameter of 282/286 mm with a hood µ = 4.35, compression in diameter Δ = 29.2% and by feeding hollow ingots-blanks to the deformation zone m = 16-18 mm, technological waste is removed from the pipe blanks by a hot cutting saw - pi Igrim heads and seed ends, billet pipes using rolling temperature are corrected in a six-roll straightening machine, billet pipes are cut into two billet pipes, respectively 338 × 25 × 5600 ± 50 and 338 × 25 × 5925 mm, bored and turned into billets of 325 × 12 × 5600 ± 50 and 325 × 12 × 5925 ± 50 mm in size with metal removal on the inner and outer surfaces of 6.5 mm each with a surface finish of R _z ≤30 μm with a diameter tolerance of ± 0.8% and wall ± 10.0%, defects in the form of drafts with a depth of not more than 0.5 mm, located on different surfaces with a displacement relative to each other around the circumference, is removed by a gentle sweep with a surface purity of R _z ≤30 μm, and the amount of displacement is determined from the expression $$L\ge \frac{\pi d}{\mathrm{twenty}}$$

where d is the outer diameter of the conversion pipe, mm, the heating of hollow ingots-blanks ESR from steels of grades 12X12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) is produced according to the technology: two carbon sleeves from steel grades 10 or 20 with a size of 480 × ext. 300 × 2500-3000 mm for setting up the pilgrim mill and heating the mandrels, then 6-8 hollow ingots-blanks are planted in one row at a temperature in the third zone of the furnace 800–900 ° C and they are kept without tilting for 30-45 minutes, heated to a temperature of 1130-1150 ° C at a speed of 3.3-3.5 ° C per minute with uniform after casting two ingots from the 22nd to the 7th window after 17-20 minutes at an angle equal to ≈290-300 °, they are kept at a temperature of 1130-1150 ° C for 30-50 minutes with a uniform pitching with 7- go to the 4th window in 10-15 minutes, turn over from the 4th window to the furnace pit and give out with the temperature of the center of the ingot blanks 1130-1150 ° C, plant the next 2 ingot blanks after turning over the grates of the first two ingot billets, hollow ingot billets are dispensed from the pit of the furnace to the ingot trolley; lubricant in the form of a mixture of sodium chloride and graphite (50/50) minutes 1000-1200 g and a tap with the maximum speed is transported to the upstream side pilger mill hollow billet ingot is rolled in pilger mill in steel making tube on the mandrel with an outer surface temperature of 500-600 ° C, which is achieved by rolling two tuning carbon sleeves.

, где d - наружный диаметр передельной трубы, мм, нагрев полых слитков-заготовок ЭШП из сталей марок 12Х12М1БФРУ-Ш (ЭП450У-Ш) и 16Х12МВСФБР-Ш (ЭП823-Ш) производят по технологии: на колосники методической печи садят две углеродистые гильзы из стали марок 10 или 20 размером 480×вн.300×2500-3000 мм для настройки пилигримового стана и разогрева дорнов, затем в один ряд садят 6-8 полых слитков-заготовок при температуре в третьей зоне печи 800-900°C и выдерживают их без кантовки в течение 30-45 минут, нагревают до температуры 1130-1150°C со скоростью 3,3-3,5°C в минуту с равномерной кантовкой по два слитка-заготовки с 22-го по 7-е окно через 17-20 минут на угол, равный ≈290-300°, выдерживают при температуре 1130-1150°C в течение 30-50 минут с равномерной кантовкой с 7-го на 4-е окно через 10-15 минут, кантуют с 4-го окна на яму печи и выдают с температурой центра слитков-заготовок 1130-1150°C, посад следующих 2-х слитков-заготовок производят после кантовки с колосников первых двух слитков-заготовок, полые слитки-заготовки выдают с ямы печи на слитковую тележку, внутрь слитков-заготовок задают смазку в виде смеси поваренной соли и графита (50/50) массой 1000-1200 грамм и краном с максимальной скоростью транспортируют на входную сторону пилигримового стана, полые слитки-заготовки прокатывают на пилигримовом стане в передельные трубы на дорнах с температурой наружной поверхности 500-600°C, которая достигается за счет прокатки двух настроечных углеродистых гильз. Таким образом, заявляемый способ соответствует критерию "изобретательский уровень".A comparative analysis of the proposed solution with the prototype shows that the claimed method differs from the known one in that electroslag remelting ingots are cast hollow from steel grade 12X12M1BFRU-Sh (EP450U-Sh) with a size of 490 × ext. 290 × 2850 ± 25 mm, and from steel grade 16X12MVSFBR -Sh (EP823-Sh) with a size of 490 × ext. 290 × 3000 ± 25 mm, which are turned and bored into hollow ingots-blanks, respectively, of a size of 480 × ext. 300 × 2850 ± 25 and 480 × ext. 300 × 3000 ± 25 mm , heated to a temperature of 1130-1150 ° C, rolled on pilgrim mills using underlay carbon rings in f hot-deformed billet pipes measuring 338 × 25 × 11200 ± 100 and 338 × 25 × 11850 ± 100 mm in caliber 340 mm on mandrels with a diameter of 282/286 mm with a hood (µ = 4.35, compression in diameter Δ = 29.2 % and by feeding hollow ingots-blanks to the deformation zone m = 16-18 mm, technological waste is removed from the blanks by a hot cutting saw — pilgrim heads and seed ends, blanks using rolling rolling temperature are corrected in a six-roll straightening machine, pipes- billets are cut into two billet pipes, respectively 338 × 25 × 5600 ± 50 and 338 × 25 × 5925 ± 50 mm, respectively grind and grind into billet pipes of sizes 325 × 12 × 5600 ± 50 and 325 × 12 × 5925 ± 50 mm with metal removal on the inner and outer surfaces of 6.5 mm with a surface finish of R _z ≤30 μm with a diameter tolerance of ± 0.8% and the wall ± 10.0%, defects in the form of drafts with a depth of not more than 0.5 mm, located on different surfaces with a displacement relative to each other around the circumference, are removed by a gentle sweep with a surface cleanliness of R _z ≤30 μm, and the value offsets are determined from the expression $$L\ge \frac{\pi d}{\mathrm{twenty}}$$

where d is the outer diameter of the conversion pipe, mm, the heating of hollow ingots-blanks ESR from steels of grades 12X12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) is produced according to the technology: two carbon sleeves from steel grades 10 or 20 with a size of 480 × ext. 300 × 2500-3000 mm for setting up the pilgrim mill and heating the mandrels, then 6-8 hollow ingots-blanks are planted in one row at a temperature in the third zone of the furnace 800–900 ° C and they are kept without tilting for 30-45 minutes, heated to a temperature of 1130-1150 ° C at a speed of 3.3-3.5 ° C per minute with uniform after casting two ingots from the 22nd to the 7th window after 17-20 minutes at an angle equal to ≈290-300 °, they are kept at a temperature of 1130-1150 ° C for 30-50 minutes with a uniform pitching with 7- go to the 4th window in 10-15 minutes, turn over from the 4th window to the furnace pit and give out with the temperature of the center of the ingot blanks 1130-1150 ° C, plant the next 2 ingot blanks after turning over the grates of the first two ingot billets, hollow ingot billets are dispensed from the pit of the furnace to the ingot trolley; lubricant in the form of a mixture of sodium chloride and graphite (50/50) minutes 1000-1200 g and a tap with the maximum speed is transported to the upstream side pilger mill hollow billet ingot is rolled in pilger mill in steel making tube on the mandrel with an outer surface temperature of 500-600 ° C, which is achieved by rolling two tuning carbon sleeves. Thus, the claimed method meets the criterion of "inventive step".

Comparison of the claimed solution (method) not only with the prototype, but also with other technical solutions in this technical field, did not reveal the signs that distinguish the claimed solution from the prototype, which allows us to conclude that the patentability condition is “inventive step”.

The method was tested on a pipe-rolling installation with 8-16 ″ pilgrim mills and on a section for processing forgings and special-purpose pipes when turning and boring hot-rolled steel tubes of 344 × 31 and 338 × 25 mm in size in 325 × 12 mm pipes. At first, 2 EAW ingot blanks with a size of 470 × 100 × 1540 mm of steel grade 12X12M1BFRU-Sh were set in production, which were uniformly heated to a temperature of 1190 and 1200 ° C for 8 hours. The firmware was produced on a mandrel with a diameter of 300 mm in sleeves with a size of 480 × ext. 315 × 2400 mm. When flashing the first ingot billet with a temperature of 1190 ° C, there were flaws on the inner surface of the liner, the depth of which was impossible to determine on the hot liners. The sleeve was rolled on a pilgrim mill in a tube measuring 344 × 31 mm on a mandrel with a diameter of 283/287 mm. The length of the pipe had through flaws. A suitable section of a pipe with a length of 1450 mm was cut from this pipe. This pipe was turned and bored until defects were removed by a size of 320 × 8.5 × 1200 mm. The second ingot billet with a center temperature at the outlet of the furnace of 1200 ° C, when piercing in a cross-helical rolling mill, fell into three parts in length and was rejected. The through flow rate of the metal from the ingot to the conversion pipe measuring 320 × 8.5 × 1200 mm was 57.186.

After this case, according to the existing technology, 2 ingot blanks with a size of 470 × 100 × 1540 mm with a total weight of 4040 kg were heated according to the proposed technology in a methodical furnace to a temperature of 1130 and 1140 ° C. The piercing of ingot blanks in a cross-helical rolling mill was performed on a mandrel with a diameter of 300 mm. When flashing on the liners there were internal captives and small flaws. Sleeves were rolled on a pilgrim mill in rolls with a caliber of 351 mm on mandrels with a diameter of 283/287 mm and a taper of 4.0 mm into transfer tubes of 344 × 31 mm in size. The tubes were rolled with carbon-based washers with feed sleeves into the deformation zone m = 20-22 mm. The pipes came off the mandrel satisfactorily, because the temperature of the end of rolling was 860-870 ° C. On pipes on the inner surface were captives and transverse flaws. The pipes were straightened on a straightening machine and cut into two pipe blanks measuring 344 × 31 × 3300 mm. Billet pipes were bored to remove internal defects, and then turned to a diameter of 325 mm. The wall thickness of the pipes ranged from 9.5 to 12.5 mm, i.e. with a tolerance of wall thickness of + 4.2 / -20.8%. The expenditure coefficient of the metal during the redistribution of the ESR ingot - 325 × 12 mm conversion pipe was 3,730, and during the machining of 344 × 31 mm conversion pipes into 325 × 12 mm pipes - 2,808. The pipes were accepted as conditionally suitable and transferred to workshop No. 5. Pipes at the KhPT 450 and KhPT 250 mills were rolled into conversion pipes of 202 × 3.5 mm in size along the routes: 325 × 12 × 3300 - 273 × 8 × 5500 - 250 × 5 × 9100 - 202 × 3.5 × 15600 mm. Pipes with a size of 202 × 3.5 × 15600 mm were accepted as conditionally suitable with a tolerance of ± 0.8% or ± 1.55 mm in diameter and a wall thickness of ± 12.5% or ± 0.44 mm. Thus, when redistributing 2 ingots with a size of 470 × 1540 mm, 13.2 meters of machined conversion tubes with a size of 325 × 12 mm with a diameter tolerance of ± 1.0% and a wall of + 4.2 / -20.8% were obtained.

According to the proposed technology, 2 hollow ingots-billets with a size of 480 × ext. 300 × 2850 mm from steel grade 12X12M1BFRU-Sh and 2 hollow ingots-bille with a size of 480 × ext. 300 × 3000 mm from steel of grade 16X12MVSFBR-Sh were heated in a methodical furnace to temperature 1140 ° C. After the ingot billets were dispensed from the furnace, a lubricant was set in the form of a mixture of graphite with sodium chloride (50/50) weighing 1000-1200 g (two shovels) and transferred by a crane to the water side of the pilgrim mill for 20-30 seconds (p. 4 claims). The billets were rolled on a pilgrim mill in a hot-rolled steel tubes measuring respectively 338 × 25 × 11200 and 338 × 25 × 11850 mm in accordance with claims 1, 3 and 5 of the claims. The pipes were cut into two equal parts, bored and turned in accordance with claim 1 of the claims into redacted machined billet pipes measuring 325 × 12 × 5600 and 325 × 12 × 5925 mm. On one pipe-workpiece made of steel 16Kh12MVSFBR-Sh, on the outer surface, blackness remained with an area of 25 × 25 mm and a depth of 0.5 mm, which was removed by abrasive cleaning with a surface finish of R _z ≤30 μm (claim 2). The expenditure coefficient of the metal during the redistribution of the ESR ingot - 325 × 12 mm conversion pipe made of 12Kh12M1BFRU-Sh steel was 2.642, and during the machining of 338 × 25 × 5600 mm conversion pipes into 325 × 12 × 5600 mm pipes - 2.083. The expenditure coefficient of the metal during the redistribution of the ESR ingot — the 325 × 12 mm conversion pipe made of 16Kh12MVSFBR-Sh steel was 2.629, and during the machining of 338 × 25 × 5925 mm conversion pipes into 325 × 12 × 5925 mm pipes — 2.083.

When redistributing 2 hollow ingots of 490 × vn. 390 × 2850 mm in size from steel grade 12Kh12M1BFRU-Sh, 22.4 meters of machined conversion tubes of 325 × 12 mm in size were obtained, and from steel 16Kh12MVSFBR-Sh-23.7 meters with a diameter tolerance ± 0.8% and wall ± 10.0%. Then, machined billet pipes of 325 × 12 × 5600 and 325 × 12 × 5925 mm in size were rolled in workshop No. 5 at the KhPT450 and KhPT 250 mills into pipes of 202 ± 1.3 × 3.5 + 0.3 / - respectively 0.2 and 194 ± 1.2 × 2.5 + 0.37-0.2 mm. Pipes of size 202 ± 1.3 × 3.5 + 0.3 / -0.2 and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm mm were profiled in a profiling “mill 400” in turnkey hexagonal pipes 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0.3 / -0, 2 × 2680 mm. Data on the production of hot-rolled machined pipes measuring 325 × 12 mm with increased accuracy in diameter and wall from steel grades 12Kh12M1BFRU-Sh (EP450U-Sh) and 16Kh12MVSFBR-Sh (EP823-Sh) for rolling them on the mills ХПТ 450 and ХПТ 250 в Conversion pipes 202 ± 1.2 × 3.5 + 0.3 / -0.2 mm and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm in size and subsequent profiling into hexagonal tubes turnkey size 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 194 ± 1.2 × 2.5 + 0.37-0.2 × 2580 + 20 / -0 mm for new generation fast neutron reactors according to existing and proposed technologies are given in the table. The table shows that in the production of hot rolled mechanically processed pipes of 325 × 12 mm in size from 12Kh12M1BFRU-Sh and 16Kh12MVSFBR-Sh steel grades, pipes with a tolerance of ± 0.8% in diameter and ± 10.0% in wall are rolled by the proposed technology, rolling which at the KhPT 450 and KhPT 250 mills makes it possible to produce pipes of 202 × 3.5 and 194 × 2.5 mm in size with a tolerance of ± 1.2 mm in diameter and a wall thickness of + 0.3 / -0.2 mm for subsequent profiling them into hexagonal pipe blanks with a turnkey size of 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 and 175 ± 0.4 × 2.5 + 0 , 3 / -0.2 × 2680 + 20 / -0 mm. In the manufacture of hot-rolled machine-made conversion tubes of 325 × 12 mm in size from steel grade 12Kh12M1BFRU-Sh, a reduction in the expenditure coefficient of metal by 1088 kg was obtained, and from steel grade 16Kh12MVSFBR-Sh by 1101 kg, the laborious operation of boring and turning of pipes of 344 × 31 mm with defects on the inner surface in the conversion machined with a size of 325 × 12 mm.

Using the proposed method for the production of hot rolled machined tubes of 325 × 12 mm in size with increased accuracy in diameter and wall of steel grades 12X12M1BFRU-Sh (EP450U-Sh), 16X12MVSFBR-Sh (EP823-Sh) for rolling them on the mills KhPT 450 and KhPT 250 into conversion pipes with a size of 202 ± 1.2 × 3.5 + 0.3 / -0.2 mm, 184 ± 1.2 × 2.5 + 0.37-0.2 mm and subsequent profiling into hexagonal pipes - blanks with a turnkey size of 181.8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 mm and 175 ± 0.4 × 2.5 + 0.3 / - 0.2 × 2680 + 20 / -0 mm for new generation reactors on fast neutrons will allow to master their production, reducing the expenditure coefficient of the metal during the redistribution of the ESR ingot is a 325 × 12 mm hot rolled pipe made of 1088 kg steel from 12Kh12M1BFRU-Sh steel and 1101 kg from 16Kh12MVSFBR-Sh steel and, therefore, reduce their cost and, consequently, the cost hexagonal billets from these steel grades.

Claims (5)

1. Method for the production of hot-rolled mechanically processed tubes of 325 × 12 mm in size with increased accuracy in diameter and wall from steel grades 12X12M1BFRU-Sh, 16X12MVSFBR-Sh, intended for rolling on steel mills ХПТ 450 and ХПТ 250 into steel tubes with dimensions of 202 ± 1, 2 × 3.5 + 0.3 / -0.2 mm and 194 ± 1.2 × 2.5 + 0.3 / -0.2 mm and subsequent profiling into hexagonal pipe blanks with turnkey dimensions 181, 8 ± 0.4 × 3.5 + 0.3 / -0.2 × 3750 + 20 / -0 mm and 175 ± 0.4 × 2.5 + 0.3 / -0.2 × 2680 + 20 / -0 mm for new generation reactors with fast neutrons, characterized in that the hollow ingots of electroslag are cast the alloy is made of steel grade 12Kh12M1BFRU-Sh with a size of 490 × ext. 290 × 2850 ± 25 mm, and from steel grade 16Kh12MVSFBR-Sh with a size of 490 × ext. 290 × 3000 ± 25 mm, which is grinded and bored into hollow ingots with dimensions of 480 × ext. 300 × 2850 ± 25 and 480 × ext. 300 × 3000 ± 25 mm, heated to a temperature of 1130–1150 ° C, rolled on pilgrim mills using carbon-based underlay rings into hot converted billet pipes with dimensions of 338 × 25 × 11200 ± 100 and 338 × 25 × 11850 ± 100 mm in caliber 340 mm on mandrels with a diameter of 282/286 mm with a hood µ = 4.35, compression in diameter Δ = 29.2% and feeding hollow ingots into blanks g deformation m = 16-18 mm, technological waste in the form of pilgrim heads and seed ends is removed from the billet pipes with a hot cutting saw, the billet pipes are adjusted using a rolling heating temperature in a six-roll straightening machine, cut into two billet pipes with dimensions of 338 × 25 × 5600 ± 50 and 338 × 25 × 5925 ± 50 mm, bored and turned into billet pipes of sizes 325 × 12 × 5600 ± 50 and 325 × 12 × 5925 ± 50 mm with metal removal along the inner and outer surfaces of 6, 5 mm with a surface roughness R _z ≤30 microns, and a tolerance of ± 0,8% diameter and wall ± 10,0%. 2. The method according to claim 1, characterized in that the defects in the form of drafts with a depth of not more than 0.5 mm, located on different surfaces with a displacement relative to each other around the circumference, are removed by a gentle sweep with a surface cleanliness of R _z ≤30 μm, and the value offsets are determined from the expression
$$L\ge \frac{\pi d}{\mathrm{twenty}}$$

,
where d is the outer diameter of the conversion pipe, mm 3. The method according to claim 1, characterized in that the heating of the hollow ingots-blanks of ESR from steels of grades 12X12M1BFRU-Sh and 16X12MVSFBR-Sh is carried out according to the technology, according to which two carbon sleeves made of steel of grades 10 or 20 are planted on the grate of the method furnace size 480 × ext. 300 × 2500-3000 mm for setting up the pilgrim mill and heating the mandrels, then 6-8 hollow ingots-blanks are put in one row at a temperature in the third zone of the furnace 800–900 ° C and they are kept without tilting for 30 -45 minutes, heated to a temperature of 1130-1150 ° C at a speed of 3.3-3.5 ° C per minute with uniform threaded by two ingot billets from the 22nd to the 7th window after 17-20 minutes at an angle = 290-300 °, kept at a temperature of 1130-1150 ° C for 30-50 minutes with a uniform pitching from the 7th to The 4th window after 10-15 minutes, turn over from the 4th window to the furnace pit and issue with the center temperature of the ingot blanks 1130-1150 ° C, and the planting of the next 2 ingot blanks is done after turning over the grates of the first two ingots - preparations. 4. The method according to claim 1, characterized in that the hollow ingots-blanks are dispensed from the pit of the furnace to the ingot cart, lubricants are set inside the ingots-blanks in the form of a mixture of sodium chloride and graphite (50/50) weighing 1000-1200 grams and using a crane with maximum speed transported to the input side of the pilgrim mill. 5. The method according to p. 1, characterized in that the hollow ingots-billets are rolled on a pilgrim mill in a conversion pipe on the mandrels with an outer surface temperature of 500-600 ° C, which is provided by rolling two tuning carbon sleeves.