RU2511199C1 - Method of producing of tube stock sized to 290x12 mm to specs 8-16 - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of 290x12 mm tube stock. Proposed method comprises casting the ingots by electric slag remelting. Produced ingots are cut over outer surface to remove casting flaws to billets. Through 100±5.0 mm-dia central bore is made and billets are heated to yield point. First, said ingots are pierced at helical rolling stand to make sleeves. Said sleeves are rolled at Pilger mill with 480xin.295×250-300 mm carbon jar washers to tube stocks to be drawn and reduced in diameter. Hot cutting saw is used to remove process wastes in the form of Pilger heads and seed ends. Socks are cut into two equal-length tubes to be straightened at six-roll straightener and machined to commercial hexagonal tube billets sized to 257+2.0/-3.0×6.0+2.0/-1.0×4300+80/-30 mm.

EFFECT: decreased number of flaws, lower metal input.

3 cl, 1 tbl

Description

The invention relates to pipe production, in particular to a method for the production of pig-sized pipes 290x12 mm in size on TPU 8-16 "with pilgrim mills from ingots-blanks of electroslag remelting of low-plastic steels of grades 04X14TZR1F-Sh and 04X14T5R2F-Sh with boron content from 1.3 to 3 , 5% for the manufacture of hexagonal tubes-blanks for compacted storage in the pools of nuclear power plants and transportation of spent nuclear fuel, and can be used in the production of seamless hot-rolled conversion pipes in tube rolling plants x with pilger.

In pipe production, there is a known method for the production of steel tubes from low-ductility steel 04Kh14T3R1F-Sh (ChS82) with a boron content of 1.3-1.8%, which provides for the smelting of steel by vacuum-arc (VD), vacuum-induction (VI), vacuum-induction with subsequent vacuum-arc remelting (ID) and plasma remelting (R) into ingots with a diameter of 460 mm followed by forging them into bars (blanks) with a diameter of 225-230 mm and machining (turning) to a size of 215 × 1850-1950 mm, heating to ductility temperatures, firmware in a cross-helical rolling mill on TPA-350 with an automatic mill in sleeves of size 220 × 45 × 2700-2850 mm, cooling, repair, firmware on the first piercing mill in sleeves of size 250 × 28 × 3400-3600 mm, firmware on the second mill in sleeves of size 292 × 13 × 5600-5950 mm, rolling in an automatic mill in three passes with reductions of 14.3%, 8.3%, 0.5%, respectively, and calibration in a calibration mill into 288 × 11 mm pipes at a temperature of 850-950 ° С (Report according to the research work “Mastering the production technology of hot-rolled large diameter pipes from ChS 82 steel in the conditions of TPA-350" UTZ ", Dnepropetrovsk, 1988).

The disadvantages of this method are interstate transportation (Chelyabinsk - Nikopol - Chelyabinsk), the laborious operation of forging ingots with a diameter of 460 mm into bars (billets) with a diameter of 225-230 mm, followed by machining (turning) and cutting to a size of 215 × 1850-1950 mm, large the expenditure coefficient of the metal during the redistribution of the ingot-billet is a six-sided billet equal to 6.53, and, as a result, the high cost of conversion tubes and finished products (hexagonal billets).

In the pipe industry, there is a known method for the production of conversion tube blanks for the manufacture of hexagonal jacketed tubes from low-alloy nickel-free steel grade 04X14T3R1F-Sh with a boron content of 1.3-1.8%, including drilling a central hole with a diameter of 100 ± 5 mm in 460 ESR ingots-blanks -480 × 1600-1750 mm, heating them to the temperature of ductility, piercing in the cross-helical mill into sleeves of size 460hvn.240 × 2100-2300 mm, rolling the sleeves on a pilgrim mill into pipe blanks of 377 × 88.5 × 3200 -3600 mm, cooling pipes and their repair (if necessary), cutting of billet pipes into two cuts - billets with a size of 377 × 88.5 × 1575-1750 mm, reheating them to a plasticity temperature, flashing (rolling) in a piercing mill into sleeves 400 × 50 × in size 2300-2550 mm, rolling on a pilgrim mill into conversion tubes of 290 × 12 × 11000-12000 mm in size and dressing on a straightening machine at a temperature not lower than 100 ° C using the temperature of rolling heating (RF Patent No. 2226133, Cl. B21B 21/00. 2004).

The known method has the following disadvantages. The technological process for the production of steel tubes 04Kh14TZR1F-Sh, including two heating, two firmware, two rolling on a pilgrim mill and cutting on workpieces of pipe blanks into two equal crates - workpieces, is time-consuming, costly, which leads to an increase in the price of steel tubes and, as a result, to the increase in the price of hexagonal billet pipes. Rolling two krats - blanks of 377 × 88.5 × 1600–1800 mm in size, obtained from one ingot, in a pilgrim mill into conversion pipes of 290 × 12 × 11500–12500 mm in size leads to an increase in technological waste in the form of two seed ends and two pilgrim heads. With an unsteady rolling process, i.e. when seeding and rolling in the pilgrim heads, end defects in the form of longitudinal cracks and flaws in the length of 0.5-0.8 meters are formed due to the low plasticity of the steel. This leads to an increase in the expenditure coefficient of the metal during the redistribution of the ESR ingot — the conversion tube. Rolling on a pilgrim mill of 290 × 12 × 11500-12500 mm pipes from liners of 400 × 50 × 2300-2550 mm in size for 3.0-3.5 minutes reduces the temperature of the sleeve to 750 ° C, i.e. pipe ends rolling at temperatures below 800 ° C, and this is significantly lower than the lower limit of the ductility interval of this steel grade (800-850X), which leads to the formation of flaws under the pilgrim head at a length of 2.0-3.0 m, and this in turn, leads to the marriage of one krat, because the minimum length of the pipe for profiling (redistribution into a hexagon) must be no shorter than 5000 mm.

The closest technical solution is a method for the production of steel tubes from low plastic steel with a boron content of 1.3-1.8% (04X14T3R1F-Sh), which includes ingots casting by electroslag remelting with a size of 480 × 1750 ± 70 or 500 × 1675 ± 70 mm, external turning surfaces to remove casting defects into ingot billets of 460 ± 10 × 1750 ± 70 or 480 ± 10 × 1675 ± 70 mm in size, drilling a central hole with a diameter of 100 ± 5.0 mm, heating the ingot billets to a temperature of 1060-1090 ° С , exposure at a temperature of 450-500 ° C on the grid-irons of methodical furnaces without edging ki for 90-120 minutes, heating to a temperature of 800-850 ° C at a speed of 1.8-2.0 ° C per minute, then heating to a plasticity temperature of 1050-1090 ° C at a speed of 2.1-2.2 ° C per minute with tilting in 15-20 minutes, holding at this temperature for 70-80 minutes with tilting at an angle of ≈ 180 ° after 10-15 minutes (RU patent No. 2255820, Cl. B21B 21/00 of 12/27/2004) , piercing ingot blanks in a cross-helical rolling mill into sleeves of 470hvn.295 × 2370-2800 and 480hvn.295 × 2310-2710 mm in size, rolling of sleeves on a pilgrim mill with lining carbon rings of 480hvn.295 × 250-300 mm in size for partial in the removal of the pilgrim heads in the conversion pipe-whip size, respectively, 290 × 12 × 21000-24000 and 290 × 12 × 21000-25000 mm with hoods, respectively, µ = 10.03 and µ-10.74 and compression in diameter Δ = 38, 3 and Δ = 39.6%, rolling of the front ends of the pipes at a length equal to 1.0-1.2 of the rollback path of the feeding apparatus with a wall thickness greater than the nominal by 2-3 mm, rolling of the rear ends of the pipes under the pilgrim head in length equal to 1.2-1.5 of the rollback path of the feeding apparatus with a wall thickness less than the nominal one by 0.5-0.8 mm due to dilution and reduction of the rolls of the pilgrim mill (patent RU No. 2334571, K l B21B 21/00. September 27, 2008), a saw cut by hot cutting of technological waste - pilgrim heads and seed ends, cutting lashes into two pipes of equal length, straightening pipes on a six-roll straightening machine using rolling heating temperature, cutting pipes into two blanks - cutting no less than 5000 mm, boring and turning them to a size of 284 + 2.0 / -3.0x6 + 2.0 / -1.0 mm and warm profiling into hexagonal tube blanks with a turnkey size of 257 + 2.0 / -3 , 0 × 6 + 2.0 / -1.0x4300 + 80 / -30 mm (TI 158-Tr. TB 1-49-2007 "Production of seamless hot-deformed steel conversion pipes from steel ChS82-04X14T3R1F-Sh brands ").

One of the main disadvantages of this prototype, as well as the above analogues, is that when rolling sleeves with a diameter of 470-480 mm in a caliber of 295 mm with an angle of transverse exhaustion of 20 ° into conversion tubes of 290 × 12 mm in size with an extractor µ = 10.03 and µ = 10.74, reductions in diameter Δ equal to 38.3 and 39.6%, and feeds over 12 mm overflow the caliber, i.e. metal flow in the cross-section of the gauge, which leads to the formation of “riots” in the transverse outlets of the gauge — a significant thickening of the wall, on the outer surface of which “tears” are formed, which upon subsequent tilting by 90 °, falling into the zone of intense longitudinal deformation, lead to formation of “flaws”, and in some cases, through through flaws “holes”, ie, marriage. From tears on the outer surface of the transfer pipes a network of microcracks with a depth of 1.0 or more mm is formed, which leads to an increase in the thickness of the front wall Since the conversion pipe must be a multiple, depending on the location of these defects, they lead to rejection of whole krats. An increase in the wall thickness of the conversion pipes and rejection of cracks according to rolled defects lead to an increased consumption coefficient of expensive boron-containing steel, and this method does not solves technological issues of the production of redistribution pipes from steel grade 04X14T5R2F-Sh.

The objective of the proposed method is to reduce the transverse flow of metal, reducing the wall thickness in the outlets of "riots", transverse tears, partial or complete elimination of through flaws on the conversion pipes, reducing the expenditure coefficient of the metal during the redistribution of the ingot-billet - the conversion pipe - commodity hexagonal pipe-billet, and consequently, the reduction in the cost of the final production of hexagonal billets from steel 04Kh14T3R1F-Sh and 04Kh14T5R2F-Sh.

The technical result is achieved by the fact that in the known method for the production of conversion pipes 290x12 mm in size on TPU 8-16 "with pilgrim mills from ingots-blanks of electroslag remelting of low plastic steels of grades 04X14TZR1F-Sh and 04X14T5R2F-Sh with boron content from 1.3 to 3, 5% for the manufacture of turnkey hexagonal tube blanks of 257 + 2.0 / -3.0 × 6 + 2.0 / -1.0 × 4300 + 80 / -30 mm for compacted storage in the exposure pools of nuclear power plants and transportation of spent nuclear fuel, including ingot casting by electroslag remelting, size 480 × 1750 ± 70 or 5 00 × 1675 ± 70 mm, turning the ingots on the outer surface to remove casting defects into ingot blanks of 460 ± 10 × 1750 ± 70 or 480 ± 10 × 1675 ± 70 mm in size, drilling a central hole with a diameter of 100 ± 5.0 mm, heating ingot blanks to ductility temperature, piercing ingot blanks in a cross-helical rolling mill into sleeves of sizes 470hvn.295x2370-2800 and 480hvn.285 × 2310-2710 mm with hoods µ from 1.41 to 1.57, diameter rise δ from 0 to 4.4% and seam Δ from 0 to 2.04%, rolling of sleeves on a pilgrim mill with lining carbon rings of size 480xvn.295 × 250-300 mm for partial removal of pilgrim heads to carbon metal in a caliber of 295 mm with a lateral angle of exit at the polishing section of 20 ° into redox pipes with a size of 290 × 12 × 21000-24000 and 290 × 12 × 21000-24500 mm with hoods , respectively, µ = 10.03 and µ = 10.74 and a diameter reduction of Δ = 38.3 and Δ = 39.6%, a hot saw for cutting technological waste — pilgrim heads and seed ends, and cutting two lashes pipes of equal length, straightening pipes on a six-roll straightening machine using rolling heating temperature, cutting pipes into two e blanks - a slab with a length of not less than 5000 mm, boring and turning them to a size of 284.75 + 2.0 / -3.0 × 6 + 2.0 / -1.0 mm and warm profiling into hexagonal tubes-blanks of size " turnkey "257 + 2.0 / -3.0 × 6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm, electroslag remelting ingots are cast with a size of 480 × 1650 ± 50 mm, grind into ingots - workpieces with a size of 465 ± 5 × 1650 ± 50 mm, drill a through central hole with a diameter of 100 ± 5 mm, ingot billets are heated to a temperature of 1060-1090 ° C, are stitched in a cross-mill mill in sleeves of size 450xvn.295 × 2740- 2840 mm with a fit in diameter Δ from 2.17 to 4.26% and a hood µ from 1.71 to 1.79, sleeves measuring 450hvn. 295 × 2740-3040 mm with carbon rings are rolled on a pilgrim mill in rolls with a caliber of 295 mm in a whip pipe measuring 290 × 12 × 23000-25500 mm with a hood µ = 8.65 and with a diameter of Δ = 35.6%, the hot ends are removed from the lash pipe using a hot cutting saw and the pilgrim heads are not fully rolled in, the lash pipe is cut into two pipes of equal length, the conversion pipes are straightened, received by STP and sent to processing into hexagonal billets of turnkey size 257 + 2.0 / -3.0 × 6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm, rolling redistribution tubes on a pilgrim mill are produced in rolls with a transverse angle of exit at a polishing section of 26-28 ° with the supply of sleeves from steel grade 04X14TZR1F-Sh to the deformation zone during the steady rolling process µ = 15-16 mm, and sleeves from steel grade 04X14T5R2F-Sh with a feed of μ = 13–15 mm, rolling of the conversion tubes on the pilgrim mill is done with the edge of the sleeve tubes at an angle of (45 ± 5) ° or (135 ± 5) °.

Comparative analysis with the prototype shows that the inventive method for the production of conversion pipes 290 × 12 mm in size on TPU 8-16 "with pilgrim mills from ingots-blanks of electroslag remelting of low plastic steels 04Х14Т3Р1Ф-Ш and 04Х14Т5Р2Ф-Ш with a boron content from 1.3 to 3.5% for the manufacture of turnkey hexagonal tube blanks 257 + 2.0 / -3.0 × 6 + 2.0 / -1.0 × 4300 + 80 / -30 mm for compact storage in holding pools NPP and transportation of spent nuclear fuel, characterized in that the electroslag remelting ingots are cast erym 480 × 1650 ± 50 mm, machined into ingots-blanks of size 465 ± 5 × 1650 ± 50 mm, drilled through a central hole with a diameter of 100 ± 5 mm, ingots-blanks are heated to a temperature of 1060-1090 ° C, stitched in the mill transversely screw rolling into sleeves with dimensions 450hvn. 295 × 2740-2840 mm with a pitch over diameter Δ from 2.17 to 4.26% and a hood µ from 1.71 to 1.79, sleeves measuring 450hvn. 295 × 2740-3040 mm with carbon lining rings are rolled on a pilgrim mill in rolls with a caliber of 295 mm in a whip pipe of 290 × 12 × 23000-25500 mm in size with an exhaust hood of μ = 8.65 and a diameter fit Δ = 35.6% of saw pipe whip For hot cutting, the seed ends and incompletely run-in pilgrim heads are removed, the lash pipes are cut into two pipes of equal length, the redirection pipes are straightened, accepted according to STP and sent for processing to hex turn-shaped pipe billets 257 + 2.0 / - 3.0 × 6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm, rolling of the pig tubes on the pilgrim mill is carried out in rolls with a transverse angle of exit at the polishing section of 26-28 ° with the supply of steel sleeves grade 04Х14Т3Р1Ф-Ш into the deformation zone during the steady rolling process µ = 15-16 mm, and sleeves made of steel grade 04Х14Т5Р2 Ф-Ш with feed µ = 13-15 mm, rolling of the conversion tubes on the pilgrim mill is done with the edge of the sleeve tubes at an angle of (45 ± 5) ° or (135 ± 5) °. Thus, these differences allow us to conclude that the criterion of "inventive step" is met.

Comparison of the proposed method not only with the prototype, but also with other technical solutions in the art did not allow them to identify signs that distinguish the claimed method from the prototype, which corresponds to the patentability "inventive step".

The proposed method for the production of conversion pipes 290 × 12 mm in size on TPU 8-16 "with pilgrim mills from ingots-blanks of electroslag remelting of low-plastic steels of grades 04Х14Т3Р1Ф-Ш and 04Х14Т5Р2Ф-Ш with boron content from 1.3 to 3.5% for manufacturing hexagonal turnkey pipe billets of 257 + 2.0 / -3.0 × 6 + 2.0 / -1.0 × 4300 + 80 / -30 mm for compacted storage in the storage pools of nuclear power plants and the transportation of spent nuclear fuel in that electroslag remelting ingots are cast with a size of 480 × 1650 ± 50 mm, grind into ingots-blanks once measure 465 ± 5 × 1650 ± 50 mm, drill a through central hole with a diameter of 100 ± 5 mm, ingot billets are heated to a temperature of 1060-1090 ° C, flashed in a cross-mill mill into sleeves measuring 450хvn.295 ± 2740-2840 mm with a fit in diameter Δ from 2.17 to 4.26% and a hood µ from 1.71 to 1.79, sleeves measuring 450hvn. 295 × 2740-3040 mm with carbon rings are rolled on a pilgrim mill in rolls with a caliber of 295 mm in lash pipes with a size of 290 × 12 × 23000-25500 mm with an exhaust hood µ = 8.65 and a diameter fit Δ = 35.6%, the seed ends are removed from the lash pipes by a hot cutting saw and fully rolled pilgrim heads, lash pipes are cut into two pipes of equal length, the conversion pipes are straightened, taken according to STP and sent for processing into hexagonal pipe blanks with a turnkey size of 257 + 2.0 / -3.0 × 6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm, rolling of the conversion tubes in the pilgrim mill is carried out in rolls with a transverse angle of exit at the polishing section of 26-28 ° with the supply of sleeves from steel grade 04X14T3R1F-Sh to the deformation zone with a steady rolling process µ = 15-16 mm, and sleeves made of steel grade 04X14T5R2F-Sh with a feed of µ = 13-15 mm, rolling of conversion pipes n Pilger mill to produce tilting liner-pipe at an angle (45 ± 5) ° or (135 ± 5) °.

The method was tested on TPU 8-16 "with pilgrim mills of ChTPZ OJSC. Using this method, for the first time in 2011, high-quality converting whip tubes of 290x12x25000 mm in size were obtained from electroslag remelting ingots 466x100x1650 mm in size 04X14T5R2F-Sh steel with grade boron 2.58-2.87 for the manufacture of hexagonal tube blanks with a turnkey size of 257 + 2.0 / -3.0x6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm.

Five bullion-blank ingots with a size of 470 × 100 × 1750 mm and 5 ingots-blanks with a size of 480 × 100 × 1675 mm of steel 04X14T5R2F-Sh delivered by OAO ZMZ (existing technology) and 5 ingots-blanks with a size of 465 × 100 were set for production × 1650 mm (proposed technology). Five ingot blanks ESR size 470 × 100 × 1750 mm with a total weight of 10.86 and 5 ingot blanks with a size of 480 × 100 × 1675 mm with a total weight of 10.87 tons were heated in a method furnace to a temperature of 1060-1070 ° C. The first five ingot billets were stitched in a cross-helical mill on a mandrel with a diameter of 280 mm into sleeves of 470hvn.295 × 2700 mm in size and rolled on a pilgrim mill in a 295 mm caliber with a transverse angle of 20 °. The value of the supply of sleeves in the deformation zone did not exceed 13-14 mm. With an increase in the feed, transverse cracks began to form on the outer surface of the "riots", leading to the formation of a microcrack on the outer surface of the conversion pipes. To reduce the likelihood of flaws at the front ends of the transfer pipes, the seed was produced with a wall of 13.5 mm. After rolling, the average length of the lash tubes in the gutter of the pilgrim mill was 26500 mm. Due to the presence of defects in the form of longitudinal at the seed ends and transverse under the pilgrim heads, their average value was 800 and 1200 mm, respectively, which were removed by a hot cutting saw. The lash pipes are cut into two pipes of equal length by a hot-cutting saw, straightened by a straightening machine and sent to workshop No. 5 for boring, turning and profiling. When cutting pipes into slots, two krats were rejected: one along the through flaw from the side of the pilgrim head, and the second along the through flaw from the side of the seed end (marriage of workshop No. 1). In the process of turning and boring, three more cracks were rejected: one on the outer captivity, the second on the inner captivity, displaying the wall thickness beyond the negative tolerance field (defective workshop No. 1 - the wall thickness at the defect location is less than 5.0 mm), and the third by cutting on the outer surface (defective workshop No. 5). Accepted 15 suitable hexagonal billets with a total weight of 2.78 tons. The metal consumption coefficient (the ratio of the mass of a given metal in production to the mass of accepted hexagonal billets) for pipes of this batch was 3.907.

The second five ingot billets were stitched in a cross-helical mill on a mandrel with a diameter of 280 mm into sleeves of size 480xvn.295 × 2700 mm and rolled on a pilgrim mill in a 295 mm caliber with a transverse angle of 20 °. The value of the supply of sleeves in the deformation zone did not exceed 12-13 mm. With an increase in the feed, transverse cracks began to form on the outer surface of the "riots", leading to the formation of a network of microcracks on the outer surface of the conversion pipes. To reduce the likelihood of flaws at the front ends of the transfer pipes, the seed was produced with a wall of 14.5 mm. After rolling, the average length of the lash tubes in the gutter of the pilgrim mill was 26500 mm. Due to the presence of defects in the form of longitudinal at the seed ends and transverse under the pilgrim heads, their average value was, respectively, 1000 and 1350 mm, which were removed by a hot cutting saw. The lash tubes with a hot-cutting saw were cut into two tubes of equal length, straightened by a straightening machine and sent to workshop No. 5 for boring, turning and profiling. When cutting pipes for crats, three krats were rejected: two on the flaw on the side of the pilgrim head, and the third on the flaw on the side of the seed end (marriage of workshop No. 1). In the process of turning and boring, two more cracks were rejected: one along the outer captivity, and the second along the inner captivity, displaying the wall thickness beyond the negative tolerance field (defect of workshop No. 1). Accepted 15 suitable hexagonal billet pipes with a total mass of 2.78 tons. The expenditure coefficient of the metal in the pipes of this batch was 3.910.

According to the proposed technology, five ESR ingots-blanks with a size of 465 × 100 × 1650 mm and a total weight of 10.02 tons were set into production. The ingots-blanks were heated to a temperature of 1060-1070 ° C, sewn in a cross-helical rolling mill on a mandrel with a diameter 280 mm in sleeves measuring 450hvn. 295 × 2890 mm with a hood µ = 1.75 and a diameter fit Δ = 3.23%. Sleeves are rolled on a pilgrim mill caliber 295 mm with an angle

 lateral exhaust 26 ° into the conversion pipe-whip size 290x12x25000 mm with a hood µ 8.65 and compression in diameter Δ = 35.6%, with the supply of sleeves in the deformation zone 13-14 mm (in accordance with paragraphs 1 and 3 of the claims ) Rolling of redistributed pipes was performed with the edge of the sleeve tubes at an angle of 45 ± 5 ° (claim 3 of the claims). There were no transverse cracks on the outer surface of the “riots”, and consequently, there was no microcrack network on the outer surface of the conversion pipes. The seed and the steady-state rolling process of the conversion pipes were carried out on a 12 mm wall. After rolling, the average length of the lash tubes in the gutter of the pilgrim mill was 25,000 mm. Due to the absence of defects in the form of longitudinal cracks at the seed ends and transverse under the pilgrim heads, the average size (length) of the trim was 700 and 600 mm, respectively, which was removed by a hot cutting saw. The lash pipes are cut into two pipes of equal length by a hot-cutting saw, straightened by a straightening machine and sent to workshop No. 5 for boring, turning and profiling. When cutting pipes to the slabs, rejection was absent. In the process of turning and boring, two krats were rejected: one on the outer captivity, and the second on the notch. Accepted 18 hexagonal billet pipes with a total weight of 3.33 t. The expenditure coefficient of metal for pipes of this batch was 3.009.

Data on rolling of conversion pipes of 290 × 12 × 23000-24500 mm in size from 04Kh14T5R2F-Sh steel ingots with a boron content of 2.58-2.87%, cast at ZMZ OJSC and rolled at 8-16 "TPU with according to the existing and proposed methods, and the production of hexagonal tube blanks from them, turnkey size 257 + 2.0 / -3.0 × 6.0 × 2.0 / -1.0х4300 + 80 / -30 mm are given in the table.

Thus, according to the proposed method, in the production of a pilot batch of conversion pipes of 290x12x23500 mm in size on tube rolling plants with piligrim mills from low-ductility steel 04X14T5R2F-Sh with a boron content of 2.58 to 2.87%, a reduction in the expenditure coefficient of the metal during the redistribution of the ingot is obtained billet - conversion pipe - hexagonal billet pipe for 898-901 kg per ton of hexagonal billet pipes.

Using the proposed method for the production of conversion pipes with a size of 290 × 12 mm on a tube rolling unit with 8-16 "pilgrim mills from electroslag ingots from low-plastic steels 04Х14Т3Р1Ф-Ш and 04Х14Т5Р2Ф-Ш with boron content from 1.3 to 3.5% for for manufacturing hexagonal tube blanks with a turnkey size of 257 + 2.0 / -3.0 × 6 + 2.0 / -1.0 × 4300 + 80 / -30 mm for compacted storage in the storage pools of nuclear power plants and transportation of spent nuclear fuel will eliminate one set of mold, reduce metal consumption due to the use of using the optimal sizes of ingot billets and deformation parameters in cross-helical rolling mills and pilgrim mills, reduce the number of defects at the seed ends and the ends under the pilgrim heads in the form of cracks and tears, eliminate the formation of tears in the body of the transfer tube-lashes, and therefore reduce the cost commodity hexagonal tubes-blanks from steel 04X14T3R1F-Sh and 04X14T5R2F-Sh.

Claims (3)

1. Method for the production of conversion pipes 290 × 12 mm in size on a pipe-rolling installation (TPU 8-16 ") with pilgrim mills from ingots-blanks for electroslag remelting of low-plastic steel grades 04Х14Т3Р1Ф-Ш and 04Х14Т5Р2Ф-Ш with boron content from 1.3 to 3, 5% for the manufacture of commercial hexagonal billets designed for compacted storage in the pools of nuclear power plants and transportation of spent nuclear fuel, including ingots casting by electroslag remelting, turning the ingots on the outer surface until defects are removed of hollow origin into ingot blanks, drilling a through central hole with a diameter of 100 ± 5.0 mm, heating ingot blanks to plasticity temperature, piercing ingot blanks in a cross-helical rolling mill into sleeves, rolling the sleeves in a pilgrim mill with lining carbon rings in conversion lash tubes with exhaust and compression in diameter, a hot-saw blade for cutting technological waste in the form of pilgrim heads and seed ends, cutting lashes into two pipes of equal length, straightening pipes into a pole new straightening machine using rolling heating temperature and processing into commodity hexagonal billets of size 257 + 2.0 / -3.0 × 6.0 + 2.0 / -1.0 × 4300 + 80 / -30 mm, differing by the fact that electroslag remelting ingots are cast with a size of 480 × 1650 ± 50 mm, machined into ingots-blanks of 465 ± 5 × 1650 ± 50 mm in size, a through hole is drilled through a central hole with a diameter of 100 ± 5 mm, the ingots-blanks are heated to a temperature of 1060-1090 ° C, flashed in a cross-rolling mill in sleeves of size 450хвн.295 × 2740-3040 mm with compression in diameter Δ from 2.17 to 4.26% and a hood µ from 1.71 to 1.79, and sleeves of size 450xvn. 295 × 2740-3040 mm with carbon rings are rolled on a pilgrim mill in rolls with a caliber of 295 mm into conversion pipes - lashes with a size of 290 × 12 × 23000-25500 mm with a hood µ = 8.65 and compression in diameter Δ=35.6%. 2. The method according to claim 1, characterized in that the rolling tubes are rolled on a pilgrim mill in rolls with an angle of transverse release at a polishing section of 26-28 ° with the supply of sleeves from steel grade 04X14T3R1F-Sh to the deformation zone during the steady rolling process μ = 15-16 mm, and sleeves made of steel grade 04X14T5R2F-Sh with a feed µ = 13-15 mm. 3. The method according to claim 1 or 2, characterized the fact that rolling of the conversion tubes on the pilgrim mill is done with the edge of the sleeve tubes at an angle of (45 ± 5) ° or (135 ± 5) °.