RU2541212C2 - Production of hexagonal pipe billets for compact storage and transportation of used nuclear fuel from low-ductile steel with boron content of 1,3-3,5% - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Ingots-billets sized to 500±2×ID330±2×2750±50 mm are fitted on grate bars at continuous furnace centre at temperature in third zone of 800-850°C and held without turnover for 45-60 minutes and heated to 550-600°C. Ingots-billets are turned over by one opening in 20-22 minutes. Here, ingots-billets from 22^nd through 7^th openings are uniformly heated to 1080-1100°C at the rate of 1.3-1.5°C/min and held for 45-50 minutes at 1080-1100°C with uniform turnover from 7^th to 4^th opening in 15-17 minutes. From 4^th opening said ingots-billets are turned over to pit and discharged onto ingot truck at centre temperature of 1080-1100°C. They are blown with compressed air to feed the mix of table salt with graphene (50/50) in amount of 800-1000 g. Now, they are carried to Pilger mill inlet and rolled to 325×12×22400-23300 mm rerolled pipes. Pipe units are cut by hot cutting saws to 7450-7750 mm lengths, bored and turned to rerolled 321×8×7450-7750 mm lengths with surface smoothness R_z≤30 mcm. The latter are heated in inductor to 200-250°C and rolled at CPR 450 milled to rerolled 284.8×6×10500-11000 mm pipes. Ultrasound control is performed; ingots-billets are shaped to hexagonal pipe billets to be cut to 257+2/-3×6+2/-1×4300+80/-30 mm pipe billets to proceed with further jobs.

EFFECT: production of cold-rerolled pipes of precise sizes for shaping to hexagonal pipes, lower metal input.

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Description

The invention relates to pipe rolling and metallurgical industries, in particular to a method for the production of hollow ingots of electroslag remelting with a size of 515 ± 5 × int. 320 ± 5 × 2750 ± 50 mm from low-ductility steel with boron content from 1.3 to 3.5%, turning and boring them into ingot billets of 500 ± 2 × vn. 330 ± 2 × 2750 ± 50 mm in size, rolling from them at 8-16 "TPU with piligrim mills of hot-rolled pipe-converters with a size of 325 ± 12 × 22400-23300 mm, pipe cutting -cracks with a length of 7450-7750 mm, boring and turning at the installation with a follow-up system in hot-rolled mechanical ski-treated pipe-krat 321 × 8 × 7450-7750 mm in size, warm rolling of machined pipes at the KhPT 450 mill into cold rolled steel pipes of 285 × 6 × 10500-11000 mm in size, ultrasonic testing, warm profiling on a roll forming mill into hexagonal pipes - blanks on a turn-key basis 257 + 2 / -3 × 6 + 2 / -1 × 10500-11000, cuts on measured pipe blanks of a size 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / - 30 mm with all subsequent operations on the technological process, for the manufacture of racks for compacted storage and transportation of spent nuclear fuel, and can be used on ESHP installations of ZMZ OJSC, on a pipe-rolling installation with pilgrim mills, on the KhPT 450 mill and on the profiling mill 400 of ChTPZ OJSC.

In pipe production, there is a known method for the production of steel tubes from low-ductility steel with a boron content of 1.3-1.8% (ChS 82), which involves the smelting of steel by vacuum-arc (VD), vacuum-induction (VI), vacuum-induction followed by vacuum -arc remelting (ID) and plasma remelting (R) into ingots with a diameter of 460 mm, followed by forging them into bar stocks with a diameter of 225-230 mm and machining with turning by turning to a size of 215 × 1850-1950 mm, heating to ductility temperature, firmware in the piercing mill on TPA-350 with automatic mill m 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 ° C, turning and boring into pipes of size 284.8 + 2 / -3 × 6 + 2 / -1 × 5250-5750 mm and profiling them into hexagonal workpieces of size 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm (Report on research "Development of the technology for the production of hot rolled pipes large diameter steel 82 in emergency conditions TPA - 350 "YUTZ" Dnipropetrovsk 1988 YG).

The disadvantage of this method is the interstate transportation (Chelyabinsk-Nikopol-Chelyabinsk), the time-consuming operation of forging ingots with a diameter of 460 mm into bar stocks with a diameter of 225-230 mm, followed by machining - turning and cutting to a size of 215 × 1850-1950 mm, high expenditure coefficient metal during the redistribution of the ingot is a hexagonal billet pipe equal to 6.53, and, as a result, the high cost of conversion pipes and finished products (hexagonal billets).

In the metallurgical and pipe industry, there is a known method for the production of solid ingots from corrosion-resistant steel grade 04X14TZR1F-Sh, smelted in electric furnaces under slag, which are turned into ingot billets of size 460-480 × 1750-1650 ± 70 mm and delivered to pipe manufacturers for the production of conversion pipes on tube rolling plants with pilgrim mills (TU 14-1-4599-89 "Billet pipe made of steel 04X14TZR1F-VI (ChS82-VI), 04X14TZR1F-PT (ChS82-PT), 04X14TZR1F-PSh (ChS82-NSh-04F14 and 04H14 ChS82-Sh) ". These ingots at ChTPZ OJSC undergo through-hole drilling on a diam. p 100 ± 5,0 mm and set at manufacture.

The disadvantage of this method is the increased expenditure coefficient of the metal during the redistribution of ESR ingots - a hexagonal tube billet, which reaches more than 4.5

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 with a boron content of 1.3-1.8%, including steelmaking by vacuum-arc, vacuum-induction, vacuum-induction followed by vacuum-arc remelting and plasma remelting into ingots of 460 × 1700-1750 mm in size, drilling a central hole with a diameter of 100 ± 5.0 mm, heating them to a plasticity temperature, piercing 8-16 "TPU piercing mill in sleeves of 460 × 110 × 2100-2300 mm in size , etc the roll of shells on the pilgrim mill in the pipe blanks of size 377 × 88.5 × 3150-3500 mm, cooling, if necessary, repair, and cutting into two equal parts-blanks of size 377 × 88.5 × 1575-1750 mm, re-heating them to plasticity temperature, firmware-rolling in a piercing mill in sleeves 400 × 50 × 2300-2550 mm in size, rolling on a pilgrim mill in redox pipes of 290 × 12 × 11000-12000 mm in size and dressing on a straightening machine at a temperature of at least 100 ° C using the temperature of the rolling heat (RF Patent No. 2226133 "Method for the production of tube blanks for manufacturing "Hexagonal jacketed tubes made of low-plastic nickel-free steel with a boron content of 1.3-1.8%," Bull. No. 9, 2004. "Development and development of a new technology for the production of hexagonal jacketed tubes from low-alloy neutron-absorbing non-nickel steel with a boron content of 1.3-1.8%." Proceedings of the Fourth Congress of Rollers ", Magnitogorsk, October 16-19, 2001, Moscow , 2002, p. 44-47).

The known method has the following disadvantages. The technological process for the production of conversion pipes from ChS 82 steel, which includes two heating, two firmware, two rolling at a pilgrim mill and cutting pipe blanks into two equal round billets, is time consuming, which leads to an increase in the price of conversion pipes and , as a result, to the increase in the price of hexagonal shell pipes. Rolling two krat-billets of 377 × 88.5 × 1600–1800 mm in size, obtained from one ingot, in a pilgrim mill to 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 in a pilgrim mill of pipes measuring 290 × 12 × 11500-12500 mm from liners of 400 × 50 × 2300-2550 mm for 3.0-3.5 minutes leads to a decrease in the temperature of the liner to 750 ° C, i.e. rolling of pipe ends occurs at a temperature below 800 ° C, and this is significantly lower than the lower limit of the ductility interval of this steel grade (800-850 ° C), which leads to the formation of flaws under the pilgrim head on a length of 2.0-3.0 meters, and this in turn leads to the marriage of one krat, as the minimum length of the pipe for profiling (redistribution into a hexagon) must be no shorter than 5000 mm. The average consumption coefficient of the metal during the redistribution of the ESR ingot — the hexagonal billet pipe by this technology amounted to 4.55, i.e. to obtain one ton of hexagonal pipes with a turnkey size of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm, 4.55 tons of ESR ingots of ChS 82-Sh steel are required. This technology for the production of conversion pipes leads to a loss in productivity of pilgrim mills "2.0 times, because double heating, double flashing and double rolling of the conversion pipes to TPU with pilgrim mills are required.

In pipe production, there is also known a method for the production of steel tubes from low-ductility 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 the 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 at a length L = (1,5-2,0) S with a thickness _of blunting h = (5,0-6,0) S _m, where S _m - wall thickness before lnyh 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 a hot-rolled pipe mill 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 the technological process of redistributing hot-rolled pipes into hexagonal pipe blanks with a turnkey size of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm (RF Patent No. 2297893. Cl. B21B 21/00. 27.04 .2007).

The disadvantage of this method of manufacturing hexagonal tubes-blanks is that it does not fully take advantage of the plastic properties of a hollow ESR ingot over a solid one, because impact strength and relative elongation of the metal along the length (from the seed to the pilgrim head) of the transfer pipes of 290 × 12 mm in size, rolled from their hollow ESR ingots, are KCU = 5.0-4.0-6.8, respectively, and δ = (14.0-14.5)%. This makes it possible to perform warm rolling of hot-rolled conversion tubes at HPT mills with wall reductions of up to 20% and diameter planting up to 16% of hollow ingots with an increased boron content of up to 3.5%.

The closest technical solution is the method of production of limit pipes from low plastic steel ingots with a boron content of 1.3-1.8% (RF Patent No. 2255820. Cl. B21B 21/00, B21B 21/04, 14.14.2005, Bull. No. 19 ), including casting ESR ingots with a diameter of 460-480 mm, drilling holes with a diameter of 100 ± 5 mm, holding at a temperature of 450-500 ° C on the grates of a methodical furnace without tilting for 90-120 min, heating to a temperature of 800-850 ° C with at a speed of 1.8-2.0 ° C per minute, then heating to a plasticity temperature of 1060-1090 ° C at a speed of 2.1-2.2 ° C per minute with a tilting in 15-20 minutes and you holding at a given temperature for 70-80 minutes with a tilt at an angle of ≈ 180 ° in 10-15 minutes, feeding into the ingots of grease in the form of graphite with sodium chloride (50/50)% weighing 300-500 g, piercing with hood 1, 6-1.75 without lifting in diameter, reducing the speed of rotation of the rolls when flashing from 40-45 revolutions per minute when filling the deformation zone, from capturing the workpiece by rolls until the sleeve is completely on the mandrel, by 20-25% - 25-30 revolutions per minute, rolling the sleeves on a pilgrim mill to conversion tubes with an exhaust hood µ = 9.0-10.5 and compression in diameter of 35-40%, the seed and dokatka - about a pack of the pilgrim head with a hood µ = 7.5–8.5, equal to 0.8–0.85 of the amount of drawing of the steady rolling process, reduction of the draw when seeding for a length of 1.0–1.1, and when rolling the pilgrim head by the length of 0.3-0.5, the rollback path of the feeding apparatus, due to the breeding of the rolls of the pilgrim mill.

One of the main disadvantages of this prototype is that it is aimed at the technology of rolling pig tubes from sleeves sewn in a cross-helical rolling mill from solid ESR ingots, without the formation of flaws during seeding and rolling - rolling in pilgrim heads and does not solve technological issues of heating hollow ESR ingots-blanks with a size of 500 ± ext. 330 ± 2 × 2750 ± 50 mm with a boron content of 1.3 to 3.5% for rolling hot rolled pipe lashes with a size of 325 × 12 × 2400-23300 mm on TPU 8-16 "with pilgrim mills. Rolling with elevated and equal the longer plastic properties of the lash pipe metal makes it possible to heat-roll hot-rolled conversion pipes at the KhPT mills into cold-rolled conversion pipes with a size of 284.8 × 6 mm with a boron content of up to 3.5% with more rigid geometric dimensions compared to machined pipes of 284.8 + 2 / -3 × 6 + 2 / -1 mm in size and, accordingly, produce hexagonal workpieces with the best geometric dimensions.

The objective of the proposed method is the development of a new technological process for the production of cold rolled cold-rolled pipes of 284.8 × 6 mm in size for warm profiling them into hexagonal tubes of "turnkey" size 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm from low-ductility steel with boron content from 1.3 to 3.5% from hot-rolled steel tubes of 325 × 12 × 22400-23300 mm in size, rolled on 8-16 "TPU with pilgrim mills from hollow ingots-billets of electroslag remelting size 500 ± 2 × ext. 330 ± 2 × 2750 ± 50 mm, reduction of the expenditure coefficient of the metal during In fact, a hollow ingot billet ESR is a hot-rolled pipe billet - a cold-rolled pipe billet is a hexagonal billet, a reduction in the cost of the final production of hexagonal billets from steel 04Kh14TZR1F-Sh (ChS82) and 04Kh14T5R2F-Sh (ChS 82M), which the queue will allow the production of hexagonal billet pipes with stiffer geometrical dimensions, and therefore, increase the reliability of racks for storing and transporting spent nuclear fuel at newly commissioned and reconstructed facilities languid energy.

The technical result is achieved by the fact that in the known method for the production of hexagonal pipes-tubes for compacted storage and transportation of spent nuclear fuel from low-plastic steel with a boron content of 1.3 to 3.5%, including casting hollow ingots of electroslag remelting size (480-490) × ext. 270 × 2300-2500 mm, boring and turning before removing shells and traces of flux into hollow billets of size (470-480) × ext. 280 × 2300-2500 mm with a surface finish of R _Z ≤40 μm, heating to ductility temperature rolling hollow billets on pilgrim st not on mandrels with a diameter of 264/265 mm, into whipping pipe lashes of 290 × 12 × 22000-23000 mm in size, cutting of lashing pipes into two pipes of equal length or a multiple of the length of the billet, dressing on a six-roll straightening machine using rolling heating temperature, subsequent cutting them into pipe-crats, machining - boring and turning to a size of 284.8 + 2.0 / -3.0 × 6 + 2.0 / -1.0 × 5250-5750 mm, ultrasonic testing, drilling holes for a king pin the pulling chain of the profiling mill, warm profiling into hexagonal pipe blanks with a turnkey size of 257 + 2 / -3 / × 6 + 2 / -1 × 5250-5750 mm , removing the transitional part from the hexagon to the circle, trimming the ends and cutting the hexagonal workpieces to a measured length of 4300 + 80 / -30 mm, checking the free passability of the caliber and accepting the hexagonal workpieces for compliance with the requirements of TU 14-3-1630-89 , hexagonal tubes-blanks are produced from hollow ingots-blanks with a size of 500 ± 2 × ext. 330 ± 2 × 2750 ± 50 mm according to the technology: hollow ingots-blanks are planted on grate in one row in the center of the methodical furnace in batches of 8-12 pieces at temperature in the third zone 800-850 ° C, can withstand without tilting for 45- 60 minutes and heated to a temperature of 550-600 ° C, the first two ingots-blanks from each row in 45-60 minutes are turned over one window with a rotation angle of ≈ 270-280 ° and the following four ingots-blanks, turning over ingot blanks are produced on one window in 20-22 minutes, during the tilting process from the 22nd to the 7th window, ingot blanks are uniformly heated to a temperature of 1080-1100 ° C at a speed of 1.3-1.5 ° C per minute , incubated for 45-50 minutes at a temperature of 1080-1100 ° C with uniform tilting from the 7th to the 4th window after 15-17 minutes, from the 4th window of the ingot and-blanks are turned over into a pit and delivered from the furnace to an ingot trolley with a center temperature of 1080-1100 ° C, purged with compressed air, lubricant is supplied inside as a mixture of graphite with sodium chloride in a percentage (50/50) of weight 800-1000 g, they are transported by a bridge crane to the entrance side of the pilgrim mill and rolled into hot-rolled pipe lashes with a size of 325 × 12 × 22400-23300 mm, hot rolled pipe lanes are cut with a hot cutting saw into pipe-crats with a length of 7450-7750 mm, bored and turned into 321 × 8 × 7450 pipe-krat -7750 mm with a surface purity of R _z ≤30 μm, which are heated in the inductor to a temperature of 200-250 ° C and rolled on a KPT 450 mill into conversion pipes of 284.8 × 6 × 10500-11000 mm in size, ultrasonic testing is carried out, profiled in hexagonal pipe turnkey billets 257 + 2 / -3 / × 6 + 2 / -1 × 10500-11000 mm and cut into pipe billets 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm with all subsequent operations on the process performed, when rolling hot rolled pipe lashes in one mill, no more than 30 ingots are put into the furnace, and when rolling with two mills, not more than 60 pieces.

Comparative analysis with the prototype shows that the inventive method for the production of hexagonal tube blanks for compacted storage and transportation of spent nuclear fuel from low plastic steel with a boron content of 1.3 to 3.5% differs in that known for the fact that the hexagonal tube blanks are made from hollow ingot blanks measuring 500 ± 2 × ext. 330 ± 2 × 2750 ± 50 mm according to the technology: hollow ingot blanks are planted on the grate in one row in the center of the methodical furnace in batches of 8-12 pieces at a temperature in the third zone of 800-850 ° C, withstand without tilting for 45-60 minutes and heated to a temperature of 550-600 ° C, the first two ingot billets from each row in 45-60 minutes are turned over to one window with a rotation angle of ≈ 270-280 ° and at the same time the following four ingot billets, the ingot billet is turned over on one window in 20-22 minutes, during the tilting from the 22nd to the 7th ingot billet window, it is uniformly heated to a temperature of 1080-1100 ° C at a speed of 1.3-1 , 5 ° С per minute, incubated for 45-50 minutes at a temperature of 1080-1100 ° С with a uniform pitching from the 7th to the 4th window through 15- 17 minutes, from the 4th window, ingots-billets are turned over into a pit and delivered from the furnace to an ingot trolley with a center temperature of 1080-1100 ° С, purged with compressed air, lubricant in the form of a mixture of graphite with sodium chloride in percentage (50 / 50) weighing 800-1000 g, they are transported by an overhead crane to the entrance side of the pilgrim mill and rolled into hot-rolled porch tubes with a size of 325 × 12 × 22400-23300 mm, hot-rolled porch tubes are cut with a hot cutting saw into 7480- krat pipes 7750 mm, bore and grind into pigs s-fold the size of 321 × 8 × 7450-7750 mm with a surface roughness R _z ≤30 microns, which is heated in the inductor to a temperature of 200-250 ° C, and rolling it at rolling mill 450 in the HPT steel making pipe size 6 × 284.8 × 10500- 11000 mm, ultrasonic testing is carried out, 257 + 2 / -3 / × 6 + 2 / -1 × 10,500-11,000 mm are formed into hexagonal pipe blanks of turnkey size and cut into 257 + 2 / -3 × pipe blanks 6 + 2 / -1 × 4300 + 807-30 mm with all subsequent operations on the technological process performed, when rolling hot rolled pipe lashes in one mill, no more than 30 ingots are put into the furnace, and when Attack by two camps - no more than 60 pieces. 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 of "inventive step".

The method was carried out at ZMZ OJSC in the production of ESW hollow ingots of 515 ± 5 × vn. 320 ± 5 × 2750 ± 50 mm in size with boron content from 2.75 to 2.83%, which were turned and bored at ZMZ OJSC "hollow ingots - billets of 500 ± 2 × 330 ± 2 × 2750 ± 50 mm in size, delivered to ChTPZ OJSC and rolled at TPU 8-16" with pilgrim mills in hot-rolled steel tubes measuring 325 × 12 × 22400-23300 mm The heating of ingot blanks for rolling hot rolled pipe lashes with a size of 325 × 12 × 22400-23300 mm on a pilgrim mill was carried out in accordance with paragraphs 1 and 2 of the claims. nye hot pipes were cut on the pipe-fold length of 7450-7750 mm and shipped to the shop №5. The shop №5 tubes were bored to grind and size 321 × 8 × 7450-7750 mm with a surface roughness R _z ≤30 microns. Then hot-rolled machined pipes were rolled at the KhPT 450 mill into conversion pipes of 284.8 × 6 × 10500-11000 mm in size, which were cut into billet pipes of 284.8 × 6 × 5250-5500 mm in size. profiled into hexagonal pipes of turnkey size 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm with all subsequent technological operations CB process. In production, 5 EAW ingot blanks with a size of 470 × 100 × 1700 mm with a boron content of 1.57-1.68% cast using existing technology (RF Patent No. 2255820), 5 hollow ESW ingot blanks with a size of 470 × int. 280 × 2450 ± 50 mm with boron content from 1.63 to 1.75% cast according to the existing technology (RF Patent No. 2317165), and 5 ingots-blanks of ESR with dimensions 500 ± 2 × ext. 330 × 2750 ± 50 mm s boron content from 2.75 to 2.83% cast by the proposed technology. Data on heating technology, rolling of hot-rolled hot-rolled pipes at TPU 8-6 "with pilgrim mills and cold-rolled hot-rolled pipes at the KhPT 450 mill made of low-ductility steel with boron content from 1.55 to 2.83% from ingot-blanks and hollow-ingot-blanks ESRs and redistributing them into hexagonal tube blanks with a turnkey size of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm according to existing and proposed technologies are shown in the table. existing technology ESR ingots of size 480 × 1700 ± 50 mm at ZMZ OJSC were turned into ingot blanks of size 47 0 × 1700 ± 50 mm, and at ChTPZ OJSC they were drilled to a diameter of 100 ± 5 mm and set into production according to the existing technology, namely: they were heated in a furnace to a temperature of 1080-1090 ° C, stitched in a cross-helical rolling mill a mandrel with a diameter of 275 mm in sleeves measuring 470 × ext. 290 × 2500-2600 mm with an extractor hood μ = 1.47, the sleeves after blowing were rolled on a pilgrim mill into conversion tubes of 290 × 12 × 22000-23000 mm in diameter with an exhaust hood μ = 10, 25. According to this technology, 5 lash pipes were rolled, which in workshop No. 1 were cut into 10 pipes 11000-11500 mm long (20 krats). In workshop No. 1, 2 krats were rejected according to flaws and external captives. 18 kits were shipped to workshop No. 5 for processing, of which one hexagonal billet was rejected during redistribution for rental defects in workshop No. 1 (external captives). Thus, according to the existing technology, 11,575 kg of ChS82 steel was set into production, 17 hexagonal tube blanks with a total weight of 3,145 kg were adopted. The expenditure coefficient of the metal for this batch was 3,680. According to the existing technology (RF Patent No. 2317165), hollow EAW blanks with a size of 480 × ext. 270 × 2450 ± 50 mm were cast, turned and bored at ZMZ OJSC into ingot blanks with a size of 470 × ext. 280 × 2450 ± 50 mm Chelyabinsk Pipe Plant was put into production according to the existing technology (RF Patent No. 2317165), namely: it was heated in a furnace to a temperature of 1040-1060 ° C and rolled on a pilgrim mill in a conversion pipe measuring 290 × 12 × 22000-23000 mm with a hood μ = 10.68. According to this technology, 5 lash pipes were rolled, which in workshop No. 1 were cut into 10 pipes 11000-11500 mm long (20 krats). In workshop No. 1, two cracks were rejected for flaws. 18 kits were shipped to workshop No. 5 for processing, of which two hexagonal pipe blanks were rejected during redistribution for rental defects in workshop No. 1 (external captives). Thus, according to the existing technology (RF Patent No. 2317165), 10277 kg of ChS82 steel were set into production, 16 hexagonal tube blanks with a total weight of 2960 kg were adopted. The expenditure coefficient of the metal for this batch amounted to 3,472.

According to the proposed technology, ESW hollow ingots of 515 ± 5 × vn. 320 × 2750 ± 50 mm in size were cast, turned and bored at ZMZ OJSC into 500 × 2 × vn. 330 × 2 × 2750 ± 50 mm ingots. At ChTPZ OJSC, hollow ingots were heated in a furnace to a temperature of 1080-1100 ° C in accordance with paragraphs 1 and 2 of the claims and rolled on a pilgrim mill in conversion tubes of 325 × 12 × 22400-23300 mm in size on mandrels with a diameter 303/304 with an extractor µ = 9.1, the hot-rolled steel tubes were cut with a hot cutting saw into crack pipes with a length of 7450-7750 mm. 325 × 12 × 7450-7750 mm hot rolled pipes were bored and turned in workshop No. 5 in a unit with a follow-up system into 321 × 8 × 7450-7750 mm red pipes with a surface finish of R _z ≤30 μm, and non-blackened outer surfaces were removed by grinding. Then, hot-rolled mechanically processed pipes 321 × 8 × 7450-7750 mm in size were rolled on the KhPT 450 mill into cold-rolled pig-sized pipes of 284.8 × 6 × 10500-11000 mm in size, which were cut into 284.8 × 6 billet pipes × 5250-5500 mm. After the ultrasonic inspection, the billet pipes were profiled into turnkey hexagonal billet pipes of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm in size, with all subsequent process operations performed. After the ultrasonic inspection, three pipe-cracks were rejected according to the external captives (rolling defect of workshop No. 1). Adopted in accordance with TU14-3-1830-89-27 of hexagonal workpieces. According to the proposed technology, 11423 kg of ChS82M steel was set into production, 27 hexagonal tube blanks with a total weight of 4995 kg were adopted. The expenditure coefficient of the metal for this batch was 2.287.

Thus, according to the results of the production of pilot batches of hexagonal billets according to the existing and proposed methods, it can be seen that the expenditure coefficient of the metal when redistributing the hollow ingot-billet ESR is the hexagonal billet according to the proposed method for the production of hexagonal billets for compacted storage and transportation spent nuclear fuel from low ductility steel with a boron content from 2.75 to 2.83% decreased relative to the analogue (with a boron content from 1.57 to 1.68) by 1393, and relative to type (with a boron content of 1.63 to 1.75) at 1185 kg.

Using the proposed method for the production of hexagonal tubes-blanks for compacted storage and transportation of spent nuclear fuel from low-plastic steel with a boron content of 1.3 to 3.5% will increase the toughness and the size of the ferritic grain, which makes it possible to convert them to cold rolled mills conversion pipes with stiffer geometrical parameters and an increased boron content, in comparison with hot-rolled machined ones, to reduce the consumption of expensive ChS 82M metal per second It reduces the number of defects on hot rolled hot-rolled pipes and the amount of metal that goes into shavings during machining for cold rolling, compared to machining hot-rolled limit pipes for direct profiling them into hexagonal billet pipes, and therefore reduce the cost of commodity hexagonal pipes -workings and master the production of hexagonal workpieces with a high content of boron.

Claims (1)

Method for the production of hexagonal tube blanks for compacted storage and transportation of spent nuclear fuel from low-plastic steel with a boron content of 1.3 to 3.5% turnkey size 257 + 2 / -3 / × 6 + 2 / -1 × 10500 -11000 mm, characterized in that the hexagonal tubes-blanks are made from hollow ingots-blanks of size 500 ± 2 × ext. 330 ± 2 × 2750 ± 50 mm, which are planted on the grate in the center of the methodical furnace at a temperature in the third zone of 800-850 ° C, incubated without tilting for 45-60 minutes and heated to a temperature of 550-600 ° C, turn over to one window after 20-22 m chickpeas, in the process of tilting from the 22nd to the 7th window, ingots of the billet are uniformly heated to a temperature of 1080-1100 ° C at a speed of 1.3-1.5 ° C per minute, incubated for 45-50 minutes at a temperature of 1080 -1100 ° С with a uniform tilting from the 7th to the 4th window in 15-17 minutes, from the 4th window the ingot-blanks are turned over into the pit and delivered from the furnace to the ingot trolley with a center temperature of 1080-1100 ° С, blown compressed air, lubricant is supplied inside in the form of a mixture of a decanter with sodium chloride in a percentage (50/50) of a mass of 800-1000 g, transported along the inlet side of the pilgrim mill and they roll it into 325 × 12 × 22400-23300 mm sized hot rolled pipe lashes, cut hot rolled pipe lashes into a hot cutting saw into 7450-7750 mm long pipes, bore it and grind it into 321 × 8 × 7450 red steel pipe cuts -7750 mm with a surface finish of R _z ≤30 μm, pipe-krats of 321 × 8 × 7450-7750 mm in size are heated in an inductor to a temperature of 200-250 ° C and are rolled on a KPT 450 mill into 284.8 × 6 × conversion tubes 10500-11000 mm, ultrasonic testing is carried out and profiled into hexagonal billet pipes and cut into billet pipes and the size of 257 + 2 / -3 × 6 + 2 / -1 × 4300 + 80 / -30 mm with all subsequent operations on the process.