RU2523382C2 - PRODUCTION OF BIMETAL "T=279×36" (351×36) mm PIPES WITH INNER PLATING LAYER FROM "10ГН2МФА"- AND "08X18H10T"-GRADE STEELS FOR NUCLEAR POWER PLANT STRUCTURES - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed method comprises casting of hollow ESR ingots from "10ГН2МФА"-grade steel to size of 535×vn.250×3100+100 mm. Said ingots are subjected to anodic-mechanical cutting to get equal-length shell ring blanks. Said shell ring blanks are turned to diameter 520±1.0 mm. They are taper-bored in ID, taper small diameter making 257±1.0 mm while its larger diameter makes 265±1.0 mm. Said shell rings are sealed by steel "08Х18Н10Т". Bimetal ingot bottom part are removed to drill the 520±1.0×gr.265±1.0×1550±50 mm through central 100±1.0 mm diameter bore. After boring to 520±1.0×gr.265±1.0×160±1.0×1550±50 mm, bimetal ingots are heated to ductility temperature at pierced at helical rolling mill to sleeves sized to 540×вн.305×1640-1770 mm at 290 mm diameter mandrels. Said sleeves are rolled at Pilger mill in passes 383 mm of 271/272 mm mandrels with carbonaceous jar rings to rerolled pipes sized to 371×50.5×4600-4900 and 446×54×4700-5100 mm. Said rerolled pies are heat treated, straightened, bores and turned to commercial hot-rolled 279×36×4000-4300 mm pipes with plating layer depth of 7±2 mm.

EFFECT: decreased consumption of steels, decreased rejects over plating layer depth.

2 cl, 3 tbl

Description

The invention relates to pipe rolling and production of ingots by electroslag remelting, namely to the production of hollow ingots from 10GN2MFA steel and bimetallic billets from 10KHN2MFA and 08Kh18N10T steels, rolling them into hot rolled bimetallic pipes of 371 × 50.5 and 446 × 54 mm in size for subsequent manufacture of them by machining - boring and turning of commodity hot-rolled mechanically machined bimetallic pipes of dimensions in.279 × 36 (351 × 36) and in.346 × 40 (426 × 40) mm with an inner cladding layer capacity of 7 ± 2 mm thick from steel grade 08Kh18N10T for nuclear facilities and can be used on ESR installations and on TPU 8-16 ″ with pilgrim mills.

Until 1991, pipes of this assortment for Du-350 pipelines of the first circuit of nuclear power plants with VVER-1000 reactors were purchased in Japan. Pipes were made by welding a stainless steel submerged layer onto the inner surface of a pre-machined pipe made of 10GN2MFA steel, followed by boring of the deposited layer to the specified dimensions.

The disadvantage of this method for the production of bimetallic pipes is that in the manufacture of bends the deposited layer cracks, and therefore, it is not possible to use bimetallic pipes for bent profiles of nuclear power facilities.

The closest technical solution is a method for the production of bimetallic pipes with dimensions of ext. 279 × 36 (351 × 36) and ext. 346 × 40 (426 × 40) mm for nuclear power plants from steel grades 10GN2MFA and 08Kh18N10T with an inner cladding layer of 08Kh18N10T steel with a thickness of 7 ± 2 mm, including casting ESR ingots from steel of 10GN2MFA grade 550 × 1600 ± 50 and 580 × 1900 ± 50 mm in size, drilling central ingots with a diameter of 100 ± 5 mm, heating the ESR ingots to a plasticity temperature, piercing ingots in a cross-screw mill rolling into sleeves of size 550 × ext. 245 × 1810-1930 and 600 × ext. 255 × 1980-2090 m m on mandrels with a diameter of 230 and 240 mm, boring and turning of sleeves into shells-blanks of size 520 + 3.0 / -5.0 × ext. 265 ± 5.0 × 1550 ± 50 and 570 + 3.0 / -5, 0 × ext. 255 ± 5.0 × 1700 ± 50 mm, melting the shells-blanks on the EShP unit with 08Kh18N10T steel, removing the bottom parts of bimetallic ingots by anodic-mechanical cutting, drilling in bimetallic ingots of size 520 + 3.0 / -5.0 × gr. 265 ± 5.0 × 1450 ± 50 and 570 + 3.0 / -5.0 × gr. 255 ± 5.0 × 1600 ± 50 mm of a through central hole with a diameter of 100 ± 5 mm, boring of bimetallic ingots size 520 + 3.0 / -5.0 × gr. 265 ± 5.0 × ext. 100 ± 5.0 × 1450 ± 50 mm into ingot blanks of size 520 + 3.0 / -5.0 × gr. 265 Vn.160 ± 5,0 × 5,0 × 1450 ± 50 mm (c. - the boundary diameter between the steels 10ГН2МФА and 08Х18Н10Т), heating the bimetallic ingots to the temperature of plasticity, piercing the bimetallic ingots in the cross-helical rolling mill into sleeves 540 × in. 300 × 1650-1770 and 600 × in. 3565 × 2090-2220 mm, rolling of sleeves on a pilgrim mill in calibers 383 and 464 mm on mandrels 271/272 and 337/338 into conversion tubes 371 × 50.5 × 4200-4500 and 446 × 54 × 4700-5100 mm in size, heat treatment, dressing, sampling for carrying out mechanical tests, machining - boring and turning of hot rolled tubes into commodity grief embossed mechanically machined pipes with dimensions of ext. 279 × 36 × 4200-4500 and ext. 346 × 40 × 4600-5000 mm with a cladding thickness of 7 ± 2 mm from 08Kh18N10T steel, ultrasonic testing of adhesion continuity of adhesion of 10GN2MFA steel with 08Kh18N10T steel, measurement of the cladding layer thickness along the perimeter and length of pipes, acceptance of pipes for compliance with the requirements of TU 14-3-1593-88 (TU 14-3-1593-88 "Seamless hot-rolled bimetallic pipes for NPP pipelines". TI 158-TR.TB1-110-2012 "Production of seamless hot-rolled bimetallic pipes from steel grades 10GN2MFA + 08X18H10T-DD"),

The disadvantages of this method are the increased deviations of the external, boundary and diameters of the central drilling of bimetallic billets, as well as the fact that when melting shirts from 10GN2MFA steel with 08X18H10T steel, the boundary diameter of steel alloying along the height of bimetallic ingots due to the increase in the temperature of the shirts from the beginning of melting to the end , i.e. due to an increase in the inner diameter, it increases by 6-10 mm, which requires measurements of the boundary diameters in the lower and upper parts of the bimetallic ingots and conversion tubes before machining. To calculate the boundary diameter, the average diameter is taken, which in turn leads to a longitudinal difference in the cladding layer and falls outside the permissible values of 7 ± 2 mm. The disadvantages of this method include the fact that according to TU 14-3-1593-88, curvature on hot-rolled pipes of not more than 5 mm to a length of 5000 mm is allowed, and boring of pipes with a curvature of 5 mm with a tolerance of the cladding layer thickness of 7 ± 2 mm is problematic .

The objective of the proposed method is to reduce the rejection of hot-rolled bimetallic machined pipes by the thickness of the cladding layer, the exclusion from the technological process of drilling a central hole in 10GN2MFA steel ingots, heating the ingots to ductility temperature, flashing them in a cross-helical rolling mill, machining boring and turning the sleeves into the shell blanks and reducing the expenditure coefficient of the steels 10GN2MFA and 08Kh18N10T in the production of bimetallic pipes of size in.279x36 (351 x36).

The technical result is achieved by the fact that in the known method for the production of bimetallic pipes for nuclear power facilities of ext. 279 × 36 (351 × 36) mm in size from 10GN2MFA and 08Kh18N10T steels with an internal cladding layer, including ESW hollow ingots casting from 10GN2MFA steel of 535 size × ext. 250 × 3100 + 100 mm, anodic-mechanical cutting of ingots into two shell-blanks equal in length, turning of shell-blanks to a diameter of 520 ± 1.0 mm, boring along the inner diameter of a cone, the smaller diameter of which is 257 ± 1.0 mm, and the larger 265 ± 1.0 mm, fused other shell blanks on an ESR unit using 08Kh18N10T steel, removal of the bottom parts of bimetallic ingots by anodic-mechanical cutting, drilling in bimetallic ingots with a size of 520 ± 1.0 × gr. 265 ± 1.0 × 1550 ± 50 mm, a through central hole with a diameter of 100+ 1.0 mm, bore of bimetallic ingots with a size of 520 ± 1.0 × gr. 265 ± 1.0 × 100 ± 1.0 × 1550 ± 50 mm to a size of 520 + 1.0 × gr. 265 ± 1.0 × 160 ± 1.0 × 1550 ± 50 mm, heating the ESR ingots to plasticity temperature, piercing the ingots in the cross-helical mill into sleeves measuring 540 × ext. 305 × 1640-1770 mm on a mandrel with a diameter of 290 mm, rolling the sleeves into pilig Imov camp in calibers of 383 mm on mandrels with a diameter of 271/272 mm, respectively, with lining carbon rings in conversion tubes 371 × 50.5 × 4600-4900 mm in size, heat treatment, dressing, sampling for mechanical testing, boring and turning converting pipes into hot-rolled commodity pipes measuring ext. 279 × 36 × 4000-4300 mm with a cladding thickness of 7 ± 2 mm, ultrasonic monitoring of adhesion of adhesion of 10GN2MFA steel to 08Kh18N10T steel, measuring the thickness of the cladding layer along the perimeter and length of pipes, pipe acceptance for compliance setting ennym requirements, and insert-molded blanks shells 08X18H10T steel produced from a larger to a smaller diameter.

A comparative analysis of the proposed solution with the prototype shows that the claimed method differs from the known one in that they cast hollow ESR ingots from 10GN2MFA steel with a size of 535 × ext. 250 × 3100 + 100 mm, anode-mechanical cutting of the ingots into two workpieces equal in length shells, turning of blanks-shells with a diameter of 520 ± 1.0 mm, boring of the inner diameter of a cone, a smaller diameter of which is 257 ± 1.0 mm, and a larger diameter of 265 ± 1.0 mm, fusion of blanks-shells on the ESR installation with steel 08X18H10T, removal of bimetallic bottom parts ingots by anodic-mechanical cutting, drilling in bimetallic ingots with a size of 520 ± 1.0 × gr. 265 ± 1.0 × 1550 + 50 mm of a through central hole with a diameter of 100 ± 1.0 mm, boring of bimetallic ingots with a size of 520 ± 1.0 × gr. 265 ± 1.0 × 100 ± 1.0 × 1550 ± 50 mm for size 520 ± 1.0 × gr. 265 ± 1.0 × 160 ± 1.0 × 1550 ± 50 mm, heating the ESR ingots to a temperature ductility, piercing ingots in a cross-helical rolling mill into sleeves measuring 540 × ext. 305 × 1640-1770 mm on a mandrel with a diameter of 290 mm, rolling the sleeves on a pilgrim mill in 383 mm calibres on mandrels with a diameter of 271/272 mm with carbon rings into conversion pipes 371 × 50.5 × 4600-4900 mm in size, heat treatment, dressing, sampling for mechanical testing, boring and turning of conversion pipes into hot-rolled commodity pipes in size 279 × 36 × 4000-4300 mm with cladding thickness of a layer of 7 ± 2 mm, ultrasonic testing of the adhesion continuity of 10GN2MFA steel with 08Kh18N10T steel is made, the thickness of the cladding layer is measured along the perimeter and length of the pipes, pipes are accepted for compliance with the established requirements, and shell blanks are melted with 08Kh18N10T steel from a larger diameter to lesser. 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 patentability "inventive step".

The method was tested on the installation of electronic ballast of JSC "ZMZ" when casting hollow ingots, making them shells-blanks, converted them into bimetallic ingots, and on TPU with pilgrim mills 8-16 '' OJSC "ChTPZ" when rolling bimetallic ingots into hot-rolled bimetallic pipes for subsequent machining by boring and turning them into commodity hot-rolled mechanically machined pipes ext. 279 × 36 (351 × 36) mm in size with increased geometric dimensions of the thickness of the cladding stainless layer.

, расточены и обточены в обечайки-заготовки размером 520+3,0/-5,0×вн.265±5,0×1550±50 мм. According to the existing technology for the manufacture of shells with a size of 520 + 3.0 / -5.0 × ext. 265 ± 5.0 × 1550 mm, 5 ESR ingots with a size of 550 × 1600 mm with a total weight of 15027 kg were set into production. ESR ingots were heated to the temperature of ductility, stitched in a cross-screw rolling mill into sleeves of size 550 × ext. 245 × 1810-1930 mm with an extract $${\mu }_{PR.351}^{\mathrm{one}}=1.17$$

, bored and turned into shell blanks measuring 520 + 3.0 / -5.0 × ext. 265 ± 5.0 × 1550 ± 50 mm.

. Прокатку гильз на пилигримовом стане производили в калибрах 383 мм на дорнах 271/272 в передельные трубы размером 371×50,5×4600-4900 с вытяжкой µ_п.пр.351=3,114. После термической обработки, правки и механических испытаний металла биметаллических труб количество выпадов по KCU при температуре испытания минус 10°C и толщине плакирующего слоя составило 40%. Расходный коэффициент металла при изготовлении обечаек размером 520×вн.265×1550 мм составил 1,572.At ZMZ OJSC, the shells on the ESR installation were melted with 08Kh18N10T steel. The bottom parts of bimetallic ingots were removed by anodic mechanical cutting. At JSC ChelPipe in bimetallic ingots measuring 520 + 3.0.0 × g. 265 ± 5.0 × 1450 ± 50 mm, through holes were drilled through the center with a diameter of 100 ± 5 mm. Bimetal ingot blanks of size 520 + 3.0 × gr. 265 ± 5.0 × ext. 100 ± 5.0 × 1450 ± 50 mm were bored into ingot blanks of size 520 + 3.0 / -5.0 × gr .265 × ext. 160 ± 5.0 × 1450 ± 50 mm. Bimetallic ingots were heated to a temperature of ductility, stitched in a cross-helical mill in bimetallic sleeves measuring 540 × ext. 300 × 1650-1770 mm, with an extract $${\mu }_{PR.351}^2=1.18$$

. Sleeves were rolled on a pilgrim mill in calibers of 383 mm on mandrels 271/272 into conversion tubes 371 × 50.5 × 4600-4900 in size with an extractor µ _{p.p. 351} = 3.114. After heat treatment, dressing and mechanical testing of the metal of the bimetallic pipes, the number of drops according to KCU at the test temperature of minus 10 ° C and the thickness of the cladding layer was 40%. The expenditure coefficient of the metal in the manufacture of shells measuring 520 × ext. 265 × 1550 mm was 1.572.

According to the proposed technology for the manufacture of shells with a size of 520 ± 1.0 × ext. 265 ± 1.0 × 1550 mm, 5 hollow ESR ingots with a size of 535 × ext. 250 × 3100 mm and a total weight of 21369 kg were set into production. ESW hollow ingots were cut by anodic-mechanical cutting into two equal lengths of the slab-blank. The blanks were turned into diameters of 520 ± 1.0 and 570 ± 1.0 mm and bored into a cone, the smaller diameter of which was 257 ± 1.0, and the larger 265 ± 1.0 mm. The process of melting the shells-blanks on the EShP installation with steel 08X18H10T in bimetallic ingots was carried out from a larger diameter to a smaller diameter. The bottom parts of bimetallic ingots were removed by anodic mechanical cutting. In bimetallic ingots with a size of 520 ± 1.0 × g. 265 ± 1.0 × 1550 ± 50 mm, through holes were drilled through the center holes with a diameter of 100 ± 1.0 mm, bimetallic ingots-blanks with a size of 520 ± 1.0 × g. 265 ± 1.0 × 100 ± 1.0 × 1450 ± 50 mm were bored to a size of 520 ± 1.0 × gr. 265 ± 1.0 × 160 ± 1.0 × 1450 ± 50 mm. Bimetallic ingots were heated to a temperature of 1250-1260 ° C, stitched in a cross-helical mill on mandrels 290 mm in sleeves measuring 540 × ext. 305 × 1650-1770 mm. The sleeves were rolled on a pilgrim mill in the caliber 383 mm, on mandrels with a diameter of 271/272 mm with lining carbon rings into conversion tubes measuring 371 × 50.5 × 4600-4900 mm. Conversion pipes were heat treated and straightened. Samples were taken from the pipes for mechanical tests, and then they were bored and turned into commercial ones with a size of ext. 279 × 36 × 4300 mm with a cladding thickness of 7 ± 2 mm from 08Kh18N10T steel.

Data on the manufacture of shells with a size of 520 ± 1.0 × ext. 265 ± 1.0 × 1550 from steel grade 10GN2MFA according to the existing and proposed technologies are given in table 1.

Data on the mass of steel 08Kh18N10T, which went into the manufacture of bimetallic billets (fusion of shells) and its expenditure coefficients from surfacing to delivery of hot-rolled machined bimetallic pipes, are given in table 2.

table 2 Type of technology The size of the bimetal. pipes (mm) Dimensions and mass of molten steel 08X18H10T The mass is stainless. steel in pipes (kg) The expense ratio is stainless. metal The size of the weld. metal (mm) Kolich. (PC.) Weight (kg) Creatures. 351 × 36 265 × 1600 5 3456 1061 3,257 Suggestion 351 × 36 265 × 1550 5 3348 1061 3,257

In bimetallic ingots cast according to the proposed technology, the boundaries of metal alloying in height (boundary diameters) were determined, i.e. start of fusion and end. The difference in diameters did not exceed ± 1.0 mm.

Thus, according to the proposed technology, 5 bimetallic ingot blanks with dimensions of 520 × gr. 265 × 160 ± 1,0 × 1550 and 570 × gr. 555 × 100 ± 1,0 × 1,700 mm were set into production, the bimetallic ingots were heated to temperatures of 1250-1260 ° C, were sewn in a cross-helical mill on a mandrel with a diameter of 290 mm with a hood µ = 1,196 into sleeves measuring 540 × ext. 305 × 1730 mm, the sleeves were rolled on a pilgrim mill in calibres 383 mm, on mandrels 271 / 272 mm with lining carbon rings in conversion pipes 371 × 50.5 × 4500 mm in size. Conversion pipes were heat treated and straightened. Mechanical tests showed that the metal of the pipes fully complies with the requirements of TU 14-3-1593-88. Then, the conversion pipes were turned and bored into commercial pipes with a size of ext. 279 × 36 × 4300 mm. Ultrasonic inspection of pipes on the continuity of adhesion of 10GN2MFA and 08Kh18N10T steels showed that there is no spacing between them, and the thickness of the cladding layer along the perimeter and length of the pipe varies from 6 to 9 mm, i.e. Meets the requirements of TU 14-3-1593-88.

The data on the rolling of bimetallic billets manufactured by the existing and proposed technologies into bimetallic pipes with a size of ext. 279 × 36 (351 × 36) mm, the expenditure coefficients of the metals for rental and delivery are shown in Table 3.

From table 3 it is seen that the expenditure coefficient of steel grade 10GN2MFA in the manufacture of commodity machined pipes measuring 351 × 36 mm according to existing technology amounted to 3.016. The expenditure coefficient of steel grade 08X18H10T in the manufacture of commodity machined pipes with a size of 351 × 36 mm according to the existing technology was 4.815. The expenditure coefficients of metals in the production of pipes measuring 351 × 36 mm according to the proposed technology amounted to - for steel 10GN2MFA 1.809, and for steel 08X18H18 - 2.890. The total expenditure coefficient of the metal in the production of commercial bimetallic pipes with a size of ext. 279 × 36 (351 × 36) mm by the existing technology was 3.333, and by the proposed technology - 2.150. When rolling commodity pipes according to the existing technology on two pipes with a size of ext. 279 × 36 (351 × 36) mm, the thickness of the cladding layer was 7 ± 4 mm instead of 7 ± 2 mm according to TU14-3-1593-88. When rolling commodity pipes according to the proposed technology, the thickness of the cladding layer was 7 ± 2.0 / -1.0 mm instead of 7 ± 2 mm according to TU.

Thus, the use of the proposed method for the production of bimetallic pipes from bimetallic billets made in accordance with claims 1 and 2 of the claims excludes from the process drilling a central hole in ingots of steel grade 10GN2MFA, heating the ingots to a ductility temperature, piercing in the mill transversely screw rolling, machining - boring and turning of sleeves into shells-blanks, reduces the expenditure coefficient of 10GN2MFA and 08Kh18N10T steels and pipe scrap by the thickness of the cladding layer.

Claims (2)

1. Method for the production of bimetallic pipes for nuclear power facilities measuring ext. 279 × 36 (351 × 36) and ext. 346 × 40 (426 × 40) mm of steel grades 10GN2MFA and 08Kh18N10T with an internal cladding layer, including the casting of hollow ESR ingots from steel grade 10GN2MFA size 535 × ext. 250 × 3100 + 100 mm and 585 × ext. 240 × 3400 + 100 mm, anodic-mechanical cutting of ingots into two equal lengths of the blank-shell, turning of blanks-shells to a diameter of 520 ± 1, 0 mm and 570 ± 1.0 mm, bore on the inner diameter into cones, smaller diameters of which are 257 ± 1.0 mm and 246 ± 1.0 mm, and large 265 ± 1.0 mm and 255 ± 1.0 mm , app digging of shell blanks on an ESR machine with 08Kh18N10T steel, removal of the bottom parts of bimetallic ingots by anodic-mechanical cutting, drilling in bimetallic ingots of size 520 ± 1.0 × gr. 265 ± 1.0 × 1550 ± 50 mm and 570 ± 1.0 × gr.255 ± 1.0 × 1700 ± 50 mm of through central holes with a diameter of 100 ± 1.0 mm, boring of bimetallic ingots of 520 ± 1.0 × gr. 265 ± 1.0 × 100 ± 1.0 × 1550 ± 50 mm to a size of 520 ± 1.0 × gr. 265 ± 1.0 × 160 ± 1.0 × 1550 ± 50 mm, heating the ESR ingots to a temperature of plasticity, piercing the ingots in a cross-helical rolling mill into sleeves measuring 540 × ext. 305 × 1640-1770 mm and 600 × ext. 365 × 2090-2220 mm on def reels with diameters of 290 and 350 mm, rolling of sleeves on a pilgrim mill in calibres of 383 and 464 mm on mandrels with a diameter of 271/272 and 337/338 mm, respectively, with lining carbon rings into conversion tubes 371 × 50.5 × 4600-4900 and 446 × 54 × 4700-5100 mm, heat treatment, dressing, sampling for mechanical testing, boring and turning of conversion pipes into hot-rolled commodity pipes with dimensions in. 279 × 36 × 4000-4300 mm and in. 346 × 40 × 4500- 4900 mm with a cladding layer thickness of 7 ± 2 mm, ultrasonic testing of continuity of adhesion of 10GN2MFA steel to 08Kh18N10T steel is carried out, plate thickness measurement casing layer around the perimeter and length of pipes, pipe acceptance for compliance with established requirements. 2. The method according to claim 1, characterized in that the melting of the shell blanks with steel 08X18H10T is carried out from a larger diameter to a smaller one.