RU2558319C1 - Method of production of seamless hot-worked boiler and steam line 530×30-75 mm pipes from "10х9к3в2мфбр-ш " grade refractory steel for power equipment with steam supercritical parameters - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method of production of seamless hot-worked boiler and steam line 530×30 - 75 mm pipes from "10Х9К3В2МФБР-Ш" grade refractory steel is characterized in that pipes are produced by melting using electroslag remelting of the hollow ingots 660×in.260-280×2100±50 mm, turning and boring to hollow cakes with size 640×in.280-360×2100±50 mm, heating of the cakes to temperature 1210-1230°C, piercing-rolling of the cakes in the helical rolling mills to shells with size 660×in.505-415×3350-2800 mm, shells rolling at Pilger mills to pipes 530×30-75×6700-3500 mm, cutting by hot cutting saw of the process wastes, straightening, heat treatment, etching, ultrasound testing and pipes acceptance.

EFFECT: reduction of metal consumption and increased capacity of tube-forming installation with pilger mills.

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Description

The invention relates to pipe rolling, metallurgical and machining industries, and in particular to a method for the production of hollow ingots from heat-resistant steel grade 10X9K3V2MFBR-Sh, converting them into ingot blanks and technology for rolling from them hot-deformed seamless boiler and steam pipes for power equipment with super-supercritical steam parameters and can be used on ESR installations for casting hollow ingots, machining - boring and turning them on turning equipment in hollow slots billets for subsequent rolling at TPU 8-16 ″ with pilgrim mills into commodity pipes measuring 530 × 30-75 mm in accordance with TU 14-3R-55-2001.

In the practice of pipe production, there is a method of manufacturing boiler pipes of large and medium diameters from forged billets of steels of grades 20, 15GS, 15XM, 12X1MF, 15X1M1F, 12X2MFSR, 10X9MFB, 12X11V2MF, 08X16H9M2, 12X18N12T, 10Kh13G12B2K2 with mechanical properties that include forging them into forgings (compaction of the structure) with a yoke of ≥2.5, machining the forgings into billets (turning with metal removal of 10-15 mm per side), drilling in the blanks of a central hole with a diameter of 100 ± 5 mm to remove the central quatational porosity and nonmetallic inclusions, heating the workpieces to the temperature of plasticity, piercing the workpieces in the cross-screw rolling mills into sleeves, rolling the sleeves into tubes with a diameter of 245-550 mm on a pilgrim installation 8-16 ″ with a diameter tolerance of + 1.25 / -1 , 0 and wall thickness + 20 / -5% (TU 14-1-2560-78 "Forged pipe billets for boiler pipes", TU 14-3-460-2003 and TU 14-3R-55-2001 "Seamless steel pipes for steam boilers and pipelines "and TU 14-3-420-75" Pipes for steam boilers and pipelines from steel 15GS and 15Kh1M1F ").

The disadvantage of this method is the high energy intensity of the process associated with heating and deformation (forging) of the ingots into forgings, followed by turning and drilling of the central hole, heating the workpieces to a plasticity temperature, piercing and rolling them into pipes on pilgrim mills with a wall tolerance of + 20 / - 5%, increased consumption coefficient of the metal during the redistribution of the ingot - forgings - billets - pipes and, as a result, the high cost of pipes, as well as the fact that pipes made of steel 10Kh9K3V2MFBR-Sh have not been produced to date l not only in Russia but also in the world.

In pipe production, there is a known method of manufacturing large diameter gas lift pipes from 09G2S steel ingots for the production of ESR and VDP (Patent RU No. 2119395, class B21B 19/04), where the ingots are deformed in the piercing mill along the crystals, setting the ingots in the mill with the head part, and stitched with a posad in diameter by the amount

,

,

where S _g - wall thickness of the sleeve, mm;

S _c - wall thickness of the drilled ingot ESR, mm;

α is the angle of inclination of the crystallization front to the axis of the ingot, deg.

The disadvantage of this method of manufacturing large diameter pipes from ingots of ESR and VDP steel grade 09G2S is the need to manufacture macro templates to determine the angle of inclination of the crystallization front to the axis of the ingot, and the piercing of the ingots with shrink (head) part forward leads to the formation of defects in the form of internal captures at the front ends of the sleeves .

In pipe production, there is also known a method for the production of large diameter boiler pipes from ESR ingots (patent RU No. 2180874, class B21B 19/04), which reduces energy costs, reduces metal consumption and, as a result, reduces the cost of boiler pipes through the use of large diameter ingots and conducting the firmware process with a posad in diameter equal to 8-16%.

The disadvantages of this method are that, due to the low power of the drive of the piercing mill of ChTPZ OJSC, it is not possible to flash ESR steel of the 10Kh9K3V2MFBR-Sh grade with an insert diameter of 8-16%.

There is also known a method of producing seamless hot-deformed pipes of large and medium diameters in tube rolling plants with pilgrim mills for steam boilers, steam pipelines and manifolds of plants with high and supercritical parameters of steam from electroslag remelting ingots and continuously cast billets (patent RU No. 232322314, class B21B 19 / 04), which provides for the piercing of ESHP and NLZ ingots in cross-helical rolling mills with a diameter fit depending on the grade of steel and the total hood during redistribution of the electric wire ingot What are the remelting - pipe or continuously cast billet, tube, wherein the values posad diameter ingots electroslag remelting in piercing mills into helical rolling determined from the expression

Δ _i′ashp = k _i′eshp µ _i ∑,

where Δ _i′eshp are the values of the sizes according to diameter when piercing in the helical rolling mills of ESR ingots of i-steel grade,%;

µ _i ∑ = µ _sp. µ _p - the total drawing coefficient when rolling pipes of the i-th size;

k _i'eshp - coefficient taking into account the size of the gang in diameter when flashing sleeves from ESR ingots of i-steel grade,%;

µ _pr. - the coefficient of drawing when flashing sleeves for rolling pipes of the i-th size;

µ _p. is the drawing coefficient when rolling j-sized pipes on a pilgrim mill, while the coefficients k _i′shp for different grades vary from 24 to 40.

The disadvantage of this method is that it is very difficult to manufacture, since each tube requires its own sizes of ESR ingots, this method extends to the production of seamless hot-deformed pipes of large and medium diameters in tube rolling plants with pilgrim mills made of carbon steel grades and does not provide production of boiler tubes from EShB ingots of steel grade 10X9V3V2MFBR-Sh.

In pipe production, in order to reduce the load on the drive of cross-helical rolling mills in the production of commodity and conversion pipes of large and medium diameters from hard-to-form steel grades and alloys at TPUs with pilgrim mills, the method of double flashing of ingot blanks is used (Patent RU No. 2247612, cl. B21B 21/00), which includes the first flashing of ESR ingots-blanks with a diameter of 460-600 mm in a cross-helical rolling mill with a hood µ = 1.2-1.4 at a speed of rotation of the work rolls of 25-50 rpm, the second and subsequent if necessary, please ki-rolling with the rise or posad diameter of not more than 5.0% stretch μ = 1,4-1,75 at operating roll speed 20-50 rev / min.

The disadvantage of this method is that it is directed to the technology for the production of pipes from stainless difficult to deform grades of steel and alloys, includes double heating, double flashing (flashing ESR ingots into billet sleeves and flashing-rolling of billet blanks into sleeves), and therefore, increased metal waste, a decrease in the performance of the pilgrim installation ≈ 2 times and does not solve the technological issues of the production of boiler pipes from heat-resistant steel 10X9K3V2MFBR-Sh.

In pipe production, there is also a method for preparing billets for rolling commodity and conversion pipes of large and medium diameters from hard-to-deform grades of steel and alloys in pipe rolling plants with pilgrim mills (Patent RU No. 2340417, class B21B 21/00), including the casting of hollow ingots electroslag remelting, turning and boring them into hollow billets with metal removal, the value of which is determined from the expressions

,

,

,

,

where Δ is the value of the removed metal layer when turning hollow ingots-shells ESR, mm; Δ ₁ - the value of the removed metal layer when boring hollow ingots-shells ESR, mm; D is the outer diameter of the hollow ingot blanks, mm; S is the wall thickness of the hollow ingots, sleeves, mm; K = 0.3-0.4 is a coefficient for determining the magnitude of the metal layer to be removed when turning ingot shells, large values of which apply to steels with a high content of alloying elements; K ₁ = 0.4-0.5 is the coefficient for determining the size of the metal layer to be removed when bore ingots-sleeves, large values of which relate to steels with a high content of alloying elements, and the bottom of the hollow ingots-sleeves ESR is removed by anode-mechanical cutting, the value of which is determined from the expression L = K ₂ ∗ D / S, where K ₂ = 15-20 is the coefficient for determining the magnitude of the removed bottom of the shell-ingots, large values of which relate to steels with a high content of alloying elements.

The disadvantage of this method is that it is aimed at the technology of converting hollow ESR ingots into hollow ingots-blanks for the production of pipes from hardly deformable steel and alloy grades and does not solve the technological issues of the production of seamless pipes for steam boilers, steam pipelines and collectors of installations with high and supercritical parameters from steel grade 10X9K3V2MFBR-Sh measuring 530 × 30-75 mm.

The closest technical solution is a method for the production of hot-rolled commodity and conversion pipes of large and medium diameters from hard-to-deform grades of steel and alloys in pipe rolling plants with pilgrim mills (Patent RU No. 2311980, class B21B 21/00), including casting ESR hollow ingots with a height of 2000- 3200 mm, turning and boring to remove scale and microcracks to a diameter of 400-620 mm with a ratio of diameter to wall thickness D / S = 4.5-7.0, large values of which correspond to ingots-shells of a smaller diameter, heating to a temperature of characteristics and rolling on a pilgrim mill, rolling of hollow ingot sleeves with a ratio D / S = 5.0-7.0 and a height of 2000-2750 mm into commodity and conversion pipes with wall thicknesses up to 30 mm, and ingots with sleeves with a ratio D / S = 4.5-5.5 and a height of 2750-3200 mm in conversion pipes with a wall thickness of more than 30 mm.

The disadvantage of this method is that for each pipe size it is necessary to use its own size of hollow ingots-billets and that it is aimed at the technology of rolling commodity and conversion pipes from hard-deformed grades of steel and alloys and does not solve the technological issues of the production of seamless hot-deformed pipes with a size of 530 × 30-75 mm for steam boilers, steam pipelines and collectors of installations with high and supercritical parameters made of 10Kh9K3V2MFBR-Sh steel.

Boiler pipes with a diameter of 530 mm with different wall thicknesses in Russia can be produced only at TPU 8-16 ″ with pilgrim mills of ChTPZ OJSC.

Rolling pipes 530 × 30-75 mm in size on TPU 8-16 ″ with pilgrim mills from ingot blanks EShP steel grade 10X9K3V2MFBR-Sh of size 600 × 100 × 1750 mm for one piercing with a diameter increase of δ = 6.7% due to for increased loads on the engine of the piercing mill is impossible. For rolling pipes with a size of 530 × 30-75 mm, sleeves with a size of 640 × internal 515 mm or hollow ingot blanks ESR with a size of 640 × internal 505-415 × 2100 ± 50 mm are required.

The objective of the proposed method (invention) is the development of technology for the production of pipes with a size of 530 × 30-75 mm for steam boilers, steam pipelines and manifolds of plants with high and supercritical parameters from heat-resistant steel grade 10X9K3V2MFBR-Sh from hollow ingot blanks EShB size 640 × v505-415 × 2100 ± 50 mm, an increase in the total exhaust when redistributing a hollow ingot-billet ESR - a commodity pipe due to firmware - rolling hollow ingots-billets into sleeves, reducing the expenditure coefficient of metal, increasing the productivity of TPU 8-16 ″, uve reducing the length of the pipes, and, consequently, reducing the cost of pipes of this assortment due to the exclusion of energy-consuming operations from the technological process - heating the ESR ingots in the methodical furnaces to the ductility temperature, flashing them in the cross-helical rolling mill into blanks, heating the blanks into methodological furnaces from cold or hot posad to the temperature of plasticity for flashing them in the cross-helical rolling mill into sleeves.

The technical result is achieved by the fact that in the known method for the production of seamless hot-deformed boiler and steam pipes 530 × 30-75 mm in size from heat-resistant steel of grade 10X9K3V2MFBR-Sh for power equipment with super-supercritical steam parameters, it is characterized by the fact that the pipes are produced by electroslag remelting of hollow ingots size 660 × ext. 260-280 × 2100 ± 50 mm, with a ratio of diameter to wall thickness D / S = 3.0-4.16, large values of which apply to hollow ingots with smaller wall thicknesses, bores and turning ingots into hollow ingots-blanks of size 640 × ext. 280-360 × 2100 ± 50 mm with a ratio of diameter to wall thickness D / S = 3.56-4.57, large values of which refer to ingots-blanks with smaller thicknesses walls, heating ingot blanks to a temperature of 1210-1230 ° C, firmware - rolling ingot blanks in a cross-helical rolling mill into sleeves measuring 660 × in. 505-415 × 3350-2800 mm with extractors µ _p equal to 1.78 -1.37 and a rise in diameter δ = 0, on mandrels with a diameter of 490, 470, 450, 425 and 400 mm, depending on the geometric dimensions of the sleeves, rolling the sleeves on pilgrim steel ah extracts with μ _ave, 2,43-1,65 equal in tube size 530 × 30-75 × 6700-3500 mm, with a total stretch μ _Σ μ = μ _{p pr} equal 4,33-2,26, large the values of which relate to pipes with smaller wall thicknesses, and a diameter reduction of Δ = 18.9%, sections of a hot saw for cutting technological waste - pilgrim heads and seed ends, dressing, heat treatment, etching, ultrasonic inspection and pipe acceptance.

Comparative analysis with the prototype shows that the inventive method for the production of seamless hot-deformed boiler and steam pipes of 530 × 30-75 mm in size from heat-resistant steel of grade 10X9K3V2MFBR-Sh for power equipment with super-supercritical steam parameters is characterized in that the pipes are produced by electroslag remelting of hollow ingots size 660 × ext. 260-280 × 2100 ± 50 mm, with a ratio of diameter to wall thickness D / S = 3.0-4.16, large values of which relate to hollow ingots with smaller wall thicknesses, ki and turning of ingots into hollow ingots-blanks of size 640 × ext. 280-360 × 2100 ± 50 mm with a ratio of diameter to wall thickness D / S = 3.56-4.57, large values of which refer to ingots-blanks with smaller wall thicknesses, heating ingot blanks to a temperature of 1210-1230 ° C, firmware - rolling ingot blanks in a cross-helical rolling mill into sleeves measuring 660 × in. 505-415 × 3350-2800 mm with hoods µ _p equal to 1, 78-1.37 and a rise in diameter δ = 0, on mandrels with a diameter of 490, 470, 450, 425 and 400 mm, depending on the geometric dimensions of the sleeves, rolling the sleeves on pilgrim Tenach with extracts μ _ave, 2,43-1,65 equal in tube size 530 × 30-75 × 6700-3500 mm, with a total stretch _Σ μ = μ _r μ _ave equal 4,33-2,26, large the values of which relate to pipes with smaller wall thicknesses, and a diameter reduction of Δ = 18.9%, sections of a hot saw for cutting technological waste - pilgrim heads and seed ends, dressing, heat treatment, etching, ultrasonic inspection and pipe acceptance. 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 method was tested on TPU 8-16 ″ with pilgrim mills when rolling pipes 530 × 35 mm in size from steel grade 10X9K3V2MFBR-Sh. Rolling of pipes 530 × 35 mm in size from 10Kh9K3V2MFBR-Sh steel was performed at TPU 8-16 ″ with pilgrim mills from hollow ingot blanks EShB dimensions of 640 × int. 300 × 2100 ± 50 (proposed technology) and from ingot-blanks of size 600 × 100 × 1450 ± 50 mm (existing technology). Data on rolling boiler pipes 530 × 35 mm in size from 10Kh9K3V2MFBR-Sh steel to TPU 8-16 ″ with Pilgrim mills of ChTPZ OJSC according to the existing and proposed technologies and the results of pipe commissioning according to TU 14-3R-55-2001 are given in table 1 Table 1 shows that for the production of pipes 530 × 35 mm in size according to the existing technology, 5 ESR ingots-blanks with a size of 600 × 100 × 1450-1500 mm with a total weight of 16.887 tons were commissioned for production. The ingots-blanks were heated in a methodical furnace up to a temperature of 1200-1210 ° C, stitched in a cross-rolling mill on a mandrel diameter m 300 mm with a drawing coefficient µ _p = 1.20 and a diameter rise of δ = 3.3% into blanks 620 × ext. 315 × 1740-1800 mm in size. The load on the drive of the piercing mill did not exceed 6.5 kA. The billet sleeves from a cold embankment were heated in a methodical furnace to a temperature of 1200-1220 ° C, stitched - rolled out in a cross-helical mill on a mandrel with a diameter of 490 mm with a draw ratio µ _p = 1.81 and a diameter rise of δ = 3, 2% in sleeves measuring 640 × in. 505 × 3150-3260 mm. When flashing - rolling the blanks into blanks, the load on the wire of the piercing mill was at the upper limit of 7.5 kA. The sleeves were rolled on TPU 8-16 ″ with pilgrim mills on mandrels with a diameter of 460/462 mm with a drawing coefficient µ _pr = 2.09 and compression in diameter Δ = 16.4% into commodity pipes measuring 530 × 35 × 4500-4700 mm . According to rolling results, in accordance with TU 14-3R-55-2001, 22.9 m of pipes with a total weight of 10.424 tons were commissioned. The total coefficient of extraction µ _∑ = µ _p µ _p µ µ _pr amounted to 4.54. The average pipe length at the rental was 4.58 m. The expenditure coefficient of metal for pipes of this batch was 1.521. According to the proposed method for rolling commodity pipes of this size, 5 hollow ingot blanks ESRs of size 640 × ext. 300 × 2050-2150 mm were cast into production and cast and manufactured at OAO ZMZ in accordance with paragraph 1 of the claims. Hollow ingots were heated in a methodical furnace to a temperature of 1210-1220 ° C, stitched - rolled out in a cross-helical mill on a mandrel with a diameter of 470 mm with a draw ratio µ _p = 1.56 and a rise in diameter of δ = 3.1% in sleeves of size 640 × ext. 485 × 3200-3350 mm, which were rolled on 8-16 ″ TPU with piligim mills into commodity pipes of size 530 × 35 × 6700-7100 mm on mandrels 450/462 mm with a drawing coefficient µ = 2 , 72 and compression in diameter Δ = 18.9%. According to rolling results, in accordance with TU 14-3R-55-2001, 34.6 m of pipes with a total weight of 15.750 tons were delivered. The total drawing coefficient µ _∑ = µ _p µ _pr amounted to 4.24, i.e. is on par with existing technology. The average length of commodity pipes was 6.92 m, i.e. increased by 51.1%. The expenditure coefficient of the metal in the pipes of this batch was 1.312, i.e. a reduction in metal consumption by 209 kg per ton of pipe was obtained.

Thus, the use of the proposed method will allow for the first time in Russia to produce seamless hot-deformed boiler and steam pipes with a size of 530 × 30-75 mm from hollow ingot blanks EShP with a size of 640 × ext. 200-300 × 2100 ± 50 mm of heat-resistant steel 10Kh9K3V2MFBR-Sh for power equipment with super supercritical steam parameters with metal mechanical properties exceeding the values of these indicators given in TU 14-3R-55-2001, which will significantly reduce energy costs due to the elimination of heating drained ESW forging blanks for flashing, exceptions from the technological process of flashing ingots-blanks into blanks-blanks, produce high-quality commodity pipes at TPU 8-16 ″ with Pilgrim mills of ChTPZ OJSC, reduce metal consumption when converting hollow ESR ingots-blanks to commodity pipes, increase the productivity of TPU 8-16 ″ with pilgrim mills ≈ 2 times, increase the length of commodity pipes, and, therefore, reduce the cost of boiler pipes made of 10Kh9K3V2MFBR-Sh steel.

Claims (1)

A method for the production of seamless hot-deformed boiler and steam pipes of 530 × 30 - 75 mm in size made of heat-resistant steel of grade 10X9K3V2MFBR-Sh for power equipment with supercritical steam parameters, characterized in that the pipes are produced by electroslag remelting of hollow ingots 660 × in. 260-280 × 2100 ± 50 mm, with a ratio of diameter to wall thickness D / S = 3.0-4.16, large values of which refer to hollow ingots with smaller wall thicknesses, boring and turning of ingots into hollow ingots of size 64 0 × ext. 280-360 × 2100 ± 50 mm with a ratio of diameter to wall thickness D / S = 3.56-4.57, large values of which relate to ingot blanks with smaller wall thicknesses, heating ingot blanks to a temperature of 1210 -1230 ° C, firmware - rolling of ingot blanks in a cross-helical rolling mill into sleeves measuring 660 × in. 505-415 × 3350-2800 mm with hoods µ _p equal to 1.78-1.37, and diameter rise δ = 0, on mandrels with a diameter of 490, 470, 450, 425 and 400 mm, depending on the geometric dimensions of the sleeves, rolling the sleeves on pilgrim mills with hoods µ _pr equal to 2.43-1.65, into pipes of size 53 0 × 30-75 × 6700-3500 mm, with a total hood µ _∑ = µ _p µ _pr equal to 4.33-2.26, large values of which apply to pipes with smaller wall thicknesses, and compression in diameter Δ = 18, 9%, segments with a hot-cutting saw of technological waste - pilgrim heads and seed ends, dressing, heat treatment, etching, ultrasonic inspection and pipe acceptance.