RU2613813C1 - METHOD OF PRODUCING COLD-DEFORMED COUPLING PIPES OF 108×18 mm SIZE FROM CORROSION-RESISTANT ALLOY OF "ХН30МДБ" GRADE - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: hollow centrifugal cast billets of 450×120×2700±50 mm size from alloy of "ХН30МДБ" grade are used as workpiece, their regulated boring, heating and rolling is carried out on Pilger mill to rerolled hot-rolled pipes, then their rolling on CRM mill to re-rolled cold-deformed pipes, rolling and cutting on CRM mill to commercial pipes is carried out.

EFFECT: reduced metal consumption.

1 tbl

Description

The invention relates to pipe rolling production, and in particular to a method for the production of cold-deformed sleeve pipes with a size of 108 × 18 mm from a corrosion-resistant alloy grade ХН30МДБ, which can be used for the manufacture of couplings for tubing with a size of 88.9 × 6.45 × 9000-10700 mm used for the extraction of gas and gas condensate in hydrogen sulfide-containing environments. The invention can also be used in the manufacture of hot-rolled chimneys measuring 285 × 45 × 8000-8300 mm on 8-16 '' TPU with pilgrim mills from bored centrifugally cast billets of 450 × 110 × 2700 ± 50 mm in size, cutting them into pipes billets of equal length, for subsequent machining, boring and turning into conversion billets of 273 × 30 × 4000-4150 mm in size and rolling them at the KhPT 250 mill into cold-deformed coupling pipes of 108 × 18 × 8000-8200 mm in size for the manufacture of couplings.

In the pipe industry, there is a known method for the production of hot-rolled conversion tubes from hard-to-deform grades of steel and alloys in plants with pilgrim mills, including drilling ESR ingots-blanks with a diameter of 100 ± 5 mm, heating them to a ductility temperature, expanding into hollow billets with an exhaust hood μ = 1, 2-1.8 without lifting in diameter, turning and boring them to remove forging defects, heating to ductility temperature and rolling on pilgrim mills with a hood μ≤5.0 or expansion of drilled ingots ok ESR into hollow billets with an exhaust hood μ = 0.9-1.5, with a diameter increase from 1.05 to 1.4% and rolling on pilgrim mills with an extraction coefficient μ≤5.5 (RF Patent No. 2242302 from 20.12 .2004, class B21B 21/04, bull. No. 35).

The disadvantage of this method is the use of drilled ESR ingots-blanks as conversion blanks, additional expansion and machining operations of expanded expanded tube blanks, increased consumption of expensive metal in the chips, which ultimately leads to a significant increase in the cost of the finished product.

The closest technical solution is a method for the production of seamless cold-deformed tubing of 114.3 × 6.88 × 9000-10700 mm in size and from a corrosion-resistant alloy of the grade ХН30МДБ-Ш for gas and gas condensate production in hydrogen sulfide-containing media, characterized in that they carry out the melting by electroslag remelting of hollow ingots of 470 × 110 × 2700 mm or 430 × 105 × 2700 mm in size, boring and turning of the ingots into hollow ingots-blanks, respectively, of 460 × 100 × 2700 mm or 420 × 95 × 2700 mm, heating the ingots preparations to temperament plasticity tours, rolling on a pilgrim mill on conical mandrels into hot-rolled steel tubes measuring 290 × 35 × 9500 mm, or 260 × 30 × 8000 mm, or 310 × 40 × 7600 mm, or 288 × 45 × 4600 mm, boring and turning hot-rolled pipes into conversion pipes measuring 273 × 25 × 4700 mm, or 245 × 16 × 2800 mm, or 245 × 16 × 5200 mm and rolling at the KhPT mill into commodity tubing pipes of 114.3 × 6.88 × 9000- 10,700 mm, and rolling at the HPT mill, conversion tubes 273 × 25 × 4700 mm in size are carried out along the routes 273 × 25-219 × 20-180 × 15-140 × 10-114.3 × 6.88 with relative reductions along the wall δ _1t = 20.0%, δ _2t = 25.0%, δ _3t = 33.3%, δ _4t = 31.2%, and the conversion pipes 245 × 16 × 2800 mm and 245 × 16 × 5200 mm are rolled at the HPT mill along the routes 245 × 16-219 × 13-168 × 11-140 × 9-114.3 × 6.88 with relative wall compressions δ _1t = 18.8%, δ _2t = 15.4%, δ _3t = 18.2%, δ _4t = 23 , 6% (RF Patent No. 2523398, publ. 07/20/2014).

One of the main disadvantages of this method is that hollow ESR ingots-blanks have an increased cost and with a metal flow rate of more than 2.0 leads to a significant increase in the price of cold-deformed sleeve pipes. Another disadvantage of this method is that it is aimed at the production technology of tubing 114.3 × 6.88 mm in size and does not solve the technological issues of the production of 108 × 18 mm pipes for the manufacture of couplings.

The objective of the proposed method is the production of competitive products due to the use of hollow centrifugally cast billets in the manufacture of hot rolled pipes, and therefore, the reduction of the expenditure coefficient of the metal and the cost of sleeve pipes of 108 × 18 mm in size.

The technical result of the proposed method is to reduce the metal consumption of the method for the production of cold-deformed sleeve pipes with a size of 108 × 18 mm from a corrosion-resistant alloy KhN30MDB and reduce their cost.

The technical result is achieved by a new method for the production of cold-deformed sleeve pipes with a size of 108 × 18 × 8000-8200 mm from a corrosion-resistant alloy of the brand ХН30МДБ, including casting of hollow centrifugally cast billets of 450 × 120 × 2700 ± 50 mm in size, their boring to sizes 450 × 110 × 2700 ± 50 mm, heating to ductility temperature, rolling on a pilgrim mill on cone mandrels with a diameter of 195/201 mm in a caliber of 295 mm with a drawing coefficient μ = 3.39 into hot-rolled steel tubes measuring 285 × 45 × 8000-8300 mm, cooling straightening on hexagonal straightening machines f, cutting them into two pipes of equal length, boring and turning to sizes of 273 × 30 × 4000-4150 mm, rolling them at the HPT mill along the routes 273 × 30 × 4000-4150-219 × 27 × 5400-5650-168 × 24 × 7900-8100-133 × 21 × 11300-11700 mm, cutting cold rolled pipes of 133 × 21 × 11300-11700 mm in size into two billets of 133 × 21 × 5650-5850 mm in size and rolling them into cold-worked commodity cold rolling mills sleeve pipes 108 × 18 × 8000-8200 mm in size with relative wall compressions δ ₁ = 10.0%, δ ₂ = 11.1%, δ ₃ = 12.5%, δ ₄ = 14.3% and drawing coefficients μ ₁ = 1.41, μ ₂ = 1.50, μ ₃ = 1.47, μ ₄ = 1.45.

A comparative analysis of the proposed solution with the prototype shows that the claimed method differs from the known one in that they produce casting of hollow centrifugally cast billets of 450 × 120 × 2700 ± 50 mm in size, their boring to sizes 450 × 110 × 2700 ± 50 mm, heating to a temperature ductility, rolling on a pilgrim mill on taper mandrels with a diameter of 195/201 mm in caliber 295 mm with a drawing coefficient μ = 3.39 into hot-rolled steel tubes measuring 285 × 45 × 8000-8200 mm, cooling, straightening with a straightening machine, cutting them into two pipes of equal length, boring ku and turning to dimensions of 273 × 30 × 4000-4150 mm, rolling them at the HPT mill along the routes 273 × 30 × 4000-4150-219 × 27 × 5400-5650-168 × 24 × 7900-8100-133 × 21 × 11300 -11700 mm, cutting of cold rolled cold-rolled pipes of 133 × 21 × 11300-11700 mm in size into two billet pipes of 133 × 21 × 5650-5850 mm in size and rolling them at the KhPT mill into commodity cold-deformed sleeve pipes of 108 × 18 × 8000-8200 mm with relative wall compressions δ ₁ = 10.0%, δ ₂ = 11.1%, δ ₃ = 12.5%, δ ₄ = 14.3% and drawing coefficients μ ₁ = 1.41, μ ₂ = 1.50, μ ₃ = 1.47, μ ₄ = 1.45.

Thus, the claimed method meets the criterion of "inventive step".

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

The method was tested on TPU 8-16 '' with pilgrim mills and a mill ХПТ 250 of Chelyabinsk Pipe-Rolling Plant OJSC. According to the proposed technology, 5 centrifugally cast billets of 450 × 120 × 2700 mm in size with a total weight of 13.261 tons were put into production, which were bored into billets of 450 × 110 × 2700 mm in size. Bored billets were heated to ductility temperature and rolled on a pilgrim mill on conical mandrels with a diameter of 195/201 mm in a caliber of 295 mm with a drawing coefficient μ = 3.39 into hot rolled pipes of 285 × 45 × 8150 mm in size. After cooling, the hot rolled pipes were straightened on a six-roll straightening machine, and then cut into two pipes of equal length. Pipes are bored and turned to sizes of 273 × 30 × 4075 mm. Mechanically processed hot rolled steel tubes were rolled at the KhPT 250 mill along the routes 273 × 30 × 4075-219 × 27 × 5500-168 × 24 × 8000-133 × 21 × 11500 mm. Converted cold-rolled pipes with a size of 133 × 21 × 11500 mm were cut into two billet pipes with a size of 133 × 21 × 5750 mm and rolled at a KhPT 250 mill into cold-deformed sleeve pipes with a size of 108 × 18 × 8100 mm with relative wall compressions δ ₁ = 10, 0%, δ ₂ = 11.1%, δ ₃ = 12.5%, δ ₄ = 14.3% and drawing factors μ ₁ = 1.41, μ ₂ = 1.50, μ ₃ = 1.47, μ ₄ = 1.45. Out of ten billet pipes of 273 × 30 × 4075 mm in size, 10 coupler pipes of 108 × 18 × 8100 mm in size with a total weight of 6.510 tons were rolled at a KhPT 250 mill. The average metal consumption coefficient for pipes of this batch was 2.037.

According to the existing technology (RF patent No. 2545950), five hollow ESR ingots of 470 × 135 × 2700 mm in size, with a total weight of 15.145 tons, which were bored and turned into ingots-blanks of 450 × 105 × 2700 mm in size, were heated to a temperature, were set into production ductility and rolled on a pilgrim mill in a hot-rolled steel tubes measuring 285 × 38 × 9200 mm. Hot-rolled steel tubes 285 × 38 × 9200 mm in size were cut into two pipes of equal length, bored and turned into tube blanks of 273 × 25 × 4600 mm in size, which were rolled at the KhPT 250 mill into commodity coupling pipes of 108 × 18 × 7600 mm in size along the routes 273 × 25 × 4600-219 × 23 × 6000-168 × 21 × 8400-133 × 19.5 × 11400 mm. Conversion pipes with a size of 133 × 19.5 × 11400 mm were cut into two pipes of equal length and rolled on a KhPT 250 mill into commodity coupling pipes of 108 × 18 × 7600 mm in size with wall reductions δ ₁ = 8.0%, δ ₂ = 8.7%, δ ₃ = 7.1%, δ ₄ = 7.7% and extraction factors μ ₁ = 1.38, μ ₂ = 1.46, μ ₃ = 1.40, μ ₄ = 1.37 . 152 m of pipes 108 × 18 × 7600 mm in size with a total weight of 6.108 tons were commissioned. The metal consumption coefficient for pipes of this lot was 2.480. Data on the production of cold-rolled coupling pipes of 108 × 18 mm size from an alloy of the grade ХН30МДБ-Ш from ESW hollow ingots of 4700 × 135 × 2700 mm size (existing technology) and from centrifugally cast billets of 450 × 120 × 2700 mm size (proposed technology) are given in table 1.

The table shows that in the production of sleeve pipes with a size of 108 × 18 mm according to the proposed technology, a decrease in the expenditure coefficient of the metal by 443 kg per ton of pipe was obtained compared with rolling when using hollow ESR ingots of 470 × 135 × 2700 mm in size as billets.

Thus, the production of pipes according to the proposed method from centrifugally cast billets with their rolling at 8-16 '' TPU with pilgrim mills into hot-rolled chimneys for subsequent machining - boring and turning into machined chisels for subsequent rolling at the KhPT mill 250 in cold-deformed coupling pipes with a size of 108 × 18 × 8100 mm for the manufacture of couplings in comparison with the existing technology (RF patent No. 2523398), reduces metal consumption by 443 kg and their cost by reducing cost CLZ bridges are more than 1.5 times compared to hollow ESR ingots.

Using the proposed method for the production of cold-deformed pipes with a size of 108 × 18 mm for the manufacture of couplings from a corrosion-resistant alloy KhN30MDB will reduce the metal consumption and their cost.

Claims (1)

Method for the production of cold-deformed pipes of size 108x18x8000-8200 mm from corrosion-resistant KhN30MDB alloy for the manufacture of couplings, including casting of hollow centrifugally cast billets of size 450x120x2700 ± 50 mm, their boring to sizes 450x110x2700 ± 50 mm, heating to ductility temperature, rolling on a pilgrim mill on cone mandrels with a diameter of 195/201 mm in caliber 295 mm with a drawing coefficient μ = 3.39 into hot-rolled steel tubes measuring 285x45x8000-8300 mm, cooling, straightening on a six-roll straightening machine, cutting them into two pipes of equal length, and point sizes to refacing 273h30h4000-4150 mm, rolling them at rolling mill HPT in steel making cold pipe routes 273x30x4000-4150 - 219x27x5400-5650 - 168x24x7900-8100 - 133x21x11300-11700 mm relative reduction of the wall, respectively, δ _1m = 10, 0%, δ _2m = 11.1%, δ _3m = 12.5% and drawing coefficients, respectively, μ ₁ = 1.41, μ ₂ = 1.50, μ ₃ = 1.47, cutting of cold rolled pipes in size 133x21x11300-11700 mm into two pipes - workpieces with a size of 133x21x5650-5850 mm and rolling them at a cold-forming mill into cold-deformed pipes of 108x18x8000-8200 mm in size with a relative wall compression of δ _4m = 14.3% and the coefficient Ohm extracts μ ₄ = 1.45.