RU2614476C1 - METHOD OF PRODUCING COLD-DEFORMED COUPLING PIPES OF 88,9 ×6,45 mm SIZE FROM CORROSION-RESISTANT ALLOY OF "ХН30МДБ-Ш" GRADE - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: pipes are made from centrifugally cast tubular workpieces of regulated size, which are bored and ground into hollow machined workpieces, heated and rolled on a Pilger mill into rerolled hot-rolled pipes, and then rolled on KhPT mills in trade pipes.

EFFECT: reduction in the products cost is ensured by the choice of the original workpiece and its regulatory processing mides in all industries.

2 cl, 1 tbl

Description

The invention relates to tube production, and in particular to a method for the production of seamless cold-deformed tubing of 88.9 × 6.45 mm in size from a corrosion-resistant alloy of the grade ХН30МДБ-Ш for gas and gas condensate production in hydrogen sulfide-containing media.

In the pipe industry, a method is known 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 for a diameter of 100 ± 5 mm, heating them to a ductility temperature, expanding into hollow billets with a hood μ = 1.2 1.8 without lifting in diameter, turning and boring to remove forging defects, heating to ductility temperature and rolling on pilgrim mills with a hood μ≤5.0 or expanding drilled ESR ingots into hollow billets with a hood μ = 0.9-1.5 with a rise in diameter from 1.05 to 1.4% and rolling on pilgrim mills with a hood μ≤5.5 (RF Patent No. 2242302 from 12.20.2004, Cl. B21B 21 / 04, Bulletin No. 35).

The disadvantage of this method is the use of ESR drilled ingots as conversion billets, additional expansion and machining operations of expanded expanded billets, 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 with a size of 88.9 × 6.45 × 9000-10700 mm from a corrosion-resistant alloy of the grade ХН30МДБ-Ш for gas and gas condensate production in hydrogen sulfide-containing media, including melting by electroslag remelting hollow ingots 470 × 110 × 2700 mm or 430 × 105 × 2700 mm, boring and turning of hollow ingots into hollow ingots of 460 × 100 × 2700 mm and 420 × 95 × 2700 mm, heating of ingots to plasticity, rolling on the pilgrim Taper on the conical mandrels into hot-rolled pipe sizes of 290 × 35 × 9000 mm or 260 × 30 × 11100 mm, pipe cutting into two pipes of equal length, boring and turning of hot rolled pipes into 273 × 25 × 4500 mm or 245 pipe billets × 16 × 5550 mm, respectively, and rolling at the HPT mill into commodity tubing pipes of 88.9 × 6.45 × 9000-10700 mm in size, and rolling at the HPT mill of converted pipe billets of 273 × 25 × 4500 mm in size is carried out along routes 273 × 25 - 219 × 21 - 180 × 17 - 140 × 13 - 114 × 9 - 88.9 × 6.45 mm with relative wall compressions δ ₁ = 16.0%, δ ₂ = 1 9.1%, δ ₃ = 23.5%, δ ₄ = 30.8%, δ ₅ = 28.3%, and conversion pipe billets of 245 × 16 × 5550 mm in size along routes 245 × 16-219 × 13- 168 × 10-140 × 8-88.9 × 6.45 mm with relative wall compressions δ ₁ = 18.8%, δ ₂ = 23.1%, δ ₃ = 20.0%, δ ₄ = 19, 4%, the planting of hollow ingots-blanks ESRs measuring 460 × 100 × 2700 and 420 × 95 × 2700 mm are planted in one row on the grates of the method furnaces at a temperature of 750-800 ° C, heating for 1.0-1.5 hours to temperature 450-500 ° C, and then uniform heating to a temperature of 1180-1200 ° C at a speed of 2.2-2.4 ° C per minute with uniform pitching from 22 to 8 window after 20-22 minutes at an angle of ≈290- 300 ° and 320-330 °, shutter speed at a temperature of 1180-1200 ° C for 0.45-1.0 hours with uniform tilting in 12-15 minutes from the 8th to the 4th window, from the 4th window they turn over to the furnace pit and discharge from the furnace with a temperature the center of the ingot blanks of 1180-1200 ° C, blowing the hollow ingot blanks with compressed air and supplying lubricant in the form of a mixture of graphite with sodium chloride weighing ≈1.0-1.5 kg into the ingot ingots and transferring them to the pilgrim receiving trolley with a crane mill, rolling of hot rolled hot-rolled pipes of 290 × 35 × 9500 and 260 × 30 × 10600 mm in size on a pilgrim mill in rolls with caliber 306 and 280 mm with hollow feeds ingot blanks in the deformation zone, respectively, m = 20-22 and m = 18-20 mm and hoods μ = 3.93, μ = 4.39 (RF patent No. 2527578, cl. B21B 21/00, 09/10/2014, bull. No. 25).

One of the main disadvantages of this method is that ESW hollow ingots-blanks have an increased cost, which, with a metal consumption coefficient of more than 2.0, leads to a significant increase in the price of commodity tubing. The disadvantages also include the fact that when boring and turning hollow ingots of ESRs of size 470 × 110 × 2700 and 430 × 105 × 2700 mm into ingots-blanks of sizes 460 × 100 × 2700 and 420 × 95 × 2700 on the outer and inner surfaces of the ingots - blanks remain of not removed defects of foundry origin, which when rolled on a pilgrim mill into hot-rolled pipe converts lead to flaws, which in turn leads to an increase in the allowance for boring and turning of hot-rolled pipes into red-steel pipe billets, and in some cases to scrap go yachekatanyh pipes.

The objective of the proposed method is the production of competitive products through the use of hollow centrifugal cast billets in the manufacture of hot rolled pipes, reducing the relative wall compressions along the passages at the HPT mills, and therefore, reducing the cost of tubing 88.9 × 6 in size. 45 mm.

The technical result is achieved by the fact that in the known method for the production of seamless cold-deformed pipes of 88.9 × 6.45 mm in size from a corrosion-resistant alloy of the brand ХН30МДБ-Ш, including smelting by electroslag remelting of hollow ingots of 470 × 110 × 2700 mm or 430 × 105 × 2700 mm, boring and turning of hollow ingots into hollow ingots-billets of size 460 × 95 × 2700 mm and 420 × 95 × 2700 mm, heating of ingots-billets to the temperature of plasticity, rolling on a pilgrim mill into hot rolled pipes of 290 × 35 × 9500 and 260 × 30 × 10600 mm, cutting over hot rolled pipes into two pipes of equal length, boring and turning of hot rolled pipes into steel machined pipes of 273 × 25 × 4750 and 245 × 16 × 5300 mm in size and rolling them at the HPT mill into 88.9 × commodity tubing pipes 6.45 mm, centrifugally cast hollow billets are smelted with a size of 460 × 105 × 2400 ± 50 mm, which are bored and machined into hollow machined billets with a size of 450 × 90 × 2400 ± 50 mm, heated to a temperature of 1180-1200 ° C, rolled on a pilgrim mill in the hot rolling mill loss of 285 × 40 × 6460-6740 mm in size, which are cut into two billet pipes of equal length, bored and turned into conversion pipes of 273 × 25 × 3230-3370 mm in size and rolled at the HPT mill along the routes: 273 × 25 × 3230- 3370 - 219 × 21 × 4500-4700 - 180 × 17 × 6500-6700 - 140 × 13 × 10500-10900 - 114 × 9 × 17900-18900 mm, pipes 114 × 9 × 17900-18900 mm in size are cut into three equal parts and rolled at the HPT mill into commodity pipes measuring 88.9 × 6.45 × 1030-10900 mm with relative wall compressions δ ₁ = 16.0%, δ ₂ = 19.1%, δ ₃ = 23.5%, δ ₄ = 30.8%, δ ₅ = 28.3% and extraction factors μ ₁ = 1.49, μ ₂ = 1.50, μ ₃ = 1.68, μ ₄ = 1.75, μ ₅ = 1 , 77.

Hot-rolled steel tubes of 285 × 40 × 6460-6740 mm in size are produced in a pilgrim mill on conical mandrels with a diameter of 205/211 mm, respectively, in rolls with a caliber of 295 mm, with the supply of m hollow machined billets into the deformation zone equal to 21-23 and the drawing coefficient μ ₁ = 3.24. At the same time, the semantic value of the signs characterizing the diameter of the conical mandrels 205/211 mm should be understood as the first of these diameters refers to the front section of the mandrel, and the second - the diameter of its rear section.

A comparative analysis of the proposed solution with the prototype shows that the claimed method differs from the known one in that the pipes are made from centrifugally cast hollow billets with a size of 460 × 105 × 2400 ± 50 mm, which are bored and turned into hollow machined billets with a size of 450 × 90 × 2400 ± 50 mm, heated to a temperature of 1180-1200 ° С, rolled on a pilgrim mill into hot-rolled steel tubes of 285 × 40 × 6460-6740 mm in size, which are cut into two workpieces of equal length, bored and turned into 273 × steel tubes 2 5 × 3230-3370 mm and rolled at the HPT mill along the routes: 273 × 25 × 3230-3370 - 219 × 21 × 4500-4700 - 180 × 17 × 6500-6700 - 140 × 13 × 10500-10900 - 114 × 9 × 17900-18900 mm, pipes 114 × 9 × 17900-18900 mm in size are cut into three equal parts and rolled on a KhPT mill into commodity pipes of 88.9 × 6.45 × 1030-10900 mm in size with relative wall reductions δ ₁ = 16 , 0%, δ ₂ = 19.1%, δ ₃ = 23.5%, δ ₄ = 30.8%, δ ₅ = 28.3% and drawing coefficients μ ₁ = 1.49, μ ₂ = 1, 50, μ ₃ = 1.68, μ ₄ = 1.75, μ ₅ = 1.77.

Hot-rolled chimneys of 285 × 40 × 6460-6740 mm in size are produced on a pilgrim mill on conical mandrels with a diameter of 205/211 mm in rolls with a caliber of 295 mm, with a feed of m hollow machined billets into the deformation zone equal to 21-23 mm and a drawing coefficient μ ₁ = 3.24.

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, allowed to identify in them the features 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 8-16ʺ with pilgrim mills and a mill ХПТ 250 of OJSC Chelyabinsk Tube-Rolling Plant. According to the proposed technology, 5 centrifugally cast billets with a size of 460 × 105 × 2400 mm with a total weight of 11.096 tons were put into production, which were bored and turned into ingots-billets with a size of 450 × 90 × 2400 mm. Billet ingots were heated in a methodical furnace to a temperature of 1180-1200 ° C. Lubricants in the form of a mixture of sodium chloride and graphite (50/50) weighing ≈1000-1200 grams were set inside the ingot blanks. Billet ingots were fed by a bridge crane to the inlet side of the pilgrim mill and rolled into hot-rolled steel tubes measuring 285 × 40 × 6600 mm in rolls with a caliber of 295 mm, with t hollow centrifugally cast billets being fed into the deformation zone 21-23 mm and an exhaust hood μ = 3.24. Hot rolled pipes were cut into two billet pipes of equal length, bored and turned

into conversion pipes measuring 273 × 25 × 3300 mm. 10 mechanical pieces of converted machined pipes of 273 × 25 × 3300 mm in size were transferred to workshop No. 5 and rolled at the KhPT 250 mill into tubing 88.9 × 6.45 mm in size along the routes: 273 × 25 × 3300 - 219 × 21 × 4600 - 180 × 17 × 6600 - 140 × 13 × 10700 - 114 × 9 × 18400 mm. Pipes 114 × 9 × 18400 mm in size were cut into three equal parts and rolled on the KhPT 250 mill into pipes of 88.9 × 6.45 × 10600 mm in size with relative wall reductions of δ ₁ = 16.0%, δ ₂ = 19 , 1%, δ ₃ = 23.5%, δ ₄ = 30.8%, δ ₅ = 28.3% and hoods μ ₁ = 1.49, μ ₂ = 1.50, μ ₃ = 1.68, μ ₄ = 1.75, μ ₅ = 1.77.

Out of ten conversion pipes with a size of 273 × 25 × 3300 mm, 30 tubing pipes with a size of 88.9 × 6.45 × 10600 mm (318 m) with a total weight of 4.277 tons were rolled at a KhPT 250 mill. The total expenditure coefficient of the metal for tubing This batch amounted to 2.594. According to the existing technology (patent No. 2527578), 5 hollow ESR ingots of 470 × 110 × 2400 mm in size with a total weight of 11.788 tons were put into production, which were bored and turned into hollow ingots-blanks of 450 × 90 × 2400 mm in size. Hollow ingots-blanks were heated in a methodical furnace to the temperature of plasticity and rolled into hot-rolled steel tubes of 285 × 40 × 6600 mm in size, which were cut into two equal parts, bored and turned into hot-rolled steel blanks of 273 × 25 × 3300 mm in size. Ten hot rolled billets of size 373 × 25 × 3300 mm were rolled in workshop No. 5 at the KhPT 250 mill along the routes: 273 × 25 × 3300 - 219 × 21 × 4600 - 180 × 17 × 6600 - 140 × 13 × 10700 - 114 × 9 × 18400 mm. Pipes 114 × 9 × 18400 mm in size were cut into three equal parts and rolled into commodity pipes of 88.9 × 6.45 × 10600 mm. Out of 10 hot-rolled machine-made billets of the size 273 × 25 × 23000 mm in workshop No. 5, 30 commodity pipes with a size of 88.9 × 6.45 × 10600 mm and a total weight of 4.277 tons were obtained. The expenditure coefficient of the metal for pipes of this lot was 2.776. Data on the production of pipes of 88.9 × 6.45 mm in size from the KhN30MDB-Sh alloy from hollow ingot blanks ESR of 470 × 110 × 2400 and 450 × 105 × 2300 mm (existing technology) and centrifugally cast billets of 460 × 105 × 2400 mm (proposed technology) are given in table No. 1.

The table shows that in the production of tubing with a size of 88.9 × 6.45 mm according to the proposed technology, a reduction in the expenditure coefficient of the metal by 162 kg per ton of pipe was obtained when comparing 470 × 110 × ESR ingots as conversion billets 2700 mm.

Thus, the table shows that in the production of pipes according to the proposed method from centrifugally cast billets with a size of 460 × 105 × 2400 mm, machining them into billets with a size of 450 × 90 × 2400 mm and rolling at TPU 8-16ʺ with pilgrim mills in hot rolled pipes and machining - turning and boring them into conversion pipes for subsequent rolling at the KhPT 250 mill into commodity tubing pipes of 88.9 × 6.45 × 10600 mm in size, compared with the existing technology, a reduction in metal consumption by 162 was obtained kg per ton of commodity n Sosno tubing, as compared with the patent №2527578.

Using the proposed method for the production of seamless cold-deformed tubing of 88.9 × 6.45 mm in size from a corrosion-resistant alloy of the ХН30МДБ-Ш grade for gas and gas condensate production in hydrogen sulfide-containing media will allow producing high-quality tubing due to the theoretically justified choice of sizes centrifugally cast hollow billets, turning and boring them into hollow machined billets, the selection of rational parameters for the redistribution of hollow machined agotovok in steel making, hot-rolled tube.

Claims (2)

1. Method for the production of seamless cold-deformed pipes of 88.9 × 6.45 mm in size from a corrosion-resistant alloy of the grade ХН30МДБ-Ш, including the smelting of centrifugally cast hollow billets of 460 × 105 × 2400 ± 50 mm in size, which are bored and machined into hollow mechanically machined billets of 450 × 90 × 2400 ± 50 mm in size, heated to a temperature of 1180-1200 ° C, rolled on a pilgrim mill into hot rolled steel tubes of 285 × 40 × 6460-6740 mm in size, which are cut into two billets of equal length, bored and grind into conversion tubes of size 273 × 25 × 3230-3370 mm and rolled at the HPT mill along the routes: 273 × 25 × 3230-3370 - 219 × 21 × 4500-4700 - 180 × 17 × 6500-6700 - 140 × 13 × 10500-10900 - 114 × 9 × 17900-18900 mm, pipes 114 × 9 × 17900-18900 mm in size are cut into three equal parts and rolled at the KhPT mill into commodity pipes of 88.9 × 6.45 × 1030-10900 mm in size with relative wall reductions δ ₁ = 16 , 0%, δ ₂ = 19.1%, δ ₃ = 23.5%, δ ₄ = 30.8%, δ ₅ = 28.3% and drawing coefficients μ ₁ = 1.49, μ ₂ = 1, 50, μ ₃ = 1.68, μ ₄ = 1.75, μ ₅ = 1.77. 2. The method according to p. 1, characterized in that the hot-rolled steel tubes measuring 285 × 40 × 6460-6740 mm are produced on a pilgrim mill on conical mandrels with a diameter of 205/211 mm in a caliber of 295 mm with a feed of m into the deformation zone equal to 21- 23 mm and a drawing coefficient μ ₁ = 3.24.