RU2542156C2 - Production of commercial and rerolled pipes at pru with pilger mills from forged or hollows esr ingots-billets from alloyed hardly-deformed steels and alloys and titanium-based steels - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to pipe rolling. ESR blanks are heated to ductility temperature and pierced at screw rolling stand to sleeves-blanks. Jar carbon washers are heated to ductility temperature. Mandrel with mandrel ring is fitted into mandrel head, jar carbon washer is fitted on carbon ring, mandrel is fitted in sleeve or hollow ESR ingot-billet to fit jar carbon washer to get seed ends and composite billet. Jar carbon ring for making of seed ends has cylindrical and conical sections. Conical part of said jar washer is used to centre sleeve front end or that of hollow ingot-billets relative to mandrel axis. Assembled sleeve is shaped at variable-profile gages to steel pipe with seed end and pilgrim head fitted on carbon jar washers.

EFFECT: complete rolling of sleeve and hollow ingot-billet front ends.

5 cl, 1 tbl

Description

The invention relates to pipe rolling production, in particular to a method for the production of commodity and conversion pipes in pipe rolling plants with pilgrim mills from forged blanks, solid or hollow ingots-blanks of electroslag remelting from alloyed hardly deformable steel grades and alloys, titanium-based alloys with the removal of pilgrim heads and seed ends on carbon ring liners, and can be used in the manufacture of pipes in pipe rolling plants with pilgrim mills.

In the process of rolling pipes at TPU with pilgrim mills, technological waste is generated in the form of pilgrim heads and seed ends, the mass of which, depending on the geometric dimensions of the pipes, ranges from 135 to 150 kg per ton (F.A. Danilov, A.Z. Gleiberg, VG Balakin // Hot rolling of pipes. Moscow. Metallurgy Publishing House, 1962, p. 266).

In the pipe industry, a method is known for preparing billets for rolling pipes without pilgrim heads on a pilgrim mill, which includes separate heating to the ductility temperatures of billets made of alloy steel grades and alloys and nozzles made from carbon steel grades, piercing of billets in a cross-helical rolling mill in sleeves and sequentially planting them on the mandrel to the junction of the ends. Rolling is carried out before the formation (removal) of the pilgrim head on the nozzle (carbon ring). After rolling, the underlay ring (pilgrim head) and pipe are removed from the mandrel. The pipe is directed along the live roll (exit chute) to the hot cutting saw to remove the seed end and cut the pipe (if necessary) into multiple lengths, and the pilgrim head is transferred by crane to boxes with carbon metal scrap. Preparation of the next sleeve for rolling is carried out as described above (ed. St. USSR No. 430908, class B21B 21/00, 1972).

The disadvantage of this method of preparing the sleeves for pilgrim rolling without pilgrim heads is that it is aimed at the technology of rolling commodity and conversion pipes from alloyed hardly deformable steel grades and alloys without pilgrim heads and does not solve the problems of reducing the consumption of alloyed steel grades and alloys for the formation of seed ends.

In the pipe industry, there is also a method of preparing billets (sleeves) for pilgrim rolling of pipes, which includes separate heating of billets of alloy steel and alloys and carbon rings with carbon rings, the outer diameter of which is 1.15-1.25 of the sleeve diameter . Moreover, in order to lower the temperature of the ring more slowly and reuse it with several sleeves, the surface of the ring is covered with heat-insulating material (ed. St. USSR No. 732043, class B21B 21/00, 1980).

The disadvantage of this method of preparing sleeves for pilgrim rolling of pipes is the low-tech coating on the underlay carbon rings of heat-insulating fusible materials and, as the above analogue, it does not solve the problems of reducing the consumption of alloyed steel grades and alloys for the formation of seed ends. This method may be acceptable only when rolling pipes from titanium-based alloys.

In the pipe industry, there is also known a method of preparing sleeve blanks from alloyed steel grades and alloys for pilgrim rolling of pipes, including heating the sleeve blanks and nozzles made of inexpensive carbon steel grades — lining carbon rings whose outer diameter is larger than the diameter of the sleeves and having a cylindrical and conical sections whose sizes are determined from the expressions L _k = (0.6-0.8) D _g , L _c.y. = (0.35-0.4) D _g , L _c.y. = (0.25-0.4) D _g , D _cu = (1.15-1.3) D _g , D _q.y. = (1.0-1.1) D _g , where D _g is the diameter of the sleeve, mm; L _to - the total length of the carbon ring, mm; L _c.y. - the length of the cylindrical section of the ring, mm; L _c.u. - the length of the conical section of the ring, mm; D _C.y. - the diameter of the cylindrical section of the ring, mm; D _to.y. - the smallest diameter of the conical section of the ring, mm, with an increase in the diameter of the cylindrical section of the ring, the length of the conical section increases from 0.25 to 0.4 D _g , and the conical section of the pipe with a smaller base adjoins the end of the sleeve (patent RU No. 2207199, class B21B 21 / 00, 06/27/2003).

This method provides multiple use of carbon linings, elimination of mandrel mandrels when rolling pipes from high alloy steel grades and alloys with an increased coefficient of linear expansion, full break-in (removal of pilgrim heads on carbon metal), but, as the above analogues, does not solve the problem of reducing consumption alloy steel grades and alloys for the formation of seed ends.

The closest technical solution is the method of pilgrim rolling, which includes inserting the mandrel into the sleeve having a section with increased taper under the mandrel head to center the rear end of the sleeve, putting on a conical ring on the mandrel, the conical part of which centers the front end of the sleeve with respect to the axis of the mandrel and deformation of the composite workpiece by rolls with a variable caliber profile in commodity pipes (patent RU No. 2346766, class B21B 21/00, 02.20.2009).

This method of pilgrim rolling is aimed at reducing the transverse difference of the seed ends of the pipes, i.e. to a partial reduction in their length, and does not solve the problem of removing the seed ends when rolling commodity and conversion pipes from alloyed steel grades and alloys to carbon metal.

The objective of the proposed method for the production of commodity and conversion pipes in pipe rolling units with pilgrim mills from forged billets, solid or hollow ingots-billets of electroslag remelting from alloyed hardly deformable grades of steel and alloys, titanium-based alloys is the full rolling (running) of the front ends of the sleeves into commodity and conversion pipes due to the removal of the seed ends on the underlay carbon rings and reducing the time for seed.

, L_п.к.=(0,20-0,25)L_к, L_ц.к.=(0,30-0,35)L_к, L_з.к.=(0,4-0,5)L_к, D_{м.∂.п.к.}=(0,98-0,99)D_в.г., D_{б.∂.п.к.}=(0,01-1,015)D_в.г., D_з.к.=(0,75-0,80)D_н.к., где D_н.к. - наружный диаметр цилиндрической части подкладного углеродистого кольца, большее значение которого относится к гильзам меньшего диаметра, мм; D_в.к. - внутренний диаметр подкладного углеродистого кольца, большее значение которого относится к дорнам меньшего диаметра, мм; D_н.г. - наружный диаметр гильзы или полого слитка-заготовки ЭШП, мм; D_в.г. - внутренний диаметр гильзы или полого слитка-заготовки ЭШП, мм; D_∂ - диаметр дорна, мм; L_к - длина подкладного углеродистого кольца, мм; L_п.к. - длина переднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; L_ц.к. - длина цилиндрической части подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; L_з.к. - длина заднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; D_{м.∂.п.к.} - меньший наружный диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_{б.∂.п.к.} - больший диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_з.к. - наружный диаметр заднего конуса подкладного углеродистого кольца, большее значение которого относится к кольцам меньшего диаметра, мм; D_m - диаметр товарной или передельной трубы, мм; S_m - толщина стенки товарной или передельной трубы, мм; L_з - длина затравочной части (затравки) товарной или передельной трубы, при прокатке товарных или передельных труб из гильз или полых слитков-заготовок электрошлакового переплава без подкладных углеродистых колец, мм, передний конический участок подкладного углеродистого кольца меньшим основанием вводят во внутреннюю полость гильзы или полого слитка-заготовки на величину, значение которой определяют из выражения L_входа=(0,75-0,85)L_п.к, где большие значения коэффициента относятся к гильзам и полым слиткам-заготовкам большего диаметра, на плоскость после переднего конического участка подкладного углеродистого кольца через 60° или 90° наносят способом наплавки выступы, которые располагают по эвольвенте от основания меньшего конуса к наружному диаметру кольца против хода вращения подающего аппарата, после первых двух подач сборной заготовки в очаг деформации угол кантовки подающего аппарата за каждую последующую подачу плавно увеличивают на угол, значения которого определяют из выражения $$\beta =\frac{\alpha }{n-2},$$

где α - угол кантовки подающего аппарата при установившемся процессе прокатки, град; n - количество подач сборной заготовки в очаг деформации до полного отката подающего аппарата, с увеличением диаметра подкладных углеродистых колец ширину и высоту выступов увеличивают соответственно с 15 до 20 мм и с 10 до 15 мм.The technical result is achieved by the fact that in the known method for the production of commodity and conversion pipes in pipe rolling plants with pilgrim mills from forged billets, solid or hollow ingots-blanks of electroslag remelting from alloyed hardly deformable grades of steel and alloys, alloys based on titanium, including heating of forged billets, solid or hollow ingots-billets of electroslag remelting and underlay carbon rings up to ductility temperature, piercing forged billets and solid ingots - preparations of electroslag remelting in a cross-helical rolling mill into sleeves, charging a mandrel with a mandrel ring into the mandrel head, putting on a carbon blank ring on the mandrel, inserting the mandrel into a sleeve or hollow ingot-electroslag ingot ingot, putting on the mandrel carbon conical centering ring, the conical part of the front end ring of the sleeve or the hollow ingot-workpiece relative to the axis of the mandrel and the deformation of the prefabricated workpiece - the underlay carbon ring-sleeve or hollow ingot-workpiece electroslag remelting from alloyed hard-deformed steel, an alloy or an alloy based on titanium - a lining carbon ring in rolls with a variable caliber profile into commodity or conversion pipes with the removal of the seed end and the pilgrim head on carbon rings, lining carbon rings for removing the seed ends are made in the form of a cylinder with conical sections, the sizes of which are determined from the expressions D _n.k. = (0.9-1.0) D _n.a. , D _century = (1,02-1,03) D _∂ , $$L_{\mathrm{to}}=\frac{\mathrm{one},5(D_m-S_m)S_m{L}_s}{(D_{n.\mathrm{to}.}-S_{n.\mathrm{to}.})S_{n.\mathrm{to}.}}$$

, L _s.c. = (0.20-0.25) L _k , L _c.c. = (0.30-0.35) L _c , L _s.c. = (0.4-0.5) L _k , D _m.∂.p.k. = (0.98-0.99) D _century , D _b.∂.p.c. = (0.01-1.015) D _century , D _c.c. = (0.75-0.80) D _n.c. where D _n.k. - the outer diameter of the cylindrical part of the lining carbon ring, the greater value of which relates to sleeves of smaller diameter, mm; D _century - the inner diameter of the lining carbon ring, the larger value of which refers to the mandrels of smaller diameter, mm; D _ng - the outer diameter of the sleeve or hollow ingot preform ESR, mm; D _century - the inner diameter of the sleeve or hollow ingot preform ESR, mm; D _∂ is the diameter of the mandrel, mm; L _to - the length of the lining carbon ring, mm; L _s.c. - the length of the front cone of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm; L _c.c. - the length of the cylindrical part of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm; L _c.c. - the length of the rear cone of the underlay carbon ring, the greater value of which relates to rings of larger diameter, mm; D _m.∂.p.c. - a smaller outer diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _b.∂.p.c. - a larger diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _c.c. - the outer diameter of the rear cone of the underlay carbon ring, the larger value of which relates to rings of smaller diameter, mm; D _m - the diameter of the commodity or conversion pipe, mm; S _m - wall thickness of a commodity or conversion pipe, mm; L _s - the length of the seed part (seed) of a commodity or conversion pipe, when rolling commodity or conversion pipes from sleeves or hollow ingots-blanks of electroslag remelting without carbon rings, mm, the front conical section of the carbon ring is inserted with a smaller base into the inner cavity of the sleeve or hollow ingot billet by a value whose value is determined from the expression L _input = (0.75-0.85) L _nk , where large values of the coefficient refer to sleeves and hollow ingots-blanks of a larger diameter, by after the front conical section of the underlay carbon ring through 60 ° or 90 °, the protrusions are applied by welding method to protrusions that are involuted from the base of the smaller cone to the outer diameter of the ring against the course of rotation of the feeding apparatus, after the first two feeds of the prefabricated workpiece into the deformation zone, the pitching angle of the feeding apparatus for each subsequent feed smoothly increase by an angle, the values of which are determined from the expression $$\beta =\frac{\alpha }{n-2},$$

where α is the pitch angle of the feeding apparatus with the steady rolling process, deg; n is the number of feeds of the prefabricated workpiece into the deformation zone until the feeding apparatus rolls back completely, with an increase in the diameter of the underlay carbon rings, the width and height of the protrusions increase respectively from 15 to 20 mm and from 10 to 15 mm.

, L_п.к.=(0,20-0,25)L_к, L_ц.к.=(0,30-0,35)L_к, L_з.к.=(0,4-0,5)L_к, D_{м.∂.п.к.}=(0,98-0,99)D_в.г., D_{б.∂.п.к.}=(0,01-1,015)D_в.г.,. D_з.к.=(0,75-0,80)D_н.к., где D_н.к. - наружный диаметр цилиндрической части подкладного углеродистого кольца, большее значение которого относится к гильзам меньшего диаметра, мм; D_в.к. - внутренний диаметр подкладного углеродистого кольца, большее значение которого относится к дорнам меньшего диаметра, мм; D_н.г. - наружный диаметр гильзы или полого слитка - заготовки ЭШП, мм; D_в.г. - внутренний диаметр гильзы или полого слитка - заготовки ЭШП, мм; D_∂ - диаметр дорна, мм; L_к - длина подкладного углеродистого кольца, мм; L_п.к. - длина переднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм: L_ц.к. - длина цилиндрической части подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; L_з.к. - длина заднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; D_{м.∂.п.к.} - меньший наружный диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_{б.∂.п.к.}- больший диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_з.к. - наружный диаметр заднего конуса подкладного углеродистого кольца, большее значение которого относится к кольцам меньшего диаметра, мм; D_m - диаметр товарной или передельной трубы, мм; S_m - толщина стенки товарной или передельной трубы, мм; длина затравочной части (затравки) товарной или передельной трубы, при прокатке товарных или передельных труб из гильз или полых слитков-заготовок электрошлакового переплава без подкладных углеродистых колец, мм, передний конический участок подкладного углеродистого кольца меньшим основанием вводят во внутреннюю полость гильзы или полого слитка-заготовки на величину, значение которой определяют из выражения L_входа=(0,75-0,85)L_п.к, где большие значения коэффициента относятся к гильзам и полым слиткам-заготовкам большего диаметра, на плоскость после переднего конического участка подкладного углеродистого кольца через 60° или 90° наносят способом наплавки выступы, которые располагают по эвольвенте от основания меньшего конуса к наружному диаметру кольца против хода вращения подающего аппарата, после первых двух подач сборной заготовки в очаг деформации угол кантовки подающего аппарата за каждую последующую подачу плавно увеличивают на угол, значения которого определяют из выражения $$\beta =\frac{\alpha }{n-2}$$

, где α - угол кантовки подающего аппарата при установившемся процессе прокатки, град; n - количество подач сборной заготовки в очаг деформации до полного отката подающего аппарата, с увеличением диаметра подкладных углеродистых колец ширину и высоту выступов увеличивают соответственно с 15 до 20 мм и с 10 до 15 мм. Таким образом, эти отличия позволяют сделать вывод о соответствии критерию "изобретательский уровень".Comparative analysis with the prototype shows that the inventive method for the production of commodity and conversion pipes in tube-rolling plants with pilgrim mills from forged billets, solid or hollow ingots-billets of electroslag remelting from alloyed hardly deformable grades of steel and alloys, titanium-based alloys, is characterized in that the underlay carbon rings for removing the seed ends are made in the form of a cylinder with conical sections, the dimensions of which are determined from the expressions D _NK = (0.9-1.0) D _n.a. , D _century = (1,02-1,03) D _∂ , $$L_{\mathrm{to}}=\frac{\mathrm{one},5(D_m-S_m)S_m{L}_s}{(D_{n.\mathrm{to}.}-S_{n.\mathrm{to}.})S_{n.\mathrm{to}.}}$$

, L _s.c. = (0.20-0.25) L _k , L _c.c. = (0.30-0.35) L _c , L _s.c. = (0.4-0.5) L _k , D _m.∂.p.k. = (0.98-0.99) D _century , D _b.∂.p.c. = (0.01-1.015) D _century ,. D _c.c. = (0.75-0.80) D _n.c. where D _n.k. - the outer diameter of the cylindrical part of the lining carbon ring, the greater value of which relates to sleeves of smaller diameter, mm; D _century - the inner diameter of the lining carbon ring, the larger value of which refers to the mandrels of smaller diameter, mm; D _ng - the outer diameter of the sleeve or hollow ingot - ESR blanks, mm; D _century - the inner diameter of the sleeve or hollow ingot - ESR blanks, mm; D _∂ is the diameter of the mandrel, mm; L _to - the length of the lining carbon ring, mm; L _s.c. - the length of the front cone of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm: L _c.k. - the length of the cylindrical part of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm; L _c.c. - the length of the rear cone of the underlay carbon ring, the greater value of which relates to rings of larger diameter, mm; D _m.∂.p.c. - a smaller outer diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _b.∂.p.c. - a larger diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _c.c. - the outer diameter of the rear cone of the underlay carbon ring, the larger value of which relates to rings of smaller diameter, mm; D _m - the diameter of the commodity or conversion pipe, mm; S _m - wall thickness of a commodity or conversion pipe, mm; the length of the seed part (seed) of a commodity or conversion pipe, when rolling commodity or conversion pipes from sleeves or hollow ingots-blanks of electroslag remelting without carbon rings, mm, the front conical section of the carbon ring is inserted with a smaller base into the inner cavity of the liner or hollow ingot the workpiece by an amount whose value is determined from the expression L _input = (0,75-0,85) L _PK where large coefficient values belong to the sleeve and the hollow billet ingots of larger diameter, on a flat after the front conical section of the underlay carbon ring, overhangs are applied through the surfacing method through 60 ° or 90 °, which are involuted from the base of the smaller cone to the outer diameter of the ring against the course of rotation of the feeding apparatus, after the first two feeds of the prefabricated workpiece into the deformation zone, the pitching angle of the feeding apparatus for each subsequent feed smoothly increase by an angle, the values of which are determined from the expression $$\beta =\frac{\alpha }{n-2}$$

where α is the pitch angle of the feeding apparatus with the steady rolling process, deg; n is the number of feeds of the prefabricated workpiece into the deformation zone until the feeding apparatus rolls back completely, with an increase in the diameter of the underlay carbon rings, the width and height of the protrusions increase respectively from 15 to 20 mm and from 10 to 15 mm. 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".

, L_п.к.=(0,20-0,25)L_к, L_ц.к.=(0,30-0,35)L_к, L_з.к.=(0,4-0,5)L_к, D_{м.∂.п.к.}=(0,98-0,99)D_в.г., D_{б.∂.п.к.}=(0,01-1,015)D_в.г., D_з.к.=(0,75-0,80)D_н.к., где D_н.к. - наружный диаметр цилиндрической части подкладного углеродистого кольца, большее значение которого относится к гильзам меньшего диаметра, мм; D_в.г. - внутренний диаметр подкладного углеродистого кольца, большее значение которого относится к дорнам меньшего диаметра, мм; D_н.г. - наружный диаметр гильзы или полого слитка-заготовки ЭШП, мм; D_в.г. - внутренний диаметр гильзы или полого слитка-заготовки ЭШП, мм; D_∂ - диаметр дорна, мм; L_к - длина подкладного углеродистого кольца, мм; L_п.к. - длина переднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; L_ц.к. - длина цилиндрической части подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; L_з.к. - длина заднего конуса подкладного углеродистого кольца, большее значение которой относится к кольцам большего диаметра, мм; D_{м.∂.п.к.} - меньший наружный диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_{б.∂.п.к.} - больший диаметр переднего конуса подкладного углеродистого кольца, большее значение которого относится к гильзам с меньшим внутренним диаметром, мм; D_з.к. - наружный диаметр заднего конуса подкладного углеродистого кольца, большее значение которого относится к кольцам меньшего диаметра, мм; D_m - диаметр товарной или передельной трубы, мм; S_m - толщина стенки товарной или передельной трубы, мм; L_з - длина затравочной части (затравки) товарной или передельной трубы, при прокатке товарных или передельных труб из гильз или полых слитков-заготовок электрошлакового переплава без подкладных углеродистых колец, мм, передний конический участок подкладного углеродистого кольца меньшим основанием вводят во внутреннюю полость гильзы или полого слитка-заготовки на величину, значение которой определяют из выражения L_входа=(0,75-0,85)L_п.к, где большие значения коэффициента относятся к гильзам и полым слиткам-заготовкам большего диаметра, на плоскость после переднего конического участка подкладного углеродистого кольца через 60° или 90° наносят способом наплавки выступы, которые располагают по эвольвенте от основания меньшего конуса к наружному диаметру кольца против хода вращения подающего аппарата, после первых двух подач сборной заготовки в очаг деформации угол кантовки подающего аппарата за каждую последующую подачу плавно увеличивают на угол, значения которого определяют из выражения $$\beta =\frac{\alpha }{n-2}$$

, где α - угол кантовки подающего аппарата при установившемся процессе прокатки, град.; n - количество подач сборной заготовки в очаг деформации до полного отката подающего аппарата, с увеличением диаметра подкладных углеродистых колец ширину и высоту выступов увеличивают соответственно с 15 до 20 мм и с 10 до 15 мм.The proposed method for the production of commodity and conversion pipes in pipe-rolling plants with pilgrim mills from forged billets, solid or hollow ingots-billets of electroslag remelting from alloyed hardly deformable grades of steel and alloys, titanium-based alloys consists in the fact that the underlay carbon rings for removing the seed ends perform in the form of a cylinder with conical sections, the dimensions of which are determined from the expressions D _n.k. = (0.9-1.0) D _n.a. , D _century = (1,02-1,03) D _∂ , $$L_{\mathrm{to}}=\frac{\mathrm{one},5(D_m-S_m)S_m{L}_s}{(D_{n.\mathrm{to}.}-S_{n.\mathrm{to}.})S_{n.\mathrm{to}.}}$$

, L _s.c. = (0.20-0.25) L _k , L _c.c. = (0.30-0.35) L _c , L _s.c. = (0.4-0.5) L _k , D _m.∂.p.k. = (0.98-0.99) D _century , D _b.∂.p.c. = (0.01-1.015) D _century , D _c.c. = (0.75-0.80) D _n.c. where D _n.k. - the outer diameter of the cylindrical part of the lining carbon ring, the greater value of which relates to sleeves of smaller diameter, mm; D _century - the inner diameter of the lining carbon ring, the larger value of which refers to the mandrels of smaller diameter, mm; D _ng - the outer diameter of the sleeve or hollow ingot preform ESR, mm; D _century - the inner diameter of the sleeve or hollow ingot preform ESR, mm; D _∂ is the diameter of the mandrel, mm; L _to - the length of the lining carbon ring, mm; L _s.c. - the length of the front cone of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm; L _c.c. - the length of the cylindrical part of the lining carbon ring, the greater value of which relates to rings of larger diameter, mm; L _c.c. - the length of the rear cone of the underlay carbon ring, the greater value of which relates to rings of larger diameter, mm; D _m.∂.p.c. - a smaller outer diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _b.∂.p.c. - a larger diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves with a smaller inner diameter, mm; D _c.c. - the outer diameter of the rear cone of the underlay carbon ring, the larger value of which relates to rings of smaller diameter, mm; D _m - the diameter of the commodity or conversion pipe, mm; S _m - wall thickness of a commodity or conversion pipe, mm; L _s - the length of the seed part (seed) of a commodity or conversion pipe, when rolling commodity or conversion pipes from sleeves or hollow ingots-blanks of electroslag remelting without carbon rings, mm, the front conical section of the carbon ring is inserted with a smaller base into the inner cavity of the sleeve or hollow ingot billet by a value whose value is determined from the expression L _input = (0.75-0.85) L _nk , where large values of the coefficient refer to sleeves and hollow ingots-blanks of a larger diameter, by after the front conical section of the underlay carbon ring through 60 ° or 90 °, the protrusions are applied by welding method to protrusions that are involuted from the base of the smaller cone to the outer diameter of the ring against the course of rotation of the feeding apparatus, after the first two feeds of the prefabricated workpiece into the deformation zone, the pitching angle of the feeding apparatus for each subsequent feed smoothly increase by an angle, the values of which are determined from the expression $$\beta =\frac{\alpha }{n-2}$$

where α is the pitch angle of the feeding apparatus during the steady rolling process, deg .; n is the number of feeds of the prefabricated workpiece into the deformation zone until the feeding apparatus rolls back completely, with an increase in the diameter of the underlay carbon rings, the width and height of the protrusions increase respectively from 15 to 20 mm and from 10 to 15 mm.

Determination of theoretically necessary geometrical dimensions of the underlay carbon rings, deposition of protrusions on the carbon rings, the method of tilting and feeding prefabricated blanks to the deformation zone will allow rolling of sleeves and hollow ingots-blanks of electroslag remelting from alloyed steel grades and alloys, titanium-based alloys on pilgrim mills in commodity and conversion pipes with fixed feed rates from seed to full run-in (removal) of seed ends and pilgrim heads on carbon monotonous metal without dividing them into its constituent parts, in-line removal of pilgrim heads and seed ends from carbon metal using a hot cutting saw, i.e. the exception of the operation of removing carbon rings from the mandrel and their transportation by crane to boxes for scrap metal, which will reduce the consumption of alloyed steel grades and alloys and increase the performance of pilgrim mills.

The method has been tested and carried out on a pipe-rolling installation with 8-16 pilgrim mills of ChTPZ OJSC when rolling redacting pipes of 426 × 40 mm in size from 08Kh18N10T grade steel from EShP ingots-blanks of 585 × 100 × 1750 mm in size.

According to the existing technology, pipes of a given size from this steel grade must be rolled on cone mandrels with a diameter of 349/355 mm in rolls with a caliber of 434 mm with lined cylindrical carbon rings of 600 × vn. 370 × 350 mm in size to bring the pilgrim heads to carbon metal. The double use of cone rings of 620 × ext. 370 × 350 mm was not advisable because of the difficulty of additional acquisition and the difficulty of putting them on the mandrel after running one end. Rolling of conversion tubes of 426x40 mm in size from ESR ingots-blanks of 585 × 100 × 1750 mm in size is carried out according to the technology: heating of ESR ingots-blanks in a methodical furnace to a temperature of 1260-1270 ° C; Firmware for ingot blanks in a cross-helical rolling mill on a mandrel with a diameter of 275 mm in sleeves 600 × in. 290 × 2070 mm in size; reheating from cold or hot surroundings to a temperature of 1260-1270 ° C; insertion (rolling) of sleeves in a cross-helical rolling mill on a mandrel with a diameter of 375 mm into sleeves measuring 620 × ext. 390 × 2410 mm; heating in the furnace pit of cylindrical underlay carbon rings measuring 620 × ext. 470 × 350 mm to a temperature of 1280-1300 ° C; putting on the mandrel rings, and then sleeves; joint rolling of a sleeve made of 08X18H10T steel and a carbon ring with the removal of the pilgrim head on a carbon ring. The average number of strokes (feeds) of the liners into the deformation zone during seeding using the existing technology was 30 innings, and the time for seeding at 36 revolutions of the pilgrim mill rolls per minute was 50 sec. The average length of pipes at the rental was 8100 mm. According to the existing technology, 5 ingot blanks with a total weight of 17.92 tons were set into production. After rolling, 5 transfer pipes were adopted with a size of 426 × 40 × 8100 mm with a total weight of 15.41 tons. The metal expenditure coefficient for rolled products was 1.163.

According to the proposed technology, before the rolling of the conversion pipes, 5 washers made of steel of grade 20 with a size of 620 × ext. 470 × 350 mm were made to remove the pilgrim heads (existing technology) and 5 washers of steel made of grade 20 to remove the seed ends (proposed technology). Carbon rings for removing the seed ends were made in accordance with claims 1, 3 and 5 of the claims. The geometric dimensions of the liner carbon rings for removing the seed ends are shown in Table 1. Heating of the ingot blanks and liner carbon rings, piercing of the ingot blanks in the sleeves and rolling the sleeves in the cross-helical rolling mill was carried out in a similar way, i.e. according to existing technology. The assembly diagram of the washer rings and sleeves is shown in Fig. 1. The front conical sections of the underlay carbon rings for introducing the seed ends with a smaller base were introduced into the inner cavity of the liners by an amount in accordance with claim 2. After the first two strokes (feeds) of the prefabricated billets into the deformation zone, the underlay carbon rings tightly entered the sleeves to remove the seed ends, forming one monolithic prefabricated sleeve. Due to the rear cone on the carbon ring, the average number of blows (feeds) of sleeves into the deformation zone during seed using the proposed technology was 14 feeds, and the seed time at 36 revolutions of the pilgrim mill rolls per minute was 24 seconds, i.e. decreased 2.08 times. After the first two feeds of prefabricated blanks into the deformation zone and tightly fit them on the mandrel, the pitch angle of the feed apparatus for each subsequent feed was increased by 8–9 °, which corresponds to claim 4. The carbon metal seed ends were removed by a hot cutting saw, i.e. without reducing the performance of the pilgrim mill. The average length of rolled pipes rolled by the proposed technology was 8600 mm. Five ESR ingots-blanks with a total weight of 17.85 tons were set into production. The mass of the hot-rolled tubes was 16.365 tons. The expenditure coefficient of the metal in the pipes of this batch was 1.091, i.e. a reduction in the expenditure coefficient of the metal (steel 08X18H10T) by 72 kg was obtained for each ton of redistribution pipes of 426x40 mm in size. The data on rolling conversion pipes of 426 × 40 mm in size from steel grade 08Kh18N10T to TPU 8-16 ′ ′ with pilgrim mills of ChTPZ OJSC according to the existing and proposed technologies are given in table 1.

Thus, the use of the proposed method for the production of commodity and conversion pipes in pipe rolling plants with pilgrim mills from forged billets, solid or hollow ingots-billets of electroslag remelting from alloyed hardly deformed steel grades and alloys, alloys based on titanium will allow the rolling process of commodity and conversion pipes with the complete removal of the seed ends on the underlay carbon rings, eliminate the tightening of the mandrels in the pipes, eliminate the likelihood of the discharge of the underlay carbon x rings when fully run-in, and, therefore, to reduce the expenditure coefficient of the metal during the redistribution of the sleeve or the hollow ingot-billet ESR pipe, to increase the performance of the pilgrim installation by reducing the auxiliary time for removing the underlay ring from the chute of the pilgrim mill and transporting it by crane to the boxes with metal waste, and, consequently, reduce the cost of commodity and conversion pipes from expensive grades of steel and alloys.

Claims (5)

1. Method for the production of commodity and conversion pipes in tube-rolling plants with pilgrim mills from alloyed hardly deformable grades of steel and alloys and titanium-based alloys, including heating forged billets, solid or hollow ingots-billets of electroslag remelting to a plasticity temperature, piercing forged billets or solid ingots - preparations of electroslag remelting in a cross-helical rolling mill into sleeves, heating of carbon rings to plasticity temperature, charging the mandrel with a new ring into the mandrel head, putting on a mandrel of a carbon ring, inserting the mandrel into a sleeve or into a hollow ingot-blank of electroslag remelting, putting on a mandrel of a carbon liner to remove the seed ends made with cylindrical and conical sections, centering the conical part of the carbon pad ring the front end of the sleeve or the hollow ingot-billet electroslag remelting relative to the axis of the mandrel and the deformation of the prefabricated, consisting of a lining carbon ring, sleeve or hollow ingot-billet of electroslag remelting and underlay carbon ring for removing seed ends, in rolls with a variable caliber profile into commodity or conversion pipes with the output of the seed end and pilgrim head to carbon rings, while the dimensions of the cylindrical and conical sections of the underlay the carbon ring for removing the seed ends is determined from the expressions:
D _n.c. = (0.9-1.0) D _n.a. ,
where D _n.k. - the outer diameter of the cylindrical part of the lining carbon ring, the greater value of which relates to sleeves and hollow ingots-blanks of a smaller diameter, mm;
D _ng - the outer diameter of the sleeve or hollow ingot billet, mm;
D _century = (1,02-1,03) D _∂ ,
where D _V.K. - the inner diameter of the lining carbon ring, the larger value of which refers to the mandrels of smaller diameter, mm;
D _∂ is the diameter of the mandrel, mm;
D _m.∂.p.c. = (0.98-0.99) D _century ,
where D _m.∂.p.k. - a smaller outer diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves and hollow ingots-blanks with a smaller inner diameter, mm;
D _century - inner diameter of the sleeve, mm;
D _b.∂.p.c. = (0.01-1.015) D _century ,
where D _b.∂.p.c. - a larger diameter of the front cone of the underlay carbon ring, the greater value of which relates to sleeves and hollow ingots-blanks with a smaller inner diameter, mm;
D _c.c. = (0.75-0.80) D _n.c. ,
where D _z.k. - the outer diameter of the rear cone of the underlay carbon ring, the larger value of which relates to rings of smaller diameter, mm;
while the length L _{to the} underlay carbon ring is determined from the expression:
$$L_{\mathrm{to}}=\frac{\mathrm{one},5(D_m-S_m)S_m{L}_s}{(D_{n.\mathrm{to}.}-S_{n.\mathrm{to}.})S_{n.\mathrm{to}.}}$$

,
where D _m is the diameter of the commodity or conversion pipe, mm;
S _m - wall thickness of a commodity or conversion pipe, mm;
L _s - the length of the seed part of a commodity or conversion pipe, when rolling commodity or conversion pipes from sleeves and hollow ingots-blanks without lining carbon rings, mm;
length L _s.c. the front cone of the underlay carbon ring, the greater value of which relates to rings of larger diameter, is determined from the expression:
L _s.c. = (0.20-0.25) L _to ,
length L _c.c. the cylindrical part of the lining carbon ring, the greater value of which relates to rings of larger diameter, is determined from the expression:
L _c.c. = (0.30-0.35) L _k ,
and the length L _C. the rear cone of the underlay carbon ring, the larger value of which relates to rings of larger diameter, is determined from the expression:
L _c.c. = (0.4-0.5) L _to . 2. The method according to claim 1, characterized in that the smaller base of the front conical portion of the underlay carbon ring is placed in the inner cavity of the sleeve by the value L of the _input , determined from the expression:
L _input = (0.75-0.85) L _s.c. ,
moreover, large values of the coefficient refer to sleeves of larger diameter. 3. The method according to claim 1, characterized in that on the conical sections of the lining carbon ring through 60 ° or 90 ° are projected protrusions, which are located on the involute from the smaller base of the conical part to the outer diameter of the ring against the course of rotation of the feeding apparatus. 4. The method according to claim 1, characterized in that after the first two feeds of the prefabricated workpiece into the deformation zone, the pitch angle of the feed apparatus for each subsequent feed is gradually increased by an angle β, the values of which are determined from the expression:
$$\beta =\frac{\alpha }{n-2}$$

,
where α is the pitch angle of the feeding apparatus with the steady rolling process, deg;
n is the number of feeds of the prefabricated workpiece into the deformation zone before the rollback of the feeding apparatus is complete. 5. The method according to claim 3, characterized in that the width and height of the protrusions increase respectively from 15 to 20 mm and from 10 to 15 mm with an increase in the diameter of the underlay carbon rings.

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