RU2569624C2 - Method of rail production - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: claimed invention relates to travelling crane structures and to railway transport. Rectangular blank is cast by continuous casting process from alloyed manganese "35ГС"-grade steel. Cast blank is cooled to ductility temperature and conveyed to rolling mill stand. Said blank is rolled and reduced on four sides by stand rolls with total rolling-out factor of at least 7.8 to rail of rectangular cross-section. Rail cross-section height h to width t makes 2.7-2.8. Rail is provided with two lateral symmetric lengthwise flanges, 15×15-20×20 mm in cross-section, on rail foot for tight securing to crane beam top belt. Rolling temperature is kept equal to 950-1050°C. Rail is water cooled to 535-580°C and cut to lengths.

EFFECT: increased moment on rail inertia at twisting.

1 dwg, 3 tbl

Description

The present invention relates to a crane construction with a heavy 8K, 7K continuous operation of bridge cranes and intensive operation, as well as to railway transport.

;

;

[1, 2, 3] в подрельсовой зоне подкрановых балок. Чем больше амплитуды колебаний локальных напряжений, тем быстрее возникают в подрельсовой зоне стенок подкрановых балок усталостные трещины и тем быстрее эти опасные усталостные трещины растут и сливаются друг с другом.Crane rails and the design of the upper part of the crane beam are macro-regulators of the amplitudes of oscillations of local stresses

;

;

[1, 2, 3] in the under-rail zone of crane beams. The greater the amplitude of oscillations of local stresses, the faster fatigue cracks arise in the under-rail zone of the walls of crane beams and the faster these dangerous fatigue cracks grow and merge with each other.

;

;

в сильной степени зависят от момента инерции кручения применяемого кранового рельса

и момента инерции его при изгибе

.Amplitudes of local stress oscillations

;

;

to a large extent depend on the torsion moment of inertia of the crane rail used

and its moment of inertia in bending

.

и изгиба

, легко управлять техническим ресурсом [4, с. 1199] и выносливостью [4, с. 235] подрельсовой зоны подкрановых балок с тяжелым режимом работы мостовых кранов 8К, 7К [1, 2, 3].By controlling the magnitude of the basic torsion characteristics of crane rails

and bending

, easy to manage the technical resource [4, p. 1199] and endurance [4, p. 235] the under-rail zone of crane beams with heavy duty operation of bridge cranes 8K, 7K [1, 2, 3].

As the closest analogue of the claimed invention, a method of manufacturing a rail is adopted, including casting a rail billet and rolling it disclosed in the document (RU 201114176 A, B21B 1/085, 04/27/2013) [5]. Known standard crane rails according to GOST 4121-62 * with a curved section profile [6, p. 60].

и изгиба

.Even the most massive (powerful) rail KR 140 according to GOST 4121-62 * does not have sufficient torsion inertia

and bending

.

и

рельса КР 140 недостаточны для уменьшения амплитуд опасных колебаний локальных напряжений

;

;

в подрельсовой зоне подкрановых балок [7, 8, 9, 10] до безопасных величин. То есть на такую величину, чтобы не допустить зарождения опасных усталостных трещин в зоне стыка верхнего пояса со стенкой подкрановой балки, следовательно,

и

не обеспечивают достаточного технического ресурса.Moments of inertia

and

rail KR 140 insufficient to reduce the amplitudes of dangerous fluctuations in local stresses

;

;

in the under-rail zone of crane beams [7, 8, 9, 10] to safe values. That is, by such a value as to prevent the generation of dangerous fatigue cracks in the zone of the junction of the upper belt with the wall of the crane beam, therefore

and

do not provide sufficient technical resource.

Fluctuations in local stresses during cyclic dynamic effects of the wheels of bridge cranes lead to fatigue cracks [1 ... 10] in the area of the welded joint of the upper belt with the wall of the crane beam.

With the accumulation of millions of dynamic impacts of the wheels, fatigue cracks rapidly grow and develop along the upper belt, which increases the likelihood of a crane beam collapsing along with a bridge crane with cargo, for example, liquid steel. Fatigue cracks dangerously reduce the period of safe operation and the technical resource of crane beams [1 ... 10]. Any cracks in steel structures are unacceptable [11].

The relevance of guaranteeing the safe operation of crane beams in the shops of ferrous and non-ferrous metallurgy is high. We offer to guarantee the safe operation of crane beams by improving the rental of rectangular crane rails and the nodes of their connection with the upper beams.

, рассчитанные Митюговым Е.А. [12], завышены [5…8]. Например, для рельса КР-140 полученное им значение

завышено в 3,584 раза [9, 10].Currently, standard crane rails with a curved section profile in accordance with GOST 4121-62 * are used [6, p. 60]. Torsion moment of inertia of these rails

calculated by Mityugov E.A. [12], overpriced [5 ... 8]. For example, for the rail KR-140, the value obtained by him

3.584 times overstated [9, 10].

The technical task of manufacturing a rail includes casting a rectangular cross-section of a workpiece by continuous casting from alloyed manganese steel grade 35GS, with the following chemical composition: carbon 0.3-0.37; manganese 0.8-1.2; silicon 0.60.9; chrome not more than 0.3%; nickel not more than 0.3%; copper no more than 0.3%; harmful impurities: sulfur no more than 0,045%; phosphorus not more than 0.04%; nitrogen not more than 0.012%; iron the rest.

Cooling the cast billet to the temperature of a plastic state, transporting it translationally into the mill stand, maintaining the rolling temperature within 950-1050 ° C, rolling with squeezing the plastic workpiece from four sides by mill rolls with a total drawing ratio of at least 7.8 in a rectangular rail h to its width t, equal to 2.7-2.8.

During rolling, with compression of the plastic billet, a symmetric pair of lateral longitudinal ridges with a cross section of 15 × 15-20 × 20 mm is formed on the sole of the rail for the fixed attachment of the sole of the rail to the upper belt of the crane beam. Cooling to a temperature of 535-580 ° C is carried out with water, and then the rail is cut into measured lengths.

в 3…3,58 раза. Такое значительное увеличение одной из главных характеристик рельса достигнуто прокатом рельса из заготовки, полученной непрерывным литьем.An increase in the technical resource of the crane beam is achieved by increasing the moment of inertia of the torsion of the rail

3 ... 3.58 times. Such a significant increase in one of the main characteristics of the rail is achieved by rolling the rail from a billet obtained by continuous casting.

The rail is rolled in a rectangular profile [10] of section of alloy steel with a ratio of the height of the section to its width n = h / t = 2.6 ... 2.8 [10], where h is the height of the section; t is the width of the section.

Reducing the complexity of rolling is achieved by a significant simplification of the cross-sectional profile (the rail has a rectangular profile).

в 3…3,58 раза. Легированная марганцовистая сталь, например, марки 35ГС [4, с. 799] обеспечивает высокую стойкость рельса к истиранию в зоне контакта с гребнями колес кранов.The rectangular profile of the rail [10] provides an increase in the moment of inertia of the torsion of the rail

3 ... 3.58 times. Alloyed manganese steel, for example, grade 35GS [4, p. 799] provides high resistance of the rail to abrasion in the zone of contact with the flanges of the wheels of the cranes.

в 3…3,58 раза, в свою очередь, повышает технический ресурс подкрановых балок.The increase in the moment of inertia of the torsion of the rail

3 ... 3.58 times, in turn, increases the technical resource of crane beams.

The rectangular rolling rail profile is fixedly attached to the upper belt of the crane beam with a friction joint using a pair of corner profiles. The friction joint provides the elimination of shifts in the joint.

Alloyed manganese steel [4, p. 632], has the following chemical composition: carbon 0.30 ... 0.37; manganese 0.8 ... 1.2; silicon 0.6 ... 0.9; chromium not more than 0.30%; nickel not more than 0.30%; copper no more than 0.30%. The content of harmful impurities: sulfur not more than 0.045%; phosphorus no more than 0,040%; nitrogen not more than 0.012%; iron is the rest. At the same time, the total hood coefficient at rental is set to at least 7.8. [4, p. 799]

The ratio of the height of the rectangular section to its width n = h / t = 2.6 ... 2.8, where h is the height of the section; t is the width of the section.

[11, с. 19] в 2,8…4,8 раза по сравнению со стандартным рельсом фигурного профиля по ГОСТ 4121-62* [9, с. 60].Increase rail torsion moment of inertia

[11, p. 19] by 2.8 ... 4.8 times in comparison with a standard rail of a figured profile in accordance with GOST 4121-62 * [9, p. 60].

The rail is fixedly connected to the upper belt of the crane beam using a symmetrical pair of corners protruding into the sides and high-resource friction pins [Art] connecting the corner shelves with both the rail and the crane beam. The nuts of the friction studs are guaranteed to be tightened with a screwdriver and eliminate joint shifts.

In FIG. 1 shows a rectangular section of a rail from a rolled thick-walled profile fixedly attached to a crane beam.

Concrete implementation example

стандартного кранового рельса с фигурным профилем сечения ГОСТ 4121-62* сильно зависит от ширины шейки рельса [5…8]. Увеличение ширины шейки t_ш рельса, при неизменной площади сечения А, приводит к быстрому увеличению момента инерции кручения

. Увеличение момента инерции кручения

продолжается вплоть до превращения фигурного профиля сечения в сплошной прямоугольный [6…8] (или квадратный) в сечении профиль. Однако момент инерции изгиба

зависит от куба высоты сечения рельса. Допускать снижение момент инерции изгиба

рельса прямоугольного профиля по отношению к стандартному рельсу с фигурным профилем сечения (ГОСТ 4121-62*) не следует, так как

рельса влияет на амплитуды колебаний локальных напряжений и на выносливость узла соединения. Поэтому принимаем равенство

у стандартного фигурного профиля и у прямоугольного профиля [1, 2, 3, 4, 5].Torsion moment of inertia

standard crane rail with a figured cross-sectional profile GOST 4121-62 * strongly depends on the width of the rail neck [5 ... 8]. An increase in the neck width t _{w of the} rail, at a constant cross-sectional area A, leads to a rapid increase in torsion inertia

. The increase in torsion moment of inertia

continues until the figured section profile turns into a solid rectangular [6 ... 8] (or square) profile in the section. However, the moment of inertia of the bend

Depends on the cube of the rail section height. To allow a decrease in the moment of inertia of the bend

a rectangular rail with respect to a standard rail with a curved section profile (GOST 4121-62 *) should not be, since

rail affects the amplitude of local stress fluctuations and the endurance of the connection node. Therefore, we accept the equality

the standard curly profile and the rectangular profile [1, 2, 3, 4, 5].

в 3,1 раза. Однако фигурный рельсовый профиль лучше вписывается в прямоугольник.In articles [7 ... 10] it was shown that the transformation of a curved rail profile into a square with the same cross-sectional area leads to an extreme increase in the torsion inertia moment

3.1 times. However, the curly rail profile fits better into the rectangle.

крановых рельсов ГОСТ 4121-62*, рассчитанные Митюговым Е.А. [9,с.60], [10].In the modern assortment, when calculating endurance, inflated torsion inertia moments are used

crane rails GOST 4121-62 *, designed by E. Mityugov [9, p. 60], [10].

рельсов и любых других сплошных профилей увеличиваются при концентрации материала в центре. Например, max моментом инерции кручения обладает круглый в сечении сплошной стержень J_Кр=J_Р=πD⁴/32, однако такой стержень для рельса плохо подходит. Прямоугольные сплошные профили также обладают большими моментами инерции кручения [11, с. 29].Torsion moment of inertia

rails and any other solid profiles increase with the concentration of the material in the center. For example, max has a moment of inertia in the torsion section round solid rod _Cr J = J _P = πD ^4/32, but such rod for rail poorly suited. Rectangular solid profiles also have large torsion inertia moments [11, p. 29].

у них будут совпадать.The article shows that the curved rail profile can easily be replaced by an equivalent I-beam thick-walled rail made up of three rectangles, and the cross-sectional area A and the moment of inertia of the rail during bending

they will match.

толстостенных двутавровых рельсов, эквивалентных стандартным двутавровым рельсам [9, с. 60], были найдены с достаточной точностью по известным математическим формулам, приведенным в «Справочнике по сопротивлению материалов» [11, с. 29]. Поскольку контур толстостенного двутаврового рельса близок по очертанию к сечению толстостенного стандартного двутаврового рельса [8, с. 60], а их площади сечения и момент инерции при изгибе

совпадают, поэтому их моменты инерции кручения

также будут с достаточной точностью совпадать (см. табл. 1).Torsion moment of inertia

thick-walled I-rails, equivalent to standard I-rails [9, p. 60], were found with sufficient accuracy according to the well-known mathematical formulas given in the "Guide to the resistance of materials" [11, p. 29]. Since the contour of a thick-walled I-rail is close in shape to the section of a thick-walled standard I-rail [8, p. 60], and their cross-sectional area and moment of inertia during bending

coincide, therefore their moments of inertia of torsion

will also coincide with sufficient accuracy (see table. 1).

стандартным крановым рельсам по ГОСТ 4121-62* [9, с. 60]. У стандартных крановых рельсов рекомендуем использовать в расчетах такие же моменты инерции при свободном кручении, так как эквивалентные профили подобраны при точном совпадении площадей А и моментов инерции рельсов

.In the table. Figure 2 shows the parameters of thick-walled I-beams in the section of rails, equivalent in area A and moments of inertia

standard crane rails according to GOST 4121-62 * [9, p. 60]. For standard crane rails, we recommend using the same moments of inertia for free torsion in the calculations, since equivalent profiles are selected when the areas A and the moments of inertia of the rails match exactly

.

Algorithm for replacing a standard crane rail with a rolling rectangular rail in section

эквивалентным равновеликим по площади сечения А готовым прямоугольным прокатным профилем.1. We replace the standard crane rail (GOST 4121-62 *) with a curved cross-section profile KR 140 [6, p. 60] with a cross-sectional area A = 195.53 cm ² , moment of inertia

equivalent equal in cross-sectional area A finished rectangular rolling profile.

высота сечения

2. Determine the approximate height of the rail section. We write the moment of inertia of the rectangular rail relative to the main axis X:

section height

; отношение

. Увеличение

3. Determine the width t of the rectangular rail

; the attitude

. Increase

4. We round the sizes:

. Ув. К_Ув=4217,06/1176,5=3,584 раза! Аналогично для нового массивного рельса КР max А=246,14 см²,

;

; A^факт=h·t=25·10=250;

. Увеличение 6235,5/2033,7=3,07 раза! Рельс КР 120.

.

.5. The ratio of the height of the rail to its width t:

. SW To _Uv = 4217.06 / 1176.5 = 3.584 times! Similarly, for a new massive rail KR max A = 246.14 cm ²

;

; A ^fact = h · t = 25 · 10 = 250;

. Increase of 6235.5 / 2033.7 = 3.07 times! Rail KR 120.

.

.

An increase of 1923.8 / 485.4 = 3.96 times!

.

. A^факт=h·t=16·7.5=120;

. Увеличение 1460,65/404,4=3,61 раза!Rail KR 100.

.

. A ^fact = h · t = 16 · 7.5 = 120;

. An increase of 1460.65 / 404.4 = 3.61 times!

.

. Увеличение 722,63/150,5=4,81 раза!Rail KR 80.

.

. An increase of 722.63 / 150.5 = 4.81 times!

и стандартного кранового рельса по ГОСТ 4121-62* совпадают с толстостенными двутавровыми рельсами, а также с рельсами прямоугольного сечения, что гарантирует эквивалентность замены.Square A and moments of inertia of rails

and standard crane rail according to GOST 4121-62 * coincide with thick-walled I-rails, as well as with rails of rectangular cross-section, which guarantees equivalence of replacement.

Comparison with standard rails revealed the following positive properties of rectangular rails in section.

в 3,07…4,81 раза, при одинаковой материалоемкости и совпадении моментов инерции рельсов при изгибе

.1. Rectangular alloy crane rails have increased torsion moment of inertia

3.07 ... 4.81 times, with the same material consumption and coincidence of the moments of inertia of the rails during bending

.

2. The rolling of rails is simplified, since the figured profile is replaced by a rolling rectangular profile.

3. A fixed connection without shear is ensured for a rectangular cross-section rail with the upper belt of a crane beam with a friction joint that excludes element shifts.

и кручении

.4. A new massive rectangular crane rail KR max was added, which has max moments of inertia during bending

and torsion

.

5. Crane rail КР max allows to reduce dangerous cycle amplitudes of local stress fluctuations leading to fatigue cracks [1 ... 8] at the junction of the upper belt with the wall of crane beams to minimum values and to prevent fatigue cracks from occurring with any bridge cranes.

6. Crane rail KR max increases the technical resource of the rail zone of the crane beams and allows you to guarantee intensive safe operation of the crane beams, with heavy 8K, 7K operating mode of bridge cranes, for 20 years or more.

и другие параметры толстостенных рельсов, эквивалентных фигурным профилям стандартных рельсов, легко определяются с достаточной точностью по формулам, полученным в прошлом столетии.7. Moments of inertia of torsion

and other parameters of thick-walled rails, equivalent to the curly profiles of standard rails, are easily determined with sufficient accuracy by the formulas obtained in the last century.

8. Significant economic effect occurs due to increased technical resource and endurance of the rail zone of crane beams with heavy duty operation of bridge cranes.

Bibliography

1. Nezhdanov, K.K. Improvement of crane structures and methods for their calculation [Text]: dis ... Dr. tech. sciences / K.K. Nezhdanov. - Penza, 1992 .-- 349 p.

2. Nezhdanov K.K. Improvement of crane structures and methods for their calculation [Text]: monograph. / K.K. Nezhdanov. - Penza: PGUAS, 2008 .-- 288 p. (Laureate of the competition for medals and diplomas of the RAASN of building sciences 2011 02.16.2012).

3. Saburov V.F. Patterns of fatigue injuries and the development of a method for calculating the durability of crane tracks of industrial buildings: Diss ... Dr. tech. sciences. - Chelyabinsk: SUSU, 2002 .-- 388 p.

4. Big Encyclopedic Dictionary. (BES). Editor-in-chief A.M. Prokhorov. SCIENTIFIC PUBLISHING HOUSE “BIG RUSSIAN ENCYCLOPEDIA” M. 1998. S. 1456.

5. RU 201114176 A, B21B 1/085. A method of manufacturing a rail. 04/27/2013.

6. Sakhnovsky M.M. Handbook of constructor of welded constructions. - Dnepropetrovsk: Promin, 1975, 238 p.

7. Nezhdanov K.K., Nezhdanov A.K., Kuzmishkin A.A. A method of guaranteeing a given endurance of a K-shaped weld in the under-rail zone of a wall of an I-beam crane beam. - M .: Structural mechanics and calculation of structures, No. 1, 2008

8. Nezhdanov K.K., Nezhdanov A.K. Calculation of moments of inertia of rails during torsion. - M.: Structural mechanics and calculation of structures, No. 3, 2008.

9. Nezhdanov K.K., Nezhdanov A.K., Garysin I.N. Extreme increase in moments of inertia of rails during torsion. - M.: Structural mechanics and calculation of structures, No. 6, 2011, p. thirty.

10. Nezhdanov K.K., Kuzmishkin A.A., Garysin I.N. The use of thick-walled I-beam crane rails. "Regional architecture and construction." - 2012. No3. - S.79 ... 84.

11. Metal structures: a textbook for students. higher training institutions [E.I. Belena, B.C. Ignatiev et al.]; under the editorship of Yu.I. Kudishin. - 9th ed. erased. - M.: Publishing Center "Academy", 2007. - 688 p.

12. Mityugov E.A. To the determination of the moments of inertia of crane rails. - M .: Structural mechanics and calculation of structures, No. 5, 1968

13. Pisarenko G.S., Yakovlev A.P., Matveev V.V. Handbook of resistance to materials. - Kiev: SCIENCE DUMKA, 1975, 704 p.

Claims (1)

A method of manufacturing a rail, including casting a rectangular cross-section of a workpiece by continuous casting from alloyed manganese steel grade 35GS with the following chemical composition, wt. %: carbon 0.3-0.37, manganese 0.8-1.2, silicon 0.6-0.9, chromium not more than 0.3%, nickel not more than 0.3%, copper not more than 0, 3%, sulfur no more than 0.045%, phosphorus no more than 0.04%, nitrogen no more than 0.012%, iron rest, cooling the cast billet to the temperature of a plastic state, transporting it progressively to the mill stand, maintaining the rolling temperature in the range of 950-1050 ° C, rolling with compression of a plastic billet on four sides by mill rolls with a total drawing ratio of at least 7.8 per rectangular rail, the ratio of the section height h to its width t in the torus is 2.7–2.8, with a symmetrical pair of lateral longitudinal ridges with a cross section of 15 × 15–20 × 20 mm at the bottom of the rail for fixed attachment to the upper belt of the crane beam, water cooling to a temperature of 535–580 ° C and cutting the rail to measured lengths.

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