Production method of heavy hot-rolled H-beam

Abstract

The present invention discloses a production method of heavy hot-rolled H-beam, comprising the steps of: S1, billet heating; S2, high-pressure water dephosphorization; S3, billet rolling; S4, universal rolling; a forming hole for forming a circular arc protrusion on the web of the rolled piece is formed in the pass of the BD rolling mill, the radius R1 of the circular arc protrusion formed on the web is 200-500mm, and the radius R2 of the arc transition on both sides of the circular arc protrusion is 100-200mm. The production method of heavy hot-rolled H-beam of the present invention, by adopting the H-H rolling method, controls the pass reduction rate, reduction amount, rolling speed, and rolling load, improves the product shape dimensional accuracy without changing the original rolling pass, rolling temperature, and product performance, and effectively solves the problem of under-processing of the outer side of the H-beam flange; the present invention has simple process, high production efficiency, stable performance, excellent appearance, high dimensional accuracy, and significant product quality improvement effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of hot-rolled H-shaped steel production, and more specifically, relates to a production method of thick and heavy hot-rolled H-shaped steel. Background Art

[0002] At present, the XH rolling method is widely used for rolling H-beams. The universal tandem rolling mill frame is arranged as follows: UR-E-UF, which consists of 1 universal roughing mill (UR), 1 edge rolling mill (E) and 1 universal finishing mill (UF). The three rolling mills are arranged in series and constitute the core unit for the entire H-beam production. When the XH rolling method is used to roll large H-shaped steel, the rolled piece is rolled by the slab mill and then universally rolled on the universal stand. Two rolling mills roll at the same time. The first rolling mill will use an X-hole design, and its horizontal roll side α' is designed to be about 5° and the vertical roll working surface β' is designed to have an inclination of about 6°, while the second rolling mill is designed to be an H-hole according to the final product; the rolled piece is rolled back and forth for multiple passes in the universal rolling mill group until it is finally formed; the XH rolling method can reduce at least one universal rolling mill and the number of universal rolling rollers compared to conventional processes when rolling large H-shaped steel. At the same time, it can increase the rolling temperature, achieve low power consumption and low roll consumption, and ensure a higher machine hour output. However, when rolling heavy hot-rolled H-shaped steel on site (when the flange thickness exceeds 50-140mm), the XH rolling method is used. Due to the limitations of the rolling mill strength and motor power, during the rolling process, the flange thickness of the billet needs to be rolled to less than 115mm in the X-hole rolling mill before the H rolling mill can be put into use, which reduces the rolling efficiency on site. Secondly, after the rolled piece passes through the X-hole rolling mill, when the H-hole rolling mill is put into use, the H-hole rolling mill cannot roll the X-shaped leg into an H-shaped one, resulting in the phenomenon that the outer leg end of the flange cannot be filled, resulting in quality problems. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a production method for thick hot-rolled H-shaped steel, the purpose of which is to prevent the thick hot-rolled H-shaped steel from being scrapped due to insufficient processing of the outer side of the flange during the production process, improve the product yield rate and qualified rate, and improve production efficiency.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a production method of heavy hot-rolled H-beam, comprising the steps of:

[0005] S1, billet heating;

[0006] S2, high pressure water dephosphorization;

[0007] S3, billet rolling;

[0008] S4, universal rolling;

[0009] The step S3 comprises:

[0010] Before the rolled piece enters the BD rolling mill, the pusher clamps the rolled piece;

[0011] The rolled piece bites into the rolling mill;

[0012] The BD rolling mill rolls the rolled product;

[0013] The stretcher is opened to a certain degree, which is 5 to 15 mm;

[0014] When the tail of the rolled piece is about to enter the BD rolling mill, the pusher clamps the rolled piece again;

[0015] After the tail of the rolled piece passes through the BD rolling mill, the pusher opens;

[0016] The hole profile of the BD rolling mill has a forming hole for forming an arc-shaped protrusion on the web of the rolled piece. The radius R1 of the arc-shaped protrusion formed on the web is 200-500 mm, and the radius R2 of the arc transition on both sides of the arc-shaped protrusion is 100-200 mm.

[0017] In the step S4, the intermediate billet is reciprocatingly rolled in a universal rolling mill unit, and the universal rolling mill unit is composed of a first H rolling mill, an E edge rolling mill and a second H rolling mill.

[0018] In step S4, the total number of rolling passes is 7-17 rolling passes.

[0019] The first H-type hole of the universal rolling mill unit is composed of a first upper horizontal roll, a first lower horizontal roll, a first left vertical roll and a first right vertical roll. The inclination angle α of the side of the first upper horizontal roll and the first lower horizontal roll is 90 to 90.5°, and the inclination angle β of the working surface of the first left vertical roll and the first right vertical roll is 90 to 90.5°.

[0020] The first upper horizontal roller and the first lower horizontal roller are driving rollers, and the first left vertical roller and the first right vertical roller are driven rollers.

[0021] The second H-type hole of the universal rolling mill unit is composed of a second upper horizontal roll, a second lower horizontal roll, a second left vertical roll and a second right vertical roll. The inclination angle α of the side of the second upper horizontal roll and the second lower horizontal roll is 90-90.25°, and the inclination angle β of the working surface of the second left vertical roll and the second right vertical roll is 90°.

[0022] The second upper horizontal roller and the second lower horizontal roller are driving rollers, and the second left vertical roller and the second right vertical roller are driven rollers.

[0023] In step S4, when T f1 =T w1 *T f0 / T w0 *K n (Where: Tf1 T is the flange thickness value of the second H-type rolling; w1 is the web thickness value of the second H-type rolling, which is a given value based on experience; T f0 is the finished flange thickness, known; T w0 is the finished web thickness value, known; K is the matching coefficient, 1.002~1.028; n is the rolling pass)

[0024] In the first three passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 30-35%, the total flange reduction rate η 翼缘 It is 35-40%. According to the H-beam specifications, the second H-hole profile begins to participate in rolling.

[0025] In the 4th to 7th passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 30-40%, the total flange reduction rate η 翼缘 It is 35-45%. According to the H-beam specifications, the second H-hole profile begins to participate in rolling.

[0026] In the 8th to 17th passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 25-40%, total flange reduction rate η 翼缘 The pass reduction rate of the flange is 25-45%. 翼缘 Satisfy: η 腹板 +γ=η 翼缘 , γ=0~5%.

[0027] In step S4, the rolling speed of the universal rolling mill is 2-8 m / s.

[0028] The production method of thick hot-rolled H-shaped steel of the present invention adopts the HH rolling method to control the pass reduction rate, reduction amount, rolling speed and rolling load. On the basis of not changing the original rolling passes, rolling temperature and product performance, the product shape and size accuracy is improved, and the problem of under-processing of the outer side of the H-shaped steel flange is effectively solved. The present invention has simple process, high production efficiency, stable performance, excellent appearance, high dimensional accuracy and remarkable product quality improvement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] This specification includes the following drawings, which show the following contents:

[0030] Figure 1 It is the HH pass rolling flow chart;

[0031] Figure 2 It is a schematic diagram of the hole structure of the BD rolling mill;

[0032] Figure 3 It is a schematic diagram of the structure of the H hole type. DETAILED DESCRIPTION

[0033] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0034] like Figure 1 As shown, the present invention provides a production method for thick hot-rolled H-beam, which converts the XH rolling method into the HH rolling method. The method can reduce the number of rolling passes. At the same time, the flange of the H-beam has no inclination. During the rolling process, the vertical roller of the universal rolling mill can directly process the outer side surface of the flange of the H-beam. The process is simple to implement, the production efficiency is high, the performance is stable, the appearance is excellent, and the dimensional accuracy is high.

[0035] Specifically, the production method of the thick and heavy hot-rolled H-beam of the present invention comprises the following steps:

[0036] S1, billet heating;

[0037] S2, high pressure water dephosphorization;

[0038] S3, billet rolling;

[0039] S4, universal rolling.

[0040] In the above step S1, the billet is heated by using a heating furnace. In the above step S2, the billet is rolled by the BD1 rolling mill and the BD2 rolling mill to form an intermediate billet.

[0041] Step S3 includes: before the workpiece enters the BD rolling mill, the push bed clamps the workpiece; the workpiece bites into the rolling mill; the BD rolling mill rolls the workpiece; the push bed opens a certain opening degree, which is 5 to 15 mm, to facilitate the workpiece to bite into the rolling mill; when the tail of the workpiece is about to enter the BD rolling mill, the push bed clamps the workpiece again; after the tail of the workpiece passes through the BD rolling mill, the push bed opens.

[0042] like Figure 2As shown, in the above step S3, a forming hole for forming an arc-shaped protrusion on the web of the rolled piece is formed in the pass of the BD rolling mill, and accordingly, an arc-shaped groove is formed on the surface of the roller, the radius R1 of the arc-shaped protrusion formed on the web is 200-500 mm, the radius R2 of the arc transition on both sides of the arc-shaped protrusion is 100-200 mm, the arc-shaped protrusion is located in the middle position in the width direction of the web of the rolled piece, and the two opposite outer surfaces in the thickness direction of the web of the rolled piece are formed with arc-shaped protrusions, and the two arc-shaped protrusions extend toward the upper and lower sides of the web of the rolled piece respectively. In the width direction of the web of the rolled piece, the parts located on the opposite sides of the arc-shaped protrusion are rectangular flat plates parallel to the axis of the arc-shaped protrusion, and the arc-shaped protrusion and the rectangular flat plate are connected by an arc transition, and the radius of the arc angle at the arc transition connection part is R2. Therefore, in order to meet the subsequent universal rolling, the hole type of the BD rolling mill must meet the above requirements, in order to cooperate with the subsequent flange reduction, so as to control the reduction of the web of the billet in the rough rolling section and better match the flange extension in the universal section.

[0043] In the above step S4, the intermediate billet is reciprocatingly rolled in the universal rolling mill unit, which is composed of a first H rolling mill, an E edge rolling mill and a second H rolling mill, and the intermediate billet is rolled by the first H rolling mill, the E edge rolling mill and the second H rolling mill. The total rolling passes are 7-17 rolling passes, and the reduction amount of each pass is determined according to the specifications of the finished H-beam and the billet shape.

[0044] like Figure 1As shown, in the above step S4, when the intermediate billet is rolled by the first H rolling mill, the first H hole type of the universal rolling mill unit is composed of the first upper horizontal roller, the first lower horizontal roller, the first left vertical roller and the first right vertical roller, the inclination angle α of the side of the first upper horizontal roller and the first lower horizontal roller is 90-90.5°, and the inclination angle β of the working surface of the first left vertical roller and the first right vertical roller is 90-90.5°. The first upper horizontal roller and the first lower horizontal roller are driving rollers, and the first left vertical roller and the first right vertical roller are driven rollers. The first upper horizontal roller is located above the first lower horizontal roller, the first left vertical roller and the first right vertical roller are horizontally arranged, the first left vertical roller and the first right vertical roller are vertically arranged and arranged oppositely, and the intermediate billet is located between the first left vertical roller and the first right vertical roller and between the first upper horizontal roller and the first lower horizontal roller. The inclination angle α of the side of the first upper horizontal roller and the first lower horizontal roller refers to the angle between the side of the first upper horizontal roller and the first lower horizontal roller and the horizontal plane, and the side of the first upper horizontal roller and the side of the first lower horizontal roller are in contact with the flange of the intermediate billet. The inclination angle β of the working surface of the first left vertical roller and the first right vertical roller refers to the angle between the working surface of the first left vertical roller and the first right vertical roller and the horizontal plane, and the working surface of the first left vertical roller and the working surface of the first right vertical roller are in contact with the two flanges of the intermediate billet respectively, and the first upper horizontal roller and the first lower horizontal roller perform rolling compression on the web in the thickness direction, and the first left vertical roller and the first right vertical roller perform rolling compression on the two side flanges in the thickness direction respectively.

[0045] like Figure 1As shown, in the above step S4, when the intermediate billet is rolled by the second H rolling mill, the second H hole type of the universal rolling mill unit is composed of the second upper horizontal roller, the second lower horizontal roller, the second left vertical roller and the second right vertical roller, the second H hole type is a finished hole, the inclination angle α of the side of the second upper horizontal roller and the second lower horizontal roller is 90-90.25°, the inclination angle β of the working surface of the second left vertical roller and the second right vertical roller is 90°, wherein the r angle of the universal horizontal roller is determined according to the r size of the finished H-shaped steel, and the roll width CW of the universal horizontal roller is the inner width value of the finished H-shaped steel. The second upper horizontal roller and the second lower horizontal roller are driving rollers, and the second left vertical roller and the second right vertical roller are driven rollers. The second upper horizontal roller is located above the second lower horizontal roller, the second left vertical roller and the second right vertical roller are horizontally arranged, the second left vertical roller and the second right vertical roller are vertically arranged and arranged relative to each other, and the intermediate billet is located between the second left vertical roller and the second right vertical roller and between the second upper horizontal roller and the second lower horizontal roller. The inclination angle α of the side of the second upper horizontal roller and the second lower horizontal roller refers to the angle between the side of the second upper horizontal roller and the second lower horizontal roller and the horizontal plane, and the side of the second upper horizontal roller and the side of the second lower horizontal roller are in contact with the flange of the intermediate billet. The inclination angle β of the working surface of the second left vertical roller and the second right vertical roller refers to the angle between the working surface of the second left vertical roller and the second right vertical roller and the horizontal plane, and the working surface of the second left vertical roller and the working surface of the second right vertical roller are in contact with the two flanges of the intermediate billet respectively, and the second upper horizontal roller and the second lower horizontal roller perform rolling compression on the web in the thickness direction, and the second left vertical roller and the second right vertical roller perform rolling compression on the flanges on both sides in the thickness direction respectively.

[0046] Preferably, the rolling loads of the first upper horizontal roller and the first lower horizontal roller are 0 to 5000 KN, the rolling load of the E edge rolling mill is 0 to 3000 KN, and the rolling loads of the second upper horizontal roller and the second lower horizontal roller are 0 to 5000 KN.

[0047] In the above step S4, when T f1 =T w1 *T f0 / T w0 *K n (Where: T f1 T is the flange thickness value of the second H-type rolling; w1 is the web thickness value of the second H-type rolling, which is a given value based on experience; T f0 is the finished flange thickness, known; T w0 is the finished web thickness value, which is known; K is the matching coefficient, 1.002~1.028; n is the number of rolling passes).

[0048] In the above step S4, the total number of rolling passes is 7-17. In the first three passes, the total pass reduction rate η of the web of the heavy hot-rolled H-beam is 腹板 30-35%, the total flange reduction rate η翼缘 The second H-pass begins to participate in rolling according to the H-beam specifications. In the 4th to 7th passes, the total pass reduction rate η of the web of the heavy hot-rolled H-beam 腹板 30-40%, the total flange reduction rate η 翼缘 The second H-pass begins to participate in rolling according to the H-beam specifications. In the 8th to 17th passes, the total pass reduction rate η of the web of the heavy hot-rolled H-beam 腹板 25-40%, total flange reduction rate η 翼缘 The pass reduction rate of the flange is 25-45%. 翼缘 Satisfy: η 腹板 +γ=η 翼缘 , γ=0~5%.

[0049] In the above step S4, the rolling speed of the universal rolling mill is 2-8 m / s. The rolling speed is adjusted according to different rolling specifications to meet the requirements of the rolling process on the final rolling temperature.

[0050] In the above step S4, the second H-type hole can be used for rolling in any target pass according to the surface quality, rolling pressure, etc. during the rolling process.

[0051] Example 1

[0052] Rolling UC356*406*634 specification hot-rolled H-shaped steel, the finished flange thickness is 77mm, the rolling process adopts 9 reciprocating rolling, on the basis of the traditional production process, after the universal hole type X hole type is changed to H hole type, by redistributing the pressing procedure, the second H hole type is advanced to the fourth pass to participate in the rolling pass, so that it participates in the rolling when the billet thickness is 118mm, wherein the first H hole type horizontal roller side inclination angle α is 90.5°, the vertical roller working surface inclination angle β is 90.5°, the second H hole type horizontal roller side inclination angle α is 90.25°, the vertical roller working surface inclination angle β is 0°, and the rolling speed is 5m / s. The rolling speed and pressing procedure allocation of the present invention can be adjusted by the secondary computer. Compared with the traditional process, the pressing amount, pressing rate and rolling load of the rolling pass are all reduced compared with the traditional process. The product's appearance and quality are significantly improved, and the problem of under-processing of the outer side of the H-shaped flange is basically eliminated. Moreover, the mechanical properties of the product have been improved, with the yield strength increased by an average of 5MPa and the impact performance increased by an average of 15J.

[0053] Example 2

[0054] Rolling UC356*406*990, W14*665 specification hot-rolled H-shaped steel, the finished flange thickness is 115mm, the rolling process adopts 7-pass reciprocating rolling, on the basis of the traditional production process, the universal hole type X hole type is changed to H hole type, by redistributing the pressing schedule, the rolling process adopts 4 passes, the second H hole type participating in the rolling pass is advanced to the second pass, so that it participates in rolling when the billet thickness is 174.6mm, wherein the first H hole type horizontal roller side inclination is 90.25°, the vertical roller working surface inclination is 90.5°, the second H hole type horizontal roller side inclination α is 90.25°, the vertical roller working surface inclination β is 0°, and the rolling speed is 5m / s. The rolling speed and pressing schedule allocation of the present invention can be adjusted by a secondary computer, and compared with the traditional process, the pressing amount, pressing rate and rolling load of the rolling pass are all reduced compared with the traditional process. The product's overall dimensions and quality have been significantly improved, and the problem of under-processing on the outer side of the H-shaped flange has been basically eliminated. In addition, the product's mechanical properties have been improved, with the yield strength increased by an average of 10MPa and the impact performance increased by an average of 25J.

[0055] Example 3

[0056] Rolling W14*873 specification hot-rolled H-shaped steel, the finished flange thickness is 140mm, the rolling process adopts 7 reciprocating rolling, on the basis of the traditional production process, the universal hole type X hole type is changed to H hole type, by redistributing the pressing procedure, the rolling process adopts 4 passes, the second H hole type is advanced to the second pass, so that it participates in rolling when the billet thickness is 182mm, wherein the first H hole type horizontal roller side inclination angle α is 90.25°, the vertical roller working surface inclination angle β is 90.25°, the second H hole type horizontal roller side inclination angle α is 90.25°, the vertical roller working surface inclination angle β is 0°, and the rolling speed is 5m / s. The rolling speed and pressing procedure allocation of the present invention can be adjusted by the secondary computer. Compared with the traditional process, the pressing amount, pressing rate and rolling load of the rolling pass are all reduced compared with the traditional process. The product's appearance and quality are significantly improved, and the problem of under-processing of the outer side of the H-shaped flange is basically eliminated. Moreover, the mechanical properties of the product have been improved, with the yield strength increased by an average of 15MPa and the impact performance increased by an average of 20J.

[0057] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for producing heavy hot-rolled H-shaped steel, comprising the steps of: S1, billet heating; S2, high pressure water dephosphorization; S3, billet rolling; S4, universal rolling; Characterized in that, step S3 comprises: Before the rolled piece enters the BD rolling mill, the pusher clamps the rolled piece; The rolled piece bites into the rolling mill; The BD rolling mill rolls the rolled product; The stretcher is opened to a certain degree, which is 5 to 15 mm; When the tail of the rolled piece is about to enter the BD rolling mill, the pusher clamps the rolled piece again; After the tail of the rolled piece passes through the BD rolling mill, the pusher opens; The pass of the BD rolling mill is formed with a forming hole for forming an arc-shaped protrusion on the web of the rolled piece. The radius R1 of the arc-shaped protrusion formed on the web is 200 to 500 mm, and the radius R2 of the arc transition on both sides of the arc-shaped protrusion is 100 to 200 mm. In the step S4, the intermediate billet is reciprocatingly rolled in a universal rolling mill unit, and the universal rolling mill unit is composed of a first H rolling mill, an E edge rolling mill, and a second H rolling mill; According to the H-beam specifications, the second H-pass begins to participate in rolling in the first 3 passes or the 4th to 7th passes; In the first three passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 30-35%, the total flange reduction rate η 翼缘 35-40%; In the 4th to 7th passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 30-40%, the total flange reduction rate η 翼缘 35-45%; In the 8th to 17th passes, the total pass reduction ratio η of the web of the heavy hot-rolled H-beam 腹板 25-40%, total flange reduction rate η 翼缘 The pass reduction rate of the flange is 25-45%. 翼缘 Satisfy: η 腹板 +γ=η 翼缘 , γ=0~5%.

2. The method for producing thick and heavy hot-rolled H-beam according to claim 1, characterized in that: The first H-type hole of the universal rolling mill unit is composed of a first upper horizontal roll, a first lower horizontal roll, a first left vertical roll and a first right vertical roll. The inclination angle α of the side of the first upper horizontal roll and the first lower horizontal roll is 90 to 90.5°, and the inclination angle β of the working surface of the first left vertical roll and the first right vertical roll is 90 to 90.5°.

3. The method for producing thick and heavy hot-rolled H-beam according to claim 2, characterized in that: The first upper horizontal roller and the first lower horizontal roller are driving rollers, and the first left vertical roller and the first right vertical roller are driven rollers.

4. The method for producing thick and heavy hot-rolled H-beam according to any one of claims 1 to 3, characterized in that: In step S4, when T f1 =T w1 *T f0 / T w0 *K n ; Where: T f1 T is the flange thickness value of the second H-type rolling; w1 is the web thickness value of the second H-type rolling, which is a given value based on experience; T f0 is the finished flange thickness; T w0 is the finished web thickness; K is the matching coefficient; n is the number of rolling passes.

5. The method for producing thick and heavy hot-rolled H-beam according to any one of claims 1 to 3, characterized in that: The second H-type hole of the universal rolling mill unit is composed of a second upper horizontal roll, a second lower horizontal roll, a second left vertical roll and a second right vertical roll. The inclination angle α of the side of the second upper horizontal roll and the second lower horizontal roll is 90-90.25°, and the inclination angle β of the working surface of the second left vertical roll and the second right vertical roll is 90°.

6. The method for producing thick and heavy hot-rolled H-beam according to claim 5, characterized in that: The second upper horizontal roller and the second lower horizontal roller are driving rollers, and the second left vertical roller and the second right vertical roller are driven rollers.

7. The method for producing thick and heavy hot-rolled H-beam according to any one of claims 1 to 3, characterized in that: In step S4, the rolling speed of the universal rolling mill is 2-8 m / s.

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