阅读说明：本技术 提升Assel轧机轧制钢管表面质量的轧辊辊型 (Roll profile for improving surface quality of rolled steel pipe of Assel rolling mill ) 是由 夏斌 杨跃强 胡瑜 谢鲲鹏 李冬华 贺慧 于 2021-08-16 设计创作，主要内容包括：本发明提供一种提升Assel轧机轧制钢管表面质量的轧辊辊型,涉及钢材加工技术领域,从所述轧辊的入口侧到出口侧依次设有入口锥区、渐变区和辗轧区；所述渐变区包含第一过渡圆弧和第二过渡圆弧,所述第一过渡圆弧与所述入口锥区相切,所述第二过渡圆弧与所述辗轧区相切,本发明能够使轧辊生产的钢管的内螺纹深度≤0.2mm；同时钢管的内外表面缺陷减少约8％；轧制变形抗力也得到降低,轧制电流降低约12％。(The invention provides a roller profile for improving the surface quality of a rolled steel pipe by an Assel rolling mill, which relates to the technical field of steel processing.A tapered inlet area, a gradual change area and a rolling area are sequentially arranged from the inlet side to the outlet side of a roller; the gradual change area comprises a first transition arc and a second transition arc, the first transition arc is tangent to the inlet cone area, and the second transition arc is tangent to the rolling area, so that the depth of the internal thread of the steel pipe produced by the roller is less than or equal to 0.2 mm; meanwhile, the defects of the inner surface and the outer surface of the steel pipe are reduced by about 8 percent; the rolling deformation resistance is also reduced, and the rolling current is reduced by about 12 percent.)

1. A roll profile for improving the surface quality of a rolled steel pipe of an Assel rolling mill is characterized in that an inlet cone area, a gradual change area and a rolling area are sequentially arranged from the inlet side to the outlet side of the roll;

the gradual change area comprises a first transition arc and a second transition arc, the first transition arc is tangent with the inlet cone area, and the second transition arc is tangent with the rolling area.

2. A roller profile for improving the surface quality of rolled steel pipe in an Assel rolling mill as claimed in claim 1, wherein said entry cone comprises a first entry sector and a second entry sector, said second entry sector being connected to said first transition arc;

the outer surface of the first inlet partition forms an included angle alpha with the axis of the roller₁The surface of the second inlet partition forms an included angle alpha with the axis of the roller₂Wherein α is₂Greater than alpha₁And α is₁And alpha₂The difference is 1-2 deg.

3. A roll profile for improving the surface quality of rolled steel pipe in an Assel mill as claimed in claim 1, wherein the diameter D of the first transition arc₁Is 200mm-500mm, the diameter D of the second transition arc₂Is 200mm-500mm, the diameter D of the first transition arc₁Diameter D of the second transition arc₂Are equal in length.

4. A roll profile for improving the surface quality of rolled steel pipes in an Assel mill according to claim 1, characterized in that the surface of the rolling area forms an angle α with the roll axis₃Is 3-5 degrees.

5. The roll profile for improving the surface quality of a rolled steel pipe of an Assel rolling mill as claimed in claim 1, wherein an outlet conical area and an outlet conical area are sequentially included between the rolling area and the outlet side of the roll.

6. A roll profile for improving the surface quality of rolled steel pipe in an Assel mill as claimed in claim 2, wherein α is₁The angle of the angle is 6-7 degrees.

7. A roll profile for improving the surface quality of rolled steel pipes in an Assel mill according to claim 1, wherein the center of the second transition arc is located on the straight line L₅Wherein the straight line L₅Is a straight line L₆The degree of the included angle between the straight lines is 4 degrees, and the straight line L₆Is a straight line perpendicular to the axis of the roll at 20:27 in the length direction of the roll;

L₅and L₆The intersection point of (a) is located at the outer surface of the roll;

compared with L₅，L₆Closer to the exit side of the roll.

8. A mill roll profile for improving the surface quality of rolled steel pipe in an Assel mill as claimed in claim 2, wherein the first inlet partition has a length L along the axis of the mill roll₁，L₁Is 14 to 20 percent of the total length of the roller.

9. A roll profile for improving the surface quality of rolled steel pipes by an Assel rolling mill according to claim 1, characterized in that the length of the rolling area along the axial direction of the roll is L₃，L₃Is 12-18% of the total length of the roller.

10. A roll profile for improving the quality of rolled steel pipe in an Assel rolling mill as claimed in claim 9, wherein the surface of the rolling area is at an angle of 4 ° to the axis of the roll.

Technical Field

The invention relates to the technical field of steel processing, in particular to a roller profile for improving the surface quality of a rolled steel pipe of an Assel rolling mill.

Background

At present, internal threads of steel pipes produced by an Assel rolling mill are obvious, the use requirements of high-precision steel pipes (such as cold-drawing oil cylinder master batch) cannot be met, and the attractiveness is influenced; meanwhile, the instantaneous rolling deformation is large, and the inner and outer surfaces are easy to crack and the like, so that the use and experience of a user are seriously influenced; and the rolling deformation resistance is large, and the requirement on the equipment capacity is high.

The traditional Assel pipe rolling mill rolls steel pipes by adopting rollers with inlet cone areas, shoulder areas, rolling areas and other areas, wherein the shoulder areas of the rollers are usually two arcs with smaller diameters (the diameter of the arc is less than or equal to 40mm), and the height change is quicker. In the process of rolling the steel pipe by the roller, the instantaneous deformation rate of the steel is high and the rolling of the material is insufficient under the influence of the height change of the step. The produced steel pipe has obvious internal threads (the depth is 0.4-0.8 mm), and cracks are easily generated on the inner surface and the outer surface; the rolling deformation resistance is large, and the rolling current is large and relatively high.

Disclosure of Invention

The invention aims to provide a roller profile for improving the surface quality of a steel pipe rolled by an Assel rolling mill, and defects of the inner surface and the outer surface of the rolled steel pipe are reduced.

In order to achieve the above purpose, the invention provides the following technical scheme: a roll profile for improving the surface quality of a steel pipe rolled by an Assel rolling mill is characterized in that an inlet cone area, a gradual change area and a rolling area are sequentially arranged from the inlet side to the outlet side of the roll; the gradual change area comprises a first transition arc and a second transition arc, the first transition arc is tangent with the inlet cone area, and the second transition arc is tangent with the rolling area.

Further, in the roll profile for improving the surface quality of the rolled steel pipe of the Assel rolling mill, the inlet cone zone comprises a first inlet subarea and a second inlet subarea, and the second inlet subarea is connected with the first transition circular arc; the outer surface of the first inlet partition forms an included angle alpha with the axis of the roller₁The surface of the second inlet partition forms an included angle alpha with the axis of the roller₂Wherein α is₂Greater than alpha₁And α is₁And alpha₂The difference is 1-2 deg.

Further, in the roll profile for improving the surface quality of the rolled steel pipe of the Assel rolling mill, the diameter D of the first transition arc₁Is 200mm-500mm, the diameter D of the second transition arc₂Is 200mm-500mm, the diameter D of the first transition arc₁Diameter D of the second transition arc₂Are equal in length.

Further, in the roller shape for improving the surface quality of the rolled steel pipe by the Assel rolling mill, the included angle alpha between the surface of the rolling area and the axis of the roller is₃Is 3-5 degrees.

Further, in the roll profile of the roll for improving the surface quality of the rolled steel pipe by the Assel rolling mill, an outlet circular cone area and an outlet cone area are sequentially arranged between the rolling area and the outlet side of the roll.

Further, in the above roll profile for improving the surface quality of rolled steel pipe by the Assel rolling mill, α₁The angle of the angle is 6-7 degrees.

Further, in the roll profile for improving the surface quality of the rolled steel pipe of the Assel rolling mill, the center of the second transition arc is positioned on the straight line L₅Wherein the straight line L₅Is a straight line L₆The degree of the included angle between the straight lines is 4 degrees, and the straight line L₆Is a straight line perpendicular to the axis of the roll at 20:27 in the length direction of the roll; l is₅And L₆The intersection point of (a) is located at the outer surface of the roll; compared with L₅，L₆Closer to the exit side of the roll.

Further, in the above roll profile for improving the surface quality of rolled steel pipe by the Assel rolling mill, the length of the first inlet partition in the axial direction of the roll is L₁，L₁Is 14 to 20 percent of the total length of the roller.

Further, in the roll profile of the roll for improving the surface quality of the rolled steel pipe by the Assel rolling mill, the length of the rolling area along the axial direction of the roll is L₃，L₃Is 12-18% of the total length of the roller.

Further, in the roll profile of the roll for improving the surface quality of the rolled steel pipe by the Assel rolling mill, the included angle between the surface of the rolling area and the axis of the roll is 4 degrees.

The analysis shows that the invention discloses a roller profile for improving the surface quality of a steel pipe rolled by an Assel rolling mill, and the depth of the internal thread of the steel pipe produced by the roller is less than or equal to 0.2 mm; meanwhile, the defects of the inner surface and the outer surface of the steel pipe are reduced by about 8 percent; the rolling deformation resistance is also reduced, and the rolling current is reduced by about 12 percent.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. Wherein:

FIG. 1 is a schematic cross-sectional view of a roll structure according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings. The various examples are provided by way of explanation of the invention, and not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. It is therefore intended that the present invention encompass such modifications and variations as fall within the scope of the appended claims and equivalents thereof.

In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are for convenience of description of the present invention only and do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. The terms "connected," "connected," and "disposed" as used herein are intended to be broadly construed, and may include, for example, fixed and removable connections; can be directly connected or indirectly connected through intermediate components; the connection may be a wired electrical connection, a wireless electrical connection, or a wireless communication signal connection, and a person skilled in the art can understand the specific meaning of the above terms according to specific situations.

One or more examples of the invention are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. As used herein, the terms "first," "second," "third," and "fourth," etc. may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of an individual component.

As shown in fig. 1, according to an embodiment of the present invention, there is provided a roll profile for improving the surface quality of a steel pipe rolled by an Assel rolling mill, which is provided with an entrance cone region, a gradual change region and a rolling region in order from an entrance side to an exit side of the roll; the gradual change area comprises a first transition circular arc and a second transition circular arc, the first transition circular arc is tangent with the inlet cone area, the second transition circular arc is tangent with the rolling area, in the figure 1, the inlet cone area is a part marked with 'A' in the figure, the gradual change area is a part marked with 'B' in the figure, and the rolling area is a part marked with 'C' in the figure.

Preferably, the inlet cone comprises a first inlet partition and a second inlet partition, the second inlet partition being connected to the first transition arc; the outer surface of the first inlet partition forms an included angle alpha with the axis of the roller₁The surface of the second inlet partition forms an angle alpha with the axis of the roll₂Wherein α is₂Greater than alpha₁And α is₁And alpha₂The difference value of the first transition arc and the second transition arc is 1-2 degrees, the length of the second inlet subarea in the axial direction of the extension roll is not fixed, and the second inlet subarea only needs to be tangent to the first transition arc, and the length of the second inlet subarea is determined by the radian of the first transition arc.

Preferably, the diameter D of the first transition arc₁200mm-500mm, e.g. 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, diameter D of the second transition arc₂From 200mm to 500mm, for example 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, with the above mentioned dimensions, an arc is obtained which gives steel pipes with the surface quality described in the present invention, below which dimensions it tends to conventional roll profiles, which produce steel pipes with significant internal threads and whose internal and external surfaces are prone to cracking, and above which dimensions it is detrimental to the roll profile. Diameter D of the first transition arc₁Diameter D of second transition arc₂Are equal in length.

Preferably, the surface of the rolling area forms an angle α with the roll axis₃The angle is 3 degrees to 5 degrees, such as 3.0 degrees, 3.5 degrees, 4.0 degrees, 4.5 degrees and 5.0 degrees, the angle range is designed by matching with a rolling mill, and a rolling line is parallel to the central line of the steel pipe after the 4-degree roller is installed; the +/-1 degree is the optimal adjusting interval.

Preferably, an outlet conical cone area and an outlet conical cone area are further sequentially included between the rolling area and the outlet side of the roll, in fig. 1, the outlet conical cone area is a part marked with "D" in the drawing, and the outlet conical cone area is a part marked with "E" in the drawing.

Preferably, alpha₁The angle of the steel tube is 6 degrees to 7 degrees, such as 6.0 degrees, 6.5 degrees and 7.0 degrees, the angle range is convenient for the steel tube to be bitten, the steel tube is difficult to be bitten due to undersize, the instantaneous deformation of the steel tube is large due to oversize, and the surface quality of the steel tube and the rolling current are adversely affected.

Preferably, the center of the second transition arc is located on the straight line L₅Wherein, the straight line L₅Is a straight line L₆The degree of the included angle between the straight lines is 4 degrees, and the straight line L₆20 in the length direction of the roll: 27, the line L perpendicular to the axis of the roll, i.e. where the "200" and "270" parts of figure 1 are joined₆A fixed line as the center of the second transition arc, L₅And L₆The intersection point of the two is positioned at the outer surface of the roller; compared with L₅，L₆Closer to the exit side of the roll.

Preferably, the first inlet partition has a length L in the axial direction of the roll₁The length of the second inlet partition in the axial direction of the roll is L₂Outlet coneThe length of the zone in the direction of the axis of the roll being L₄，L₁The range of 14% -20%, for example 14%, 14.5%, 15.0%, 15.5%, 16.0%, 16.5%, 17.0%, 17.5%, 18.0%, 18.5%, 19.0%, 19.5%, 20.0%, 14% -20% of the total length of the rolls ensures that there is a sufficient reduction interval after the tube is bitten so that the tube reaches the desired size during rolling. If the length of the segment is short, the angle is increased to ensure the biting to generate the angle problem; if the length is longer, the rolling time of the part is longer, the temperature of the steel is lower, and other adverse effects are caused by the invasion of other areas.

Preferably, the rolling area has a length L in the axial direction of the roll₃，L₃The total length of the rolls is 12% -18%, for example, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, 15.0%, 15.5%, 16.0%, 16.5%, 17.0%, 17.5%, 18.0%, and the range of 12% -18% is selected to ensure that the steel tube can be rolled sufficiently, and can not be rolled sufficiently when the length is too short, and can not be expanded sufficiently after being rolled excessively, and even can occupy other areas to cause other adverse effects.

Preferably, the surface of the rolling area is at an angle of 4 ° to the axis of the roll.

Example 1

In this embodiment, L₁19.04% of the roll length, alpha₁Is 6.5 DEG, alpha₂Has an angle of 8 ° (6.5 ° +1.5 °) and a diameter D₁And diameter D₂All have a length of 200mm, L₃When the roll length is 12.73%, the quality of the inner and outer surfaces of the 168 × 16 specification 20# steel pipe is obviously improved when the roll is adopted to roll the steel pipe, and the specific application is shown in table 1:

TABLE 120 # Steel Rolling Effect table

Contrast item	The invention	Conventional roll form
			Depth of internal thread	0.1～0.25mm	0.4～0.6mm
Internal and external surface defects	4.73％	12.65％
			Rolling current	4192A	4268A

Example 2

In this embodiment, L₁19.04% of the roll length, alpha₁Is 6.0 DEG, alpha₂Is at an angle of 7.5 ° (6.0 ° +1.5 °), diameter D₁And diameter D₂Are all 400mm in length, L₃When 165 x 12 specification C45E + N steel pipe (C45E steel pipe has more strict contents of phosphorus and sulfur than C45, and + N indicates that the material delivery state is normalized) is rolled by the present invention at 14.14% of the roll length, the quality of the inner and outer surfaces of the steel pipe is significantly improved, as shown in table 2:

TABLE 2C 45E + N Steel Rolling Effect table

Contrast item	The invention	Conventional roll form
			Depth of internal thread	0.1～0.2mm	0.4～0.6mm
Internal and external surface defects	5.68％	13.32％
			Rolling current	4385A	4982A

According to the minimum resistance law, when the metal is subjected to plastic deformation under the action of external force, all mass points in the metal always flow along the direction with the minimum resistance; meanwhile, the curvature or the straight line angle of each area of the roller shape is optimized, the instantaneous flow rate of metal is slowed down, and the metal is fully flowed, so that the aim of improving the quality of the inner surface and the outer surface of the steel pipe is fulfilled, and the depth of the internal thread of the steel pipe produced by the roller is less than or equal to 0.2 mm; meanwhile, the defects of the inner surface and the outer surface of the steel pipe are reduced by about 8 percent; the rolling deformation resistance is also reduced, and the rolling current is reduced by about 12 percent.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.