Continuous rolling pass system for rolling square billet into round bar
By improving the groove bottom design of the continuous rolling mill system and increasing the reduction in the central area, the problem of workpiece torsion caused by material fluctuations and stand jumps during the rolling of square billets into round bars was solved, thereby improving the stability of the rolling process and the quality of the finished product.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DAYE SPECIAL STEEL CO LTD
- Filing Date
- 2025-04-24
- Publication Date
- 2026-05-12
AI Technical Summary
During the rolling of square steel billets into round bars, fluctuations in the incoming material dimensions and the jumping of the rolling mill stand cause the rolled piece to twist, resulting in a "tail-down" phenomenon, which causes folding defects and affects production stability and safety.
A continuous rolling pass system is adopted, which includes 6 passes. The bottom of the square passes in the 3rd and 4th stands is changed to a raised arc shape to increase the reduction in the central area, provide lateral restraint force, and prevent the rolled piece from twisting.
It effectively prevents the rolled material from twisting during the rolling process, improves rolling stability, avoids the "tail-down" phenomenon, and ensures the quality of the finished bar product.
Smart Images
Figure CN224222327U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of steel rolling technology, and in particular to a continuous rolling pass system for rolling square billets into round bars. Background Technology
[0002] Square billets are a common raw material for rolling round bars. To obtain the desired bars, the billet cross-section must first undergo sequential rolling deformation, changing from square to elliptical to circular. This stage is commonly referred to as the roughing stage in continuous rolling mills. During the roughing stage, after the cross-section of the rolled piece changes from square to circular, its center of gravity stability is poor during roll table operation. As rolling progresses, the proportion of circular rolled pieces increases, further increasing the instability of the center of gravity. If the billet dimensions are unstable or the mill runout is excessive, the roll pass cannot constrain the rolled piece, causing it to twist during the rolling process. This results in the steel material being squeezed into the roll gap, and the extruded material forms folding defects after the next rolling pass. This process usually occurs at the tail of the rolled piece, commonly known as the "tail-end" phenomenon, which often occurs in the first two passes of elliptical roll passes.
[0003] Folding is a serious rolling defect (such as...) Figure 1 As shown, folded bars often have to be downsized or scrapped, causing significant economic losses to manufacturers. Furthermore, "tail-end" defects are affected by fluctuations in the dimensions of the incoming billet, exhibiting randomness and poor preventability. If missed during detection, they can lead to serious quality problems, causing not only economic losses and damaging the manufacturer's brand image but also posing safety hazards. Therefore, improving rolling stability and preventing "tail-end" defects are particularly important in the steel rolling industry. Utility Model Content
[0004] The purpose of this invention is to provide a continuous rolling pass system for rolling square billets into round bars. By using this pass system to roll square billets into round bars, the rolling process can be prevented from being twisted due to factors such as fluctuations in incoming material dimensions and mill stand jump, thereby improving rolling stability.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A continuous rolling pass system for rolling square billets into round bars includes six passes: four square passes, one elliptical pass, and one round pass. The bottom of the groove of the third square pass is an arc, and the bottom of the groove of the fourth square pass is an arc.
[0007] Furthermore, in the continuous rolling mill system for rolling square billets into round bars, the bottom radius of the square groove of the third stand is 1005 mm and the depth is 4 mm.
[0008] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the bottom radius of the fourth square rolling mill is 620 mm and the depth is 4 mm.
[0009] Furthermore, in the above-mentioned continuous rolling mill system for rolling square billets into round bars, the square billet is a 240 square billet, and the round bar is a 135 round bar.
[0010] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the center of the groove bottom of the third square roll is outside the roll.
[0011] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the center of the groove bottom of the fourth square pass is outside the pass.
[0012] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the center of the bottom of the square roll groove of the third stand lies on the extension line of the roll's axis.
[0013] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the center of the bottom groove of the fourth square roll is on the extension line of the roll's axis.
[0014] Furthermore, in the aforementioned continuous rolling mill system for rolling square billets into round bars, the bottom of the groove of the third square rolling mill protrudes into the interior of the rolling mill, and the bottom of the groove of the fourth square rolling mill protrudes into the interior of the rolling mill.
[0015] Furthermore, in the above-mentioned continuous rolling pass system for rolling square billets into round bars, the first square pass is a flat rolling pass, the second square pass is a vertical rolling pass, the third square pass is a flat rolling pass, and the fourth square pass is a vertical rolling pass.
[0016] Analysis shows that this utility model discloses a continuous rolling pass system for rolling square billets into round bars. This pass system changes the flat-bottomed grooves of the third and fourth square passes to convex arc-shaped groove bottoms, increasing the reduction in the central area of the square billet. This prevents the rolled piece from twisting during the rolling process due to factors such as fluctuations in incoming material dimensions and mill stand jumps, thereby improving rolling stability. Attached Figure Description
[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. Wherein:
[0018] Figure 1 This is a schematic diagram of the structure of the first square hole type according to an embodiment of the present invention.
[0019] Figure 2This is a schematic diagram of the structure of the second square hole type according to an embodiment of the present invention.
[0020] Figure 3 This is a schematic diagram of the structure of the third square hole type according to an embodiment of the present invention.
[0021] Figure 4 This is a schematic diagram of the fourth square hole type according to an embodiment of the present invention.
[0022] Figure 5 This is a schematic diagram of an elliptical hole structure according to an embodiment of the present invention.
[0023] Figure 6 This is a schematic diagram of a circular hole structure according to an embodiment of the present invention. Detailed Implementation
[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation of the present invention and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present invention encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.
[0025] In the description of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and do not require that this utility model be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. The terms "connected," "linked," and "set up" used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0026] The accompanying drawings illustrate one or more examples of the present invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the present invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.
[0027] like Figures 1 to 6 As shown, according to an embodiment of this utility model, a continuous rolling pass system for rolling a square billet into a round bar is provided, wherein the square billet is a 240 square billet and the round bar is a 135 round bar. The pass system includes six passes: four square passes, one elliptical pass, and one round pass. The bottom of the grooves in the third and fourth square passes is arc-shaped. This pass system changes the flat-bottomed grooves of the third and fourth square passes to convex arc-shaped grooves, increasing the reduction in the central area of the square billet and improving the rolling stability of the third and fourth square passes. This allows the groove bottoms to provide a lateral constraint force, preventing the rolled piece from twisting in the third and fourth square passes, thereby preventing the folding defect of a "reverse tail" phenomenon.
[0028] Furthermore, such as Figure 3 As shown, the bottom radius of the square die in the third stand is 1005 mm, and the depth is 4 mm. This arrangement can improve the restraining effect of the square die in the third stand on the torsion of the rolled piece, and prevent the rolled piece from torsion in the square die in the third stand.
[0029] Furthermore, such as Figure 4 As shown, the bottom radius of the fourth square die is 620 mm and the depth is 4 mm. This arrangement improves the restraint effect of the fourth square die on the torsion of the rolled piece, preventing the rolled piece from twisting in the fourth square die.
[0030] Furthermore, such as Figure 3 As shown, the center of the groove bottom of the third square hole is outside the hole. The groove bottom of the third square hole protrudes into the hole, and the center of the groove bottom of the third square hole is on the extension line of the hole's axis, so that the groove bottom of the third square hole forms an arc-shaped groove bottom that protrudes into the hole.
[0031] Furthermore, such as Figure 4 As shown, the center of the bottom of the fourth square hole is outside the hole. The bottom of the fourth square hole protrudes into the hole, and the center of the bottom groove of the fourth square hole is on the extension line of the hole's axis, so that the bottom of the fourth square hole forms an arc-shaped bottom that protrudes into the hole.
[0032] Furthermore, the first stand has a square rolling pass, the second stand has a square rolling pass, the third stand has a square rolling pass, the fourth stand has a square rolling pass, the elliptical pass is a square rolling pass, and the round pass is a vertical rolling pass.
[0033] In one embodiment of this utility model, the die system is used to roll a 240 square billet into a 135 round bar, and the first square die is as follows: Figure 1As shown, the second frame has a square hole shape as follows: Figure 2 As shown, the third frame has a square hole shape as follows: Figure 3 As shown, the fourth frame has a square hole shape as follows: Figure 4 As shown, the elliptical hole shape is as follows Figure 5 As shown, the circular hole type is as follows Figure 6 As shown, there is no twisting or "tail-turning" phenomenon in the rolled product during the rolling process, and there is no folding at the tail of the finished bar.
[0034] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:
[0035] A continuous rolling pass system for rolling square billets into round bars. This pass system changes the flat-bottomed grooves of the third and fourth square passes to convex arc-shaped groove bottoms, increasing the reduction in the central area of the square billet. This prevents the rolled piece from twisting during the rolling process due to factors such as fluctuations in incoming material dimensions and mill stand jumps, thereby improving rolling stability.
[0036] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A continuous rolling pass system for rolling square billets into round bars, characterized in that, It includes 6 hole types: 4 square hole types, 1 oval hole type, and 1 round hole type. The bottom of the square-shaped slot in the third frame is rounded. The bottom of the square-shaped slot of the fourth frame is rounded.
2. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The third square-shaped slot has a bottom radius of 1005mm and a depth of 4mm.
3. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The fourth square hole has a bottom radius of 620mm and a depth of 4mm.
4. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The billet is a 240mm billet, and the round bar is a 135mm round bar.
5. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The center of the groove bottom of the third square hole is outside the hole.
6. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The center of the groove bottom of the fourth square hole is outside the hole.
7. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The center of the bottom of the square hole of the third frame is on the extension line of the axis of the hole.
8. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The center of the bottom groove of the fourth square hole is on the extension line of the hole's axis.
9. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The bottom of the square-shaped groove in the third frame protrudes inwards from the center of the groove. The bottom of the square-shaped groove of the fourth frame protrudes into the interior of the hole.
10. The continuous rolling pass system for rolling square billets into round bars according to claim 1, characterized in that, The first stand has a square rolling pass for flat rolling, and the second stand has a square rolling pass for vertical rolling. The third stand has a square rolling pass for flat rolling, and the fourth stand has a square rolling pass for vertical rolling.