CN-224222327-U - Tandem rolling hole pattern system for rolling square billets into round bars

Abstract

The utility model provides a tandem rolling hole pattern system for rolling square billets into round bars, which comprises 6 hole patterns, wherein the 6 hole patterns comprise 4 square hole patterns, 1 oval hole pattern and 1 round hole pattern in sequence, the bottom of the 3 rd square hole pattern is an arc, and the bottom of the 4 th square hole pattern is an arc. The pass system changes the square pass of the 3 rd frame and the square pass of the 4 th frame from flat bottom grooves to convex arc-shaped groove bottoms, increases the rolling reduction of the central area of the square billet, prevents the rolling piece from twisting in the rolling process caused by factors such as fluctuation of the feeding size, jump of the rolling mill frame and the like, and improves the rolling stability.

Inventors

• YANG PAN
• WANG ZHEN
• LIN YA
• LI HUAN
• HU JINYUAN
• WU JIAN
• REN KANG
• LI DONGNING
• GUO YUHUA

Assignees

• 大冶特殊钢有限公司

Dates

Publication Date

20260512

Application Date

20250424

Claims (10)

1. 1. A tandem rolling hole type system for rolling square billets into round bars is characterized in that, Comprises 6 holes, namely 4 square holes, 1 elliptical hole and 1 circular hole in sequence, The bottom of the 3 rd square hole is an arc, The groove bottom of the 4 th square groove is an arc.
2. 2. A tandem rolling pass system for rolling billets into round bars according to claim 1 wherein the bottom radius of the 3 rd square pass is 1005mm and the depth is 4mm.
3. 3. A tandem rolling pass system for rolling billets into round bars according to claim 1 wherein the groove bottom radius of the 4 th square pass is 620mm and the depth is 4mm.
4. 4. A tandem rolling pass system for rolling billets into round bars according to claim 1 wherein said billets are 240 billets and said round bars are 135 round bars.
5. 5. The tandem rolling pass system for rolling square billets into round bars according to claim 1 wherein the center of the groove bottom of the 3 rd square pass is outside the pass.
6. 6. The tandem rolling pass system for rolling square billets into round bars according to claim 1 wherein the center of the groove bottom of the 4 th square pass is outside the pass.
7. 7. A tandem rolling pass system for rolling billets into round bars according to claim 1 wherein the center of the groove bottom of the 3 rd square pass is on the extension of the axis of the pass.
8. 8. A tandem rolling pass system for rolling billets into round bars according to claim 1 wherein the center of the bottom groove of the 4 th square pass is on the extension of the axis of the pass.
9. 9. A tandem rolling pass system for rolling square billets into round bars according to claim 1 wherein the bottom of the 3 rd square pass is convex toward the inside of the pass, The groove bottom of the 4 th square groove type protrudes to the inner part of the groove type.
10. 10. A tandem rolling pass system for rolling billets into round bars according to claim 1, wherein, The 1 st square hole is a flat rolling hole, the 2 nd square hole is a vertical rolling hole, The 3 rd square hole is a flat rolling hole, and the 4 th square hole is a vertical rolling hole.

Description

Tandem rolling hole pattern system for rolling square billets into round bars Technical Field The utility model relates to the technical field of steel rolling, in particular to a continuous rolling hole type system for rolling square billets into round bars. Background Square billet is a steel raw material commonly used for rolling round bars, and in order to obtain the required bar, the section of the billet is subjected to rolling deformation of square shape, oval shape and round shape in sequence, and the rolling process of a continuous rolling unit is commonly called a rough rolling stage. In the rough rolling stage, after the section of the rolled piece is changed into a round shape from a square shape, the stability of the gravity center is poor when the roller way runs. With the progress of rolling, the proportion occupied by a round rolled piece is increased, the gravity center instability is increased, if the size of a billet incoming material is unstable or the runout of a rolling mill is bigger, a pass cannot restrain the rolled piece, the rolled piece is twisted in the rolling process, so that the rolled piece steel material is extruded into a roll gap of a roll, the extruded material forms a folding defect after the next rolling, the process usually occurs at the tail part of the rolled piece, commonly called as a 'reverse tail' phenomenon, and the phenomenon occurs in the first 2 passes of an elliptical hole. Folding is a serious rolling defect (shown in figure 1), the folded bar is often changed into small specification or scrapped, heavy economic loss is caused to a production factory, and the inverted tail is influenced by the fluctuation of the size of the incoming material of the blank, so that the method has the characteristics of randomness and poor preventability, and serious quality problems are caused if the bar is missed to be detected, so that economic loss is caused, brand image of the production manufacturer is influenced, and certain potential safety hazard is caused. Therefore, the rolling stability is improved, the phenomenon of 'tailing falling' is prevented, and the method is particularly important in the field of steel rolling. Disclosure of utility model The utility model aims to provide a continuous rolling pass system for rolling square billets into round bars, which is used for rolling square billets into round bars, and can prevent rolling pieces from twisting in the rolling process caused by factors such as fluctuation of feed size, rolling mill frame runout and the like, thereby improving rolling stability. In order to achieve the above object, the present utility model provides the following technical solutions: A tandem rolling pass system for rolling square billets into round bars comprises 6 passes, wherein the pass system comprises 4 square passes, 1 elliptical pass and 1 round pass in sequence, the bottom of the 3 square passes is an arc, and the bottom of the 4 square passes is an arc. Further, in the continuous rolling pass system for rolling the square billets into round bars, the radius of the groove bottom of the 3 rd square pass is 1005mm, and the depth is 4mm. Further, in the continuous rolling pass system for rolling the square billets into round bars, the radius of the groove bottom of the 4 th square pass is 620mm, and the depth is 4mm. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the square billet is 240 square billets, and the round bar is 135 round bars. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the center of the bottom of the 3 rd square pass is outside the pass. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the center of the bottom of the 4 th square pass is outside the pass. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the center of the bottom of the 3 rd square pass is on the extension line of the axis of the pass. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the center of the bottom groove of the 4 th square pass is on the extension line of the axis of the pass. Further, in the tandem rolling pass system in which the square billet is rolled into a round bar, the groove bottom of the 3 rd square pass protrudes toward the inside of the pass, and the groove bottom of the 4 th square pass protrudes toward the inside of the pass. Further, in the continuous rolling pass system for rolling the square billet into the round bar, the 1 st square pass is a flat rolling pass, the 2 nd square pass is a vertical rolling pass, the 3 rd square pass is a flat rolling pass, and the 4 th square pass is a vertical rolling pass. Analysis shows that the continuous rolling pass system for rolling square billets into round bars changes the 3 rd square pass and the 4 th square pass from flat bottom grooves to