阅读说明：本技术 一种直条圆钢切分生产轧制工艺 (Straight round steel cutting production rolling process ) 是由 王晓军 赵仁宇 郭金科 杨林 张敏 赵天喜 王东 陈志强 蔡正财 常德君 李永成 于 2019-11-15 设计创作，主要内容包括：本发明公开了一种直条圆钢切分生产轧制工艺,160mm方坯经步进式加热炉加热至1030℃～1050℃后,轧制后,利用1#剪剪头后进入中轧区6架设计孔型轧制后,利用2#剪剪头剪尾后进入精轧区6架轧机轧制。轧件经预切分孔型轧制后哑铃状中间连接带根据不同规格控制在10-13mm。预切分孔型切分楔顶角角度控制在64°-68°。切分孔型连接带厚度1mm,切分孔型切分楔顶角角度控制在50°-60°,切分轮顶角角度为90°。采用该工艺轧制关键在于预切分料型控制精准,保证料型大小一致,减小线差。本发明解决了圆钢切分架次依托导卫轮对钢料连接带撕裂后产生的不对称微裂纹缺陷。(The invention discloses a slitting production rolling process for straight round steel, which comprises the steps of heating a 160mm square billet to 1030-1050 ℃ through a stepping heating furnace, rolling, utilizing a 1# shear head to cut heads, then entering a middle rolling area 6 frame design hole type to roll, utilizing a 2# shear head to cut tails, and then entering a finish rolling area 6 frame rolling mill to roll. And after the rolled piece is subjected to pre-cutting split rolling, the dumbbell-shaped intermediate connecting belt is controlled to be 10-13mm according to different specifications. The angle of the top angle of the pre-cut split type splitting wedge is controlled to be 64-68 degrees. The thickness of the splitting hole type connecting belt is 1mm, the angle of the apex angle of the splitting wedge of the splitting hole type is controlled to be 50-60 degrees, and the angle of the apex angle of the splitting wheel is 90 degrees. The key point of the process is that the precutting and distributing material type is accurately controlled, the material type size is ensured to be consistent, and the line difference is reduced. The invention solves the defect of asymmetric microcrack generated after the steel connecting belt of the round steel cutting frame is torn by the guide and guard wheel.)

1. A straight round steel cutting production rolling process is characterized in that: heating a 160mm square billet to 1030-1050 ℃ by a stepping heating furnace, performing design pass rolling by 6 rolling mills in a rough rolling area, performing design pass rolling by using a 1# shearing head, entering a middle rolling area, setting a design pass, rolling by using a 6-frame design pass, entering a finish rolling area by using a round steel material, and entering the 6 rolling mills in the finish rolling area for rolling by using a 2# shearing head, shearing a tail, wherein the key of the process is the design of the pass of the 6 rolling mills in the finish rolling area; the pass and the shape of the steel material adopted by the finish rolling area are as follows in sequence: the method comprises the following steps of (flat roll) flattening, (vertical box type hole type) box type material- (pre-cut split hole type) dumbbell-shaped material- (split hole type) parallel round material- (oval hole type) oval material-finished hole type (finished round steel), wherein the structural size of each hole type is as follows:

area proportional relation of hole patterns in a finish rolling area: a flat roll pass F6= (1.12-1.25) a vertical box pass area F5= (1.2-1.35) a pre-cut split pass area F4= (1.15-1.25) a split pass area F3=2 (1.2-1.3) an oval pass area F2=2 (1.2-1.27) and a finished pass area F1;

the height H6 of the flat pass K6 = the roll gap S6= the width b of the groove bottom of the vertical box pass K5_K50.5 to 1.5, width B of the notch_k6=（1.12～1.20）F5/H6；

Vertical box type hole type groove bottom width b of vertical box type hole type K5_K5= H6- (0-6), notch width B_k6= H6+ shelf spread coefficient β× shelf rolling reduction Δ H + (5-10), pass height H5= B_k6-the racking reduction Δ h; radius of fillet r of groove bottom₁=（0.12～0.2）B_k6Radius of external fillet r₂=（0.1～0.12）B_k6Sidewall slope Tan ψ = y =10% -15%, convexity f = (0.03-0.05) B_k6Roll gap S5= (0.02-0.05) × nominal diameter D of frame roller₀；

The hole pattern height H4= (0.9-0.95) H5 of the precut hole splitting pattern K4, and the distance b between two circle centers_k4=2r1/cos ψ, slot width B_K4=b_k4+2r1/cos psi, the apex angle 2 theta of the splitting wedge = 64-68 degrees, the slope psi of the groove side wall = 25-30 degrees, the roll gap S4= (0.13-0.15) H4, the fillet radius r2 of the wedge tip is more than or equal to 3mm, the fillet radius r3= (0.05-0.15) H4, the arc radius r1= (0.3-0.4) H4 of the groove bottom, and the height H = (0.40-0.48) of the connecting belt H4;

the pass height H3= (0.80-0.9) H4 of the cut pass K3, and the parallel circle center distance b_k3=2r1/cos ψ, notch width Bk3= Bk +2r1/cos ψ to S3tan ψ, cutting wedge apex angle 2 θ =50 ° to 60 °, hole type side wall inclination ψ =25 ° to 30 °, parallel circular radius r1=0.5H3, cutting wedge apex radius r2= (0.5 to 1.5), external circular radius r3=0.1H3, S3=1mm, web height H =1mm,

oval hole type K2 hole type height H2= (0.75-0.88) finished product nominal diameter d₀Width of notch B_k2= (1.42-1.80) finished product nominal diameter d₀Arc radius of groove bottom r1= (d)1.35-1.6)) nominal diameter d of the finished product₀Roll gap S2= (2.0 ~ 4.0), caliber excircle radius r2= [ (H2 ~ S2)²+B_k2]/4（H2～S2）；

The finished product hole pattern adopts a double-radius circular arc design, the design tolerance deviation is +/-0.3 mm, the hole pattern height H1= (1.007-1.02) and the nominal diameter d of the finished product₀Width of notch B_k1= (1.007-1.02) [ nominal diameter of finished product d)₀+ (0.5-1) × allow for a positive deviation △⁺]The circular arc radius r =1/2H1, the roll gap S1= (1.5-2), the expansion angle psi = (15-30 ℃), and the finished hole type external fillet r1= (0.5-1.5).

2. The straight round steel cutting production rolling process according to claim 1, characterized in that: the flat roll in the finish rolling area is a common bainite roll; the vertical box type hole pattern roller, the pre-cut split hole pattern roller, the oval hole pattern roller and the finished hole pattern roller are made of high-speed steel rollers.

3. The straight round steel cutting production rolling process according to claim 1, characterized in that: the vertical box type hole pattern has a certain convexity, and the oval hole pattern is rolled and then twisted by adopting a twisting guide and guard to enter a finished hole pattern.

Technical Field

The invention relates to a steel rolling technology, in particular to a straight round steel cutting production rolling process.

Technical Field

The development practice process of producing round steel by double segmentation of the bar production line comprehensively plans from hole pattern design, guide design to material speed matching and process control, eliminates defects and line differences generated in the segmentation process, and achieves the uniformity of two line sizes. Aiming at key control points which are difficult to ensure such as surface quality, finished product size fluctuation and out-of-roundness when round steel is different from deformed steel two-cutting rolling, measures are made from the aspects of hole pattern system design, material speed matching, cutting process control, rolling mill bounce, guide installation and the like. One is to eliminate surface quality defects in the finished product, such as inwardly extending scratches and folds, that may result from slitting the tape. Secondly, the size and the out-of-roundness of the finished product are ensured to meet the national standard requirements.

At present, the cutting production technology of the deformed steel bar on the bar production line in China is generally popularized and applied, if the deformed steel bar with the specification of 12mm is rolled by adopting a three-cutting production process, the deformed steel bar with the specification of 14 mm-18 mm is rolled by adopting a two-cutting production process, and the round steel is rolled by adopting the cutting process and is not applied to actual production. Compared with the cutting production process of the deformed steel bar, the round steel cutting production process has higher requirements on precision control of process equipment and adjustment of the production process, the non-roundness national standard requirement range of the round steel is small, traces on the surface of a finished product due to a cutting belt are difficult to control, and folding or surface protrusion is easy to generate. The cut strip is easy to produce pitted surface after the finished product is rolled for a plurality of times, so that the surface of the finished product is not smooth. Therefore, the requirements of hole pattern design, material type control in the production process, rolling mill precision, splitting process and guide control technology are higher than those of deformed steel. At present, the domestic round steel production generally adopts a single-line production process, but the production efficiency of small-specification straight round steel products is low due to the small cross-sectional area of the finished products and the limitation of the speed of the finished products of a bar wire rolling mill unit.

At present, in the field of producing straight round steel by domestic steel rolling enterprises, a typical process method is a single-line production rolling process. Eight iron and steel companies in Xinjiang roll round steel by adopting a cutting production process when producing small-size round steel. The hole type system is a plum blossom square hole type system: a system of rhombic hole-arc side square hole-dumbbell type pre-splitting hole-double circular splitting hole-oval hole-circular hole.

The pass system has the main advantages that (1) the control precision of the size of a rolled piece is high. (2) The hole type system has larger extension coefficient which can reach about 2.8 from K6 to K3. (3) The edge of the plum blossom square rolled piece is sunken to play a centering role in the precutting split hole, so that the precutting two parts can be ensured to have equal volumes, and in addition, the impact on the splitting wedge is small, and the tops of two circles in the precutting split hole are easily filled. (4) The plum blossom square hole rolled piece is out of shape relatively evenly, and the side has sunken also difficult ear of appearing.

The hole type system has the main defects that (1) the hole type requires high control precision and is sensitive to abrasion. 4 small arc protrusions of the K5 arc side square hole shape are easy to wear, the groove bottom wear speed is high, and the material shape is easy to be irregular. (2) The shape of the rolled piece is provided with a sharp corner, so that the temperature on the section of the rolled piece is easy to be uneven. (3) The quincunx square rolled piece needs to be twisted by 45 degrees to influence the stability of continuous rolling. (4) Is not suitable for the cutting specification with small face shrinkage. Therefore, the plum blossom square hole type system is suitable for the cutting rolling of round steel with large extension coefficient, large surface shrinkage rate and small specification of phi 10 mm-phi 14mm and needing precise control.

The flat square hole type system comprises the following steps: the hole type system mainly has the following defects that the hole type system comprises a flat rolling hole, a vertical box type hole, a dumbbell hole, a splitting hole, an elliptical hole and a finished product hole: (1) the control accuracy of the flat roll and the flat square hole is not high. The flat roll has no clamping effect on the side wall of the hole pattern during rolling, and the guide and guard wear quickly reduces the clamping effect of the rolled piece, so that the moving range of incoming materials on the flat roll is large, the roll wear is uneven, the thickness of the K6 outlet rolled piece is uneven, and the sizes of two rolled pieces after subsequent splitting are influenced. (2) The elongation coefficient of the hole pattern system is small. The elongation of the K6K5 pores is small, and the elongation coefficient of K6 to K3 is only about 1.8, so that a large deformation amount is required for rough and medium rolling. (3) The impact of uneven deformation of the flat and square rolled piece on the cutting wedge is large, and the abrasion of the cutting wedge is large. (4) Because the rolled pieces rolled from the flat square holes have poor centering property when entering the pre-splitting holes, the sizes of the two rolled pieces after splitting are easily different in the pre-splitting process, the lengths of the two finished products are different, and the yield is influenced. Therefore, the installation accuracy of the K4 hole inlet guide must be strictly required to ensure that the cutting is right in the precut split holes.

Disclosure of Invention

The invention provides a cutting production rolling process (rolling specification phi 16 mm-phi 20 mm) for straight round steel, which ensures the stable quality of finished products and does not generate appearance quality defects such as surface folding, microcrack and the like of the finished products.

The main technical route of the invention is as follows: the hole pattern and steel material shape forming steps adopted by the finish rolling area are as follows in sequence: the method comprises the following steps of (flat roll) flattening, (vertical box type hole type) box type material, (pre-cut split hole type) dumbbell-shaped material, (split hole type) parallel round material, (oval hole type) oval material and finished hole type (finished round steel).

The area proportional relation of the hole patterns of the finish rolling area is as follows: the production process comprises the following steps of flat roll pass F6= (1.12-1.25), vertical box pass area F5= (1.2-1.35), precut split pass area F4= (1.15-1.25), split pass area F3=2 (1.2-1.3), oval pass area F2=2 (1.2-1.27) and finished pass area F1.

Flat roll passK6 height H6= roller gap S6= groove bottom width b of vertical box pass K5_K50.5 to 1.5, width B of the notch_k6=（1.12～1.20）F5/H6；

Vertical box type hole type groove bottom width b of vertical box type hole type K5_K5= H6- (0-6), notch width B_k6= H6+ shelf spread coefficient β× shelf rolling reduction Δ H + (5-10), pass height H5= B_k6-the racking reduction Δ h; radius of fillet r of groove bottom₁=（0.12～0.2）B_k6Radius of external fillet r₂= （0.1～0.12）B_k6Sidewall slope Tan ψ = y =10% -15%, convexity f = (0.03-0.05) B_k6Roll gap S5= (0.02-0.05) × nominal diameter D of frame roller₀；

The hole pattern height H4= (0.9-0.95) H5 of the precut hole splitting pattern K4, and the distance b between two circle centers_k4=2r1/cos ψ, slot width B_K4=b_k4+2r1/cos psi, the apex angle 2 theta of the splitting wedge = 64-68 degrees, the slope psi of the groove side wall = 25-30 degrees, the roll gap S4= (0.13-0.15) H4, the fillet radius r2 of the wedge tip is more than or equal to 3mm, the fillet radius r3= (0.05-0.15) H4, the arc radius r1= (0.3-0.4) H4 of the groove bottom, and the height H = (0.40-0.48) of the connecting belt H4;

the pass height H3= (0.80-0.9) H4mm of the cut pass K3, and the parallel circle center distance b_k3=2r1/cos ψ mm, notch width Bk3= Bk +2r1/cos ψ to S3tan ψ, cutting wedge apex angle 2 θ =50 ° to 60 °, hole-type side wall inclination ψ =25 ° to 30 °, parallel circular radius r1=0.5H3mm, cutting wedge apex angle radius r2= (0.5 to 1.5), external circular angle radius r3=0.1H3, S3=1mm, connecting band height H =1mm,

oval hole type K2 hole type height H2= (0.75-0.88) finished product nominal diameter d₀Width of notch B_k2= (1.42-1.80) finished product nominal diameter d₀Arc radius r1= (1.35-1.6)) of groove bottom and nominal diameter d of finished product₀Roll gap S2= (2.0 ~ 4.0), caliber excircle radius r2= [ (H2 ~ S2)²+B_k2]/4（H2～S2）。

The finished product hole pattern adopts a double-radius circular arc design, the design tolerance deviation is +/-0.3 mm, the hole pattern height H1= (1.007-1.02) and the nominal diameter d of the finished product₀Width of notch B_k1= (1.007-1.02) [ nominal diameter of finished product d)₀+ (0.5-1) × allow for a positive deviation △⁺]The circular arc radius r =1/2H1, the roll gap S1= (1.5-2), the expansion angle psi = (15-30 ℃), and the finished hole type external fillet r1= (0.5-1.5).

The design convexity of the bottom of the vertical box type hole is improved, the possibility of inconsistent feeding and discharging shapes on the K6 flat material width side is solved, and the symmetrical specification of the K5 material shape is ensured;

the invention redesigns the screw rod for adjusting the guide of the K4-stand rolling mill, controls the wire distance to be 3mm, ensures the adjustment precision of the guide and guarantees that the pre-segmentation of K4 can effectively distribute material types;

in order to ensure the surface defects of finished products, the K3 double-circle connecting band is solidified to be 1mm, the angle of the apex angle of the slitting wheel is 90 degrees, and the tearing band is minimized after the slitting wheel tears steel materials;

the vertical box type hole pattern roller, the pre-cut split hole pattern roller, the oval hole pattern roller and the finished hole pattern roller are made of high-speed steel rollers, so that the problem of frequent groove replacement due to groove abrasion in a finish rolling area is solved.

The steel rolling bar line production specification of the invention is 16-32 straight round steel originally produced by adopting a single line production process, but the yield is lower, and the steel rolling is started in 2018, the steel rolling is carried out on the straight round steel with the specification of 16-20 by a double-cutting production process development, so that the batch rolling of the double-cutting production process of the straight round steel is realized, the yield is greatly improved, the quality of a finished product meets the standard requirement, and the production efficiency of the straight round steel is greatly improved.

Drawings

FIG. 1a is a schematic diagram of the pass shape of the flat rolls (flat rolls) in the finishing section of the present invention;

FIG. 1b is a schematic diagram of the shape of the pass of the stand box in the finishing section of the present invention;

FIG. 1c is a schematic view of the pre-cut split shape of the finishing zone of the present invention;

FIG. 1d is a schematic view of the shape of the pass of the finishing section of the present invention;

FIG. 1e is a schematic view of the oval pass shape of the finishing zone of the present invention;

FIG. 1f is a schematic diagram of the finished pass shape of the finishing zone of the present invention;

FIG. 2 is a schematic diagram of the detailed sizing of the flat roll pass;

FIG. 3 is a schematic diagram of the detailed dimension processing of a vertical box type hole pattern;

FIG. 4 is a schematic diagram of a detailed dimensional processing of pre-cut split holes;

FIG. 5 is a schematic view of detailed sizing of a slit pass;

FIG. 6 is a detailed dimension machining schematic of an oval hole pattern;

FIG. 7 is a detailed dimension machining schematic of the finished pass;

fig. 8 is a schematic view of the apex angle of the slitting wheel.

Detailed Description

In order to clearly describe the technical scheme of the invention, a design data set related to actual production with the specification of phi 20mm multiplied by 2 is described by combining the attached drawings. The detailed description is briefly described.

As shown in fig. 1a to fig. 1f to fig. 8, the embodiment of the present invention uses a straight round steel cutting production rolling process to produce straight round steel with specification of phi 20mm × 2. Heating a 160mm square billet to 1030-1050 ℃ by a stepping heating furnace, performing design pass rolling by 6 rolling mills in a rough rolling area, performing design pass rolling in a middle rolling area after shearing a head by using a No. 1 shear head, performing design pass rolling in the 6 rolling mills in a middle rolling area, performing design pass rolling in a finish rolling area after shearing a tail by using a No. 2 shear head, performing finish rolling in 6 rolling mills in the finish rolling area, wherein the key point of the process is the design of the pass of the 6 rolling mills in the finish rolling area, and the shape of a steel material in the: the method comprises the following steps of (flat roll) flattening, (vertical box type hole type) box type material, (pre-cut split hole type) dumbbell-shaped material, (split hole type) parallel round material, (oval hole type) oval material and finished hole type (straight round steel).

The structure size of each hole type is as follows in sequence: area proportional relation of hole patterns in a finish rolling area: area proportional relation of hole patterns in a finish rolling area: flat roll pass F6=1516.9mm²(ii) a Upright box type hole area F5=1346mm²(ii) a Precut hole-dividing area F4=1109.1mm²(ii) a The area of the split hole is F3=942.9mm²(ii) a Oval hole area F2=383.7mm²(ii) a Finished hole type area F1=314.2mm²。

Pass height H6= S6=30.5mm for flat rolling K6 notch width B_k6=52mm；

Vertical box type hole type groove bottom width b of vertical box type hole type K5_K5=30mm, slot width B_k6=34.5mm, hole pattern height H5=46.5 mm; radius of fillet r of groove bottom₁=7mm, radius of external fillet r₂=6mm, sidewall slope ψ =6.5, crown f =1.6mm, roll gap S5=7 mm;

the hole type height H6=29.5mm of the precut hole dividing type K4 and the distance b between two circle centers_k4=25.83mm, slot width B_K4=52.61mm, apex angle of the slitting wedge 2 θ =65 °, groove sidewall slope ψ =28 °, roll gap S4=4.0mm, wedge tip fillet radius r2=3.0mm, external fillet radius r3=2.5mm, groove bottom arc radius r1=11 mm; the height h =13mm of the connecting belt;

the hole pattern height H3=24.5mm of the splitting hole pattern K3 and the parallel circle center distance b_k3=28.1mm, notch width Bk3=55mm, slitting wedge apex angle 2 θ =56 °, groove side wall inclination ψ =28 °, parallel circle radius r1=12mm, slitting wedge apex radius r2=1mm, external corner radius r3=2mm, S3=1mm, web height h =1mm, slitting groove rear slitting guide, slitting wheel apex angle 90 °;

oval hole type K2 hole type height H2=15.5mm, notch width B_k2=35.3mm, the radius of the circular arc r1=29mm at the bottom of the groove, the roll gap S2=3.5mm, and the radius r2=4mm at the type of pass.

Finished hole type K1 hole type height H1=20.28mm, notch width B_k1=20.66mm, arc radius r =10.14mm, roll gap S1=2mm, divergence angle ψ =18 °. Finished hole type bullnose r1=1 mm.