CN102974624A

CN102974624A - Edge plane shape control method of large-expansion-ratio high strength grade pipeline steel

Info

Publication number: CN102974624A
Application number: CN2012105173012A
Authority: CN
Inventors: 郭伟; 董占斌; 张跃飞; 邱志宏; 王传财
Original assignee: Shougang Corp; Qinhuangdao Shouqin Metal Materials Co Ltd
Current assignee: Shougang Group Co Ltd
Priority date: 2012-12-06
Filing date: 2012-12-06
Publication date: 2013-03-20
Anticipated expiration: 2032-12-06
Also published as: CN102974624B

Abstract

The invention discloses an edge plane shape control method of large-expansion-ratio high strength grade pipeline steel, belonging to the technical field of a heavy and medium plate rolling technology. Proper technical parameters are controlled in a three-stage process for rough rolling of a heavy and medium plate mill. Variable cross-section thickness rolling is performed at a forming pass of the first stage of the rough milling, so that a digging effect is formed at a middle position in the length direction after the steel plate is rolled, the middle position of the steel plate is thinner than the head and the tail of the steel plate, and the thickness difference is delta h. Next, a plate blank is revolved at an angle of 90 degrees and then is expanded, and the length of the steel plate is changed into the actual rolling width at the time; and since the thickness in the width direction is different, the reduction rate from the plate edge to the plate center is also different, thereby improving the edge plane shape. The yield is improved, and the production cost is reduced.

Description

Large broadening is than the limit facial planes shape control method of high-strength level pipeline pipeline steel

Technical field

The invention belongs to the Medium and Heavy Plate Rolling technical field, the limit facial planes shape control method of a kind of large broadening than high-strength level pipeline pipeline steel particularly is provided.

Background technology

In Heavy Plate Production, how not rectangular the flat shape after steel plate rolls is, must carry out crop end and the processing of cutting edge before delivery, directly causes the loss of lumber recovery.At present, the steel plate flat shape control method of heavy and medium plate mill adopts MAS rolling, dogbone rolling method (DBR method) etc. more both at home and abroad, and its essence all is the rolling with varying section by pony-roughing pass, realizes the rectangle of finished steel plate.But for large broadening than high-strength level pipeline pipeline steel, the flat shape control effect of its limit section is unsatisfactory, and Width middle part width is narrow end to end behind the steel plate rolling, and namely limit section " jujube nuclear " shape is serious, directly cause the reduction of this specification kind lumber recovery, production cost increases.

Summary of the invention

The object of the present invention is to provide a kind of large broadening than the limit facial planes shape control method of high-strength level pipeline pipeline steel, improved lumber recovery, reduced production cost.

The present invention is at the three phases (being moulding, broadening and axial rolling) of heavy and medium plate mill roughing, technique in the following technical parameter of control:

At first, in roughing phase I moulding passage, it is rolling to carry out variable cross-section thickness, forms " digging pit " effect in the centre position of length direction after making steel plate rolling, and the steel plate centre position is than steel plate thin thickness end to end, and thickness difference is the Δ h(degree of depth of " digging pit ").Afterwards broadening is carried out in 90 ° of slab revolutions, this moment, steel plate length became actual rolling width, because wide different to thickness, the reduction ratio from edges of boards to the plate center is also different, thereby so that limit facial planes shape be improved.

" digging pit " degree of depth of steel plate forming passage is to set in the milling train second-level model, and milling train one-level executing agency sets value according to secondary afterwards, by HGC hydraulic cylinder dynamic adjustments roll gap, finally makes steel plate reach along its length the thickness difference of regulation.

The applicable steel grade of the present invention is high-strength level pipeline pipeline steel, comprises X65, X70, X80 kind, and suitable thicknesses is (15-25) mm.

8500 tons of roughing mill maximum rolling forces, rolling torsion 3200KNm, maximum reduction 40mm, the diameter * stroke of HGC hydraulic roll gap control piston is φ 1500/1350 * 80mm, the maximum 29MPa of hydraulic pressure.Arrange on the condition basis in above capacity of equipment and parameter, the roughing important technological parameters is as follows:

Roughing moulding reduction in pass is set as (14-26) mm, in the variable cross-section THICKNESS CONTROL process, the depth delta h that " digs pit " sets than size according to broadening: when broadening than 1.5≤A＜2.2, need to increase " digging pit " depth delta h of steel plate middle part, " digging pit " depth delta h is made as (4.1-6.1) mm; When broadening than 1.3＜A＜1.5, " digging pit " depth delta h is made as (3.0-4.0) mm.

Simultaneously, moulding passage mill speed must satisfy the adjusting requirement to roll gap in the Varying-thickness control procedure of HGC hydraulic cylinder, adopts and stings at a slow speed steel, rolling strategy, specifically controls setting parameter and is: biting speed (1.0-1.2) m/s, mill speed (1.2-1.5) m/s, acceleration 0.5m/s ²

Roughing broadening rolling (3-6) passage, draught per pass (15-30) mm.

By above measure, " digging pit " shape of moulding passage is symmetric, realize that finally the steel plate edge shape well controls, thereby control shear amount improves lumber recovery.

Description of drawings

Fig. 1 roughing moulding passage figure that " digs pit ".

Fig. 2 depth delta h3mm that " digs pit ".

Fig. 3 depth delta h5mm that " digs pit ".

Fig. 4 depth delta h8mm that " digs pit ".

Fig. 2～Fig. 4 is " digging pit " depth delta h effect of optimization comparison diagram.

The specific embodiment

Embodiment 1,17.5mmX80-1 pipe line steel

Billet bloom size: 302*1990*2985mm

Contract size: 17.5*3827*11800 mm

Broadening ratio: 1.92

Conclusion: to the 17.5mmX80-1 pipe line steel, broadening is than 1.92, and the shaping reduction in pass is established 25mm.The conventional model moulding passage depth delta h that " digs pit " is 2.6mm, is 48.7mm through measuring the steel plate middle part with the head and tail width difference; The inventive method moulding passage depth delta h that " digs pit " adopts 6mm, width difference 22.8mm, and routine arranges and reduces 53.2%.

Embodiment 2,19.2mm X70-W pipe line steel

Billet bloom size: 248*1802*2920mm

Contract size: 19.2*2552*12000 mm

Broadening ratio: 1.42

Conclusion: to the 19.2mmX70-W pipe line steel, broadening is than 1.42, and the moulding reduction in pass is established 20mm.The conventional model moulding passage depth delta h that " digs pit " is 2.2mm, through measuring steel plate middle part and head and tail width difference 21.7mm; The inventive method moulding passage depth delta h that " digs pit " adopts 3.5mm, steel plate edge " jujube nuclear " 4.6mm, and routine arranges minimizing 77.4%.

Embodiment 3,22mmX80-1 pipe line steel

Billet bloom size: 301*2375*3145mm

Contract size: 22*3812*12100 mm

Broadening ratio: 1.61

Conclusion: to the 22mmX80-1 pipe line steel, broadening is than 1.61, and the moulding reduction in pass is established 15mm.The conventional model moulding passage depth delta h that " digs pit " is 3mm, through measuring steel plate middle part and head and tail width difference 25.6mm; The inventive method moulding passage depth delta h that " digs pit " adopts 5mm, steel plate edge " jujube nuclear "-0.25mm, and routine arranges minimizing 99.0%, improves successful.

Claims

1. a large broadening is characterized in that than the limit facial planes shape control method of high-strength level pipeline pipeline steel, the following technical parameter of control in the technique of the moulding of heavy and medium plate mill roughing, broadening and axial rolling three phases:

In roughing phase I moulding passage, it is rolling to carry out variable cross-section thickness, forms " digging pit " effect in the centre position of length direction after making steel plate rolling, and the steel plate centre position is than steel plate thin thickness end to end, and thickness difference is Δ h, the degree of depth of namely " digging pit "; Afterwards broadening is carried out in 90 ° of slab revolutions, this moment, steel plate length became actual rolling width;

" digging pit " degree of depth of steel plate forming passage is to set in the milling train second-level model, and milling train one-level executing agency sets value according to secondary afterwards, by HGC hydraulic cylinder dynamic adjustments roll gap, finally makes steel plate reach along its length the thickness difference of regulation;

8500 tons of roughing mill maximum rolling forces, rolling torsion 3200KNm, maximum reduction 40mm, the diameter * stroke of HGC hydraulic roll gap control piston is φ 1500/1350 * 80mm, the maximum 29MPa of hydraulic pressure; Arrange on the condition basis in above capacity of equipment and parameter, the roughing technical parameter is as follows:

Roughing moulding reduction in pass is set as 14-26mm, in the variable cross-section THICKNESS CONTROL process, the depth delta h that " digs pit " sets than size according to broadening: when broadening than 1.5≤A＜2.2, need to increase " digging pit " depth delta h of steel plate middle part, " digging pit " depth delta h is made as 4.1-6.1mm; When broadening than 1.3＜A＜1.5, " digging pit " depth delta h is made as 3.0-4.0mm.

Moulding passage mill speed satisfies the adjusting requirement to roll gap in the Varying-thickness control procedure of HGC hydraulic cylinder, adopts and stings at a slow speed steel, rolling strategy, specifically controls setting parameter and is: biting speed 1.0-1.2m/s, mill speed 1.2-1.5m/s, acceleration 0.5m/s ²

The rolling 3-6 passage of roughing broadening, draught per pass 15-30mm.

2. control method according to claim 1 is characterized in that, applicable steel grade is high-strength level pipeline pipeline steel, and described high-strength level pipeline pipeline steel is X65, X70, X80 kind, and suitable thicknesses is 15-25mm.