CN102266866B - Technology for producing hot-rolled pipeline steel of roll mill with single frame furnace - Google Patents
Technology for producing hot-rolled pipeline steel of roll mill with single frame furnace Download PDFInfo
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Abstract
The invention discloses technology for producing hot-rolled pipeline steel of roll mill with a single frame furnace. Tapping temperature of steel billet is more than or equal to 1100 DEG C; rolling temperature of the second process is no more than 900 DEG C, and thickness of billet to be waited in temperature is less than or equal to 3.3 hours; pass rolling reduction rate in the second last is less than or equal to 9% and no more than 13%, the final pass rolling reduction rate is 0%; rolling speed of the second last pass of the final rolling is reduced to enable the final rolling temperature to be 780-820 DEG C; after the water temperature is 695-740 DEG C, online speed casting steel without rolling reduction rate is finished and the steel is cooled in a layer flow cooling system; temperature uniformity of rolled piece entering water and temperature uniformity of flat cooling are guaranteed; before entering a straightener, the rolled piece is produced with plastic deformation requirement no less than 80% according to thickness direction; and roll gaps of an entrance and an exit of the straightener are arranged. When rolling the pipeline steel for a special purpose, the invention can control steel plate shape and improve economic benefit while meeting performance requirement of the final product.
Description
Technical field
The invention belongs to the steel rolling field, relate to a kind of rolling mill practice of single chassis steekle mill hot rolling specific use pipe line steel.
Background technology
Be when using the blank flat-rolled specific use pipe line steel of 220mm, 180mm, 150mm making thickness at present, performance and plate shape are needed simultaneously control.Be guaranteed performance, to finishing temperature, enter coolant-temperature gage, red temperature has extremely strictly accurately requirement.For example, large-deformation-resistance pipeline steel X70HD, needing the 2nd passage finishing temperature reciprocal be 780 ℃ ~ 820 ℃, between the temperature control to 695 ℃ before the steekle mill machine ~ 740 ℃, obtains the part pro-eutectoid ferrite, enters afterwards the laminar flow cooling and accelerates cooling.This just requires steekle mill the 2nd passage reciprocal to reduce mill speed, to satisfy the requirement of finishing temperature, swings temperature control before the throwing steel before the steekle mill machine, after steel billet temperature satisfies the entry temperature requirement, comes into operation and throws steel without the automatic speed-raising of reduction ratio.Because large deformation pipe line steel X70HD is lower than 100 ℃, lower red temperature has increased the difficulty that plate shape is controlled, and not only will guarantee the original milled sheet shape of steekle mill, more will guarantee to cool off simultaneously rear plate shape, straightener straightening plate shape.Because of the original blank length used all more than 7m, in any case improve heating-up temperature or mill speed etc., because finish rolling stage rolled piece is long, in the operation of rolling, with thinning down in the steel plate rolling process, the steel plate temperature drop can be more and more faster, causes along on the length of rolled piece direction, Temperature Distribution is extremely inhomogeneous, has increased the milled sheet shape of rolled piece and the difficulty of Properties Control.For this reason, developing a kind of rolling mill practice of specific use pipe line steel, is a problem, particularly charge length be badly in need of solving when above greater than 7m, the series of problems such as the too fast performance that causes of rolled piece excessive temperature differentials and temperature drop and plate shape can occur.
Summary of the invention
In order to overcome the problem that hot rolling specific use pipe line steel exists in the prior art, the production technology that the purpose of this invention is to provide a kind of hot-rolled pipeline steel of roll mill with single frame furnace, this technique is 15m adopting charge length the longest, when thickness is the specific use pipe line steel of long blank rolling thickness≤30mm of 150mm ~ 220mm, can be when satisfying the final products performance requirement, the control steel-plate shape.This technique has not only improved performance and plate shape comprehensive qualified rate, has also improved economic benefit.
The objective of the invention is to be achieved through the following technical solutions:
A kind of production technology of hot-rolled pipeline steel of roll mill with single frame furnace is characterized in that this technique may further comprise the steps:
1) steel billet tapping temperature 〉=1180 ℃, two-stage start rolling temperature≤900 ℃, temperature control plate blank thickness≤3.3h;
2) rolling pass is 9 passages or 11 passages, 9%≤the 2nd percentage pass reduction reciprocal≤13%, and the final pass reduction ratio is 0%; Such as unrestrained milled sheet shape in occurring, then increase the end and roll 2 percentage pass reductions;
3) mill speed of reduction finish to gauge the 2nd passage reciprocal makes finishing temperature at 780 ℃ ~ 820 ℃; The 2nd passage reciprocal and finish to gauge speed V satisfy: 1.45m/s≤V≤1.75m/s, according to finishing temperature, adjust the 2nd passage mill speed reciprocal.After the rolling end of the 2nd passage reciprocal, steel plate swings at the machine front roller-way, until after temperature reaches 695 ℃ ~ 740 ℃ of coolant-temperature gages, finish without the online speed-raising of reduction ratio and throw steel, enters the laminar cooling system cooling; Throw in the steel passage 0≤acceleration≤0.02m/s
2, the uniformity of assurance rolled piece head and tail red temperature;
4) board shape situation is selected secondary roller coefficient, and if there is limit wave wooden dipper bent plate shape, the secondary bending roller force then uses 2.0 ~ 2.5, increases bending roller force with this, eliminates limit wave wooden dipper bent plate shape; If milled sheet shape is middle wave, the secondary bending roller force then uses 0 ~ 1.5, reduces bending roller force with this, unrestrained wooden dipper bent plate shape in the elimination;
5) working roll roll crown: be that wave wooden dipper in limit is bent such as milled sheet shape, then open the working roll edge cooling water; Be that middle unrestrained wooden dipper is bent such as milled sheet shape, then open cooling water in the middle of the working roll;
6) before rolled piece entered cooling system, rolled piece required to swing at the machine front roller-way, guaranteed that temperature is even on the steel plate through-thickness; Guarantee rolled piece entry temperature homogeneity and red temperature uniformity;
7) rolled piece enters before the straightener, according to 〉=80% above plastic deformation requirement occurs on the through-thickness, sets straightener inlet and outlet roll gap; If there is wooden dipper is bent end to end, arrange to adjust entrance and Exit-edge roller height, optimize aligning speed; If there is bilateral unrestrained wooden dipper bent plate shape, then align with bending roller force; Bent if there is monolateral unrestrained wooden dipper, then transfer fore side and transmission side roll gap difference to align, finish the production of pipe line steel.
The present invention is in the side program automatic reduction of speed of exploitation and temperature automatically controlled function, the rolling reduction of speed function of the steekle mill that namely comes into operation the 2nd passage reciprocal, throw temperature controlling function before the steel passage machine, throw steel, the on-line automatic diminishing function of laminar cooling system without the on-line automatic speed-raising of reduction ratio, both satisfied technique to finishing temperature, enter the requirement of coolant-temperature gage, red temperature, in conjunction with rolling and straightening process, Comprehensive Control performance and plate shape.
The present invention has successfully solved single chassis steekle mill hot rolling specific use Pipeline Steel Properties and plate shape problem, has especially solved performance issue.Not only improve performance and plate shape comprehensive qualified rate, also improved to a certain extent economic benefit.It is the long blank (the longest 15m of being) of 150mm ~ 220mm that the present invention is applicable to thickness, and the high specific use pipe line steel of rolling thickness≤30mm under the prerequisite that satisfies the final products performance requirement, is controlled steel-plate shape simultaneously, and all functions all realize automatically.
Description of drawings
Fig. 1 is flow sheet of the present invention.
The specific embodiment
The control technique of a kind of single chassis steekle mill hot rolling flat-rolled specific use Pipeline Steel Properties and plate shape, 1200 ℃ of this technological requirement tapping temperatures, rolling pass 4+6+1 road, 900 ℃ of two-stage start rolling temperatures, temperature control plate blank thickness 3.3h, the 10th percentage pass reduction are that 10%, the 11 percentage pass reduction is 0%; Secondary bending roller force coefficient is 2.5 of maximum; Finish to gauge speed is 1.70m/s, and acceleration is 0.01m/s2; After working roll is produced more than 800 tons, open working roll section's cooling water at one's side; The come into operation edge-masking of cooling system, cooling water water ratio is 1.50; Straightener gateway roll gap is set according to along steel plate thickness 85% above plastic deformation occuring, and aligns end to end speed 0.40m/s, intermediate body member aligning speed 0.80m/s.
Present embodiment is selected 1 flat-rolled plate X70HD large-deformation-resistance pipeline, and the blank actual size is 150*3175*8500mm, and finished product thickness is 17.5mm, and rolling 11 passages are divided into two rolling sequences: 4 passages of one-phase flat-rolled, 7 passages of two-stage flat-rolled.Detailed process is as follows, see Fig. 1, among the figure, the 1st, heating furnace, the 2nd, coiler furnace, 4 is four roll reversing rollers, the 5th before the descaling mill, the 3rd, machine, coiler furnace, the 6th behind the machine, laminar cooling system, the 7th, thermal straightening machine, 1# pyrometer, 2# pyrometer, 3# pyrometer, 4# pyrometer.
(1) heating-up temperature of blank in heating furnace 1 is increased to 1200 ℃, and first by descaling mill 2 thick de-scalings, after the thick de-scaling, the 1# pyrometer detects blank temperature and is not less than 1150 ℃ after the heating furnace tapping.
(2) enter four roll reversing rollers 4, rolling pass 4+6+1 road, produce more than 800 tons such as the working roll of milling train 4 after, the working roll of opening milling train is section's cooling water at one's side.After the rolling end of one-phase, be introduced into laminar flow cooling system 6 systems and wear water, shorten time of staying temperature.Before rolled piece is got back to machine afterwards, swing cooling in 2# pyrometer zone, when the 2# pyrometer detected temperature and is down to 900 ℃, rolled piece entered milling train, beginning finish rolling stage rolling.
(3) the finish rolling stage, the roller secondary coefficient of adjusting milling train 4 is 2.5, and bending roller force is with extremely maximum.After the 10th percentage pass reduction was the rolling end of 10%, the 10 passage, rolled piece entered 2# pyrometer zone and treats temperature, swung at roller-way simultaneously, guaranteed temperature homogeneity.When the 2# pyrometer detected temperature and is 740 ℃, rolled piece entered 4 milling trains and throws steel, and corresponding the 11st percentage pass reduction is 0%, and rolled piece enters before the laminar cooling system 6, and the 3# pyrometer detects rolled piece and enters coolant-temperature gage at 715 ℃ ± 10 ℃; It is 1.70m/s that 4 milling trains are thrown steel speed, and acceleration is 0.01m/s
2
(4) after rolled piece enters cooling system 6, the edge-masking function that comes into operation, water is than 1.50 simultaneously.After rolled piece left 6 laminar cooling systems, the 4# pyrometer detected 330 ℃ ~ 380 ℃ of rolled piece red temperatures.
(5) after rolled piece entered thermal straightening machine 7, the straightener inlet roll gap was 13.0mm, and the outlet roll gap is 17.5mm, and straightening force is more than 1000 tons.Rolled piece end to end aligning speed is 0.40m/s, intermediate body member aligning speed 0.80m/s.
The control technique of a kind of single chassis steekle mill hot rolling flat-rolled specific use Pipeline Steel Properties and plate shape, 1180 ℃ of this technological requirement tapping temperatures, rolling pass 4+4+1 road, 800 ℃ of two-stage start rolling temperatures, temperature control plate blank thickness 3.2h, the 8th percentage pass reduction are that 12%, the 9 percentage pass reduction is 0%; Secondary bending roller force coefficient is 2.2 of maximum; Finish to gauge speed is 1.45m/s, and acceleration is 0.01m/s
2After working roll is produced more than 800 tons, open working roll section's cooling water at one's side; The come into operation edge-masking of cooling system, cooling water water ratio is 1.60; Straightener gateway roll gap is set according to along steel plate thickness 80% above plastic deformation occuring, and aligns end to end speed 0.50m/s, intermediate body member aligning speed 0.90m/s.
Present embodiment is selected 1 block of flat-rolled plate X65MO submerged pipeline steel, and the blank actual size is 220*2075*9500mm, and finished product thickness is 28m, and rolling 9 passages are divided into two rolling sequences: 4 passages of one-phase flat-rolled, 5 passages of two-stage flat-rolled.Detailed process is as follows:
(1) heating-up temperature of blank in 1 is increased to 1180 ℃, and first by descaling mill 2 thick de-scalings, after the thick de-scaling, the 1# pyrometer detects blank 1 temperature and is not less than 1150 ℃ after the heating furnace tapping.
(2) enter milling train 4, rolling pass 4+4+1 road, produce more than 800 tons such as the working roll of milling train 4 after, the working roll of opening 4 milling trains is section's cooling water at one's side.After the rolling end of one-phase, be introduced into 6 laminar cooling systems and wear water, shorten time of staying temperature.Before rolled piece is got back to machine afterwards, swing cooling in 2# pyrometer zone, when the 2# pyrometer detected temperature and is down to 800 ℃, milling train entered 4 milling trains, beginning finish rolling stage rolling.
(3) the finish rolling stage, the roller secondary coefficient of adjusting milling train 4 is 2.2.After the 8th percentage pass reduction was the rolling end of 12%, the 8 passage, rolled piece entered 2# pyrometer zone and treats temperature, swung at roller-way simultaneously, guaranteed temperature homogeneity.When the 2# pyrometer detected temperature and is 730 ℃, rolled piece entered 4 milling trains and throws steel, and corresponding the 11st percentage pass reduction is 0%, and rolled piece enters before 6 laminar cooling systems, and the 3# pyrometer detects rolled piece and enters coolant-temperature gage at 710 ℃ ± 20 ℃; It is 1.45m/s that 4 milling trains are thrown steel speed, and acceleration is 0.01m/s
2
(4) after rolled piece enters cooling system 6, the edge-masking function that do not come into operation, water is than 1.60 simultaneously, and after rolled piece left 6 laminar cooling systems, the 4# pyrometer detected 480 ℃ ~ 520 ℃ of rolled piece red temperatures.
(5) after rolled piece entered thermal straightening machine 7, the straightener inlet roll gap was 25mm, and the outlet roll gap is 28mm, and straightening force is more than 900 tons.Rolled piece end to end aligning speed is 0.50m/s, intermediate body member aligning speed 0.90m/s.
The present invention be 15m adopting charge length the longest, when thickness is the specific use pipe line steel of long blank rolling thickness≤30mm of 150mm ~ 220mm, can when satisfying the final products performance requirement, control steel-plate shape.This technique has not only improved performance and plate shape comprehensive qualified rate, has also improved economic benefit.
Claims (2)
1. the production technology of a hot-rolled pipeline steel of roll mill with single frame furnace is characterized in that this technique may further comprise the steps:
1) steel billet tapping temperature 〉=1180 ℃, two-stage start rolling temperature≤900 ℃, temperature control plate blank thickness≤3.3h;
2) rolling pass is 9 passages or 11 passages, 9%≤the 2nd percentage pass reduction reciprocal≤13%, and the final pass reduction ratio is 0%; Such as unrestrained milled sheet shape in occurring, then increase the 2nd percentage pass reduction reciprocal;
3) mill speed of reduction finish to gauge the 2nd passage reciprocal makes finishing temperature at 780 ℃ ~ 820 ℃; The 2nd passage reciprocal and finish to gauge speed V satisfy: 1.45m/s≤V≤1.75m/s, after the rolling end of the 2nd passage reciprocal, steel plate swings at the machine front roller-way, until after temperature reaches 695 ℃ ~ 740 ℃ of coolant-temperature gages, finish without the online speed-raising of reduction ratio and throw steel, enter the laminar cooling system cooling; Throw in the steel passage 0≤acceleration≤0.02m/s
2, the uniformity of assurance rolled piece head and tail red temperature;
4) board shape situation is selected secondary roller coefficient, and if there is limit wave wooden dipper bent plate shape, the secondary bending roller force then uses 2.0 ~ 2.5, increases bending roller force with this, eliminates limit wave wooden dipper bent plate shape; If milled sheet shape is middle wave, the secondary bending roller force then uses 0 ~ 1.5, reduces bending roller force with this, unrestrained wooden dipper bent plate shape in the elimination;
5) working roll roll crown: be that wave wooden dipper in limit is bent such as milled sheet shape, then open the working roll edge cooling water; Be that middle unrestrained wooden dipper is bent such as milled sheet shape, then open cooling water in the middle of the working roll;
6) before rolled piece entered cooling system, rolled piece required to swing at the machine front roller-way, guaranteed that temperature is even on the steel plate through-thickness; Guarantee rolled piece entry temperature homogeneity and red temperature uniformity;
7) rolled piece enters before the straightener, according to 〉=80% plastic deformation requirement occurs on the through-thickness, sets straightener inlet and outlet roll gap; If there is wooden dipper is bent end to end, arrange to adjust entrance and Exit-edge roller height, optimize aligning speed; If there is bilateral unrestrained wooden dipper bent plate shape, then align with bending roller force; Bent if there is monolateral unrestrained wooden dipper, then transfer fore side and transmission side roll gap difference to align, finish the production of pipe line steel.
2. the production technology of hot-rolled pipeline steel of roll mill with single frame furnace according to claim 1 is characterized in that: in the step 3), according to finishing temperature, adjust the 2nd passage mill speed reciprocal.
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| CN102513370A (en) * | 2011-12-16 | 2012-06-27 | 南京钢铁股份有限公司 | Control process for single-stand Steckel mill to produce special-purpose pipeline steel |
| CN102699023B (en) * | 2012-06-01 | 2014-04-09 | 南京钢铁股份有限公司 | Plate shape control method of hot-rolling and coiled-rolling steel plate of single-rack steekle mill |
| CN102671941B (en) * | 2012-06-11 | 2014-04-09 | 南京钢铁股份有限公司 | Process for producing thin gauge pipeline steel by using double-stand medium and heavy plate mill |
| CN102806233B (en) * | 2012-08-14 | 2014-11-26 | 南京钢铁股份有限公司 | Controlled rolling and controlled cooling process for manufacturing double-phase steel by single-shelf steckel mill |
| CN105834226B (en) * | 2015-01-12 | 2018-08-10 | 内蒙古包钢钢联股份有限公司 | A kind of Q345E steel grades steel-plate shape control method |
| CN110548763B (en) * | 2019-08-22 | 2020-12-18 | 南京钢铁股份有限公司 | Method for reducing buckling of thick plate |
| CN112207138B (en) * | 2020-09-25 | 2022-08-05 | 攀钢集团西昌钢钒有限公司 | Method for stably controlling finish rolling temperature of high-grade pipeline steel |
| CN114160609B (en) * | 2021-11-18 | 2023-07-04 | 山东钢铁集团日照有限公司 | Method for efficiently cold straightening thin-specification buckling steel plate |
| CN114535325B (en) * | 2022-03-10 | 2023-10-31 | 山东钢铁集团日照有限公司 | Plate shape control process for producing pipeline steel based on single-frame steckel mill |
| CN115537636A (en) * | 2022-09-23 | 2022-12-30 | 南京钢铁股份有限公司 | Method for improving rolling efficiency of A32-grade marine medium plate |
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| JPS5772720A (en) * | 1980-10-24 | 1982-05-07 | Kawasaki Steel Corp | Manufacture of cold rolled steel strip |
| JP4377873B2 (en) * | 2005-11-17 | 2009-12-02 | 新日本製鐵株式会社 | Steel sheet controlled cooling device and cooling method |
| CN101407894A (en) * | 2008-11-20 | 2009-04-15 | 南京钢铁股份有限公司 | High strength X100 pipeline steel produced by steekle mill and production technique thereof |
| GB2468713B (en) * | 2009-03-20 | 2011-02-16 | Siemens Vai Metals Tech Ltd | Edge flatness monitoring |
| CN101700525A (en) * | 2009-11-20 | 2010-05-05 | 南京钢铁股份有限公司 | Rolling process of thick steel plate of single-rack steckel mill |
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