CN104307911B - Improve the method for high surface grade IF steel percentage elongation - Google Patents
Improve the method for high surface grade IF steel percentage elongation Download PDFInfo
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- CN104307911B CN104307911B CN201410431306.2A CN201410431306A CN104307911B CN 104307911 B CN104307911 B CN 104307911B CN 201410431306 A CN201410431306 A CN 201410431306A CN 104307911 B CN104307911 B CN 104307911B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/56—Elongation control
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
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Abstract
The invention provides a kind of method improving high surface grade IF steel percentage elongation, key control point comprises: slab tapping temperature controls at 1200 ± 20 DEG C by (1); (2) high temperature coiling of 730 ~ 750 DEG C is adopted; (3) rough rolling step edger roll adopts when gap normal water supply, steel rolling for water system and reduces water supply pattern to reduce steel edge portion temperature drop; (4) optimize rough rolling step edger roll passage and subtract the distribution of wide amount, adopt 1,3,5 passages to subtract wide, subtract wide amount and be respectively 15-10mm, 10-5mm and 5-0mm; (5) slab is carried out chamfered.The invention has the advantages that: method is simple, and economical and efficient, can use existing equipment to improve zinc-plated IF steel percentage elongation under the condition not affecting steel grades and other performance, keep the surface quality that steel plate is good simultaneously.
Description
Technical field
The invention belongs to technical field of steel rolling, particularly a kind of method improving high surface grade IF steel percentage elongation.
Background technology
Gapless atomic steel (IF steel, full name Interstitial-FreeSteel) as third generation deep drawing sheet steel, there is high plastic strain ratio, high work hardening index and without the feature such as ageing, be the steel plate that the current group of drawing is the highest, be widely used in the industry such as automobile making, household electrical appliances.In recent years, along with the fast development of automobile and household electric appliances, the demand with high-grade surface and excellent mechanical property IF steel is become increasingly conspicuous.
Catch interstitial atom by adding strong C, N compound forming element such as Ti, Nb in IF steel, form precipitate (second phase particles), precipitate kind, size, distribution etc. directly affect the mechanical property of IF steel.The precipitation order of the compound that Ti and C, N are formed and temperature are TiN (1508 DEG C)-TiS (1401 DEG C)-Ti
4c
2s
2(1280 DEG C)-TiC (887 DEG C), front four kinds of precipitates are just separated out in heating furnace, continue precipitation in the follow-up operation of rolling to grow up, TiC separates out in the cold process of layer, in coiling process, continue precipitation grow up, by controlling tapping temperature and finish to gauge, the major temperature parameter such as to batch and significantly can affect precipitate situation, thus affect the mechanical properties such as the percentage elongation that finished product rolls up.
Existing research and knowhow all show, IF steel in the hot rolling easy border sticks up the defects such as skin, main cause is that after slab goes out heating furnace, edge temperature drop is larger, subtract the wide stage at edger roll and easily cause that edge is coarse, fine rule, IF steel is owing to being ultra-low-carbon steel, and austenite is higher to ferritic critical phase temperature, in addition the alloys producing such as Ti, the trickle edge fault that rough rolling step is formed very easily amplifies in the finish rolling stage, and the defects such as skin are stuck up in the final finished product Surface Edge portion that formed.It is very responsive that this defect subtracts wide system etc. to tapping temperature, edger roll, strongly limit the production of high surface grade, high-elongation IF steel.
Summary of the invention
The object of this invention is to provide a kind of method improving high surface grade IF steel percentage elongation, under the condition not affecting steel grades and other performance, use existing equipment to improve the percentage elongation of zinc-plated IF steel, and ensure the surface quality that steel plate is good.
For solving the problems of the technologies described above, the invention provides a kind of method improving high surface grade IF steel percentage elongation, its production process comprise that continuous casting of molten steel obtains slab successively, heating slab, Vertical Rolling subtract wide, hot rolling flat rolling is thinning and high temperature coiling.In process of production production technology is controlled as follows:
(1) slab tapping temperature is controlled at 1200 ± 20 DEG C;
(2) by oiler temperature control at 730 ~ 750 DEG C;
(3) edger roll adopts when steel rolling gap normal water supply, steel rolling for water system and reduces the pattern supplied water;
(4) rough rolling step the 1st, 3,5 passage adopts edger roll to subtract wide, subtracts wide amount and is respectively 10 ~ 15mm, 5 ~ 10mm and 0 ~ 5mm;
(5) carry out chamfered, continuous casting steel billet four edges is along its length carried out chamfering, is pruned by original right-angle side, width and thickness direction chamfered edge length are respectively 30 ~ 35mm and 25 ~ 30mm.
Further, the output of described steel rolling gap normal water supply is 60m
3reducing the output supplied water when/h, steel rolling is 25 ~ 30m
3/ h.
Further, described in batch before need to carry out section cooling, described section cooling Schema control is the intensive cooling of leading portion.
Further, described chamfered uses chamfer crystallizer.
A kind of method improving high surface grade IF steel percentage elongation provided by the invention, IF steel in course of hot rolling can be avoided to occur pit, fine rule, stick up the defects such as skin, and obtain the high surface grade IF steel that surface quality is good, percentage elongation is high, concrete manifestation is as follows:
(1) slab tapping temperature is controlled at 1200 ± 20 DEG C, can effectively suppress precipitate back dissolving, be conducive to obtaining comparatively thick TiN, TiS and Ti
4c
2s
2deng precipitate, thus reduce the pining force to crystal boundary migration, be conducive to grain growth and improve finished product percentage elongation.
(2) controlling coiling temperature is 730 ~ 750 DEG C, TiC particle can be made to continue to separate out in ferrite, make it in coiling process, obtain alligatoring, thus improve finished product percentage elongation.
(3) optimize edger roll for water system, edger roll adopts when steel rolling gap normal water supply, steel rolling for water system and reduces the pattern supplied water, and can also reduce steel edge portion temperature drop, avoid border defect while guarantee edger roll normally works.
(4) optimize edger roll and subtract wide system, adopt edger roll to subtract wide rough rolling step the 1st, 3,5 passage, subtract wide amount and be respectively 15-10mm, 10-5mm and 5-0mm, can effectively suppress edge to stick up the defect such as skin, fine rule.
(5) slab carries out chamfered, can eliminate because cold melt causes that strip edge bight temperature is too low and edge that is that cause sticks up the defects such as skin.
Accompanying drawing explanation
The process control process figure of the method for the raising high surface grade IF steel percentage elongation that Fig. 1 provides for the embodiment of the present invention.
Reduce tapping temperature after heat flanging part in the method for the raising high surface grade IF steel percentage elongation that Fig. 2 provides for the embodiment of the present invention and stick up skin defect pattern.
Hot rolling surface topography after edger roll cooling water land use reform is optimized in the method for the raising high surface grade IF steel percentage elongation that Fig. 3 provides for the embodiment of the present invention.
Optimize edger roll in the method for the raising high surface grade IF steel percentage elongation that Fig. 4 provides for the embodiment of the present invention and subtract the rear hot rolling surface topography of wide amount distribution.
Cross sectional representation in the method for the raising high surface grade IF steel percentage elongation that Fig. 5 provides for the embodiment of the present invention after plate blank chamfering.
The hot rolling surface topography produced after slab being carried out edge chamfering in the method for the raising high surface grade IF steel percentage elongation that Fig. 6 provides for the embodiment of the present invention.
Detailed description of the invention
A kind of method improving high surface grade IF steel percentage elongation that the embodiment of the present invention provides, its production process comprises that continuous casting of molten steel obtains slab successively, heating slab, Vertical Rolling subtract wide, hot rolling flat rolling is thinning and high temperature coiling, in production process, production technology is controlled as follows:
(1) slab tapping temperature is controlled: slab tapping temperature controlled at 1200 ± 20 DEG C; Because reduce slab heating temperature to be conducive to separating out thick Ti
4c
2s
2particle, reduces tiny TiC particle, and lower heating-up temperature can also reduce the reverse amount of precipitation of second phase particles simultaneously, thus the Ti that the continuous casting stage has been separated out
4c
2s
2alligatoring more, thus the raising contributing to finished product percentage elongation.Therefore tapping temperature is controlled at 1200 ± 20 DEG C, can effective alligatoring second phase particles, improve finished product percentage elongation.
(2) high temperature coiling is adopted: the section cooling pattern adopting the intensive cooling of leading portion, by oiler temperature control at 730 ~ 750 DEG C; Because tiny precipitate can hinder the development of recrystallization texture, thick sparse precipitate is conducive to the formation of deep-draw texture, and then improves percentage elongation and the deep drawability of IF steel.Therefore 730 ~ 750 DEG C of high temperature coilings are adopted can effectively to improve finished product percentage elongation.
(3) edger roll is optimized for water system: edger roll adopts when steel rolling gap normal water supply, steel rolling for water system and reduces the pattern supplied water; The determination of finished width subtracts wide realization mainly through edger roll, need aborning to cool with recirculated water opposite roller, if cooling water inflow is too small, edger roll repeatedly contacts with high temperate zone steel and easily occurs crack due to thermal stress, if cooling water inflow is excessive, easily causes steel edge portion temperature drop excessive thus increase the weight of edge fault.Therefore adopt when steel rolling gap normal water supply, steel rolling and reduce the pattern supplied water, the output of steel rolling gap normal water supply is controlled as 60m
3/ h, to be reduced to by output during steel rolling be 25 ~ 30m
3/ h.Can edge be suppressed to stick up the defect such as skin, fine rule while guarantee edger roll normally works.
(4) optimize edger roll and subtract wide system: rough rolling step the 1st, 3,5 passage adopts edger roll to subtract wide, subtracts wide amount and is respectively 10 ~ 15mm, 5 ~ 10mm and 0 ~ 5mm; Needing to carry out edger roll at rough rolling step subtracts wide to ensure finished width requirement, and edger roll subtracts wide amount and divides pairing finished product quality of edges to have material impact, subtracts the excessive or passage unreasonable distribution of wide amount and easily increases the weight of edge fault.Therefore adopt the 1st, 3,5 passage edger rolls to subtract wide, and will to subtract wide amount profile set be 15-10mm, 10-5mm and 5-0mm, can ensure IF steel quality of edges.
(5) plate blank chamfering process: continuous casting steel billet four edges is along its length carried out chamfering, use chamfer crystallizer to be pruned by original right-angle side, width and thickness direction chamfered edge length are respectively 30 ~ 35mm and 25 ~ 30mm.What have the greatest impact to IF steel surface quality is that edge sticks up skin defect, the generation of this defect main low with edge metal temperature, poor fluidity is relevant.Chamfering is carried out to slab four direct limits along its length, can effectively improve edge Temperature Distribution, improve quality of edges.
Illustrate inventing a kind of method improving high surface grade IF steel percentage elongation provided below by embodiment.
Embodiment 1
Obtain slab through continuous casting of molten steel successively, heating slab, Vertical Rolling subtract wide, hot rolling flat rolling is thinning and the processing step such as high temperature coiling produces high surface grade IF steel.When other process conditions are identical, adopt the slab tapping temperature that two kinds different, contrast the impact of furnace temperature on mechanical properties such as finished product percentage elongation, two tapping temperatures are 1270 DEG C and 1210 DEG C.The mechanical property situations such as the percentage elongation of the finished product obtained are produced as shown in table 1 under two tapping temperatures.
Table 1
As can be seen from Table 1, lower slab tapping temperature is adopted effectively can to improve finished product percentage elongation and r value.Compared with the high temperature of 1270 DEG C is come out of the stove, the low temperature of 1210 DEG C is adopted to come out of the stove the percentage elongation and r value that can significantly improve finished product, percentage elongation is increased to 46.9% by 45.1%, r value is increased to 2.88 by 2.71, and yield strength and tensile strength only have the decline less than 3MPa, the serviceability of finished product can not be affected.
Embodiment 2
Other processing step is identical with process conditions, and under 1210 DEG C of low temperature come out of the stove situation, the present embodiment passes through two kinds of different coiling temperature comparative illustration coiling temperatures of height to the impact of the mechanical properties such as finished product percentage elongation.Two kinds of volume temperature are 650 DEG C and 750 DEG C.The mechanical property situations such as the percentage elongation of the finished product obtained are produced as shown in table 2 under two kinds of coiling temperatures.
Table 2
As can be seen from Table 2, improve coiling temperature and effectively can improve finished product percentage elongation and r value.Under 1210 DEG C of low temperature come out of the stove situation, when adopting the high temperature coiling of higher 750 DEG C that percentage elongation can be made to batch by 650 DEG C 46.9% is promoted to 48.9%, r value is promoted to 3.03 by 2.88, and yield strength and tensile strength slightly decline, but can not affect finished product serviceability.
Embodiment 3
See Fig. 2, reduce tapping temperature and can increase the weight of edge temperature drop while raising finished product percentage elongation, thus easily cause hot rolling edge fault to occur.Slab quality of edges is improved under coming out of the stove situation at slab low temperature, when processing step and other technological parameter are constant, opposite roller is optimized for water system, adopt when steel rolling gap normal water supply, steel rolling and reduce the edger roll of water supply pattern for water system, by cooling water flow in edge rolling process by 60m before
3/ h is reduced to 25 ~ 30m
3/ h, and rolling gap cooling water flow keeps 60m
3/ h is constant, and the hot rolling surface topography finally obtained as shown in Figure 3.Contrast from Fig. 2 and Fig. 3, during edge rolling, cooling water flow is reduced to 25 ~ 30m
3/ h effectively can improve the quality of edges of high surface grade IF steel.
Embodiment 4
The present embodiment be come out of the stove at slab low temperature, high temperature coiling and the cooling water flow in edge rolling process is reduced to 25 ~ 30m
3when/h, opposite roller subtracts wide system and is optimized.When processing step and other technological parameters are constant, change the wide amount that subtracts of edger roll 1,3,5 passage into 12mm, 8mm and 3mm respectively by original 25mm, 25mm, 10mm, the hot rolling surface topography that final production obtains as shown in Figure 4.As seen from Figure 4, after taking above-mentioned aggregate measures, the surface quality of high surface grade IF steel is improved.
Embodiment 5
Come out of the stove at slab low temperature, high temperature coiling, in the operation of rolling, steel edge portion temperature drop is larger, edge temperature is inevitably lower than heart portion temperature, can significantly improve hot rolling quality of edges by optimizing edger roll cooling water system and optimizing after edger roll subtracts wide system, but still thoroughly cannot eliminate coiled sheet edge fault.The present embodiment is when processing step and other technological parameters are constant, come out of the stove by slab low temperature in process of production in order to illustrate, high temperature coiling, optimization edger roll cooling water system and optimize after edger roll subtracts wide system, then the surface quality situation of change that chamfered produces the high surface grade IF steel obtained is carried out to slab.See Fig. 5, continuous casting steel billet is carried out chamfered, the length of the 35mm that pruned at four right angles along its length, the width of the 30mm that pruned at four right angles in the width direction entering stokehold.Slab rolling after final utilization chamfering produces the surface topography of the finished product obtained as shown in Figure 6.As seen from Figure 6, edge can be eliminated after further slab being carried out chamfered completely and stick up the defect such as skin, fine rule, the surface quality of high surface grade IF steel can be significantly improved.
A kind of method improving high surface grade IF steel percentage elongation provided by the invention, can significantly avoid producing the defect easily occurring pit in high surface grade IF steel course of hot rolling, obtain good surface quality, the percentage elongation of finished product can also be improved simultaneously, obtain the high surface grade IF steel having premium properties and excellent surface quality concurrently, can be used for follow-up preparation and require higher automobile exterior panel.
It should be noted last that, above detailed description of the invention is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to example to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.
Claims (4)
1. one kind is improved the method for high surface grade IF steel percentage elongation, its production process comprises that continuous casting of molten steel obtains slab successively, heating slab, Vertical Rolling subtract wide, hot rolling flat rolling is thinning and high temperature coiling, it is characterized in that, in production process, technique controls as follows:
(1) slab tapping temperature is controlled at 1200 ± 20 DEG C;
(2) by oiler temperature control at 730 ~ 750 DEG C;
(3) edger roll adopts when steel rolling gap normal water supply, steel rolling for water system and reduces the pattern supplied water;
(4) rough rolling step the 1st, 3,5 passage adopts edger roll to subtract wide, subtracts wide amount and is respectively 10 ~ 15mm, 5 ~ 10mm and 0 ~ 5mm;
(5) carry out chamfered, continuous casting steel billet four edges is along its length carried out chamfering, is pruned by original right-angle side, width and thickness direction chamfered edge length are respectively 30 ~ 35mm and 25 ~ 30mm.
2. the method for raising according to claim 1 high surface grade IF steel percentage elongation, is characterized in that: the output of described steel rolling gap normal water supply is 60m
3reducing the output supplied water when/h, steel rolling is 25 ~ 30m
3/ h.
3. the method for raising according to claim 1 high surface grade IF steel percentage elongation, is characterized in that: need before described high temperature coiling to carry out section cooling, and described laminar flow cooling control is the intensive cooling of leading portion.
4. the method for raising according to claim 1 high surface grade IF steel percentage elongation, is characterized in that: described chamfered uses chamfer crystallizer.
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| CN106607470A (en) * | 2015-10-25 | 2017-05-03 | 巨贾实业（上海）有限公司 | Manufacturing technology of high elongation steel plate |
| CN107096795A (en) * | 2017-05-23 | 2017-08-29 | 宁波钢铁有限公司 | A kind of manufacture method for reducing edge defects of hot rolled strip steel |
| CN108246812B (en) * | 2017-12-22 | 2019-06-04 | 包头钢铁（集团）有限责任公司 | A kind of hot rolled steel plate edge sticks up the control method of skin |
| CN109201747B (en) * | 2018-08-01 | 2020-03-17 | 北京首钢股份有限公司 | Control method for heating temperature of plate blank |
| CN109772883A (en) * | 2019-01-30 | 2019-05-21 | 北京首钢股份有限公司 | A kind of production method of IF steel |
| CN110576044B (en) * | 2019-09-05 | 2020-12-15 | 首钢集团有限公司 | Method for eliminating thin lines on hot-rolled edge of 440 MPa-level IF steel |
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| JPH01233005A (en) * | 1988-03-14 | 1989-09-18 | Sumitomo Metal Ind Ltd | Method for controlling plate width in hot rolling of thin cast billet |
| JPH0550130A (en) * | 1991-08-19 | 1993-03-02 | Nisshin Steel Co Ltd | Method for preventing oil pattern from being generated on cold rolled steel strip |
| CN101618396B (en) * | 2008-06-30 | 2011-01-19 | 上海梅山钢铁股份有限公司 | Method for rolling interstitial free steel ferrite on traditional hot rolling mills |
| CN101608285B (en) * | 2009-07-13 | 2011-06-01 | 山西太钢不锈钢股份有限公司 | Interstitial free (IF) hot rolled strip and manufacturing method thereof |
| CN101941024B (en) * | 2010-07-22 | 2012-06-27 | 河北省首钢迁安钢铁有限责任公司 | Method for eliminating peeling of IF steel edge in hot continuous rolling process |
| CN103014500B (en) * | 2012-12-26 | 2015-02-25 | 首钢总公司 | Ultrawide SEDDQ deep-drawing automobile sheet and production method thereof |
| CN103551382B (en) * | 2013-11-07 | 2015-08-26 | 首钢总公司 | A kind of production method solved containing P high-strength IF hot-strip straightening broken belt |
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Address after: 100041 Shijingshan Road, Beijing, No. 68, No. Patentee after: Shougang Group Co. Ltd. Address before: 100041 Shijingshan Road, Beijing, No. 68, No. Patentee before: Capital Iron & Steel General Company |
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