CN104307897B - Process method for eliminating pockmark defects on surface of strip steel - Google Patents
Process method for eliminating pockmark defects on surface of strip steel Download PDFInfo
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- CN104307897B CN104307897B CN201410542359.1A CN201410542359A CN104307897B CN 104307897 B CN104307897 B CN 104307897B CN 201410542359 A CN201410542359 A CN 201410542359A CN 104307897 B CN104307897 B CN 104307897B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 100
- 239000010959 steel Substances 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 69
- 230000007547 defect Effects 0.000 title claims abstract description 31
- 238000005096 rolling process Methods 0.000 claims abstract description 77
- 239000000498 cooling water Substances 0.000 claims abstract description 75
- 238000010079 rubber tapping Methods 0.000 claims abstract description 17
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 73
- 229910052742 iron Inorganic materials 0.000 claims description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 238000001816 cooling Methods 0.000 claims description 14
- 238000003801 milling Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000005516 engineering process Methods 0.000 description 7
- 238000005070 sampling Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 238000005098 hot rolling Methods 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000012876 topography Methods 0.000 description 1
Abstract
The invention discloses a process method for eliminating pockmark defects on the surface of strip steel, which comprises the following steps: controlling the slab tapping temperature of the strip steel to be 1130-1135 ℃; controlling a rough rolling unit to perform rough rolling on the plate blank by adopting a 3+ 5-pass rolling mode, and performing full-pass dephosphorization on the plate blank through a rough rolling procedure; carrying out finish rolling on the intermediate blank after rough rolling, and controlling the inlet temperature of the finish rolling of the intermediate blank to be 940-980 ℃; controlling the opening amount of cooling water between the first frame and the second frame between the first finishing mill and the second finishing mill to be 25-27%; controlling the opening amount of cooling water between the second frame and the third finishing mill to be 18-20%; controlling the opening amount of cooling water between the third frame and the fourth finishing mill to be 18-20%; controlling the opening amount of cooling water between the fourth finishing mill and the fifth finishing mill to be 45-50%; and controlling the rolling speed of the seventh finishing mill to be 4.5-5.5 m/s. Therefore, the defect of pockmarks on the surface of the strip steel is avoided from the source by optimizing the process of the rolling production line.
Description
Technical field
The present invention relates to technical field of steel rolling, particularly relate to a kind of technique side eliminating belt steel surface pit defect
Method.
Background technology
At present, in hot-strip production process, belt steel surface pit defect is to affect product surface quality
Key factor, pit defect has higher generation on think gauge (thickness G T.GT.GT 11.5mm) hot-rolled coil surface
Rate, especially has high incidence rate in the steel grade production processes such as think gauge wheel steel.Car wheel structure portion
Part typically uses rolling, spinning and Sheet Metal Forming Technology technology to shape, if belt steel surface has pit defect, then
Described strip steel easily produce in wheel arrangement forming process stress concentrate phenomenon, cause steel plate layering and
Cracking.Additionally, strip steel finished surface pit defect all cannot eliminate before and after spraying paint, have impact on product appearance
Quality, have impact on the market share of consumer products to a great extent.Therefore, the strip steel table that finishing is clean
In the face of car wheel structure product product is particularly important.
And causing the basic reason of belt steel surface pit defect is that belt steel surface iron scale is blocked up, prior art
In the mode on commonly used manual polishing surface to eliminate belt steel surface pit defect, this mode is the most time-consuming,
Effort, inefficiency, and also relatively costly.
Summary of the invention
The problem existed for prior art, embodiments provides a kind of belt steel surface pockmark that eliminates and lacks
The process fallen into, by hot rolling produces the process optimization of line, avoids belt steel surface fiber crops from source
The generation of hole defect.
The technical scheme is that and be achieved in that:
The embodiment of the present invention provides a kind of process eliminating belt steel surface pit defect, and described method includes:
The slab tapping temperature controlling described strip steel is 1130～1135 DEG C；
Controlling roughing mills uses the rolling mode of 3+5 passage described slab to be carried out roughing, by roughing work
Slab described in ordered pair carries out full passage dephosphorization；
Intermediate blank after roughing is carried out finish rolling, controls described intermediate blank entry temperature at finishing and be 940-980 DEG C；
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is
25%～27%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is
18%～20%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is
18%～20%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is
45%～50%；
Controlling the 7th finishing mill mill speed is 4.5～5.5m/s；Reduce the thickness of described belt steel surface iron scale
Degree.
In such scheme, control the slab tapping temperature of described strip steel and be 1130～1135 DEG C and include:
It it is 1130～1135 DEG C by the slab tapping temperature of strip steel described in Heating Furnace Control.
In such scheme, described control roughing mills uses the rolling mode of 3+5 passage to carry out described slab
Roughing includes:
First roughing mill uses the rolling mode of 3 passes and the second roughing mill to use 5 passes
Rolling mode, carries out roughing to described slab.
In such scheme, described by roughing operation, described slab carried out full passage dephosphorization include:
By the 1st, 2,3 rolling pass entrances of the first roughing mill, described slab carried out dephosphorization, and pass through
The 1st of second roughing mill, 2,3,4,5 rolling pass entrances described slab is carried out dephosphorization.
In such scheme, described control described intermediate blank entry temperature at finishing is 940-980 DEG C and includes: by control
Making the delay table between described second roughing mill and mm finishing mill unit and crossing steel speed is 5.0～6.0m/s, it is ensured that institute
State entry temperature at finishing and be 940-980 DEG C.
The first interstand cooling water in such scheme, between described control the first finishing mill and the second finishing mill
Open amount is 25%～27% to include: by control to arrange between described first finishing mill and the second finishing mill the
One interstand cooling (operating) water nozzle flow valve, controlling described first interstand cooling water open amount is 25%～27%.
The second interstand cooling water in such scheme, between described control the second finishing mill and the 3rd finishing mill
Open amount is 18%～20% to include: by control to arrange between described second finishing mill and the 3rd finishing mill the
Two interstand cooling (operating) water nozzle flow valves, controlling described second interstand cooling water open amount is 18%～20%.
The 3rd interstand cooling water in such scheme, between described control the 3rd finishing mill and the 4th finishing mill
Open amount is 18%～20% to include: by control to arrange between described 3rd finishing mill and the 4th finishing mill the
Three interstand cooling (operating) water nozzle flow valves, controlling described 3rd interstand cooling water open amount is 18%～20%.
The 4th interstand cooling water in such scheme, between described control the 4th finishing mill and the 5th finishing mill
Open amount is 45%～50% to include: by control to arrange between described 4th finishing mill and the 5th finishing mill the
Four interstand cooling (operating) water nozzle flow valves, controlling described 4th interstand cooling water open amount is 45%～50%.
The invention provides a kind of process eliminating belt steel surface pit defect, described method includes: control
The slab tapping temperature making described strip steel is 1130～1135 DEG C；Control roughing mills and use rolling of 3+5 passage
Molding formula carries out roughing to described slab, by roughing operation, described slab carries out full passage dephosphorization；To slightly
Intermediate blank after rolling carries out finish rolling, controls described intermediate blank entry temperature at finishing and is 940-980 DEG C；Control first
The first interstand cooling water open amount between finishing mill and the second finishing mill is 25%～27%；Control the second essence
The second interstand cooling water open amount between milling train and the 3rd finishing mill is 18%～20%；Control the 3rd finish rolling
The 3rd interstand cooling water open amount between machine and the 4th finishing mill is 18%～20%；Control the 4th finishing mill
And the 4th interstand cooling water open amount between the 5th finishing mill is 45%～50%；Control the 7th finishing mill to roll
Speed processed is 4.5～5.5m/s.So, band can be significantly reduced on the premise of not affecting other performances of product
Steel thickness of scale on surface, is greatly reduced the incidence rate of belt steel surface pit defect.
Accompanying drawing explanation
The process flow process signal eliminating belt steel surface pit defect that Fig. 1 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the first process that Fig. 2 provides for the embodiment of the present invention micro-
See structural representation；
The surface signal of the strip steel opening plate under the first process that Fig. 3 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the second process that Fig. 4 provides for the embodiment of the present invention micro-
See structural representation；
The surface signal of the strip steel opening plate under the second process that Fig. 5 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the third process that Fig. 6 provides for the embodiment of the present invention micro-
See structural representation；
The surface signal of the strip steel opening plate under the third process that Fig. 7 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the 4th kind of process that Fig. 8 provides for the embodiment of the present invention micro-
See structural representation；
The surface signal of the strip steel opening plate under the 4th kind of process that Fig. 9 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the 5th kind of process that Figure 10 provides for the embodiment of the present invention
Microstructure schematic diagram；
The surface signal of the strip steel opening plate under the 5th kind of process that Figure 11 provides for the embodiment of the present invention
Figure；
The iron scale of the belt steel surface under the 6th kind of process that Figure 12 provides for the embodiment of the present invention
Microstructure schematic diagram；
The surface signal of the strip steel opening plate under the 7th kind of process that Figure 13 provides for the embodiment of the present invention
Figure.
Detailed description of the invention
In various embodiments of the present invention, in order to fundamentally solve the pit defect of belt steel surface, it is provided that
A kind of process eliminating belt steel surface pit defect, described method includes: described method includes: control
The slab tapping temperature of described strip steel is 1130～1135 DEG C；Control roughing mills and use the rolling of 3+5 passage
Pattern carries out roughing to described slab, by roughing operation, described slab carries out full passage dephosphorization；To roughing
After intermediate blank carry out finish rolling, control described intermediate blank entry temperature at finishing and be 940-980 DEG C；Control the first essence
The first interstand cooling water open amount between milling train and the second finishing mill is 25%～27%；Control the second finish rolling
The second interstand cooling water open amount between machine and the 3rd finishing mill is 18%～20%；Control the 3rd finishing mill
And the 3rd interstand cooling water open amount between the 4th finishing mill is 18%～20%；Control the 4th finishing mill with
The 4th interstand cooling water open amount between 5th finishing mill is 45%～50%；Control the 7th finishing mill rolling
Speed is 4.5～5.5m/s；Reduce the thickness of described belt steel surface iron scale.
Below by drawings and the specific embodiments, technical scheme is described in further detail.
Embodiment one
The embodiment of the present invention provides a kind of process eliminating belt steel surface pit defect, as it is shown in figure 1,
Described method mainly includes several step:
Step 110, the slab tapping temperature controlling described strip steel is 1130～1135 DEG C；
In this step, before hot rolling, need the slab that molten steel casting is formed to heat, pass through
The slab tapping temperature of strip steel described in Heating Furnace Control is 1130～1135 DEG C, to guarantee that described strip steel finish rolling enters
Mouth temperature can be reduced to 940-980 DEG C.
Step 111, controls roughing mills and uses the rolling mode of 3+5 passage that described slab is carried out roughing,
By roughing operation, described slab carried out full passage dephosphorization；
In this step, by roughing mills, described slab being carried out roughing, described roughing mills uses 3+5 to roll
Molding formula carries out roughing to described slab；Wherein, described roughing mills includes: the first roughing mill R1, second
Roughing mill R2；Described first roughing mill R1 uses the rolling mode of 3 passages, and described second roughing mill R2
Use the rolling mode of 5 passages, described slab is carried out roughing.
Meanwhile, by roughing operation, described slab carried out full passage dephosphorization, it is ensured that the raw oxidation of steel slab surface stove
The removal effect of iron sheet；
Specifically, by the 1st, 2, the 3 rolling pass entrances of the first roughing mill R1, described slab is carried out
Dephosphorization, and by the 1st, 2,3,4, the 5 rolling pass entrances of the second roughing mill R2, described slab is entered
Row dephosphorization.
Step 112, carries out finish rolling to the intermediate blank after roughing, controls described intermediate blank entry temperature at finishing and is
940-980℃；
In this step, the intermediate blank that described slab is formed after roughing, through described second roughing mill R2 and essence
Delay table between milling train group enters the entrance of finishing mill；Wherein, described intermediate blank is at described delay table
During motion, the steel speed of crossing controlling described roller-way is 5.0～6.0m/s, to ensure that described intermediate blank enters finish rolling
Temperature during entrance is 940-980 DEG C.
Here, the finish rolling dephosphorization apparatus before finish rolling entrance uses the mode of double dephosphorization to remove institute's intermediate blank
Phosphorus, to remove the secondary oxidation iron sheet that on rough rolling process and delay table, belt steel surface is formed, it is ensured that strip steel
Surface quality.
Step 113, controls the first interstand cooling water open amount between the first finishing mill and the second finishing mill
It is 25%～27%；
Here, it is provided with the first interstand cooling water device between described first finishing mill and the second finishing mill,
By controlling the first interstand cooling (operating) water nozzle flow valve, the described first interstand cooling water open amount is made to be
25%～27%, to reduce surface temperature when described strip steel runs between the first finishing mill and the second finishing mill
Degree, controls the belt steel surface iron scale speed of growth, safeguards the apparent condition that the first precision rolling working roll is good,
The first precision rolling working roll surface film oxide is prevented to be destroyed the roll surface caused coarse.
Step 114, controls the second interstand cooling water open amount between the second finishing mill and the 3rd finishing mill
It is 18%～20%；
Here, it is provided with the second interstand cooling water device between described second finishing mill and the 3rd finishing mill,
By controlling the second interstand cooling (operating) water nozzle flow valve, the described second interstand cooling water open amount is made to be
18%～20%, to reduce described strip steel surface temperature between the second finishing mill and the 3rd finishing mill, control
The belt steel surface iron scale speed of growth, safeguards the apparent condition that finish rolling the second working roll is good, prevents second
It is coarse that precision rolling working roll surface film oxide is destroyed the roll surface caused.
Step 115, controls the 3rd interstand cooling water open amount between the 3rd finishing mill and the 4th finishing mill
It is 18%～20%；
Here, it is provided with the 3rd interstand cooling water device between described 3rd finishing mill and the 4th finishing mill,
By controlling the 3rd interstand cooling (operating) water nozzle flow valve, the described 3rd interstand cooling water open amount is made to be
18%～20%, to reduce described strip steel surface temperature between the 3rd finishing mill and the 4th finishing mill, control
The belt steel surface iron scale speed of growth, safeguards the apparent condition that the 3rd precision rolling working roll is good, prevents the 3rd
It is coarse that precision rolling working roll surface film oxide is destroyed the roll surface caused.
Step 116, controls the 4th interstand cooling water open amount between the 4th finishing mill and the 5th finishing mill
It is 45%～50%；
Here, it is provided with the 4th interstand cooling water device between described 4th finishing mill and the 5th finishing mill,
By controlling the 4th interstand cooling (operating) water nozzle flow valve, the described 4th interstand cooling water open amount is made to be
45%～50%, to reduce described strip steel surface temperature between the 4th finishing mill and the 5th finishing mill, control
The belt steel surface iron scale speed of growth, safeguards the apparent condition that the 4th precision rolling working roll is good, prevents the 4th
It is coarse that precision rolling working roll surface film oxide is destroyed the roll surface caused.
Here, between described 5th finishing mill and the 6th finishing mill, it is provided with the 5th interstand cooling water device；
The 6th interstand cooling water device, the present embodiment it is again provided with between the 6th finishing mill and the 7th finishing mill
The process provided only need to control the first interstand cooling water device, the second interstand cooling water device, the
Three interstand cooling water devices, the 4th interstand cooling water device and the 5th interstand cooling water device cold
But water open amount i.e. can reach the intended finish rolling interval belt steel surface iron scale thickness that controls, maintenance the first essence
Roll working roll, the second precision rolling working roll, the 3rd precision rolling working roll, the 4th precision rolling working roll roll surface kilter
Purpose.
Step 117, controlling the 7th finishing mill mill speed is 4.5-5.5m/s；
In this step, when strip steel runs to described seven finishing mill, controlling the 7th finishing mill mill speed is
4.5～5.5m/s, to control described strip steel in the section cooling district time of staying subsequently, reduce described belt steel surface
The thickness of iron scale.
The process eliminating belt steel surface pit defect that the embodiment of the present invention provides, rolls by optimizing hot rolling
System produces Wiring technology, avoids the generation of belt steel surface pit defect, improve strip surface quality from source
And production efficiency.
Embodiment two
The process eliminating belt steel surface pit defect that the present embodiment provides produces line at 2250mm hot continuous rolling
It is embodied as, is achieved the effect in anticipation.Here, the invention discloses following six kinds of technique sides
Method, carries out contrast test, and the control process in the case of every kind is different, specifically:
The first process: control actual tapping temperature 1168-1202 DEG C of band plate slab, roughing uses 1+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 1002-1044 DEG C, finish rolling to described slab rough rolling
Entrance is set to the mode of double de-scaling and described intermediate blank is carried out double de-scaling.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 28%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 20%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 20%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 49%；
The mill speed controlling the 7th finishing mill is 4.6m/s.By the first process, described band steel plate
Actual finishing temperature 820-860 DEG C of base.Sampling in strip width centre position, belt steel surface iron scale is micro-
As shown in Figure 2, the thickness of described iron scale is 15.5 microns for sight structure and thickness；Strip steel opening plate table
Face pattern is as shown in Figure 3.Owing to entry temperature at finishing is higher in the first process, cause strip steel table
Face iron scale is the thickest, and opening plate surface exists obvious pit defect.
The second process: control actual tapping temperature 1131-1160 DEG C of band plate slab, roughing uses 1+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 942-980 DEG C to described slab, and finish rolling entrance sets
The mode being set to double de-scaling carries out double de-scaling to described slab.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 20%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 18%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 18%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 18%；
The speed controlling the 7th finishing mill is 5.5m/s.By the second process, described band plate slab
Actual finishing temperature 820-860 DEG C.Sampling in strip width centre position, belt steel surface iron scale microcosmic is tied
As shown in Figure 4, the thickness of described iron scale is 19.3 microns for structure and thickness；Strip steel opening plate surface shape
Looks are as shown in Figure 5.Not enough owing to cooling down water open amount in the second process between finishing stand, cause
Belt steel surface iron scale is the thickest, and opening plate surface exists obvious pit defect.
The third process: control actual tapping temperature 1134-1174 DEG C of band plate slab, roughing uses 1+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 940-978 DEG C to described slab, and finish rolling entrance sets
The mode being set to double de-scaling carries out double de-scaling to described slab.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 30%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 20%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 20%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 50%；
The speed controlling the 7th finishing mill is 3.8m/s.By the third process, described band plate slab
Actual finishing temperature 820-860 DEG C.Sampling in strip width centre position, belt steel surface iron scale microcosmic is tied
As shown in Figure 6, the thickness of described iron scale is 21.2 microns for structure and thickness；Strip steel opening plate surface shape
Looks are as shown in Figure 7.Owing to, in the third process, finish rolling mill speed is relatively low, strip steel is in finish rolling district
And the layer-cold roller way time of staying is longer, causing belt steel surface iron scale the thickest, opening plate surface exists substantially
Pit defect.
4th kind of process: control actual tapping temperature 1130-1167 DEG C of band plate slab, roughing uses 3+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 940-977 DEG C to described slab, and finish rolling entrance sets
The mode being set to double de-scaling carries out double de-scaling to described slab.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 25%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 20%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 19%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 48%；
The speed controlling the 7th finishing mill is 4.5m/s.By the 4th kind of process, described band plate slab
Actual finishing temperature 820-860 DEG C.Sampling in strip width centre position, belt steel surface iron scale microcosmic is tied
As shown in Figure 8, the thickness of described iron scale is 10 microns for structure and thickness；Strip steel opening plate surface topography
As shown in Figure 9.Owing to, in the 4th kind of process, technology point controls good, belt steel surface ferrum oxide
Skin is relatively thin, and opening plate surface finishing is clean, has no obvious pit defect.
5th kind of process: control actual tapping temperature 1135-1170 DEG C of band plate slab, roughing uses 3+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 944-980 DEG C to described slab, and finish rolling entrance sets
The mode being set to double de-scaling carries out double de-scaling to described slab.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 30%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 18%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 20%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 46%；
The speed controlling the 7th finishing mill is 5.5m/s.By the 5th kind of process, described band plate slab
Actual finishing temperature 820-860 DEG C.Sampling in strip width centre position, belt steel surface iron scale microcosmic is tied
As shown in Figure 10, the thickness of described iron scale is 8.85 microns for structure and thickness；Strip steel opening plate surface
Pattern is as shown in figure 11.Owing to, in the 5th kind of process, technology point controls good, belt steel surface oxygen
Changing iron sheet relatively thin, opening plate surface finishing is clean, has no obvious pit defect.
6th kind of process: control actual tapping temperature 1132-1169 DEG C of band plate slab, roughing uses 3+5
Rolling mode, carries out full passage de-scaling, entry temperature at finishing 940-976 DEG C to described slab, and finish rolling entrance sets
The mode being set to double de-scaling carries out double de-scaling to described slab.
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is 27%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is 19%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is 18%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is 20%；
The speed controlling the 7th finishing mill is 5.0m/s.By the 6th kind of process, described band plate slab
Actual finishing temperature 820-860 DEG C.Sampling in strip width centre position, belt steel surface iron scale microcosmic is tied
As shown in Figure 12, the thickness of described iron scale is 7.82 microns for structure and thickness；Strip steel opening plate surface
Pattern is as shown in figure 13.Owing to, in the 6th kind of process, technology point controls good, belt steel surface oxygen
Changing iron sheet relatively thin, opening plate surface finishing is clean, has no obvious pit defect.
To sum up, use the process eliminating belt steel surface pit defect that the embodiment of the present invention provides, can have
Effect controls the thickness of belt steel surface iron scale, eliminates the pit defect of belt steel surface.
The above, only presently preferred embodiments of the present invention, it is not intended to limit the protection model of the present invention
Enclose, all any amendment, equivalent and improvement etc. made within the spirit and principles in the present invention, all should
Within being included in protection scope of the present invention.
Claims (9)
1. the process eliminating belt steel surface pit defect, it is characterised in that described method includes:
The slab tapping temperature controlling described strip steel is 1130～1135 DEG C；
Controlling roughing mills uses the rolling mode of 3+5 passage described slab to be carried out roughing, by roughing work
Slab described in ordered pair carries out full passage dephosphorization；
Intermediate blank after roughing is carried out finish rolling, controls described intermediate blank entry temperature at finishing and be 940-980 DEG C；
The the first interstand cooling water open amount controlled between the first finishing mill and the second finishing mill is
25%～27%；
The the second interstand cooling water open amount controlled between the second finishing mill and the 3rd finishing mill is
18%～20%；
The 3rd interstand cooling water open amount controlled between the 3rd finishing mill and the 4th finishing mill is
18%～20%；
The 4th interstand cooling water open amount controlled between the 4th finishing mill and the 5th finishing mill is
45%～50%；
Controlling the 7th finishing mill mill speed is 4.5～5.5m/s；Reduce the thickness of described belt steel surface iron scale
Degree.
2. the method for claim 1, it is characterised in that control the slab tapping temperature of described strip steel
It is 1130～1135 DEG C to include:
It it is 1130～1135 DEG C by the slab tapping temperature of strip steel described in Heating Furnace Control.
3. the method for claim 1, it is characterised in that described control roughing mills uses 3+5
The rolling mode of passage carries out roughing to described slab and includes:
First roughing mill uses the rolling mode of 3 passes and the second roughing mill to use 5 passes
Rolling mode, carries out roughing to described slab.
4. the method for claim 1, it is characterised in that described by roughing operation to described slab
Carry out full passage dephosphorization to include:
By the 1st, 2,3 rolling pass entrances of the first roughing mill, described slab carried out dephosphorization, and pass through
The 1st of second roughing mill, 2,3,4,5 rolling pass entrances described slab is carried out dephosphorization.
5. the method for claim 1, it is characterised in that described control described intermediate blank finish rolling entrance
Temperature is 940-980 DEG C and includes: by controlling the delay table mistake between described second roughing mill and mm finishing mill unit
Steel speed is 5.0～6.0m/s, it is ensured that described entry temperature at finishing is 940-980 DEG C.
6. the method for claim 1, it is characterised in that described control the first finishing mill and the second essence
The first interstand cooling water open amount between milling train is 25%～27% to include: by controlling described first finish rolling
The the first interstand cooling (operating) water nozzle flow valve arranged between machine and the second finishing mill, controls described first frame
Between cool down water open amount be 25%～27%.
7. the method for claim 1, it is characterised in that described control the second finishing mill and the 3rd essence
The second interstand cooling water open amount between milling train is 18%～20% to include: by controlling described second finish rolling
The the second interstand cooling (operating) water nozzle flow valve arranged between machine and the 3rd finishing mill, controls described second frame
Between cool down water open amount be 18%～20%.
8. the method for claim 1, it is characterised in that described control the 3rd finishing mill and the 4th essence
The 3rd interstand cooling water open amount between milling train is 18%～20% to include: by controlling described 3rd finish rolling
The 3rd interstand cooling (operating) water nozzle flow valve arranged between machine and the 4th finishing mill, controls described 3rd frame
Between cool down water open amount be 18%～20%.
9. the method for claim 1, it is characterised in that described control the 4th finishing mill and the 5th essence
The 4th interstand cooling water open amount between milling train is 45%～50% to include: by controlling described 4th finish rolling
The 4th interstand cooling (operating) water nozzle flow valve arranged between machine and the 5th finishing mill, controls described 4th frame
Between cool down water open amount be 45%～50%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410542359.1A CN104307897B (en) | 2014-10-14 | Process method for eliminating pockmark defects on surface of strip steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410542359.1A CN104307897B (en) | 2014-10-14 | Process method for eliminating pockmark defects on surface of strip steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104307897A CN104307897A (en) | 2015-01-28 |
| CN104307897B true CN104307897B (en) | 2017-01-04 |
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Address after: 100041 Shijingshan Road, Beijing, No. 68, No. Co-patentee after: Shougang Jingtang United Iron & Steel Co., Ltd. Patentee after: SHOUGANG GROUP Co.,Ltd. Address before: 100041 Shijingshan Road, Beijing, No. 68, No. Co-patentee before: Shougang Jingtang United Iron & Steel Co., Ltd. Patentee before: SHOUGANG Corp. |