CN105057351A - Ultrathin type hot rolled ribbon steel production line and matched process thereof - Google Patents

Abstract

The invention discloses an ultrathin type hot rolled ribbon steel production line and a matched process thereof. A heat preservation cover is installed on a steel passing roller path from a second roughening mill to a first intermediate vertical rolling machine set, and a first intermediate flat rolling machine set and a second intermediate vertical rolling machine set are sequentially installed between the first intermediate vertical rolling machine set and a second intermediate flat rolling machine set; and an eighth finish flat rolling machine set is installed between a seventh finish flat rolling machine set and a rolling and bundling procedure. According to the invention, the purpose of stably producing ultrathin type hot rolled ribbon steel can be achieved through adding and improvement of main equipment and auxiliary equipment of a 3/4 continuous tandem mill production line and the adjustment and optimization in the aspects such as rolling lines, blanks, rolling temperatures, rolling speeds and roll matching systems.

Description

Ultrathin mill coil production line and process matched therewith thereof

Technical field

The present invention relates to mill coil manufacturing technology, particularly ultrathin mill coil production line and process matched therewith thereof.

Background technology

At present, when supply exceed demand in mill coil market, competition, produce the mill coil of a kind of thickness at below 1.3mm, replace dimension cold-strip steel, become the economical substitute of its product, to expand the market scope of mill coil, have important practical significance.Adopt 3/4 continous way Continuous mill train to produce mill coil, for medium and small enterprise, have simplified apparatus and independent superiority of producing, the thickness of production is generally at 1.5 ~ 5.0mm; For producing the ultrathin mill coil of thickness at below 1.3mm, due to the defect of Design of Production Line aspect, rolling is unstable, and production difficulty is large, and lumber recovery is low, and production cost is high.

Summary of the invention

Technical problem to be solved by this invention is supplemented original rolling line equipment, complete the transformation to production line, by to rolling line, blank, rolling temperature, rolling mill speed, the adjustment of joining the aspects such as roller system, optimization, to reach the object of the ultrathin mill coil of steady production.

For achieving the above object, this invention takes following technical scheme, ultrathin mill coil production line, blank preparation, heating furnace, the first roughing milling train are connected successively with the second roughing milling train, thereafter be roll vertical miller group in first, offset rolling unit, finish rolling vertical miller group and the first to the 7th finish rolling flat roll mill group in second, third to connect successively, it is characterized in that, roll in vertical miller group and second to offset to be provided with successively in first to offset in rolling unit and second between rolling unit in first and roll vertical miller group; Roll up between bundling operation in the 7th finish rolling flat roll mill group and collection and the 8th finish rolling flat roll mill group is installed.

In order to middle blank reduces temperature drop, in the second roughing milling train to the first, roll crossing on steel rider road of vertical miller group stay-warm case is installed.

Described stay-warm case is casing arc frame cover body structure, and cover body central filler has heat-insulation layer.

Described heat-insulation layer is heat-preservation cotton or felt insulation.

A process matched therewith for ultrathin mill coil production line, its step is as follows:

1) steel billet is heated, preheating section, bringing-up section, soaking zone heating temperature range respectively: 800 ~ 1000 DEG C, 1200 ~ 1290 DEG C, 1200 ~ 1310 DEG C;

2) blank start rolling temperature 1140 ~ 1260 DEG C, adds up deflection by the steel billet passage crossing first, second roughing mill and is set as 50% ~ 70%, and in the middle of outlet, the gauge of blank is 38 ~ 42mm;

3) in the middle of, blank rolls in stay-warm case that to cross between vertical miller group and steel rider road increases and passes through in the second roughing mill and first;

4) in the middle of blank roll in first in vertical miller group, first offset in rolling unit, second roll vertical miller group, in second and third, offset rolling unit, finish rolling vertical miller group, the first to the 3rd finish rolling flat roll mill group and the work roll diameter by the 4th to the 6th finish rolling flat roll mill group be set to 280mm, 7th to the 8th finish rolling flat roll mill group work roll diameter is set to the mill milling of 250mm, finishing temperature >=855 DEG C;

5) cooling water pressure controls constant voltage by frequency modulation device, and each frame is imported and exported cooling water inflow and adopted gate valve to control, and roll coolant system cooling water injects directly on work roll, and is flowed away by work roll both sides;

6) flat roll mill group backing roll roll neck deviation from cylindrical form is less than 0.008mm, deviation from circular from is less than 0.003mm;

7) the mill speed fine setting scope of often overlapping milling train unit is ± 2m/s, and the highest mill speed reaches 10 ~ 15m/s.

Advantage of the present invention is by the increase to 3/4 continous way Continuous mill train production line capital equipment and auxiliary equipment, transformation, and optimizes on process system, reaches and realizes the object of stable rolling thickness at the mill coil of below 1.3mm.

1, optimize roughing technique, reduce the middle sotck thinkness of Continuous mill train entrance.

2, increase in, finishing mill line, in minimizing, the machine utilization of mm finishing mill unit, to reduce the elastic deformation of the stressed members such as the finisher frame, roll, roll bearing and the housing screw that cause because draught pressure is excessive and roll Fast Wearing and the thickness fluctuation caused.

3, reduce the diameter of four-high mill working roll, realize the object reducing draught pressure, four-high mill working roll bascule adopts reliable and stable hydraulic balance device.

4, by carry out heating furnace, roughing train improving improve in the middle of blank leave roughing mills time rolling temperature, and adopt effective in the middle of blank stay-warm case ensure the rolling temperature of middle blank.

5, each frame uses independent import and export cooling water inflow control system, with in strengthening, in the control ability, particularly low speed rolling of mm finishing mill unit cooling water inflow, the control ability of mm finishing mill unit cooling water inflow; Roll coolant system uses practical cooling water baffle device for water, realizes cooling water and injects directly on roll, and be not splashed on the steel band of rolling, avoids roll cooling water and injects directly on the rolling temperature drop that rolled steel strip causes on the surface.

6, DC power-supply system is adopted.In, mm finishing mill unit adopts reversible control system.

7, the backing roll roll neck of four-high mill unit is refined, make its bearing inner sleeve and its roll neck realize interference fit, to eliminate the problem producing gap between the two after a certain period of use time, meanwhile, the belt steel thickness fluctuation caused thus when reducing rolling.

8, improve the mill speed of mm finishing mill unit, reduce temperature drop.

Accompanying drawing explanation

Fig. 1 is production technological process of the present invention.

Fig. 2 is the stay-warm case schematic diagram in the present invention.

Detailed description of the invention

Below in conjunction with drawings and Examples, the invention will be further described, and see in Fig. 1 and Fig. 2, figure, each frame represents a production process or a set of production unit, and solid box is expressed as the original unit of rolling line, and empty wire frame representation is that rolling line increases unit newly; Arrow represents the direction that steel band runs; Z is intermediate mill classification, and J is mm finishing mill unit classification, and L is the working roll of unit is edger roll form, and P is the working roll of unit is plain-barreled roll form, and wherein numeral is the milling train unit of the identical working roll form of the identical unit classification of difference.Roll vertical miller group in ZL-, in ZP-, offset rolling unit, JL-finish rolling vertical miller group, JP-finish rolling flat roll mill group.

Ultrathin mill coil production line, blank prepares 101, heating furnace 102, first roughing milling train 103 is connected successively with the second roughing milling train 104, thereafter be roll vertical miller group ZL1 in first, second, rolling unit ZP2 is offseted in three, ZP3, finish rolling vertical miller group JL and first connects successively to the 7th finish rolling flat roll mill group JP1 ~ JP7, it is characterized in that, roll crossing on steel rider road of vertical miller group ZL1 in second roughing milling train 104 to the first and stay-warm case 105 is installed, roll in vertical miller group ZL1 and second to offset to be provided with successively in first to offset in rolling unit ZP1 and second between rolling unit ZP2 in first and roll vertical miller group ZL2, roll up between bundling operation 106 at the 7th finish rolling flat roll mill group JP7 and collection and the 8th finish rolling flat roll mill group JP8 is installed.

In order to middle blank reduces temperature drop, in the second roughing milling train 104 to the first, roll crossing on steel rider road of vertical miller group ZL1 stay-warm case 105 is installed.

Described stay-warm case 105 is made up of cover body 1051 and heat-insulation layer 1052, and be casing arc frame cover body structure, cover body 1051 central filler has heat-insulation layer.

Described heat-insulation layer 1052 is heat-preservation cotton or felt insulation.

A process matched therewith for ultrathin mill coil production line, its step is as follows:

1) steel billet is heated, preheating section, bringing-up section, soaking zone heating temperature range respectively: 800 ~ 1000 DEG C, 1200 ~ 1290 DEG C, 1200 ~ 1310 DEG C;

2) blank start rolling temperature 1140 ~ 1260 DEG C, adds up deflection by the steel billet passage crossing first, second roughing mill 103,104 and is set as 50% ~ 70%, and the gauge in the middle of outlet is 38 ~ 42mm;

3) in the middle of, blank rolls in stay-warm case 105 that to cross between vertical miller group ZL1 and steel rider road increases and passes through in the second roughing mill 104 and first;

4) in the middle of blank roll in first in vertical miller group ZL1, first offset in rolling unit ZP1, second roll vertical miller group ZL2, in second and third, offset rolling unit ZP2, ZP3, finish rolling vertical miller group JL, first to the 3rd finish rolling flat roll mill group JP1 ~ JP3 and the work roll diameter of the 4th to the 6th finish rolling flat roll mill group JP4 ~ JP6 is set to 280mm, 7th to the 8th finish rolling flat roll mill group JP7 ~ JP8 work roll diameter is set to the mill milling of 250mm, finishing temperature >=855 DEG C;

5) cooling water pressure controls constant voltage by frequency modulation device, and each frame is imported and exported cooling water inflow and adopted gate valve to control, and roll coolant system cooling water injects directly on work roll, and is flowed away by work roll both sides;

6) flat roll mill group backing roll roll neck deviation from cylindrical form is less than 0.008mm, deviation from circular from is less than 0.003mm;

7) the mill speed fine setting scope of often overlapping milling train unit is ± 2m/s, and the highest mill speed reaches 10 ~ 15m/s.

The present invention has following features:

1, increase a set of in roll two-roller mill unit ZP1, a set of in roll vertical miller unit ZL2 and a set of finish rolling four-high mill unit JP8 (see Fig. 1), according to newly added equipment, transform the transmission case hold down gag of original vertical miller unit ZL1, transform original finish rolling four-high mill unit JP5 ~ JP7 hydraulic working roll bascule.By in increasing unit and original Transformation of Unit and efficiently reducing, the machine utilization of finish rolling milling train unit, the thickness fluctuation caused to reduce the elastic deformation of the stressed members such as the finisher frame, roll, roll bearing and the housing screw that cause because draught pressure is excessive and roll Fast Wearing.

2, roughing rolling mill practice is optimized.Under the precondition meeting machine utilization, the roughing rolling schedule of first, second roughing milling train 103,104 is adjusted, the redesign of its to the effect that design of section of rolling mill major parameter, redistribute the deflection of the every a time steel billet of roughing milling train unit rolling, steel billet passage is made to add up deformation amount controlling 50% ~ 70%, make blank deformation more even, more rationally.Through rolling, efficiently reduce the gauge of middle blank, and stably control at 38 ~ 42mm, for its enter in, finish rolling Continuous mill train creates good condition, also thinly creates precondition for Continuous mill train rolls.

3, the optimization of heating steel billet system.Effective length 26 meters in heating-furnace, is divided into three sections to heat steel billet.Be respectively preheating section 8 meters, temperature range 800 ~ 1000 DEG C, heating steel billet; Bringing-up section 8 meters, temperature range 1200 ~ 1290 DEG C, makes steel billet temperature reach the required temperature of rolling; Soaking zone 12 meters, temperature range 1200 ~ 1310 DEG C, makes steel billet temperature completely even.By the optimization to heating steel billet system, for the rolling temperature of steel band ensures, rolled products performance is qualified provides precondition.

4, original four-high mill working roll roller system is transformed, the work roll diameter of first three frame finish rolling four-high mill unit of mm finishing mill unit JP4 ~ JP6 is reduced to 280mm, and last two frame finish rolling four-high mill unit JP7, JP8 work roll diameter are reduced to 250mm.Its main purpose is, thinly provides direct advantage for steel band rolls, and meanwhile, decreases steel band and to nip the nip angle of roll, for roll thin after steel band can enter lower a time rolling machine group smoothly and be rolled and create favorable conditions.

5, on the steel rider road excessively entering first 18 meters of Continuous mill train, stay-warm case 105 (see Fig. 2) is increased.Its material adopts the Q345B steel plate of 40 mm of thickness to make, and stay-warm case divides four sections to cover, and controls four sections of stay-warm cases respectively carry out opening and closing by four oil cylinders.The overall structure of every section of stay-warm case is identical, and be casing arc frame cover body structural design, central hollow, is wherein full of heat-preservation cotton or felt insulation, controls four sections of stay-warm case opening and closings respectively by four oil cylinders, and opening and closing mode is side turnover; The Main Function of stay-warm case is that in the middle of reducing, blank contacts with the direct of cold air in the operation of rolling, to reduce the cooling velocity of middle blank, reaches rolling temperature when improving tandem rolling, ensures the object of product mechanical performance.

6, cooling water pressure controls constant voltage by frequency modulation device, each frame is imported and exported cooling water inflow and is adopted gate valve to control, with in strengthening, the control ability of finish rolling Continuous mill train cooling water inflow, particularly in low speed rolling, the control ability of finish rolling Continuous mill train cooling water inflow, reach the object reduced with thickness, width difference before and after bar steel band; Namely roll coolant system uses harder real but the bakelite material plank not injuring roll surface abuts against on the work roll of rotation, realize cooling water can inject directly on work roll, major part cooling water is flowed away by work roll both sides, and do not flow directly on the steel band of high-speed rolling, avoid roll cooling water directly to flow in high-speed rolling steel strip surface, the rolling temperature drop caused.

7, increase the backing roll roll neck of a set of grinding machine to four-high mill unit to refine, the grinding accuracy of grinding machine reaches higher level, and namely deviation from cylindrical form is less than 0.008mm, deviation from circular from is less than 0.003mm.The Main Function of backing roll roll neck grinding makes its roller seat bearing inner sleeve and its roll neck realize interference fit, to eliminate the problem producing gap between the two after a certain period of use time, and the belt steel thickness caused thus when reducing rolling fluctuation.

8, Continuous mill train adopts full DC power-supply system, can realize the reversible rolling of Continuous mill train, and the mill speed enabling often to overlap milling train unit after interlock is finely tuned in ± 2m/s, to reach optimum efficiency, can realize the highest mill speed and reach 10 ~ 15m/s.

Embodiment 1: this embodiment is rolling grade of steel is Q235, specification is 132 × 1.3mm mill coil.

The strict rolling temperature controlling steel band in the operation of rolling, the heating-up temperature (soaking zone) of steel band, start rolling temperature and finishing temperature control respectively 1200 ~ 1310 DEG C, 1140 ~ 1260 DEG C, >=855 DEG C.The present embodiment: heating-up temperature 1290 DEG C, Optimal Control is at 1250 ~ 1300 DEG C; Start rolling temperature 1250 DEG C, Optimal Control is at 1240 ~ 1260 DEG C; Finishing temperature 865 DEG C, Optimal Control >=870 DEG C.

The rolling pattern of strict steel band in the operation of rolling.Specific as follows:

1. roughing: single chassis rolling, wherein Φ 600 milling train unit rolling 5 passage, mill speed 2.7mm/s, Φ 500 milling train unit rolling 3 passage, mill speed 2.6mm/s.Every time rolling procedure and the change of rolling blank area of section, represented by length × wide, and the length of blank can constantly stretch elongated according to the degree of distortion.The thickness of blank (be equivalent to the height of pass, lower with), specifically every time change is as shown in the table for width (be equivalent to the width of pass, lower with):

2. in, finish rolling: continual rolling is totally 14 passages, is respectively 1 vertical (edge rolling), 1 flat (flat rolling), 1 vertical (edge rolling), 2 flat (flat rollings), 1 vertical (edge rolling), 8 flat (flat rollings); Wherein edge rolling controls width, and flat rolling controls thickness, and mill speed and rolling thickness control to mate, as shown in the table:

Milling train	ZL1	ZP1	ZL2	ZP2	ZP3	JL	JP1	JP2	JP3	JP4	JP5	JP6	JP7	JP8
															Thickness mm	129	30	129	23	16	129	11	7.8	5.5	3.6	2.7	2.0	1.6	1.3
Width mm	42	133	31	131	133	17	130	130	131	131	131	132	132	132
															Speed m/s	0.3	0.4	0.4	0.5	0.7	0.7	1.1	1.5	2.1	3.3	4.3	5.9	7.3	9.0

Embodiment 2:

This embodiment is rolling grade of steel is Q195, specification is 163 × 1.2mm mill coil.

The present embodiment: heating-up temperature 1280 DEG C, Optimal Control is at 1240 ~ 1290 DEG C; Start rolling temperature 1240 DEG C, Optimal Control is at 1230 ~ 1260 DEG C; Finishing temperature 878 DEG C, Optimal Control >=860 DEG C.

1. roughing: single chassis rolling, wherein Φ 600 milling train unit rolling 3 passage, mill speed 2.7mm/s, Φ 500 milling train unit rolling 3 passage, mill speed 2.6mm/s.Every time rolling procedure and the change of rolling blank area of section, represented by length × wide, and the length of blank can constantly stretch elongated according to the degree of distortion.Specifically every time change is as shown in the table:

2. in, finish rolling: continual rolling is totally 14 passages, is respectively 1 vertical (edge rolling), 1 flat (flat rolling), 1 vertical (edge rolling), 2 flat (flat rollings), 1 vertical (edge rolling), 8 flat (flat rollings); Wherein edge rolling controls width, and flat rolling controls thickness, and each passes speed and rolling thickness control to mate, as shown in the table.

Milling train	ZL1	ZP1	ZL2	ZP2	ZP3	JL	JP1	JP2	JP3	JP4	JP5	JP6	JP7	JP8
															Thickness mm	160	30	160	23	16	160	11	7.8	5.5	3.6	2.7	2.0	1.5	1.2
Width mm	42	164	31	162	164	17	161	161	162	162	162	163	163	163
															Speed m/s	0.3	0.4	0.4	0.5	0.7	0.7	1.1	1.5	2.1	3.3	4.3	5.9	7.3	9.0

Technological process illustrates:

The present invention is is square by this kind of manufacture method and technique by cross section or the long base of rectangle is rolled into thickness at below 1.3mm, and width range is at the ribbon steel of 90 ~ 250mm, and its technological process is described as follows:

Blank preparatory process, provides blank by for base factory, detects according to concerned countries standard to the physical dimension of blank and metallographic structure.Detect qualified after enter next process.

Heating process, capital equipment is heating furnace.Detecting qualified square billet pushes in heating furnace, requires to heat it, enter next process after being heated to the rolling temperature of technological requirement according to heating process.

Roughing operation, capital equipment is Φ 600 roughing milling train unit, Φ 500 roughing milling train unit.Successively enter two cover milling train units carries out single chassis rolling to square billet, be square or the long base of rectangle by cross-sectional area, require to be rolled into thickness range at 38 ~ 42mm according to rolling mill practice, width is the middle blank of finished product requirement width, the qualified middle blank of rolling laggard enter next process.

In, finishing rolling step, capital equipment is stay-warm case, Z series rolling mill unit, J series rolling mill unit.Under middle blank keeping warm mode, enter each milling train unit successively and carry out interlock rolling, require middle blank to be rolled into qualified finished strip according to rolling mill practice.In order to coordinate rolling rhythm, the middle blank after roughing is incubated middle blank before entering tandem rolling, describes before the present invention of stay-warm case function; In the operation of rolling, the width of L series rolling mill unit allocation steel band, the thickness of P series rolling mill unit allocation steel band, the mill speed of milling train unit is often overlapped by PLC programme-control, the object of stable rolling steel band is reached with this, in order to reach the ultrathin mill coil of qualified below the 1.3mm of stable rolling further, the present invention has increased equipment newly to original production line and the equipment of reusing is transformed, and its summary of the invention describes above; Next process is entered after the qualified finished product of rolling.

Collection volume bundling operation, capital equipment is type reeling complexes and bundling complexes.Qualified band steel is carried out coil into band coil of strip and bundling, be beneficial to be with putting and protecting of steel.Next process is entered after bundling.

Weighman puts operation in storage, enters warehouse for finished product by after the steel coil strip weighman accomplishing fluently bundle.

The above is only the preferred embodiment of the present invention; should be understood that; for those skilled in the art; under the prerequisite not departing from the technology of the present invention principle; can also make some improvement and modification for different steel grade, these improve and modification also should be considered as protection scope of the present invention.

Claims (5)

1. ultrathin mill coil production line, blank preparation, heating furnace, the first roughing milling train are connected successively with the second roughing milling train, thereafter be roll vertical miller group in first, offset rolling unit, finish rolling vertical miller group and the first to the 7th finish rolling flat roll mill group in second, third to connect successively, it is characterized in that, roll in vertical miller group and second to offset to be provided with successively in first to offset in rolling unit and second between rolling unit in first and roll vertical miller group; Roll up between bundling operation in the 7th finish rolling flat roll mill group and collection and the 8th finish rolling flat roll mill group is installed.

2. ultrathin mill coil production line according to claim 1, is characterized in that, rolls crossing on steel rider road of vertical miller group and be provided with stay-warm case in the second roughing milling train to the first.

3. ultrathin mill coil production line according to claim 2, is characterized in that, described stay-warm case is casing arc frame cover body structure, and cover body central filler has heat-insulation layer.

4. ultrathin mill coil production line according to claim 3, is characterized in that, described heat-insulation layer is heat-preservation cotton or felt insulation.

5. a process matched therewith for a kind of ultrathin mill coil production line as claimed in claim 1, its step is as follows:

1) steel billet is heated, preheating section, bringing-up section, soaking zone heating temperature range respectively: 800 ~ 1000 DEG C, 1200 ~ 1290 DEG C, 1200 ~ 1310 DEG C;

2) blank start rolling temperature 1140 ~ 1260 DEG C, adds up deflection by the steel billet passage crossing first, second roughing mill and is set as 50% ~ 70%, and in the middle of outlet, the gauge of blank is 38 ~ 42mm;

3) in the middle of, blank rolls in stay-warm case that to cross between vertical miller group and steel rider road increases and passes through in the second roughing mill and first;

4) in the middle of blank roll in first in vertical miller group, first offset in rolling unit, second roll vertical miller group, in second and third, offset rolling unit, finish rolling vertical miller group, the first to the 3rd finish rolling flat roll mill group and the work roll diameter by the 4th to the 6th finish rolling flat roll mill group be set to 280mm, 7th to the 8th finish rolling flat roll mill group work roll diameter is set to the mill milling of 250mm, finishing temperature >=855 DEG C;

5) cooling water pressure controls constant voltage by frequency modulation device, and each frame is imported and exported cooling water inflow and adopted gate valve to control, and roll coolant system cooling water injects directly on work roll, and is flowed away by work roll both sides;

6) flat roll mill group backing roll roll neck deviation from cylindrical form is less than 0.008mm, deviation from circular from is less than 0.003mm;

7) the mill speed fine setting scope of often overlapping milling train unit is ± 2m/s, and the highest mill speed reaches 10 ~ 15m/s.