CN107904503A - Pickling vehicle structure steel plate and its production method are exempted from 510MPa grades of hot rollings - Google Patents
Pickling vehicle structure steel plate and its production method are exempted from 510MPa grades of hot rollings Download PDFInfo
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- CN107904503A CN107904503A CN201711190855.5A CN201711190855A CN107904503A CN 107904503 A CN107904503 A CN 107904503A CN 201711190855 A CN201711190855 A CN 201711190855A CN 107904503 A CN107904503 A CN 107904503A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
Abstract
The invention belongs to metallurgical technology field, and in particular to pickling vehicle structure steel plate and its production method are exempted from a kind of 510MPa grades of hot rolling.Pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling of the present invention, it is characterised in that：By weight percentage, its chemical composition is C：0.06~0.09%, Si：0.05~0.15%, Mn：1.10~1.20%, N：0.002~0.006%, P：0~0.025%, S：0~0.015%, Nb：0.015~0.030%, Ti：0.010~0.030%, Al：0.02~0.06%, remaining is Fe and inevitable impurity.The method of the present invention is by controlling suitable chemical composition, coordinate the process conditions such as suitable hot rolling heating-up temperature, finishing temperature, coiling temperature again, the finished steel sheet yield strength >=355MPa finally obtained, tensile strength >=510MPa, elongation percentage >=24%, cold-bending property are excellent.
Description
Technical field
The invention belongs to metallurgical technology field, and in particular to a kind of 510MPa grades of hot rolling exempt from pickling vehicle structure steel plate and its
Production method.
Background technology
Hot-rolled sheet coil is derusting and antirust, it is surface-treated always using technique skills such as pickling, cold rolling, galvanizing or coatings
Art, the scope that these technology for widening plate uses, but production cost is generally higher and inevitably environment is brought
Certain pollution, the pickling steel of exempting from for improving and developing for oxidation Rotating fields and thickness efficiently solve this problem.According to existing
For demands such as automobiles " energy-saving and emission-reduction, environmental protection, safety ", car manufactures can be exempted to proposing exploitation in terms of automobile component steel
The requirement of the steel products of pickling.The iron scale form that this hot-strip product surface produces is Fe3O4+ Fe, rather than often
Advise the Fe of product3O4+ FeO types.Due to Fe3O4Hardness with reduction, preferable plasticity and good adhesion, are adding deeply
It will not peel and rupture because of bending during work, therefore, can simplify or even fully phase out hot rolling using pickling steel is exempted from
Acid cleaning process afterwards, plays the role of steel industry environment-friendly type processing method positive.
At present, it is domestic to have developed the antirust agent for being sprayed at Surfaces of Hot Rolled Strip in terms of oxide layer structure control, although
It can promote surface Fe3O4Generation, but need increase cooling device, investment it is larger；And this method cannot produce Fe3O4+ Fe is easy
In the iron scale tissue of deformation.The technology that the country such as Japan, South Korea, Australia uses is to control oxidation in hot rolling production
The type production black rust steel of iron sheet, Japanese NKK, Nippon Steel and Kawasaki Steel etc. are in exploitation hot-rolled black-skin steel
Technical elements maintain the leading position.The exploitation that pickling steel is exempted from China's steel bound pair hot rolling is still in the exploratory stage at present, and automobile
The hot rolled plate user such as manufacturer is to this existing strong requirement.
For Miniature riding car material, 510MPa grades of hot rolled steel plates, which belong in automotive frame structure, mainly applies material
Material, common processing method for acid cleaning process remove surface oxide layer, using phosphating process formed phosphating coat improve steel plate with
The binding ability of finishing coat.In recent years, in order to adapt to the demand of vehicle lightness, partial automobile manufacturing enterprise is in 510MPa grades of buying
Low cost is proposed when vehicle structure is with hot rolled steel plate, exempts from the requirement of coil pickled surface quality, it is mainly shown in Table 1.
1 510MPa grades of hot-rolled structural steel mechanical property of table and processing performance requirement
The 510MPa grades of vehicle structures low C-Mn-V microalloyings of the domestic and international generally use of hot rolled steel plate Design of Chemical Composition
Scheme, Mn contents are generally 1.30%, and C content is generally 0.08% or so, and V content 0.08% or so, hot rolling technology is using control
Roll control it is cold, its technical characterstic is the effect for more considering alloying element solid solution strength and refined crystalline strengthening, but needs the later stage to increase
Add pickling process, there are production cost is higher and spent acid environmental protection treatment fringe cost.
The content of the invention
For existing 510MPa grades of vehicle structure steel plate, the present invention provides a kind of new 510MPa levels vehicle structure use
Pickled plate and its production method are exempted from hot rolling.The present invention is using the low micro- Nb+Ti alloyings schemes of Si- of low C-Mn-, with reference to controlled rolling control
Cold mode is produced, and hot rolling obtains a certain amount of ferrite, pearlite group using the method for controlled rolling and control cooling
Knit.The 510MPa level vehicle structures of the method for the present invention production have good room-temperature mechanical property and craftsmanship with hot rolled steel plate
Can, Fe in finished surface iron scale3O4For shared ratio more than 85%, iron scale thickness≤10 μm, adapt to automobile structure
Part enterprise exempts from pickling production requirement, steel it is cost-effective, promote the use of and have good prospects.
The 510MPa level hot rollings that first technical problem to be solved by this invention is to provide a kind of high comprehensive performance are exempted from
Pickling vehicle structure steel plate.Pickling vehicle structure steel plate is exempted from the 510MPa grades of hot rolling, and by weight percentage, its chemical composition is
C：0.06~0.09%, Si：0.05~0.15%, Mn：1.10~1.20%, N：0.002~0.006%, P：0~0.025%,
S：0~0.015%, Nb：0.015~0.030%, Ti：0.010~0.030%, Al：0.02~0.06%, remaining is for Fe and not
Evitable impurity.
Second technical problem to be solved by this invention is to provide above-mentioned 510MPa grades of hot rolling and exempts from pickling automobile structural steel
The production method of plate.The production method comprises the following steps：It is blast-melted to be made through converter smelting, LF refining, electrical heating, continuous casting
Steel billet, steel billet is heated, hot rolling, cools down, batches up to steel plate finished product；Wherein, steel billet chemical composition is C：0.06~0.09%,
Si：0.05~0.15%, Mn：1.10~1.20%, N：0.002~0.006%, P：0~0.025%, S：0~0.015%,
Nb：0.015~0.030%, Ti：0.010~0.030%, Al：0.02~0.06%, remaining is Fe and inevitable impurity；
Billet heating temperature is 1215~1230 DEG C, when the time is 1.2~1.8 small；The start rolling temperature of hot rolling roughing is 1175~1200
DEG C, 22.0~27.0MPa of de-scaling water pressure；950~1010 DEG C of finish rolling start rolling temperature, finish rolling open rolling 1.70~2.50m/s of speed,
Finishing temperature is 860~890 DEG C, finish to gauge outlet 8.0~14.0m/s of mill speed；Cooling uses the sparse type of cooling；Batch temperature
Spend for 570~590 DEG C.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, the speed of the cooling
For 10~30 DEG C/sec, 570~590 DEG C are cooled to.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, the tapping of converter smelting
Temperature is 1665~1685 DEG C, and oxygen activity condition is [a during tapping0] 100~450PPm.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, the time of converter smelting
For 35~45 minutes.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, the steel in converter smelting
The deoxidier that water deoxygenation step adds is ferro-aluminum, and the addition of deoxidier is 400~550Kg/ stoves.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, the temperature of argon bottom-blowing
For 1600~1650 DEG C, pressure is 200~500 pas, and the time is 4~8 minutes.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, secondary to feed Al line traffic controls
Molten steel oxygen activity is 20~40ppm.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, right after secondary hello Al lines
Molten steel pot bottom is passed through the argon gas 4~6 minutes of 200~500Pa of pressure, and argon flow amount is not turned over as condition very much with molten steel.
Preferably, above-mentioned 510MPa grades of hot rolling is exempted from the production method of pickling vehicle structure steel plate, is fed in electrical heating and benefit
Ca Si wire feeding, wherein Ca >=24% again after Al lines,1000~1200 meters/stove of addition.
The method of the present invention is by controlling suitable chemical composition, then coordinates suitable hot rolling heating-up temperature, finishing temperature, volume
The process conditions such as temperature are taken, the finished steel sheet yield strength >=355MPa finally obtained, tensile strength >=510MPa, elongation percentage >=
24%, cold-bending property is excellent.The 510MPa grades of vehicle structure hot rolling exempt from pickled plate have good room-temperature mechanical property and
Processing performance, complies fully with the requirement of technical indicator.Its heterogeneous microstructure includes ferrite and pearlite, with crystal structure
On the basis of cumulative volume, ferritic percentage by volume is 88~90%, and the percentage by volume of pearlite is 10~12%.Ferrite
And the percentage by volume of pearlite can be measured using well known to a person skilled in the art method, such as 6394 metallographics of GB/T
Method.
Fe in gained steel plate finished surface iron scale of the invention3O4Shared ratio is more than 85%, iron scale thickness
≤ 10 μm, user can be effectively adapted to and exempt from pickling requirement.
Compared with the same level hot rolled steel plate method that low C-Mn-V alloyings produce, the method for the present invention has the method for the present invention
The advantages of technique is simple, production cost is relatively low, can effectively substitute acid cleaning process, have higher cost performance, before promoting the use of
Scape is good.
Embodiment
The 510MPa grades of the present invention technological process of production for exempting from pickling vehicle structure hot rolled steel plate is as follows：Converter smelting
Refining → LF refining → electrical heating → continuous casting → hot rolling → cools down → batches → finishing → packaging and storage.
Wherein, converter smelting is specially and smelts blast-melted and smelting furnace material in converter to obtain molten steel, then by steel
Water deoxygenation simultaneously carries out alloying；Carbonaceous material, aluminum-manganese-iron alloy and aluminum shot are added to the steel after deoxidation in alloying step
In water, it is C to obtain molten steel (on the basis of molten steel gross weight, in terms of simple substance)：0.06~0.09%, Si：0.05~0.15%,
Mn：1.10~1.20%, N：0.002~0.006%, P：0~0.025%, S：0~0.015%, Nb：0.015~0.030%,
Ti：0.010~0.030%, Al：0.02~0.06%, remaining is Fe and inevitable impurity.In order to make S in feed stock for blast furnace
Content be less than or equal to 0.015% into stove molten iron gross weight, low-sulfur molten iron or semisteel smelting can be used.It is golden in order to prevent
Belong to the scaling loss of element especially manganese element, strictly to control oxygen activity when smelting process temperature and tapping, smelting condition is
1665~1685 DEG C of steel temperature, oxygen activity condition is [a during tapping0] 100~450PPm.Smelting process addition carbonaceous material be
Carbonaceous material known in this field, is preferably at least one of pitch coke, anthracite or carbon dust.The time of smelting is conventional smelting
Time, be preferably 35~45 minutes.
Wherein, the purpose of deoxidation of molten steel is the oxygen activity for reducing molten steel to improve yield of alloy.The deoxidier is aluminium
Iron.The addition of deoxidier is preferably 400~550Kg/ stoves.
Wherein, alloying step by the way of batch charging, external refining is using well known to a person skilled in the art side
Method.Alloying step after deoxidation includes ferro-aluminum, carbonaceous material, silicomangan, ferro-niobium being added in the molten steel after deoxidation, obtains
To molten steel (on the basis of the molten steel gross weight, in terms of simple substance) C：0.06~0.09%, Si：0.05~0.15%, Mn：1.10
~1.20%, N：0.002~0.006%, P：0~0.025%, S：0~0.015%, Nb：0.015~0.030%, Ti：
0.010~0.030%, Al：0.02~0.06%, remaining is Fe and inevitable impurity.
Wherein, in order to ensure that the chemical composition of steel is uniform, argon bottom-blowing processing is carried out to ladle after alloying.The bottom
The condition of Argon gas disposal is 1600~1650 DEG C of temperature, 200~500 pa of pressure, 4~8 minutes time.
Wherein, it is that the oxygen activity, degree of purity and temperature of molten steel are finely adjusted the purpose of LF refining step, Al is fed using secondary
It is 20~40ppm that line final deoxidizing, which controls the oxygen activity of molten steel, and molten steel pot bottom is passed through 4~6 points of the argon gas of 200~500Pa of pressure
Clock, argon flow amount are not turned over as condition very much with molten steel, can occur secondary oxidation to avoid molten steel and temperature declines too fast, make to press from both sides in steel
Debris fully floats, and further improves steel cleannes.External refining process is vulcanized using Si-Ca lines in the method for the present invention
Thing denaturation treatment, sulfide usually exist in steel grade with ribbon or corynebacterium, are unfavorable for the punching performance of steel, thus outside stove
Sulfide denaturation treatment, Ca are used during refining treatment:S >=2.0, improve molten steel cleanliness, and make to remain nonmetallic folder in steel
Miscellaneous shape is abnormal, is rolled from ribbon from the edge of last before processing to distribution or corynebacterium and becomes hammer-imitation type or spherical, improves steel plate
Cold forming capability.Ca Si wire feeding, which is carried out, after Al lines are fed in electrical heating and benefit (contains Ca >=24%, specification：) processing, add
Enter 1000~1200 meters/stove of amount.
Wherein, the purpose of electrical heating step it is the operation that reaches steel billet suitable for cast temperature, is the base of continuous casting steel production
This process.Heating is carried out to steel billet can be using well known to a person skilled in the art various heating equipments and heating means.
Wherein, direct casting step can be used well known to a person skilled in the art method, and the method for the present invention is by after refining
Molten steel cast to the tundish roasted in advance, through whole process protect continuous casting machine be cast into slab., can be by after casting
More solito is cooled down, such as natural cooling at room temperature.
Wherein, the start rolling temperature of hot rolling refers to the temperature that steel billet enters milling train, is heated, can fully consolidated at such a temperature
Molten microalloy element, eliminates that skewness causes the bad work of performance in steel because of continuous casting steel billet dendritic segregation, microalloy element
With.The finishing temperature of hot rolling refers to the temperature that steel band goes out mm finishing mill unit, in order to make the thickness of finished product and mechanical property uniform, using heat
Roll middle base Coil Box technology, make the hot-rolled intermediate billet material head before finish rolling, in, afterbody keep specific finishing temperature.This
Invention hot rolling heating-up temperature is 1215~1230 DEG C, the time for 1.2~1.8 it is small when, the roughing temperature of hot-rolled step for 1175~
1200 DEG C, de-scaling 22.0~27.0MPa of water pressure, 950~1010 DEG C of finish rolling start rolling temperature, open rolling 1.70~2.50m/s of speed,
Finishing temperature is 860~890 DEG C, finish to gauge outlet 8.0~14.0m/s of mill speed；Temperature control in course of hot rolling can make
Steel is in complete austenite structure before finish rolling outlet；And avoid austenite structure excessively thick, be conducive to control and be rolled into
Product ferrite grain size is 5.6~7.9 microns, improves refined crystalline strengthening effect.Due to exempting from the oxide layer of pickling steel requirement finished product
Thickness is thin, structure is mainly 10-20%FeO+Fe3O4, finish rolling start rolling temperature mainly influences the thickness of iron scale original thickness three times
It is thin, it is directly related to finished product thickness；Open rolling speed is higher, and strip is shorter in the high-temperature region residence time, and oxide layer is thinner；Finish to gauge speed
Degree is also same reason.Coiling temperature is set according to FeO eutectoids curve, and it is 570~590 to control coiling temperature
DEG C, it may be such that the oxidation Rotating fields that eutectoid reaction is required occur as far as possible for the structure FeO of oxide layer in the temperature.
Wherein, hot-rolled step be by the slab of casting it is heated after rolled.It is to make 510MPa grades of automobiles to roll purpose
The continuous casting steel billet of structural steel reaches required thickness.The rolling pass of hot rolled plate steel band of the present invention is roughing 6, finish rolling 6~7
A, every time rolling makes the thickness of hot rolling material base reduce 3~9 millimeters together for every frame rack rolling.General rolling raw thickness
230mm, producible thickness range cover 4~10.0mm.
Wherein, cooling step uses the sparse type of cooling, it is therefore an objective to reduces the thermal stress of surface oxide layer, avoids cooling speed
Spend fast surface oxide layer and form microcrack, cause oxide layer to decline with combining power substantially.For sheet steel band, including
Sheet steel band by rolling have adjusted the structural state inside steel after supercooling, then carry out batching coiled.In order to full
The tissue and performance requirement of sufficient hot rolled plate, the steel band come out from milling train must in a short period of time, in very high cooling velocity
Under be cooled to coiling temperature and batched.For example, the speed of the cooling is 10~30 DEG C/sec, 570~590 DEG C are cooled to.
The detection method of chemical composition is respectively carbon steel and middle-low alloy steel spark source atomic emission spectrometry in the present invention
Analysis method, national standard GB/T4336.
The invention will be further elaborated with reference to embodiments.Embodiment is merely to illustrate the present invention, rather than with
Any mode limits the present invention.
Embodiment 1
A, smelting molten steel：Smelting equipment is 220 tons of combined blown converters, blast-melted to be used as raw material, blast-melted temperature 1375
DEG C, add steelmaking ingredient melting to 1678 DEG C of tappings and arrive ladle, (Anyang is good prosperous for addition 1000Kg alfers during tapping 1/3
Nai Cai Co., Ltds) pre-deoxidation, pitch coke (the limited public affairs of Panzhihua Yangcheng metallurgic auxiliary materials are then added into the molten steel after deoxidation
Department) and silicomangan (Dechang ferroalloy Co., Ltd) so that the content of each component is (using the gross weight of molten steel as base in molten steel
Standard, wt%) C：0.07、Si：0.09、Mn：1.15、P：0.010、S：0.005、Nb：0.022、Ti：0.015、Al：0.04、N：
0.0040, remaining is Fe.Then outside stove chain-wales to ladle carry out argon bottom-blowing processing, 200~500Pa of argon pressure,
Time is 4 minutes.
The content for making oxygen in molten steel by controlling the additive amount of deoxidier is 10~50ppm, prevents manganese from aoxidizing as far as possible,
So as to ensure that manganese exists with simple substance in the hot-rolled structural steel of preparation, rather than exist in the form of an oxide, to give full play to list
The function of matter manganese.
B, LF electrical heating：Secondary to feed Al line final deoxidizings, molten steel pot bottom is passed through the argon gas 5 of certain pressure (200~500Pa)
Minute, argon flow amount is not turned over very much with molten steel adds the Si-Ca lines of 1050m by wire feeder to ladle backward for condition, blowing argon gas,
LF handles 1595 DEG C of final temperature.
C, continuous casting：Ladle is transported to casting position, basal sliding mouth of a river Al matter stopper (the auxiliary limited public affairs of Anyang smelting of ladle
Department), molten steel automatically flows into tundish, through Al matter stopper, is drained to crystallizer progress direct casting.Whole process using covering slag into
Row protective casting, casting postcooling is into hot rolled plate steel billet.
D, hot rolling：Slab comes out of the stove rolling temperature as 1225 DEG C (eliminating dendritic segregation, control original austenite grains size),
When time is 1.8 small；Roughing temperature is 1180 DEG C, de-scaling water pressure 22.5MPa, 1000 DEG C of finish rolling start rolling temperature, open rolling speed
1.75m/s, finishing temperature are 875 DEG C, finish to gauge outlet mill speed 8.8m/s；Cooling step uses the sparse type of cooling；Batch
578 DEG C of step temperature.The rolling pass of finish rolling is 7, every time roll so that among base thickness be respectively 42~30 millimeters,
30~21 millimeters, 21~18 millimeters, 18~14 millimeters, 14~11 millimeters, 11~8 millimeters, 8~5 millimeters.
E, finishing：Packaging and storage after the flattened unit of steel band is rolled up separately.
The coiled sheet of preparation is subjected to measuring mechanical property, yield strength Rel, the tensile strength Rm of room temperature is detected respectively and stretches
Long rate A tensile properties are carried out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is
480MPa, tensile strength (Rm) are 569MPa, and elongation percentage (A) is 27%, and cold bending process experimental performance is qualified, and finished product oxygen iron sheet is thick
7.6 μm of degree, Fe in scale on surface3O4Ratio reach 88%, meet the skill that 510MPa exempts from pickled hot vehicle structure steel plate
The requirement of art condition.
Embodiment 2
Preparation method is substantially the same manner as Example 1, the difference is that the molten steel composition that converter smelting obtains is C：0.08、Si：
0.10、Mn：1.12、P：0.013、S：0.006、Nb：0.020、Ti：0.013、Al：0.05、N：0.0036, remaining is Fe, (heavy
Measure percentage, %) and with foregoing molten steel production hot rolled steel plate, 1220 DEG C of slab tapping temperature, finish rolling open rolling speed 1.72m/
S, finish to gauge outlet mill speed 8.5m/s；Finishing temperature is 885 DEG C, and coiling temperature is 580 DEG C, hot-rolled finished product thickness 6.0mm.
The coiled sheet of preparation is subjected to measuring mechanical property, yield strength Rel, the tensile strength Rm of room temperature is detected respectively and stretches
Long rate A, tensile property are carried out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is
485MPa, tensile strength (Rm) are 575MPa, and elongation percentage (A) is 26%, and cold bending process experimental performance is qualified, and finished product oxygen iron sheet is thick
8.5 μm of degree, Fe in scale on surface3O4Ratio reach 85%, meet the skill that 510MPa exempts from pickled hot vehicle structure steel plate
The requirement of art condition.
Comparative example
Preparation method is substantially the same manner as Example 1, the difference is that the molten steel composition that converter smelting obtains is C：0.08%,
Si：0.25%, Mn：1.30%, P：0.016%, S：0.007%, V：0.08%, Als:0.054% remaining be Fe, and with foregoing
The hot rolled steel plate of molten steel production, 1210 DEG C of slab tapping temperature, finish rolling open rolling speed 1.30m/s, finish to gauge outlet mill speed
5.0m/s；Finishing temperature is 870 DEG C, and coiling temperature is 630 DEG C, hot-rolled finished product thickness 5.0mm.
The coiled sheet of preparation is subjected to measuring mechanical property, detects the tensile strength Rm and elongation A of room temperature, draftability respectively
It can be carried out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is 510MPa, tensile strength
(Rm) it is 535MPa, elongation percentage (A) is 27%, and cold bending process experimental performance is qualified, 13 μm or so of finished product oxygen thickness of scale, surface
Fe in iron scale3O4Ratio be 60%, mechanical property and scale structure do not meet 510MPa and exempt from pickled hot automobile knot
The technical conditions requirement of structure steel plate.
Claims (10)
- Pickling vehicle structure steel plate is exempted from 1.510MPa grades of hot rollings, it is characterised in that：By weight percentage, its chemical composition is C： 0.06~0.09%, Si：0.05~0.15%, Mn：1.10~1.20%, N：0.002~0.006%, P：0~0.025%, S： 0~0.015%, Nb：0.015~0.030%, Ti：0.010~0.030%, Al：0.02~0.06%, remaining is Fe and can not The impurity avoided.
- 2. the production method of pickling vehicle structure steel plate is exempted from the 510MPa level hot rollings described in claim 1, it is characterised in that：Including Following steps：It is blast-melted that steel billet is made through converter smelting, LF refining, electrical heating, continuous casting, steel billet is heated, hot rolling, cooling, Batch up to steel plate finished product；Wherein, steel billet chemical composition is C：0.06~0.09%, Si：0.05~0.15%, Mn：1.10~ 1.20%th, N：0.002~0.006%, P：0~0.025%, S：0~0.015%, Nb：0.015~0.030%, Ti：0.010 ~0.030%, Al：0.02~0.06%, remaining is Fe and inevitable impurity；Billet heating temperature is 1215~1230 DEG C, when the time is 1.2~1.8 small；The start rolling temperature of hot rolling roughing is 1175~1200 DEG C, de-scaling water pressure 22.0~ 27.0MPa；950~1010 DEG C of finish rolling start rolling temperature, finish rolling open rolling 1.70~2.50m/s of speed, finishing temperature are 860~890 DEG C, finish to gauge outlet 8.0~14.0m/s of mill speed；Cooling uses the sparse type of cooling；Coiling temperature is 570~590 DEG C.
- 3. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The speed of the cooling is 10~30 DEG C/sec, is cooled to 570~590 DEG C.
- 4. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The tapping temperature of converter smelting is 1665~1685 DEG C, and oxygen activity condition is [a during tapping0] 100~450PPm.
- 5. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The time of converter smelting is 35~45 minutes.
- 6. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The deoxidier that deoxidation of molten steel step in converter smelting adds is ferro-aluminum, and the addition of deoxidier is 400~550Kg/ stoves.
- 7. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The temperature of argon bottom-blowing is 1600~1650 DEG C, and pressure is 200~500 pas, and the time is 4~8 minutes.
- 8. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： Secondary Al line traffic control molten steel oxygen activity of feeding is 20~40ppm.
- 9. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, it is characterised in that： The argon gas of 200~500Pa of pressure is passed through after secondary hello Al lines to molten steel pot bottom 4~6 minutes, argon flow amount is not turned over very much with molten steel For condition.
- 10. the production method of pickling vehicle structure steel plate is exempted from 510MPa grades of hot rolling according to claim 2, its feature exists In：Ca Si wire feeding, wherein Ca >=24% again after Al lines are fed in electrical heating and mending,Addition 1000~1200m/ stoves.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201711190855.5A CN107904503A (en) | 2017-11-24 | 2017-11-24 | Pickling vehicle structure steel plate and its production method are exempted from 510MPa grades of hot rollings |
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| CN201711190855.5A CN107904503A (en) | 2017-11-24 | 2017-11-24 | Pickling vehicle structure steel plate and its production method are exempted from 510MPa grades of hot rollings |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101935802A (en) * | 2010-09-30 | 2011-01-05 | 攀钢集团钢铁钒钛股份有限公司 | Method for producing 490MPa level acid-washing-free hot rolled steel plate |
| CN105369134A (en) * | 2015-11-12 | 2016-03-02 | 攀钢集团攀枝花钢铁研究院有限公司 | Hot rolled steel plate for 400MPa-level acid-pickling-free automobile structure and production method of hot rolled steel plate |
-
2017
- 2017-11-24 CN CN201711190855.5A patent/CN107904503A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101935802A (en) * | 2010-09-30 | 2011-01-05 | 攀钢集团钢铁钒钛股份有限公司 | Method for producing 490MPa level acid-washing-free hot rolled steel plate |
| CN105369134A (en) * | 2015-11-12 | 2016-03-02 | 攀钢集团攀枝花钢铁研究院有限公司 | Hot rolled steel plate for 400MPa-level acid-pickling-free automobile structure and production method of hot rolled steel plate |
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