CN105369134B - 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method - Google Patents

400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method Download PDF

Info

Publication number
CN105369134B
CN105369134B CN201510778750.6A CN201510778750A CN105369134B CN 105369134 B CN105369134 B CN 105369134B CN 201510778750 A CN201510778750 A CN 201510778750A CN 105369134 B CN105369134 B CN 105369134B
Authority
CN
China
Prior art keywords
hot
rolled steel
rolling
steel plate
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201510778750.6A
Other languages
Chinese (zh)
Other versions
CN105369134A (en
Inventor
刘庆春
郑之旺
李卫平
许哲峰
张功庭
方勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Original Assignee
Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd filed Critical Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
Priority to CN201510778750.6A priority Critical patent/CN105369134B/en
Publication of CN105369134A publication Critical patent/CN105369134A/en
Application granted granted Critical
Publication of CN105369134B publication Critical patent/CN105369134B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226Hot rolling
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/005Ferrite
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/009Pearlite

Abstract

The invention belongs to metallurgical technology field, more particularly to a kind of 400MPa grades is exempted from production method of pickled hot vehicle structure steel plate and preparation method thereof.The present invention provides a kind of 400MPa grades and exempts from pickling vehicle structure hot rolled steel plate, and its chemical composition percentage meter by weight includes:C:0.05~0.10, Si:0.05~0.15, Mn:0.7~1.00, N:0.002~0.006, P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe.Finished steel sheet yield strength >=255MPa that the present invention is obtained, tensile strength >=400MPa, elongation percentage >=34%, cold-bending property is excellent.

Description

400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method
Technical field
The invention belongs to metallurgical technology field, the more particularly to a kind of 400MPa grades life for exempting from pickled hot vehicle structure steel plate Product method and preparation method thereof.
Background technology
Growing with national economy, automobile industry has turned into the pillar industry of China, automobile hot-rolled steel The consumption of plate increases year by year, and according to Hyundai Motor " energy-saving and emission-reduction, environmental protection, safety etc. " demand, car manufactures are to automobile component The requirement for developing the steel products that can exempt from pickling or be easy to pickling is proposed with steel aspect.This hot-strip product surface is produced Raw iron scale form is Fe3O4+ Fe, rather than Fe3O4+ FeO types, or even need generation multilayer Fe3O4Oxide.Due to Fe3O4With relatively low hardness (HV350~500), preferable plasticity and good adhesion, therefore in subsequent deep processing Will not peel and rupture because of bending in journey, simultaneous oxidation iron sheet can play the lubrication between instrument and workpiece.This Sample, can simplify or even fully phase out the acid cleaning process after hot rolling, while being favorably improved the adhesive force of plating enamelled coating.
At present, domestic someone is based on the control climate in iron scale forming process, have developed and is sprayed at hot-strip The antirust agent on surface, makes that Fe can be promoted in this way3O4Generation, however it is necessary that increase cooling device, it is therefore desirable to it is larger Investment, meanwhile, this method can not produce Fe3O4+ Fe easily deformable iron scale tissue.Japan, South Korea, Australia The technology used Deng state is the type and thickness that iron scale is controlled in hot rolling production, it is only necessary to course of hot rolling, particularly Roller repairing process carries out careful control, without increasing new equipment.The states such as Japan, South Korea and Australia are herein Aspect has carried out substantial amounts of work.NKK, Nippon Steel and Kawasaki Steel of Japan etc. are in exploitation hot-rolled black-skin steel Technical elements maintain the leading position.The exploitation of China's steel bound pair hot-rolled black-skin steel is still in the exploratory stage at present, and automobile is given birth to The hot rolled plate users such as producer are produced to this existing strong requirement.Therefore, develop the easy pickling of hot rolling or exempt from pickling black rust steel into The important technical research work of item.
For Miniature riding car material, 400MPa grades of hot rolled steel plate mainly applies material in belonging to body structure of getting off Material, steel requirement possesses good obdurability, processability, the enough rigidity of structure and welding performance, to meet auto parts Punch forming, welding process requirement and loading process resistance local deformation, at utmost apparatus with shock absorbing, it is ensured that vehicle body Safety.The common mode of production mainly considers the obdurability matching of steel, is carried using refined crystalline strengthening and solution strengthening to greatest extent The performance of steel plate high, the later stage removes surface oxide layer using acid cleaning process, and the phosphating coat formed using phosphating process improves steel plate With the binding ability of finish paint.In recent years, in order to adapt to the demand of vehicle lightness, partial automobile manufacturing enterprise is in buying 400MPa Low cost is proposed during level vehicle structure hot rolled steel plate, exempts from the use requirement of coil pickled surface quality, it is mainly shown in Table 1.
The 400MPa grades of hot-rolled structural steel mechanical property of table 1 and processing performance requirement
400MPa grades of vehicle structure hot rolled steel plate Design of Chemical Composition generally uses low C-Mn microalloying sides both at home and abroad Case, Mn contents are generally 1.0%, and C content is generally 0.10% or so, and hot rolling technology uses controlled rolling and controlled cooling, and its technical characterstic is The effect of alloying element solid solution strength and refined crystalline strengthening is more considered, but needs the later stage to increase pickling process, there is production High expensive and spent acid environmental protection treatment fringe cost.
The content of the invention
For drawbacks described above, the present invention provides a kind of the 400MPa of high comprehensive performance grades and exempts from pickled hot automobile structural steel Plate, it has good room-temperature mechanical property and processing performance, Fe in finished surface iron scale3O4Shared ratio exceedes 80%, adapt to automobile component enterprise and exempt from pickling production requirement, the cost performance of steel is high.
Technical scheme:
First technical problem to be solved by this invention is to provide a kind of 400MPa grades and exempts from pickling vehicle structure hot rolling Steel plate, its chemical composition percentage by weight is calculated as:C:0.05~0.10, Si:0.05~0.15, Mn:0.7~1.00, N:0.002 ~0.006, P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe.
Further, described 400MPa grades heterogeneous microstructure for exempting from pickling vehicle structure hot rolled steel plate include ferrite and Pearlite, on the basis of the cumulative volume of crystal structure, ferritic percentage by volume is 88~90%, the volume basis of pearlite Number is 10~12%.The percentage by volume of ferrite and pearlite can be used and surveyed well known to a person skilled in the art method , such as metallographic methods of GB/T 6394.The 400MPa grades of vehicle structure hot rolled steel plate that the present invention is provided has good room temperature power Performance and processing performance are learned, the requirement of technical indicator is complied fully with.
Further, the yield strength >=255MPa of the hot rolled steel plate, tensile strength >=400MPa, elongation percentage >=34%.
Further, Fe in the iron scale of the hot rolled sheet metal surface3O4Content >=80%.
Further, the iron scale thickness of the hot rolled sheet metal surface is 7~9 μm.
Second technical problem to be solved by this invention is to provide above-mentioned 400MPa grades and exempts from pickling vehicle structure hot rolling The preparation method of steel plate, including converter smelting, LF refining, continuous casting, continuous casting billet reheating, hot rolling, cool down and batch;Wherein,
Continuous casting billet relation reheating temperature is 1210~1230 DEG C, and the heat time is 1.2~1.8 hours;
In hot-rolled process, roughing start rolling temperature is 1173 DEG C~1200 DEG C, de-scaling water pressure >=21MPa;Finish rolling open rolling temperature ≤ 1020 DEG C of degree, open rolling speed >=1.5m/s, finish rolling finishing temperature is 860~890 DEG C, finish rolling finish to gauge mill speed >=7.8m/ s;
Coiling temperature is 560 DEG C~590 DEG C;
The chemical composition of steel billet is:C:0.05~0.10, Si:0.05~0.15, Mn:0.7~1.00, N:0.002~ 0.006、P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe.
Further, in hot-rolled process, roughing de-scaling water pressure >=21MPa;Finish rolling open rolling speed >=1.5m/s, finish rolling finish to gauge Mill speed >=7.8m/s.
Further, in the above method, refrigerating work procedure uses the sparse type of cooling.
Further, in converter smelting operation, tapping temperature is 1660~1680 DEG C, the oxygen activity of pre-deoxidation terminal during tapping <80ppm。
Beneficial effects of the present invention:
1st, the inventive method production process using control chemical composition ranges, hot rolling heating-up temperature, finishing temperature, batch The technological measures such as temperature, the finished steel sheet yield strength >=255MPa of acquisition, tensile strength >=400MPa, elongation percentage >=34%, Cold-bending property is excellent.
2nd, low equivalent scheme is used during Design of Chemical Composition, steel plate welding performance is excellent.
3rd, external refining process carries out sulfide degenerative treatments using Si-Ca lines, and sulfide is in steel grade generally with ribbon Or corynebacterium is present, it is unfavorable for the punching performance of steel, thus sulfide degenerative treatments is used when external refining is processed, Ca:S≥ 2.0, molten steel cleanliness is improve, and make to remain the metamorphosis of nonmetal inclusion shape in steel, rolled to distribution from untreated preceding edge Ribbon or corynebacterium become hammer-imitation type or spherical, improve the cold forming capability of steel plate.
4th, Fe in finished surface iron scale3O4Shared ratio more than 80%, can effectively adapt to user exempt from pickling will Ask.
5th, compared with the same level hot rolled steel plate of low C-Mn-Si alloyings production, the simple production process of present invention use, Production cost is relatively low, can effectively substitute acid cleaning process, with cost performance higher, promotes the use of and has good prospects.
Specific embodiment
The 400MPa grades of the present invention production method technological process for exempting from pickling vehicle structure hot rolled steel plate is as follows:
Converter smelting → LF refining → electrical heating → continuous casting → hot rolling → cool down → batch → finishing → packaging and storage;This hair In bright, steel billet can use well known to a person skilled in the art method by it is blast-melted through converter smelting, LF refining, electrical heating, Continuous casting working procedure is obtained.
Converter smelting is specially to smelt blast-melted and smelting furnace material in converter and obtains molten steel, then by deoxidation of molten steel And carry out alloying;In molten steel after carbonaceous material, aluminum-manganese-iron alloy and aluminum shot are added into deoxidation in alloying step, obtain To molten steel (on the basis of molten steel gross weight, in terms of simple substance) as C:0.05~0.10, Si:0.05~0.15, Mn:0.7~1.00, N:0.002~0.006, P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe.In order that S in feed stock for blast furnace Content be less than or equal into stove molten iron gross weight 0.015%, low-sulfur molten iron or semisteel smelting can be used.In order to prevent gold The scaling loss of category element especially manganese element, will strictly control oxygen activity when smelting process temperature and tapping, and smelting condition is 1660~1680 DEG C of steel temperature, the oxygen activity condition of pre-deoxidation terminal is [a during tapping0]<80ppm.The carbon of smelting process addition One or more in the carbonaceous material that material is known in the art, preferably pitch coke, anthracite and carbon dust.Smelting when Between be conventional smelting time, preferably 35~45 minutes.
The purpose of deoxidation of molten steel be the oxygen activity for reducing molten steel to improve yield of alloy, the deoxidier is ferro-aluminum, is taken off The addition of oxygen agent is preferably 400~550Kg/ stoves.
The mode of alloying step batch charging, external refining are used well known to a person skilled in the art method.After deoxidation Alloying step include ferro-aluminum, carbonaceous material, silicomangan, ferro-niobium are added in the molten steel after deoxidation, obtain molten steel (with On the basis of the molten steel gross weight, in terms of simple substance) C:0.05~0.10, Si:0.05~0.15, Mn:0.7~1.00, N:0.002 ~0.006, P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe.
In order to the chemical composition for ensureing steel is uniform, argon bottom-blowing treatment is carried out to ladle after alloying.The BOTTOM ARGON BLOWING The condition of gas disposal is 1600~1650 DEG C of temperature, the handkerchief of pressure 200~400,4~8 minutes time.
LF refining step is finely adjusted to the oxygen activity of molten steel, degree of purity and temperature, and Al line final deoxidizing controls are fed using secondary The oxygen activity of molten steel processed is 20~40ppm, and molten steel pot bottom is passed through the argon gas 4~6 minutes of 200~400Pa of pressure, argon flow amount Do not turned over as condition very much with molten steel, can avoid that secondary oxidation occurs in molten steel and temperature drop is too fast, steel inclusion is fully gone up It is floating, further improve steel cleannes.Ca Si wire feeding is carried out in electrical heating and after mending hello Al lines (containing Ca >=24%, specification:φ 10mm) process, addition 1000~1200m/ stoves.
Electrical heating step is to reach steel billet to be suitable to the operation of cast temperature, is the basic working procedure of continuous casting steel production.It is right Steel billet carries out heating can be used well known to a person skilled in the art various firing equipments and heating means.
Direct casting step can be used well known to a person skilled in the art method, and the inventive method is by the molten steel after refining Casting to the tundish roasted in advance, the continuous casting machine protected through whole process is cast into slab.After casting, can be according to routine Method is cooled down, such as natural cooling at room temperature.
Hot-rolled step be by the slab of casting it is heated after rolled.The purpose of rolling is to make 400MPa grades of vehicle structure The continuous casting steel billet of steel reaches required thickness.The rolling pass of hot rolled plate steel band of the present invention be roughing 6, finish rolling 5~6, often Every time rolling makes the thickness of hot rolling material base reduce 3~9 millimeters to the rolling of frame frame together.
The start rolling temperature of hot rolling refer to steel billet enter milling train temperature, heated at such a temperature, can fully solid solution it is micro- Alloying element, because of continuous casting steel billet dendritic segregation, microalloy element, skewness causes the not good effect of performance in steel for elimination.Heat The finishing temperature rolled refers to that steel band goes out the temperature of mm finishing mill unit, in order that the thickness and mechanical property of finished product are uniform, using in hot rolling Between base Coil Box technology, make the hot-rolled intermediate billet material head before finish rolling, in, afterbody keep specific finishing temperature.The present invention Hot rolling heating-up temperature is 1210~1230 DEG C, and the time is 1.2~1.8 hours, and the breaking down temperature of hot-rolled step is 1130~1200 DEG C, de-scaling water pressure >=21MPa, finish rolling start rolling temperature≤1020 DEG C, open rolling speed >=1.5m/s, finishing temperature is 860~890 DEG C, finish to gauge outlet mill speed >=7.8m/s;Finishing temperature is 860~890 DEG C;Temperature control in course of hot rolling can make steel Complete austenite structure is in before finish rolling outlet;And avoid austenite structure excessively thick, be conducive to controlling hot-rolled finished product Ferrite grain size is 5.6~7.9 microns, improves refined crystalline strengthening effect.
Cooling step uses the sparse type of cooling, it is therefore an objective to reduce the thermal stress of surface oxide layer, it is to avoid cooling velocity mistake Fast surface oxide layer forms microcrack, causes oxide layer to decline with basic adhesion.For sheet steel band, including pass through The sheet steel band of rolling have adjusted the structural state inside steel after supercooling, then carry out batching in rolls.In order to meet heat The tissue and performance requirement of plate are rolled, must be cold under cooling velocity very high in a short period of time from milling train steel band out But batched to coiling temperature.For example, the speed of the cooling is 10~30 DEG C/sec, 560~590 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 is GB/T4336.
The present invention is produced using low C-Mn-Si alloyings scheme and controlled rolling and controlled cooling mode, using targetedly stove after smelting Outer refining measure, reduces influence of the field trash to cold roll forming performance, and hot rolling is obtained using controlled rolling and the method for control cooling Obtain a certain amount of ferrite, pearlitic structrure.Assay shows the 400MPa grades of vehicle structure heat produced by the method Rolled steel plate has good room-temperature mechanical property and processing performance, Fe in finished surface iron scale3O4Shared ratio exceedes 80%, adapt to automobile component enterprise and exempt from pickling production requirement, the cost performance of steel is high, promotes the use of and has good prospects.
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 as raw material, blast-melted temperature 1365 DEG C, (Anyang is good prosperous to add steelmaking ingredient melting to 1680 DEG C of tappings that 1000Kg alfers are added to ladle, during tapping 1/3 Nai Cai Co., Ltds) pre-deoxidation, then to addition pitch coke (Panzhihua Yangcheng limited public affairs of metallurgic auxiliary materials in the molten steel after deoxidation Department) and silicomangan (Dechang ferroalloy Co., Ltd) so that the content of each composition is for (gross weight with molten steel is as base in molten steel Standard, wt%) C:0.07、Si:0.10、Mn:0.90、P:0.014、S:0.006、Al:0.05、N:0.0040, remaining is Fe.Then Argon bottom-blowing treatment, 200~400Pa of argon pressure are carried out to ladle in the outer chain-wales of stove, the time is 4 minutes.
Steel oxygen content in water after controlling the addition of deoxidier to make deoxidation is 10ppm~50ppm, is prevented as far as possible Manganese is aoxidized, so as to ensure that manganese exists with simple substance in the hot-rolled structural steel for preparing, rather than existing in the form of an oxide, with abundant Play the function of simple substance manganese.
B, LF electrical heating:Secondary to feed Al line final deoxidizings, molten steel pot bottom is passed through the argon of certain pressure (200Pa~400Pa) Gas 6 minutes, argon flow amount is not turned over as condition very much with molten steel, and blowing argon gas add the Si-Ca of 1000m by wire feeder to ladle backward Line, LF 1590 DEG C of final temperatures for the treatment of.
C, continuous casting:Ladle is transported to casting position, and using aluminum stopper, (Anyang smelting is auxiliary to be had at the basal sliding mouth of a river of ladle Limit company), molten steel automatically flows into tundish, through aluminum stopper, is drained to crystallizer and carries out direct casting;Whole process is using protection Slag carries out protective casting, and slab is cooled to after casting.
D, hot rolling:Continuous casting steel billet relation reheating temperature is 1226 DEG C and (eliminates dendritic segregation, control original austenite grains chi It is very little), the time is 1.6 hours;Roughing temperature is 1140 DEG C, de-scaling water pressure 22MPa, 1010 DEG C of finish rolling start rolling temperature, open rolling speed Degree 1.8m/s;Finish rolling finishing temperature is 872 DEG C, finish rolling finish to gauge outlet mill speed 8.5m/s;Cooling step uses sparse cooling Mode;570 DEG C of coiling temperature.The rolling pass of finish rolling is 7, and every time rolls and causes that the thickness of middle base is respectively 38~21 Millimeter, 21~13 millimeters, 13~9 millimeters, 9~6.7 millimeters, 6.7~5.6 millimeters and 5.6~5 millimeters.
E, finishing:Packaging and storage after the flattened unit parted hair volume of steel band.
The coiled sheet of preparation is carried out into measuring mechanical property, yield strength Rel, the tensile strength Rm of room temperature is detected respectively and is stretched Rate A long200mm, tensile property carries out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is 311MPa, tensile strength (Rm) is 425MPa, elongation percentage (A50mm) it is 38%, cold bending process experimental performance is qualified, gained hot rolling The thickness of the iron scale of steel plate finished surface is 8.5 μm, Fe in scale on surface3O4Ratio reach 85%, meet 400MPa exempts from the technical conditions requirement of pickled hot vehicle structure steel plate.
Embodiment 2
Preparation method is substantially the same manner as Example 1, the difference is that the molten steel composition that converter smelting is obtained is C:0.07、Si: 0.11、Mn:0.87、P:0.015、S:0.007、Al:0.04、N:0.0036, remaining is Fe;And the hot rolling produced with foregoing molten steel Steel plate, 1220 DEG C of slab tapping temperature, finish rolling open rolling speed 1.88m/s, finish to gauge outlet mill speed 8.7m/s;Finishing temperature is 878 DEG C, coiling temperature is 565 DEG C, hot-rolled finished product thickness 4.5mm.
The coiled sheet of preparation is carried out into measuring mechanical property, the tensile strength Rm and elongation A of room temperature are detected respectively200mm, draw Stretch performance is carried out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is 310MPa, tension Intensity (Rm) is 420MPa, elongation percentage (A50mm) it is 39%, cold bending process experimental performance is qualified, 7.9 μm of finished product oxygen thickness of scale, Fe in scale on surface3O4Ratio reach 86%, meet 400MPa exempt from pickled hot vehicle structure steel plate technical conditions will Ask.
Comparative example 1
Preparation method is substantially the same manner as Example 1, the difference is that the molten steel composition that converter smelting is obtained is C:0.09%, Si:0.19%, Mn:0.90%, P:0.016%, S:0.007%, Al:0.056%, remaining is Fe, and is produced with foregoing molten steel Hot rolled steel plate, 1200 DEG C of slab tapping temperature, finish rolling open rolling speed 1.30m/s, finish to gauge outlet mill speed 6.0m/s;Finish to gauge Temperature is 890 DEG C, and coiling temperature is 620 DEG C, hot-rolled finished product thickness 5.0mm.
The coiled sheet of preparation is carried out into measuring mechanical property, the tensile strength Rm and elongation A of room temperature are detected respectively50mm, draw Stretch performance is carried out according to GB/T228 metal materials tensile testing at ambient temperature.Finished product yield strength (Rel) is 330MPa, tension Intensity (Rm) is 430MPa, elongation percentage (A50mm) it is 34%, cold bending process experimental performance is qualified, finished surface iron scale thickness It is 12 μm, Fe in scale on surface3O4Ratio be 60%, it is seen then that the thickness and iron oxide of gained surface of steel plate iron scale Skin structure does not meet the technical conditions requirement that 400MPa exempts from pickled hot vehicle structure steel plate.

Claims (10)

1.400MPa grades is exempted from pickling vehicle structure hot rolled steel plate, it is characterised in that its chemical composition percentage meter by weight includes: C:0.05~0.10, Si:0.05~0.11, Mn:0.7~1.00, N:0.002~0.006, P:0~0.025, S:0~0.015, Al:0.02~0.06, remaining is Fe;
The described 400MPa grades preparation method for exempting from pickling vehicle structure hot rolled steel plate, including converter smelting, LF refining, continuous casting, Continuous casting billet reheating, hot rolling, cool down and batch;
Continuous casting billet relation reheating temperature is 1210~1230 DEG C, and the heat time is 1.2~1.8 hours;
In hot-rolled process, roughing start rolling temperature is 1173 DEG C~1200 DEG C, finish rolling start rolling temperature≤1020 DEG C, finish rolling finishing temperature It is 860~890 DEG C, de-scaling water pressure >=21MPa, finish rolling open rolling speed >=1.5m/s, finish rolling finish to gauge mill speed >=7.8m/s;
Refrigerating work procedure uses the sparse type of cooling;
Coiling temperature is 560 DEG C~590 DEG C.
2. according to claim 1 400MPa grades exempt from pickling vehicle structure hot rolled steel plate, it is characterised in that the hot-rolled steel The heterogeneous microstructure of plate includes ferrite and pearlite, on the basis of the cumulative volume of crystal structure, ferritic volume basis Number is 88~90%, and the percentage by volume of pearlite is 10~12%.
3. pickling vehicle structure hot rolled steel plate is exempted from 400MPa grades according to claim 1 or claim 2, it is characterised in that the heat Yield strength >=the 255MPa of rolled steel plate, tensile strength >=400MPa, elongation percentage >=34%.
4. pickling vehicle structure hot rolled steel plate is exempted from 400MPa grades according to claim 1 or claim 2, it is characterised in that the heat Fe in the iron scale of steel rolling plate surface3O4Content >=80%.
5. according to claim 3 400MPa grades exempt from pickling vehicle structure hot rolled steel plate, it is characterised in that the hot-rolled steel Fe in the iron scale of plate surface3O4Content >=80%.
6. pickling vehicle structure hot rolled steel plate is exempted from 400MPa grades according to claim 1 or claim 2, it is characterised in that the heat The iron scale thickness of steel rolling plate surface is 7~9 μm.
7. according to claim 4 400MPa grades exempt from pickling vehicle structure hot rolled steel plate, it is characterised in that the hot-rolled steel The iron scale thickness of plate surface is 7~9 μm.
8. according to claim 5 400MPa grades exempt from pickling vehicle structure hot rolled steel plate, it is characterised in that the hot-rolled steel The iron scale thickness of plate surface is 7~9 μm.
9. the 400MPa grades of preparation method for exempting from pickling vehicle structure hot rolled steel plate described in any one of claim 1~8, including turn Stove smelting, LF refining, continuous casting, continuous casting billet reheating, hot rolling, cool down and batch;Characterized in that,
Continuous casting billet relation reheating temperature is 1210~1230 DEG C, and the heat time is 1.2~1.8 hours;
In hot-rolled process, roughing start rolling temperature is 1173 DEG C~1200 DEG C, finish rolling start rolling temperature≤1020 DEG C, finish rolling finishing temperature It is 860~890 DEG C, de-scaling water pressure >=21MPa, finish rolling open rolling speed >=1.5m/s, finish rolling finish to gauge mill speed >=7.8m/s;
Refrigerating work procedure uses the sparse type of cooling;
Coiling temperature is 560 DEG C~590 DEG C.
10. the 400MPa grades of preparation method for exempting from pickling vehicle structure hot rolled steel plate according to claim 9, its feature exists In in converter smelting operation, tapping temperature is 1660~1680 DEG C, the oxygen activity of pre-deoxidation terminal during tapping<80ppm.
CN201510778750.6A 2015-11-12 2015-11-12 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method Active CN105369134B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510778750.6A CN105369134B (en) 2015-11-12 2015-11-12 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510778750.6A CN105369134B (en) 2015-11-12 2015-11-12 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method

Publications (2)

Publication Number Publication Date
CN105369134A CN105369134A (en) 2016-03-02
CN105369134B true CN105369134B (en) 2017-07-04

Family

ID=55371757

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510778750.6A Active CN105369134B (en) 2015-11-12 2015-11-12 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method

Country Status (1)

Country Link
CN (1) CN105369134B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106636924B (en) * 2016-12-30 2018-04-03 武钢集团昆明钢铁股份有限公司 A kind of building structure of 235MPa ranks earthquake-resistant hot rolled steel plate, steel band and preparation method thereof
CN107904503A (en) * 2017-11-24 2018-04-13 攀钢集团攀枝花钢铁研究院有限公司 Pickling vehicle structure steel plate and its production method are exempted from 510MPa grades of hot rollings
CN109440005A (en) * 2018-11-14 2019-03-08 河钢股份有限公司承德分公司 A kind of SAPH440 crystal grain refinement steel and its production method

Citations (3)

* Cited by examiner, † Cited by third party
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
CN102086495A (en) * 2010-12-22 2011-06-08 山西太钢不锈钢股份有限公司 Production method of oxide film hot-rolled strip steel with high adhesion
CN102719754A (en) * 2012-05-31 2012-10-10 攀钢集团攀枝花钢铁研究院有限公司 Hot-rolled deep-punched pickled plate for automobile structures and production method thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4061996B2 (en) * 2002-07-11 2008-03-19 Jfeスチール株式会社 Black skin hot-rolled steel sheet excellent in blackness and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
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
CN102086495A (en) * 2010-12-22 2011-06-08 山西太钢不锈钢股份有限公司 Production method of oxide film hot-rolled strip steel with high adhesion
CN102719754A (en) * 2012-05-31 2012-10-10 攀钢集团攀枝花钢铁研究院有限公司 Hot-rolled deep-punched pickled plate for automobile structures and production method thereof

Also Published As

Publication number Publication date
CN105369134A (en) 2016-03-02

Similar Documents

Publication Publication Date Title
CN101935802B (en) Method for producing 490MPa level acid-washing-free hot rolled steel plate
CN104250703B (en) A kind of 340MPa grades of cold rolling low-alloy high-strength steel and its manufacture method
CN103667906B (en) Tensile strength 590MPa level hot rolling High Tensile Thin Steel Plate and production method thereof
CN102925817A (en) Cold-rolled steel sheet with yield strength of 980 MPa grade and manufacturing method thereof
CN104805352A (en) Production method of cold-rolled steel plate for electro-galvanization
CN108842024A (en) A kind of phosphorous IF high-strength steel band of 390MPa grades of cold rolling and its LF-RH duplex production technology
CN107151763A (en) The high-strength cold-formed use hot rolled strip of Thin Specs and its production method
CN107868911A (en) A kind of yield strength 600MPa level hot rolled steel plates and its manufacture method
CN105369134B (en) 400MPa grades is exempted from pickling vehicle structure hot rolled steel plate and its production method
CN101935801A (en) Hot rolled steel plate of 490 MPa level and production method thereof
CN106399835A (en) Production method of high-strength automobile hub steel
CN101906570A (en) Tinning substrate for deep-punching food can and production method thereof
CN107419078A (en) Yield strength 345MPa level low cost hot rolled steel plates and its manufacture method
CN100560773C (en) A kind of high-strength anti-fatigue steel products and manufacture method thereof
CN109136755A (en) A kind of automobile cold-rolled high strength steel and its production method
CN102925794B (en) Cold-rolled steel strip for double-layer welded tube and its manufacture mathod
CN107699798A (en) Pickling vehicle structure steel plate and its production method are exempted from 610MPa level hot rollings
CN101139685A (en) High-strength antifatigue steel products and method for manufacturing same
CN106978566A (en) A kind of rail truck weather resisting steel and preparation method thereof
CN106811684B (en) 750Mpa grades of container hot rolled steel plates of yield strength and its manufacturing method
CN101487097B (en) High strength cold rolling packaging steel belt and production method thereof
CN103695775A (en) 345MPa-level steel plate for high-rise building structure and production method thereof
CN107385319A (en) Yield strength 400MPa level Precision Welded Pipe steel plates and its manufacture method
CN109609845A (en) A kind of 500MPa grades of weathering steel and its production method
CN109504898A (en) The effective hot rolled strip of one kind 700MPa grades of truck drive shafts of 3 ~ 8mm yield strength and its production method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant