CN105603322A - Steel plate with super-low cost, 800MPa-grade high toughness and excellent weldability and manufacture method thereof - Google Patents
Steel plate with super-low cost, 800MPa-grade high toughness and excellent weldability and manufacture method thereof Download PDFInfo
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- CN105603322A CN105603322A CN201610064771.6A CN201610064771A CN105603322A CN 105603322 A CN105603322 A CN 105603322A CN 201610064771 A CN201610064771 A CN 201610064771A CN 105603322 A CN105603322 A CN 105603322A
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
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- 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
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- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
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Abstract
The invention provides a steel plate with super-low cost, 800MPa-grade high toughness and excellent weldability and a manufacture method thereof. According to the manufacture method, metallurgical technical control methods of selecting super-low C-super-low Si-high Mn-highAls-(low Mo+high Cr) alloying-(Ti+Nb+V+B)microalloying composition system as basis, properly increasing the content of acid solution Als in steel, performing Ca treatment and leading the value of [(%C)+(%Mn)/6+(%Si)/24+(%Ni)/40+(%Cr)/5+(%Mo)/4+(%V)/14+7.3(%B)]*V cooling speed/(T starting cooling temperature-T terminating cooling temperature)*t to be more than or equal to 0.60 and less than or equal to 1.00, and the like are adopted, a specific controlled-rolling and online tempering process is optimized, the tempered steel plate has excellent weldability while the strength, low-temperature toughness, obdurability and plasticity of the tempered steel plate are matched, the problem of the weldability of a nickel-free tempered steel plate can be successfully solved, the welding HAZ has high strength, high toughness and excellent plasticity. The steel plate is especially suitable for hydroelectric pressure pipelines/volute casings/steel bifurcated pipes, marine platforms, large maritime working machinery and other large steel structures and equipment.
Description
Technical field
The present invention relates to a kind of Ultra Low Cost 800MPa grade high ductility, superior weldability steel plate andManufacture method, its tensile strength >=780MPa, yield strength >=690MPa, percentage elongation δ5≥18％、－40 DEG C of summers are than side knock merit (single value) >=100J, good weldability and welding point plasticity and toughness, welderingMeet Charpy ballistic work (single the value) >=47J of-40 DEG C of heat affected area (HAZ), welding point stretchesPercentage elongation >=15%.
Background technology
As everyone knows, low-carbon (LC) (high strength) low-alloy steel is one of most important structural timber, extensivelyBe applied to petroleum natural gas pipeline, ocean platform, shipbuilding, bridge structure, boiler vessel, building knotAmong structure, auto industry, railway transportation and machine-building. Low-carbon (LC) (high strength) low-alloy steel performance is gotCertainly, in the process system of its chemical composition, manufacture process, wherein intensity, toughness and weldability are low-carbon (LC)sThe most important performance of (high strength) low-alloy steel, its final decision is in the microscopic structure state of finished steel.Along with metallurgical science and technology constantly advances, obdurability, the strong plasticity coupling of people to high-strength steel proposesHigher requirement improves significantly the integrated machine of steel plate in maintaining lower manufacturing costTool performance and serviceability, cost-saving to reduce the consumption of steel, alleviate steel construction own wt,Stability and security, what is more important is for further improving steel construction security and stability and cold and hot addingWork. Within the scope of European Union of Japan and Korea S, start at present that to develop the research of high-performance steel iron material of new generation highTide, tries hard to be established and optimized meter and better tissue of innovation manufacturing process technology acquisition by alloy combinationJoin, make high-strength steel obtain better obdurability, strong plasticity coupling.
Traditional tensile strength >=780MPa, the high strength steel plate of steel plate are mainly by off-line hardening and tempering process (Q+ T) produce; In order to obtain good obdurability, strong plasticity coupling, when steel plate Design of Chemical Composition,Except C content is higher (C >=0.10%), steel plate necessity has sufficiently high quenching degree, i.e. through hardeningSex index DI >=2 × finished steel plate thickness [DI=0.311C1/2(1+0.64Si)×(1+4.10Mn)×(1+0.27Cu) × (1+0.52Ni) × (1+2.33Cr) × (1+3.14Mo) × 25.4 (mm)], to guarantee steel plateHave sufficiently high intensity, good low-temperature flexibility and along thickness of slab direction microscopic structure and performance allEven, thereby inevitably in steel, add the alloying elements such as a large amount of Cr, Mo, Ni, Cu, especiallyNeed to add a large amount of precious alloy element Ni and Mo, cause steel plate manufacturing cost high (asThe clear 59-129724 of Japan Patent, flat 1-219121 and Nippon Steel steel research processed No. 314-1984,NKK skill is reported No.107-1985, Nippon Steel's skill report No. 348-1993, Kawasaki Steel skill reportVol.4 (No.3)-1972, Kawasaki Steel skill are reported Vol.7 (No.2)-1975, US Patent No.Patent4855106、USPatent5183198、USPatent4137104、USPatent4790885、USPatent4988393, European patent EP 0867520A2).
In addition especially uniform elongation is significantly, to add the steel plate of a large amount of alloying elements to cause steel plate percentage elongationDegree ground reduces, and lower uniform elongation is not only bad for steel plate cold-forming property, and to steel plateFatigue crack-resistant characteristic, anti-stress concentration sensitivity and structural stability impact are larger, in hydroelectric projectIn penstocks/volute and steel bifurcated pipe, thermoelectricity steam turbine generator structure, offshore oil production platform and seaWhile use in the Huge Steel Open structures such as crane barge peculiar to vessel, there is the hidden danger that safety is larger, especially in earthquake, seaWhen the natural calamities such as howl occur, steel construction exists and destroys the danger of even collapsing; Therefore large-scale tired heavyCarry steel construction and adopt when high-strength steel, generally wish 80 feather weight high-strength steel have good obdurability,Strong plasticity coupling, tension percentage elongation δ5More than 18%, especially uniform elongation reaches more than 10%.
Existing a large amount of patent documentation just illustrates the intensity and the low-temperature flexibility that how to realize mother metal steel plate, justImprove Plate Welding energy, obtain the HAZ low-temperature flexibility explanation of good welding heat affected zone less, moreHow not relate in improving steel plate tensile strength, improve tension percentage elongation and the thickness of steel plateDirection mechanical property uniformity, especially welding heat affected zone has good plasticity and toughness.
Summary of the invention
The object of the present invention is to provide a kind of Ultra Low Cost 800MPa grade high ductility, superior weldabilitySteel plate and manufacture method thereof, by modular design and the special fabrication processes of steel plate alloying element(CR+DQ+T) combine, under the condition of not cupric, nickel element, obtain good 800MPa level and adjustWhen the intensity of matter steel plate, low-temperature flexibility, obdurability mate with strong plasticity, the weldability of steel plate alsoSame excellent, successfully solve the weldability without nickel content hardened and tempered steel plate, welded H AZ presentsHigh strength, high tenacity and good plasticity (being high fracture elongation and uniform elongation); This is thisOne of difficult point of exploitation steel grade maximum is also key core technology; Steel plate tensile strength >=780MPa,Tensile strength >=690MPa, percentage elongation δ5>=18% ,-40 DEG C the summer than side knock merit (single value) >=100J,Good weldability and welding point plasticity and toughness, the Charpy of-40 DEG C of welding heat affected zone (HAZ)Ballistic work (single value) >=47J, welding point stretch percentage elongation >=15%.
For achieving the above object, technical scheme of the present invention is:
The present invention adopts the high Als-of the high Mn-of the ultralow Si-of ultralow C-(the high Cr of low Mo+) alloying-(Ti+Nb+V+B) the composition system of microalloying, as basis, suitably improves acid-soluble Als in steelContent, Ca process, and Ca/S compares between 0.80～3.00, (%Ca) (%S)0.18≤2.5×10－3, controlSystem 0.60≤[(%C)+(%Mn)/6+ (%Si)/24+ (%Ni)/40+ (%Cr)/5+ (%Mo)/4+ (%V)/14+7.3(％B)]×VCooling velocity/(TOpen cold temperature-TStop cold temperatureBetween) × t≤1.00, wait metallurgical technology control device (whereinT is finished steel plate thickness), optimize special controlled rolling+online hardening and tempering process (DQ+T), make finished steel plateMicroscopic structure be lower bainite+lath martensite, average colony size, below 20 μ m, obtains excellentWhen the intensity of good 800MPa level hardened and tempered steel plate, low-temperature flexibility, obdurability mate with strong plasticity,The weldability of steel plate is excellent too, and has successfully solved the weldability without nickel content hardened and tempered steel plate,Welded H AZ present high strength, high tenacity and good plasticity (be high fracture elongation with evenlyPercentage elongation), be specially adapted to hydraulic power pressure water pipe/volute/steel bifurcated pipe, ocean platform, large-scale extra large work machineThe large-scale steel structures such as tool and equipment, and can realize the stable suitability for industrialized production in batches of Ultra Low Cost.
Concrete, the steel plate of Ultra Low Cost 800MPa grade high ductility of the present invention, superior weldability,Its composition percentage by weight is:
C：0.030％～0.070％
Mn：1.60％～1.90％
P：≤0.015％
S：≤0.0030％
Cr：0.80％～1.20％
Mo：0.10％～0.30％
Nb：0.010％～0.030％
V：0.030％～0.060％
Ti：0.004％～0.010％
B：0.0008％～0.0016％
Als：0.040％～0.070％
Ca：0.001％～0.004％
All the other are Fe and are inevitably mingled with, and above-mentioned constituent content must meet as follows simultaneouslyRelation:
0.60≤[(％C)+(％Mn)/6+(％Si)/24+(％Ni)/40+(％Cr)/5+(％Mo)/4+(％V) /14+7.3(％B)]×VCooling velocity/(TOpen cold temperature-TStop cold temperature) × t≤1.00, t is finished steel plate thickness, singlePosition, mm; VCooling velocityUnit, DEG C/s; TOpen cold temperature、TStop cold temperatureUnit, DEG C;
The tendency of hardenability that ensures steel itself is mentioned component combination and cooling velocity, opens cold temperature, stopsCoupling between cold temperature and steel plate thickness, guarantee:
1) ensure that in Cooling Process for Steel Plate Based, phase transformation microscopic structure type is lower bainite (BL)+lath horseThe two-phase structure of family name's body (M), farthest refinement bainite/martensite colony size, realizes notContaining the hardened and tempered steel plate obdurability of nickel element, strong plasticity good match time, steel plate ductile-brittle transitonTemperature is lower than-40 DEG C;
2) Plate Welding, welding procedure are good, can bear larger heat input welding(45kJ/cm), obdurability, the plasticity and toughness of Plate Welding joint (being welding heat affected zone) are good;
Ca/S between 0.80～3.00, and, 5 × 10－4≤(Ca)(S)0.18≤2.5×10－3. To protectPure property, viability and the homogenieity (being that steel plate UT flaw detection is superior in quality) of card internal quality of steel plate,Improve the low-temperature flexibility of hardened and tempered steel plate, anti-lamellar tearing, weldability and welding point (being HAZ)Low temperature plasticity and toughness.
Further, in composition of steel of the present invention, also comprise one in 0 < Si≤0.10%, 0 < N≤0.0050%Above.
In the composition System Design of steel plate of the present invention:
Intensity, low-temperature flexibility, percentage elongation and the weldability impact of C on 800MPa level quenched and tempered steel is very large;From improving 800MPa level hardened and tempered steel plate low-temperature flexibility and weldability angle, wish C content control in steelMust be more low better, but from the quenching degree of quenched and tempered steel, obdurability mate with plasticity by force, manufacture processMicrostructures Control and manufacturing cost angle, C content should not be controlled too lowly, especially to 800MPaLevel hardened and tempered steel plate, C content can cause serious original austenite crystal prevention to weaken lower than 0.03%, largeAmplitude reduces the plasticity and toughness of steel plate and weld joint; When C content in steel is higher than 0.07% time, Gao GehanThe plasticity and toughness of dimension plate welding point are seriously deteriorated, modified online for ensureing Ultra Low Cost manufacture800MPa grade high-strength steel plate, C content zone of reasonableness is 0.030%～0.070%.
Mn is as most important alloying element intensity except raising 800MPa level hardened and tempered steel plate in steelAlso there is the austenite of expansion phase region outward,, reduce Ar3Point temperature, refinement hardened and tempered steel plate colony and improvingEffect, the promotion low temperature phase change tissue of steel plate low-temperature flexibility form and the work of raising hardened and tempered steel plate intensityWith; But easily there is segregation in Mn in molten steel solidification process, especially when Mn too high levels, noOnly can cause pouring operation difficulty, and easily and the element generation conjugation such as C, P, S, Mo, CrSegregation phenomena, especially, in the time that C content is higher in steel, increases the weight of the segregation in strand centre with loose,Serious strand central area is segregated in follow-up rolling, heat treatment and welding process and easily forms extremelyTissue, causes hardened and tempered steel plate low-temperature flexibility lowly and crackle appears in welding point, when the C content in steelWhen extremely low, in steel, Mn content can suitably improve; Therefore modified for the ultralow C content of the present inventionSteel plate, being applicable to Mn content is 1.60%～1.90%.
Si promotes deoxidation of molten steel and can improve hardened and tempered steel plate intensity, still adopts the molten steel of Al deoxidation,The deoxidation of Si is little, although Si can improve the intensity of hardened and tempered steel plate, Si element (especiallyUnder the higher condition of Si content) reduce the critical cooling rate that martensite forms, suppress lower bainite shapeBecome, the plasticity and toughness of the high-strength hardened and tempered steel plate of grievous injury, especially input under welding condition Si in larger heatNot only promote M-A island to form, and formation M-A island size is comparatively thick, skewness,Grievous injury welding heat affected zone (HAZ) toughness, welding point percentage elongation (especially uniform elongation),Therefore the Si content in steel should be controlled extremely lowly as far as possible; Therefore in steel, Si content is controlled at 0.10%Below.
P is as harmful mechanical performance being mingled with hardened and tempered steel plate in steel, especially low-temperature impact toughness, prolongStretch rate, weldability and welding point plasticity and toughness and there is huge detrimental effect, require in theory more more lowGood; But consider steel-making operability and steel-making cost, tough for requiring superior weldability ,-40 DEG CProperty and the hardened and tempered steel plate of excellent strength-toughness coupling, P content need to be controlled at≤0.015%.
S has very large detrimental effect as harmful being mingled with in steel to the low-temperature flexibility of hardened and tempered steel plate, moreImportantly S is combined with Mn in steel, forms MnS field trash, in course of hot rolling, and MnSPlasticity make MnS along rolling to extension, form along rolling to MnS field trash band, grievous injury steel plateLow-temperature impact toughness, percentage elongation (especially uniform elongation), Z-direction performance, weldability and welding connectPlasticity and toughness produce hot short essential element in S or course of hot rolling simultaneously, require in theory moreLow better; But consider steel-making operability, steel-making cost and the smooth and easy principle of logistics, excellent for requiringThe hardened and tempered steel plate of good weldability ,-40 DEG C of toughness and excellent strength-toughness coupling, S content need to be controlled at≤0.0030％。
Cr is as weak carbide former, adds Cr and not only improve the quenching degree, short of hardened and tempered steel plateEnter martensite/bainite and form, and between martensite/lath of bainite, position increases to poor, increases crackleThrough the resistance of martensite/bainite colony, in improving armor plate strength, tool has some improvementThe effect of steel plate plasticity and toughness; But in the time that Cr addition is too much, in drawing process at original austenite crystalline substanceIn boundary, separate out the carbide of thick chain chromium and form the poor C of crystal boundary district, weakening the adhesion of crystal boundary,The low temperature plasticity and toughness of deteriorated hardened and tempered steel plate; In the time that the extremely low and Cr content of C content in steel is higher, not onlySuppressed the Carbide Precipitation of crystal boundary chromium, and the Cr segregation of a large amount of solid solutions is at original austenite crystal prevention,Strengthen crystal boundary and improved the low-temperature flexibility of steel plate; Therefore suitable Cr content be controlled at 0.80%～Between 1.20%.
Add the quenching degree of Mo raising steel plate, promote martensite/bainite to form, but Mo conductCarbide, in promoting that martensite/bainite forms, increases martensite/Bei ShiBetween the size of body colony and the martensite/lath of bainite of formation, position, to poor very little, reduces crackle through horseThe resistance of family name's body/bainite colony; Therefore Mo, in increasing substantially hardened and tempered steel plate intensity, fallsLow low-temperature flexibility and the percentage elongation of hardened and tempered steel plate; And when Mo adds when too much, not only seriously damagePercentage elongation, weldability and the welding point plasticity and toughness of evil steel plate, and increase production cost; But rightIn 80 feather weight hardened and tempered steel plates, must there is certain Mo content, to ensure that steel plate has enough quenchingProperty and anti-temper softening thoroughly. Therefore consider the phase transformation strengthening effect of Mo and low to mother metal steel plateThe impact of temperature toughness, percentage elongation and weldability, Mo content is controlled between 0.10%～0.30%.
B content is controlled between 0.0008%～0.0016%, when guaranteeing hardened and tempered steel plate quenching degree,Do not damage weldability, HAZ plasticity and toughness and the Surface Quality of Steel Billet of steel plate.
Ti content, between 0.004%～0.010%, suppresses austenite crystal in soaking and course of hot rollingToo grow up, improve steel plate low-temperature flexibility, the more important thing is that in inhibition welding process, HAZ crystal grain is longImprove HAZ plasticity and toughness greatly; In addition, when Ti content exceedes 0.010%, may cause TiC particle altogetherLattice are separated out, the not only plasticity and toughness of serious deteriorated high-strength hardened and tempered steel plate, unhelpful to improving Plate Welding,The more important thing is the plasticity and toughness of same serious deteriorated welding point.
Als in steel can fix the freedom [N] in steel, except reducing welding heat affected zone (HAZ) freely[N], improves outside the plasticity and toughness effect of welded H AZ, the more important thing is ensure to have in steel certainSolid solution B, improve steel plate through hardening hardenability; Therefore Als lower limit is controlled at 0.040%; But add in steelEnter excessive Als and not only can cause casting difficulty, and can in steel, form the needle-like of a large amount of dispersesAl2O3Field trash, infringement steel plate endoplasm viability, low-temperature flexibility and weldability, therefore the Als upper limitBe controlled at 0.070%.
In order to ensure the existence of solid solution in steel plate [B] and prevent that a large amount of AlN are along original austenite crystal prevention necklaceShape is separated out, the strong plasticity coupling of obdurability of infringement hardened and tempered steel plate surface quality, quenching degree and steel plate, steelIn N content must not exceed 0.0050%.
In steel, add micro-Nb element object and be carry out non-recrystallization controlled rolling, refinement steel plate is aobviousMicro-tissue, suppresses AlN and separates out along original austenite crystal prevention chain, improves the intensity of hardened and tempered steel plate and moulds toughProperty, when Nb addition is lower than 0.010% time, except the controlled rolling effect that can not effectively bring into play; When Nb addsWhen dosage exceedes 0.030%, be easy to cause under large heat input welding condition and bring out upper bainite (Bu) formationAnd Nb (C, N) secondary precipitation embrittling effect, the large heat input welding heat affected zone of grievous injury (HAZ)Plasticity and toughness, therefore Nb content is controlled between 0.010%～0.030%, obtain best controlled rolling effect,When realizing high-strength hardened and tempered steel plate obdurability, strong plasticity coupling, do not damage again large heat input weldingAnd the plasticity and toughness of multi-pass welded H AZ.
V content is between 0.030%～0.060%, and along with the increase of steel plate thickness, V content can be fittedWhen capping value. Adding V object is to separate out in bainite/martensite lath by V (C, N), carriesThe intensity of high hardened and tempered steel plate. V add very few, lower than 0.030%, the V (C, N) separating out very little, noCan effectively improve the intensity of utmost point thick quenched and tempered steel plate; V addition is too much, higher than 0.060%, damages extremely thickHardened and tempered steel plate ultralow-temperature flexibility, percentage elongation, weldability and welding point plasticity and toughness.
Steel is carried out to Ca processing, on the one hand can further pure molten steel, on the other hand to sulphur in steelCompound is carried out degenerative treatments, make it to become non deformable, stablize tiny spherical sulfide, inhibitionThe red brittleness of S, improve steel plate low-temperature flexibility, percentage elongation and Z-direction performance, improve steel plate toughnessAnisotropy. The number of Ca addition, depends on the height of S content in steel, and Ca addition is too low,Treatment effect is little; Ca addition is too high, forms Ca (O, S) oversize, and fragility also increases, canBecome fracture crack starting point, reduce low-temperature flexibility and the percentage elongation of steel, also reduce steel pure simultaneouslyDegree, pollution molten steel, therefore the OK range of Ca content is 0.0010%～0.0040%.
The manufacture of the steel plate of Ultra Low Cost 800MPa grade high ductility of the present invention, superior weldabilityMethod, comprises the steps:
1) smelt
Press mentioned component and smelt, adopt continuous casting casting, cast degree of superheat Δ T is controlled at 8 DEG C～30 DEG C,And adopting light Reduction Technology, Continuous Casting Soft Reduction rate is controlled between 2%～5%, casting speed0.6m/min～1.0m/min, liquid level fluctuation of molten steel≤5mm;
2) rolling, steel plate overall compression ratio (thickness of strand/finished steel plate thickness) >=3.6
First stage is common rolling, for ensureing generation [Al]+BN in heating and the operation of rolling→ AlN+[B], guarantee solid solution in steel [B] >=5ppm, slab heating temperature is controlled atBetween 1100 DEG C～1170 DEG C; Milling train is with continual pattern, the slab rolling of coming out of the stove continuouslyTreat temperature thickness (being second stage austenite non-recrystallization controlled rolling open rolling thickness) to intermediate blank,Large degree ground is by static and dynamic recrystallization refine austenite crystal grain;
Second stage adopts the controlled rolling of austenite non-recrystallization, controlled rolling start rolling temperature≤ 880 DEG C, rolling pass reduction ratio >=7%, austenite is crystal region accumulative total reduction ratio >=50% not,780 DEG C～850 DEG C of austenite one phase district finishing temperatures;
3) cooling
After controlled rolling finishes, steel plate is transported to cooling device place (DQ, ACC) immediately to carry out steel plateAccelerate coolingly, steel plate is opened 750 DEG C～820 DEG C of cold temperature, and cooling velocity >=7 DEG C/s, stops cold temperatureDegree is 200 DEG C～300 DEG C, subsequently steel plate from stop cold junction bundle to enter burial pit insulation betweenInterval is not more than 30min, and heat preservation method is the condition that steel billet temperature surface is greater than 300 DEG CUnder be at least incubated more than 24 hours, ensure steel plate abundant dehydrogenation, prevent that hydrogen causes delayCrackle;
4) Technology for Heating Processing
Steel plate temperature is 585～645 DEG C, tempering retention time >=(0.60～1.0) × finished steel plateThickness, the tempering retention time is that steel plate central temperature starts timing while reaching tempering target temperatureTemperature retention time, chronomere is min, steel plate thickness unit is mm; After tempering finishesSteel plate natural air cooling is to room temperature.
Steel of the present invention is even for guaranteeing the seam of continuous casting billet center porosity, steel plate centre microscopic structure,Steel plate overall compression ratio (thickness of strand/finished steel plate thickness) >=3.6.
First stage is common rolling, for ensureing generation [Al]+BN → AlN in heating and the operation of rolling+ [B], guarantees solid solution in steel [B] >=5ppm, slab heating temperature be controlled at 1100 DEG C～1170 DEG C itBetween; Milling train is with continual pattern, and the slab rolling of coming out of the stove is continuously treated temperature thickness (second to intermediate blankStage austenite non-recrystallization controlled rolling open rolling thickness), farthest by static thin with dynamic recrystallizationChange austenite crystal.
Second stage adopts the controlled rolling of austenite non-recrystallization, controlled rolling start rolling temperature≤880 DEG C, rollingPercentage pass reduction >=7%, austenite is crystal region accumulative total reduction ratio >=50% not, austenite one phase district finish to gauge temperatureSpend 780 DEG C～850 DEG C, refine austenite crystallite dimension, improves hardened and tempered steel plate obdurability, strong plasticityJoin and low-temperature impact toughness.
After controlled rolling finishes, steel plate is transported to cooling device place (DQ, ACC equipment) immediately to steel plateAccelerate cooling; Steel plate is opened 750 DEG C～820 DEG C of cold temperature finishing temperatures, cooling velocity >=7 DEG C/s,Stopping cold temperature is 200 DEG C～300 DEG C, subsequently steel plate from stop cold junction bundle to enter burial pit insulation betweenInterval is not more than 30min, and heat preservation method is that steel billet temperature surface is greater than under the condition of 300 DEG C at leastInsulation more than 24 hours, ensures the abundant dehydrogenation of steel plate, prevents that hydrogen causes delayed crack.
In Technology for Heating Processing, steel plate temperature (plate temperature) is 585～645 DEG C, when steel plate is relatively thinTemperature limit on the lower side when temperature limit on the upper side, steel plate are relatively thick, tempering retention time >=(0.60～1.0) × finished steel plate thickness, the tempering retention time is that steel plate central temperature is opened while reaching tempering target temperatureThe temperature retention time of beginning timing, chronomere is min; Tempering finishes rear steel plate natural air cooling to room temperature.
Beneficial effect of the present invention:
The present invention is by the modular design and special fabrication processes (CR+DQ+T) phase of steel plate alloying elementIn conjunction with, under the condition of not cupric, nickel element, obtain good 800MPa level hardened and tempered steel plate intensity,When low-temperature flexibility, obdurability mate with strong plasticity, the weldability of steel plate is excellent too, successSolved the weldability without nickel content hardened and tempered steel plate, welded H AZ presents high strength, high tenacityAnd good plasticity (being high fracture elongation and uniform elongation); This is steel maximum of the present inventionOne of difficult point is also key core technology.
Obtaining good 80 kilogram level high-tensiles, high tenacity hardened and tempered steel plate obdurability, strong plasticity couplingTime, the welding procedure of steel plate is excellent (the low temperature plasticity and toughness of welding point are good) too,And successfully solved hardened and tempered steel plate not under the condition containing Cu, Ni precious alloy element, realize high-strengthThe requirement of toughness, high welding point plasticity and toughness, has realized Ultra Low Cost manufacture, good tough of steel plateProperty, strong plasticity and good weldability, especially the good plasticity and toughness of welding point have improved large-scale heavy steelThe peace of structure (ocean platform, crane barge peculiar to vessel, water power steel bifurcated pipe, giant excavator and crawler crane etc.)Total stability, anti-fatigue performance; Good weldability has been saved the cost that user's steel member is manufactured, contractingThe time that short user's steel member is manufactured, for user has created huge value, thereby this type of steel plate is notIt is only the product of high added value, green environmental protection.
Brief description of the drawings
Fig. 1 is the microscopic structure (1/4 thickness) of the embodiment of the present invention 5 steel.
Detailed description of the invention
Below in conjunction with embodiment and accompanying drawing, the present invention will be further described.
The composition of steel embodiment of the present invention is referring to table 1, and manufacturing process is referring to table 2～table 4. The present invention is realExecute the performance of routine steel referring to table 5, table 6.
As seen from Figure 1, steel plate microscopic structure of the present invention is tiny evenly, and steel plate microscopic structure is thinLittle lower bainite+lath martensite, bainite/martensite colony is small-sized, below approximately 20 microns,The intensity, low-temperature flexibility, the obdurability that have obtained good 800MPa level hardened and tempered steel plate mate with strong plasticityTime, the weldability of steel plate is excellent too.
The object of the invention is exactly to pass through modular design and the special fabrication processes of steel plate alloying element(CR+DQ+T) combine, under the condition of not cupric, nickel element, obtain good 80 feather weight highWhen intensity, high tenacity hardened and tempered steel plate obdurability, strong plasticity coupling, the welding procedure of steel plate alsoSame excellent (the low temperature plasticity and toughness of welding point are good), and successfully solved hardened and tempered steel plate and do not containUnder the condition of Cu, Ni precious alloy element, realize wanting of high-strength tenacity, high welding point plasticity and toughnessAsk, realized Ultra Low Cost manufacture, obdurability, strong plasticity and good weldability that steel plate is good,Especially the good plasticity and toughness of welding point have improved large-scale heavy steel construction (ocean platform, crane barge peculiar to vessel, waterElectricity steel bifurcated pipe, giant excavator and crawler crane etc.) security and stability, anti-fatigue performance; Good welderingConnecing property has been saved the cost that user's steel member is manufactured, and has shortened the time that user's steel member is manufactured, for usingHuge value has been created at family, thereby this type of steel plate is not only the product of high added value, green environmental protection.
800MPa level of the present invention, high tenacity hardened and tempered steel plate are mainly as the pressure steel of manufacturing hydroelectric projectThe large-scale heavy steel constructions such as pipe, volute and steel bifurcated pipe, large-scale engineering machinery structure, offshore platform,Be the critical material of the great development of the national economy, current domestic Ge great steel mill all can produce above-mentioned steel grade;But manufacturing process and cost vary, how to ensure the good comprehensive mechanical property of steel plate and weldabilityPrerequisite under, realizing Ultra Low Cost manufacture is the key factor that market competition is won; The present invention is not addingAdd Cu, Ni precious alloy element, in conjunction with online hardening and tempering process (omitting the modified operation of off-line), ultralow one-tenthThe 800MPa grade steel plate of combination property and excellent weldability is produced in this locality, estimates obtaining strongerMarket competition advantage. Along with Chinese national economy development, the requirement of building economizing type harmonious society, stateFamily's foundation engineering construction, energy project construction, ocean development construction and build required Large-Scale Equipment systemMake exploitation and put day thing agenda, as strategic basic material--800MPa level hardened and tempered steel plate is notOnly there are wide market prospects, and demand is being accelerated increase year by year.
Claims (7)
1. the steel plate of Ultra Low Cost 800MPa grade high ductility, superior weldability, its composition percentage by weight is:
C：0.030％～0.070％
Mn：1.60％～1.90％
P：≤0.015％
S：≤0.0030％
Cr：0.80％～1.20％
Mo：0.10％～0.30％
Nb：0.010％～0.030％
V：0.030％～0.060％
Ti：0.004％～0.010％
B：0.0008％～0.0016％
Als：0.040％～0.070％
Ca：0.001％～0.004％
All the other are Fe and are inevitably mingled with, and above-mentioned constituent content must meet as follows simultaneouslyRelation:
0.60≤[(％C)+(％Mn)/6+(％Si)/24+(％Ni)/40+(％Cr)/5+(％Mo)/4+(％V)/14+7.3(％B)]×VCooling velocity/(TOpen cold temperature-TStop cold temperature) × t≤1.00, t is finished steel plate thickness, singlePosition, mm; VCooling velocityUnit, DEG C/s; TOpen cold temperature、TStop cold temperatureUnit, DEG C;
Ca/S between 0.80～3.00, and, 5 × 10－4≤(Ca)(S)0.18≤2.5×10－3。
2. the steel plate of Ultra Low Cost 800MPa grade high ductility as claimed in claim 1, superior weldability,It is characterized in that, also comprise in 0 < Si≤0.10%, 0 < N≤0.0050% more than one.
3. the steel of Ultra Low Cost 800MPa grade high ductility as claimed in claim 1 or 2, superior weldabilityPlate, is characterized in that, the microscopic structure of steel plate is lower bainite+lath martensite, average colony chiVery little below 20 μ m.
4. Ultra Low Cost 800MPa grade high ductility, the superior weldability as described in claim 1 or 2 or 3Steel plate, it is characterized in that steel plate tensile strength >=780MPa, yield strength >=690MPa, extensionRate δ5>=18% ,-40 DEG C the summer is than the single value >=100J of side knock merit, welding heat affected zone HAZThe single value >=47J of Charpy ballistic work of-40 DEG C, welding point stretch percentage elongation >=15%.
5. as Ultra Low Cost 800MPa grade high ductility, the good welding of claim 1～4 as described in any oneThe manufacture method of the steel plate of property, is characterized in that, comprises the steps:
1) smelt
Press mentioned component and smelt, adopt continuous casting casting, cast degree of superheat Δ T is controlled at 8 DEG C～30 DEG C,And adopting light Reduction Technology, Continuous Casting Soft Reduction rate is controlled between 2%～5%, casting speed0.6m/min～1.0m/min, liquid level fluctuation of molten steel≤5mm;
2) rolling, steel plate overall compression ratio (thickness of strand/finished steel plate thickness) >=3.6
First stage is common rolling, for ensureing generation [Al]+BN in heating and the operation of rolling→ AlN+[B], guarantee solid solution in steel [B] >=5ppm, slab heating temperature is controlled atBetween 1100 DEG C～1170 DEG C; Milling train is with continual pattern, the slab rolling of coming out of the stove continuouslyTreat temperature thickness to intermediate blank, i.e. second stage austenite non-recrystallization controlled rolling open rolling thickness,Large degree ground is by static and dynamic recrystallization refine austenite crystal grain;
Second stage adopts the controlled rolling of austenite non-recrystallization, controlled rolling start rolling temperature≤ 880 DEG C, rolling pass reduction ratio >=7%, austenite is crystal region accumulative total reduction ratio >=50% not,780 DEG C～850 DEG C of austenite one phase district finishing temperatures;
3) cooling
After controlled rolling finishes, steel plate be transported to immediately cooling device place steel plate is accelerated cooling, steelPlate is opened 750 DEG C～820 DEG C of cold temperature, cooling velocity >=7 DEG C/s, stop cold temperature and be 200 DEG C～300 DEG C, steel plate is little to entering interval time burial pit insulation from stopping cold junction bundle subsequentlyIn 30min, heat preservation method is that steel billet temperature surface is greater than at least insulation under the condition of 300 DEG CMore than 24 hours, ensure the abundant dehydrogenation of steel plate, prevent that hydrogen causes delayed crack;
4) Technology for Heating Processing
Steel plate temperature is 585～645 DEG C, tempering retention time >=(0.60～1.0) × finished steel plateThickness, the tempering retention time is that steel plate central temperature starts timing while reaching tempering target temperatureTemperature retention time, chronomere is min, steel plate thickness unit is mm; After tempering finishesSteel plate natural air cooling is to room temperature.
6. the steel plate of Ultra Low Cost 800MPa grade high ductility as claimed in claim 5, superior weldabilityManufacture method, is characterized in that, the microscopic structure of the steel plate of acquisition is lower bainite+lath martensite,Average colony size is below 20 μ m.
7. the Ultra Low Cost 800MPa grade high ductility as described in claim 5 or 6, the steel of superior weldabilityThe manufacture method of plate, is characterized in that, the steel plate tensile strength >=780MPa of acquisition, yield strength>=690MPa, percentage elongation δ5>=18% ,-40 DEG C the summer, than the single value >=100J of side knock merit, weldsSingle value >=the 47J of Charpy ballistic work of-40 DEG C of heat affected area HAZ, welding point stretches and prolongsStretch rate >=15%.
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|---|---|---|---|---|
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59136418A (en) * | 1983-01-26 | 1984-08-06 | Nippon Steel Corp | Preparation of high toughness and high strength steel |
| JP2002339037A (en) * | 2001-03-13 | 2002-11-27 | Sumitomo Metal Ind Ltd | High tensile strength steel having excellent low temperature joint toughness and ssc resistance, and production method therefor |
| CN1276988C (en) * | 2003-03-27 | 2006-09-27 | 杰富意钢铁株式会社 | Hot-rolled steel strip for high strength electric resistance welding pipe and mfg. method thereof |
| CN100491575C (en) * | 2005-11-22 | 2009-05-27 | 株式会社神户制钢所 | Welding heat influenced ductility-excellent high yield ratio high tension steel plate |
| CN104046908A (en) * | 2014-06-27 | 2014-09-17 | 宝山钢铁股份有限公司 | Low-cost and high-performance ultrahigh-strength steel for engineering machinery and manufacturing method thereof |
| CN104480406A (en) * | 2014-11-28 | 2015-04-01 | 宝山钢铁股份有限公司 | Low-alloy high-strength high-toughness steel plate and manufacturing method thereof |
| JP2016006209A (en) * | 2014-06-20 | 2016-01-14 | Ｊｆｅスチール株式会社 | Hot rolled steel sheet having high strength and excellent in low temperature toughness and production method therefor |
-
2016
- 2016-01-29 CN CN201610064771.6A patent/CN105603322B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59136418A (en) * | 1983-01-26 | 1984-08-06 | Nippon Steel Corp | Preparation of high toughness and high strength steel |
| JP2002339037A (en) * | 2001-03-13 | 2002-11-27 | Sumitomo Metal Ind Ltd | High tensile strength steel having excellent low temperature joint toughness and ssc resistance, and production method therefor |
| CN1276988C (en) * | 2003-03-27 | 2006-09-27 | 杰富意钢铁株式会社 | Hot-rolled steel strip for high strength electric resistance welding pipe and mfg. method thereof |
| CN100491575C (en) * | 2005-11-22 | 2009-05-27 | 株式会社神户制钢所 | Welding heat influenced ductility-excellent high yield ratio high tension steel plate |
| JP2016006209A (en) * | 2014-06-20 | 2016-01-14 | Ｊｆｅスチール株式会社 | Hot rolled steel sheet having high strength and excellent in low temperature toughness and production method therefor |
| CN104046908A (en) * | 2014-06-27 | 2014-09-17 | 宝山钢铁股份有限公司 | Low-cost and high-performance ultrahigh-strength steel for engineering machinery and manufacturing method thereof |
| CN104480406A (en) * | 2014-11-28 | 2015-04-01 | 宝山钢铁股份有限公司 | Low-alloy high-strength high-toughness steel plate and manufacturing method thereof |
Cited By (13)
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|---|---|---|---|---|
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