CN106048408A - Extremely-simple component steel plate for high-strength structures and manufacture method thereof - Google Patents

Extremely-simple component steel plate for high-strength structures and manufacture method thereof Download PDF

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Publication number
CN106048408A
CN106048408A CN201610463631.6A CN201610463631A CN106048408A CN 106048408 A CN106048408 A CN 106048408A CN 201610463631 A CN201610463631 A CN 201610463631A CN 106048408 A CN106048408 A CN 106048408A
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steel plate
manufacture method
strength
extremely
strength structure
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Inventor
侯东华
周兰聚
宋国栋
冯勇
王杰
李彩霞
薛艳龙
侯登义
梁英
宋志超
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Shandong Iron and Steel Group Co Ltd SISG
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Shandong Iron and Steel Group Co Ltd SISG
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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
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • 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
    • 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

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

The invention discloses an extremely-simple component steel plate for high-strength structures and a manufacture method thereof. The extremely-simple component steel plate mainly comprises the following chemical components in percentage by weight: 0.12-0.20% of C, 0.15-0.50% of Si, 1.30-1.80% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, 0.020-0.050% of Al, 0.015-0.035% of Ti, 0.020-0.060% of Nb, 0.0015-0.0035% of B and the balance of Fe and inevitable impurities. The steel plate provided by the invention is simple in component, but the strength, tenacity, plasticity and other mechanical performance indexes of the steel plate are excellent, so that the steel plate is good in quality and stable and uniform in performance; the carbon equivalent is low, so that welding is easy; and the steel plate can be absolutely applied to manufacture of mechanical structural components which have high requirements on strength and tenacity.

Description

One extremely letter composition high-strength structure steel plate and manufacture method thereof
Technical field
The invention belongs to metal material manufacture field, relate to a kind of have extremely letter composition tensile strength 800MPa level high Strength structure steel plate and manufacture method thereof, this high-strength steel sheet alloying element kind is few, with low cost, and obdurability is good, suitable Manufacture for mechanical structured member.
Background technology
Along with economic development and technological progress, at jumbo manufacture row such as coal mine machinery, engineering machinery and harbour machineries Industry, Welding Structure increasingly tends to high parameter and maximization direction is developed, and more carrys out armor plate strength index request for alleviating deadweight The highest.At present, tensile strength 800MPa level high-strength steel progressively replaces the low-alloy high-strength steel with Q345 as representative, becomes machinery and sets The emphasis steel products in standby field, along with metallurgical equipment and the raising of steel rolling technology, domestic large iron and steel enterprise is the most capable Volume shipment high-strength structure product made from steel, along with the raising of application amount, its Technology relative maturity.While it is true, by Needing to use hardening and tempering process to produce in this intensity rank steel plate, each big steel enterprise is for ensureing that quenching degree have employed relatively on composition The alloys such as high C element and Cr, Mo, Ni, additionally add the micro alloying elements such as Nb, V, and along with thickness improves, alloy adds Measure higher.Mo, Ni, Nb, Cr alloy price costly, significantly increases product cost of alloy and smelts difficulty, also causing Carbon equivalent raises, welding crack sensibility increases.
Patent " 800MPa grade high-strength Large Heat Input Welding slab (CN 102839330 B) " provides one 800MPa level high input energy welding steel plate, containing precious alloys such as a large amount of Cu, Cr, Mo, Ni in its chemical composition, cost is relatively High.
Patent " low composition low Pcm value 800MPa level high-strength steel and production method (CN 103725973 B) thereof " provides one The 800MPa level high strength steel plate of kind of low Pcm value, its chemical composition is relatively easy, but the steel plate comparing the present invention with the addition of Cr, The alloying elements such as V.
Patent " tensile strength 800MPa rank low yield strength ratio structural steel and iron and manufacture method (CN 102851615 A) thereof " Provide a kind of 800MPa level low yield strength ratio high-strength steel sheet, valuable containing substantial amounts of Cu, Cr, Mo, Ni etc. in its chemical composition Alloy, relatively costly.
Patent " a kind of 800MPa level low welding crack sensitivity steel plate and manufacture method (CN 10273279713 B) thereof " Provide a kind of low welding crack sensitivity steel plate, compared with patent of the present invention, its chemical composition intentionally adds Cr, Mo etc. Expensive alloying elements.
Patent " a kind of 800MPa Economic corrosion-resistant high-strength steel sheet (CN 102796967 B) " provides one 800MPa level anti-corrosion and high strength steel plate, for ensureing that corrosion resistance has intentionally added the alloying elements such as Cu-Cr-Ni.
" a kind of tensile strength reaches high strength steel plate and the manufacture method (CN 103131956 thereof of more than 800MPa to patent A) " provide the high-strength steel of a kind of more than 800MPa intensity, compared with patent of the present invention, its chemical composition with the addition of Cr, Mo Deng expensive alloying elements.
Summary of the invention
In view of the foregoing, it is an object of the invention to provide a kind of 800MPa grade high-strength structure with extremely letter composition to use Steel plate and manufacture method thereof, solve that 800MPa level high-strength steel complicated component, cost of alloy are high, easily asking of weld crack occur Topic.
Technical scheme: this kind extremely letter composition high-strength structure steel plate, it is characterised in that its primary chemical Composition by weight percent is: C:0.12～0.20%, Si:0.15～0.50%, Mn:1.30～1.80%, P≤0.020%, S ≤ 0.010%, Al:0.020～0.050%, Ti:0.015～0.035%, Nb:0.020～0.060%, B:0.0015～ 0.0035%, remaining is Fe and inevitable impurity.Meanwhile, the chemical composition of steel also meet carbon equivalent require:
Carbon equivalent: Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Cu/+Ni)/15≤0.50% (wherein, Cr, Mo, V, Cu, Ni is residual elements).
The thickness range of this kind extremely letter composition high-strength structure steel plate is 10～60mm, it is characterised in that it main Mechanical performance index is yield strength (Rp0.2) >=690MPa, tensile strength (Rm) 770～930MPa, elongation after fracture (A) >= 14% ,-40 DEG C and above test temperature Charpy impact energy (KV2)≥47J。
The manufacture method of described extremely letter composition high-strength structure steel plate, its smelting process is characterised by pre-by adopting molten iron Process desulfurization to 0.008% and following, converter top and bottom complex blowing less-slag melting and reduce phosphorus content 0.017% and following, use LF stove Outer essence even+RH circulating vacuum deaerate and controls inclusion balling, coordinates whole process to protect sheet slab continuous casting process, it is thus achieved that steel billet Internal soundness is C class segregation≤2.0, center porosity≤0.5, non-stop layer crackle, additionally, steel billet main chemical compositions weight percent Than meeting following condition: C:0.12～0.20%, Si:0.15～0.50%, Mn:1.30～1.80%, P≤0.020%, S≤ 0.010%, Al:0.020～0.050%, Ti:0.015～0.035%, Nb:0.020～0.060%, B:0.0015～ 0.0035%, remaining is the inevitable impurity of Fe, simultaneously its carbon equivalent Ceq≤50%.
The manufacture method of described extremely letter composition high-strength structure steel plate, its rolling mill practice is characterised by using recrystallization zone The dual-stage controlled rolling of+Unhydrated cement, steel billet stacking enters after placing more than 48 hours after checking billet surface zero defect Heating furnace heats, and heat time heating time is not less than 4 hours, heating-up temperature 1200～1280 DEG C；High-pressure water descaling 2～3 times before rolling, Billet rolling is become intermediate blank in austenite recrystallization district by the first stage, this stage control at least 2 more than reduction in pass 20mm, More than workpiece thickness is finished product thickness 2.0～2.5 times obtained；Second stage is at austenite Unhydrated cement generation ferrum element Before body phase transformation, intermediate blank is rolled into finished product thickness steel plate, this stage control total reduction more than 50%, rolling temperature range 890 ～790 DEG C, roll air cooling after aligning.
The manufacture method of described extremely letter composition high-strength structure steel plate, Technology for Heating Processing is characterised by using out-line quenching + tempering process, Shot Blasting before quenching, hardening heat is 900～930 DEG C, and time inside furnace is adjusted according to steel plate thickness (δ) specification Whole, circular is 2.0min/mm × δ+0～15min；Temperature is 450～600 DEG C, and time inside furnace is according to steel plate Thickness (δ) specification adjusts, and circular is 2.0～2.5min/mm × δ+0～15min, aligning, finishing, spray number after tempering Identify and check.
The present invention removes outside the big element of ferrous materials five, only has a mind to the addition of Al, Ti, Nb, B totally 4 kinds of elements, in order in order to Ensure the purpose of the present invention, while making steel plate have high intensity, there is good plasticity and toughness, good welding performance, below The concrete addition of C, Si, Mn, S, P, Al, Ti, Nb, B in the present invention is illustrated.
C element is most economical intensified element, plays obvious solution strengthening effect during as interstitial atom.C element can To significantly improve the essential quenching degree of steel plate, increase steel plate through hardening ability during quenching, but C element easily causes toughness and welding Property decline, content is unsuitable too high.The present invention selects C content scope to be 0.12～0.20%, has been effectively shielded from peritectoid district and has prevented Only strand crackle, on the basis of the quenching degree ensureing steel plate, is unlikely to that C content is too high to be caused bigger to weldability and plasticity and toughness Harm.
The Si content of the present invention is 0.15～0.50%, and Si is the deoxidant element in steel, it is also possible to carried by solution strengthening High armor plate strength, owing to Si is unfavorable to toughness and surface quality, should not add too high.
The Mn constituent content of the present invention is 1.30～1.80%, is different from the common tempering type high-strength steel present invention and properly increases Mn content, it is therefore an objective to compensate, by the Strengthening and Toughening effect of Mn, the intensity caused without precious alloy and decline, utilize Mn simultaneously The facilitation of bainitic transformation is improved quenching degree.
The present invention limits P content and is not more than 0.020%, and P can cause the decline of steel plate plasticity and toughness as impurity element, suitably Reduce P content and be conducive to the raising of steel plate toughness index.
The present invention limits S content and is not more than 0.010%, and S is the impurity element that in steel, another harm is bigger, tough to steel plate Property Index Influence relatively big, S content is the lowest more good, but de-S more low cost is the highest, from economy and the performance requirement angle of de-S Degree considers, it is the most suitable that S content controls in≤0.010%.
Al element content range of the present invention is 0.020～0.050%, as main deoxidant element, limit content lower limit as Guarantee deoxidation effect, also has certain effect, but too much Al is easily caused field trash and produces, and therefore sets crystal grain thinning Determining the upper limit is 0.050%.
Restricted T i element content range of the present invention is 0.015～0.035%, and the Ti easily N in steel is combined, and forms height Melting point compounds, hinders austenite grain boundary to move, suppresses Austenite Grain Growth, play refined crystalline strengthening effect, and during welding, TiN can With effective anchoring austenite grain boundary, prevent welding heat affected zone grain coarsening.
It is 0.020～0.060 that the present invention limits Nb element content range, fits relative to the conventional quenching and tempering type high-strength steel present invention When improve the consumption of Nb, solid solution Nb can suppress austenite recrystallization to improve roughing rolling temperature, it is also possible to improves steel plate Quenching degree, the carbonitride of the Nb that rolling induction simultaneously separates out plays stronger refined crystalline strengthening effect, to the toughness improving steel plate Favourable with intensity.
It is 0.0015～0.0035 that the present invention limits B element content range, and B is by austenite grain boundary segregation suppression ferrum element Body phase transformation, thus improve matrix quenching degree, B is strong quenching degree element, but too much B is unfavorable to toughness and weldability.
The mechanical performance of the steel plate that the present invention provides is basically identical compared with above-mentioned patent, but the high intensity of present invention knot Structure steel plate and manufacture method advantage thereof are the most prominent.Steel plate of the present invention removes outside ferrous materials five big Elements C, Si, Mn, P, S, Only with the addition of tetra-kinds of elements of Al, Ti, Nb, B, composition is extremely simple, with other compared with type 800MPa grade high-strength structural steel, Having saved molybdenum-iron 3.4～6.8kg/t, electrolytic nickel 1.5～3.5kg/t, ferrochrome 4～8kg/t, cost of alloy reduces by more than 30%. Although steel plate composition is simple, but logical manufacture method of the present invention has fully excavated Metallurgical Industry rolling and Equipment for Heating Processing is dived Can, it is ensured that steel plate yield strength (Rp0.2) it is not less than 690MPa, tensile strength (Rm) meet on the basis of 770～930MPa, its Low-temperature impact absorbs merit and is not less than 47J (test temperature-40 DEG C, KV2), elongation after fracture (A) is more than 14%, and steel plate plasticity and toughness are excellent Good.Plate quality is good, stable performance is uniform, and carbon equivalent is low, and steel plate material object carbon equivalent (Ceq), mostly below 0.45%, belongs to In having the steel plate of good welds, suitable low-temperature prewarming, just it can be avoided that welding cold cracking, is fully applicable to plant equipment The manufacture of structural member.
Accompanying drawing explanation
Fig. 1 is embodiment 1 light plate metallographic structure；
Fig. 2 is embodiment 4 light plate metallographic structure；
Detailed description of the invention
Below by embodiment 1,2,3,4 and combine accompanying drawing the present invention is described in more detail, the steel plate thickness of embodiment 1 For 10mm, the steel plate thickness 20mm of embodiment 2, the steel plate thickness 40mm of embodiment 3, the steel plate thickness of embodiment 3 is 60mm.Real Execute example steel plate all to produce according to following technological process:
KR molten iron pretreatment → top and bottom combined blown converter smelting → CAS microalloying → LF+RH refine → slab is cast → is added Heat → high-pressure water descaling → recrystallization zone rolling → Unhydrated cement rolling → aligning → cooling → ball blast → Quenching Treatment → return Fire process → aligning → finishing → spray mark → pick test.
Embodiment 1
Producing in strict accordance with the technological process of production, main technique link key parameter controls as follows:
KR pretreatment: after process, S content is 0.007%；
Top and bottom combined blown converter smelting: use high-quality steel scrap, be sequentially added into aluminium block, manganeisen, silicomangan, ferrosilicon, niobium Ferrum, smelting endpoint carbon content controls according to than desired value low 0.04%, and P content is 0.014%, and S content is 0.018%, converter Outlet temperature 1679 DEG C；
CAS stands: adding the aluminum steel 0.5～1.0m/t of Ф 13mm, argon blowing time 11min, be disposed, P content is 0.016%, S content is 0.015%, Al content: 0.034%
LF external refining: making white slag and take off S, heating terminates to add ferrotianium, ferro-boron, and terminal S content is 0.004% out-station temperature 1635℃；
RH external refining: the process time of vacuum≤200Pa is 17min, carries out trimming；
Slab is poured into a mould: fluctuate in the range of controlling degree of supercooling 15～25 DEG C, it is thus achieved that slab thickness is 250mm, in plate blank coarse micro-grain Heart C class segregation 2.0, center porosity 0.5, non-stop layer crackle, the smelting component that the present embodiment finally obtains is C:0.12%, Si: 0.30%, Mn:1.35%, P:0.018%, S:0.005%, Al:0.035%, Ti:0.023%, Nb:0.022%, B: 0.0018%, remaining is the inevitable impurity of Fe, and being computed its carbon equivalent Ceq is 0.36%.
Heating of plate blank: slow cooling fed to boiler heating in 90 hours placed by slab, and heat time heating time is 4.2 hours, and soaking temperature is 1220℃；
High-pressure water descaling 3 times before rolling, billet surface is without obvious iron scale；
Recrystallization zone rolls: start rolling temperature 1100 DEG C, finish to gauge 1080 DEG C, and inverse the 2nd, the drafts of 3 passages are respectively 25mm, 23mm, the final workpiece thickness obtained is 40mm；
Unhydrated cement rolls: open rolling 890 DEG C, finish to gauge 840 DEG C, total reduction is 75%, it is thus achieved that thickness is 10mm steel plate；
Off-line heat treatment: quenching after Shot Blasting, Quenching Treatment soaking temperature is 900 DEG C, at stove 35min；Temper Soaking temperature is 600 DEG C, and at stove 35min, after coming out of the stove, aligning slow cooling is to room temperature, then finishing, spray number mark and a pick test. The mechanical performance of embodiment 1 is shown in Table 1, and Fig. 1 is shown in its metallographic structure.
Embodiment 2
Producing in strict accordance with the technological process of production, main technique link key parameter controls as follows:
KR pretreatment: after process, S content is 0.006%；
Top and bottom combined blown converter smelting: use high-quality steel scrap, be sequentially added into aluminium block, manganeisen, silicomangan, ferrosilicon, niobium Ferrum, smelting endpoint carbon content is according to lower by 0.04% than desired value, and P content is 0.015%, and S content is 0.018%, converter terminal Temperature 1673 DEG C；
CAS stands: adding the aluminum steel 0.5～1.0m/t of Ф 13mm, argon blowing time 12min, be disposed, P content is 0.017%, S content is 0.016%, aluminum content: 0.028%
LF external refining: making white slag and take off S, heating terminates to add ferrotianium, ferro-boron, and terminal S content is 0.006% out-station temperature 1632℃；
RH external refining: the process time 18min of vacuum≤200Pa, carries out trimming；
Slab is poured into a mould: fluctuate in the range of controlling degree of supercooling 15～25 DEG C, it is thus achieved that slab thickness is 250mm, in plate blank coarse micro-grain Heart C class segregation 1.5, center porosity 0.5, non-stop layer crackle, the smelting component that the present embodiment finally obtains is: C:0.14%, Si: 0.28%, Mn:1.45%, P:0.017%, S:0.007%, Al:0.028%, Ti:0.020%, Nb:0.032%, B: 0.0025%, remaining is the inevitable impurity of Fe, and being computed its carbon equivalent Ceq is 0.39%.
Heating of plate blank: slow cooling fed to boiler heating in 106 hours placed by slab, and heat time heating time is 4.5 hours, and soaking temperature is 1270℃；
High-pressure water descaling 2 times before rolling, billet surface is without obvious iron scale；
Recrystallization zone rolls: start rolling temperature 1080 DEG C, finish to gauge 1060 DEG C, and inverse the 2nd, the drafts of 3 passages are respectively 24mm, 27mm, the final workpiece thickness obtained is 80mm；
Unhydrated cement rolls: open rolling 880 DEG C, finish to gauge 850 DEG C, total reduction is 75%, it is thus achieved that thickness is 20mm steel plate；
Off-line heat treatment: quenching after Shot Blasting, Quenching Treatment soaking temperature is 910 DEG C, at stove 50min；Temper Soaking temperature is 560 DEG C, and at stove 55min, after coming out of the stove, aligning slow cooling is to room temperature, then finishing, spray number mark and a pick test. The mechanical performance of embodiment 2 is shown in Table 1.
Embodiment 3
Producing in strict accordance with the technological process of production, main technique link key parameter controls as follows:
KR pretreatment: S content≤0.007% after process；
Top and bottom combined blown converter smelting: use high-quality steel scrap, be sequentially added into aluminium block, manganeisen, silicomangan, ferrosilicon, niobium Ferrum, smelting endpoint carbon content is according to lower by 0.03% than desired value, and P content is 0.014%, and S content is 0.015%, converter terminal Temperature 1678 DEG C；
CAS stands: adding the aluminum steel 0.5～1.0m/t of Ф 13mm, argon blowing time 14min, be disposed, P content is 0.015%, S content is 0.010%, aluminum content: 0.032%
LF external refining: making white slag and take off S, heating terminates to add ferrotianium, ferro-boron, and terminal S content is 0.006% out-station temperature 1635℃；
RH external refining: the process time 20min of vacuum≤200Pa, carries out trimming；
Slab is poured into a mould: fluctuate in the range of controlling degree of supercooling 15～25 DEG C, it is thus achieved that slab thickness is 250mm, in plate blank coarse micro-grain Heart C class segregation 1.0, center porosity 0.5, non-stop layer crackle, the smelting component that the present embodiment finally obtains is: C:0.14%, Si: 0.32%, Mn:1.78%, P:0.016%, S:0.007%, Al:0.029%, Ti:0.023%, Nb:0.043%, B: 0.0023%, remaining is the inevitable impurity of Fe, and being computed its carbon equivalent Ceq is 0.44%.
Heating of plate blank: slow cooling fed to boiler heating in 120 hours placed by slab, and heat time heating time is 4.3 hours, and soaking temperature is 1200℃；
High-pressure water descaling 3 times before rolling, billet surface is without obvious iron scale；
Recrystallization zone rolls: start rolling temperature 1100 DEG C, finish to gauge 1070 DEG C, reciprocal 2nd, the drafts of 3 passages is respectively 26, 24mm, workpiece thickness is 110mm；
Unhydrated cement rolls: open rolling 860 DEG C, finish to gauge 850 DEG C, total reduction is 55%, and the mechanical performance of embodiment 1 is shown in Table 1, Fig. 1 is shown in its metallographic structure.；
Off-line heat treatment: quenching after Shot Blasting, Quenching Treatment soaking temperature is 920 DEG C, at stove 110min；Temper Soaking temperature is 480 DEG C, and at stove 110min, after coming out of the stove, aligning slow cooling is to room temperature, then finishing, spray number mark and sampling inspection Test.The mechanical performance of embodiment 3 is shown in Table 1.
Embodiment 4
Producing in strict accordance with the technological process of production, main technique link key parameter controls as follows:
KR pretreatment: after process, S content is 0.007%；
Top and bottom combined blown converter smelting: use high-quality steel scrap, be sequentially added into aluminium block, manganeisen, silicomangan, ferrosilicon, niobium Ferrum, smelting endpoint carbon content is according to lower by 0.02% than desired value, and P content is 0.016%, and S content is 0.015%, converter terminal Temperature is 1671 DEG C；
CAS stands: adding the aluminum steel 0.5～1.0m/t of Ф 13mm, argon blowing time 12min, be disposed, P content is 0.015%, S content is 0.013%, aluminum content: 0.031%
LF external refining: making white slag and take off S, heating terminates to add ferrotianium, ferro-boron, and terminal S content is 0.005% out-station temperature 1638℃；
RH external refining: the process time 20min of vacuum≤200Pa, carries out trimming；
Slab is poured into a mould: fluctuate in the range of controlling degree of supercooling 15～25 DEG C, it is thus achieved that slab thickness is 250mm, in plate blank coarse micro-grain Heart C class segregation 1.5, center porosity 0.5, non-stop layer crackle, the smelting component that the present embodiment finally obtains is: C:0.20%, Si: 0.35%, Mn:1.42%, P:0.016%, S:0.005%, Al:0.030%, Ti:0.025%, Nb:0.055%, B: 0.0028%, remaining is the inevitable impurity of Fe, and its carbon equivalent Ceq is 0.45% simultaneously.
Heating of plate blank: slow cooling fed to boiler heating in 60 hours placed by slab, and heat time heating time is 4.2 hours, and soaking temperature is 1280℃；
High-pressure water descaling 3 times before rolling, billet surface is without obvious iron scale；
Recrystallization zone rolls: start rolling temperature 1120 DEG C, finish to gauge 1100 DEG C, and inverse the 2nd, the drafts of 3 passages are respectively 27,28mm, workpiece thickness is 130mm；
Unhydrated cement rolls: open rolling 830 DEG C, finish to gauge 800 DEG C, total reduction is 54%, it is thus achieved that the steel plate of thickness 60mm；
Off-line heat treatment: quenching after Shot Blasting, Quenching Treatment soaking temperature is 930 DEG C, at stove 120min；Temper Soaking temperature is 450 DEG C, and at stove 150min, after coming out of the stove, aligning slow cooling is to room temperature, then finishing, spray number mark and sampling inspection Test.The mechanical performance of embodiment 4 is shown in Table 1, and Fig. 2 is shown in its metallographic structure.
Table 1 embodiment 1-4 steel plate mechanical performance
As it can be seen from table 1 thickness range span of the present invention is big, but steel plate is functional, becomes although with extremely letter Set up meter separately and reduce alloy consumption, but performance meets standard-required and comparison is excellent.
Table 2 be embodiment 4 thickness be the welding point oblique Y groove result of the test of 60mm steel plate.Welding cold crack sensitivity It is a key index of high-strength steel application, along with the increase cool attenuation of steel plate thickness also increases.From the point of view of table 2, steel Plate only occurs a small amount of underbead crack under room temperature not preheating condition, preheats 50 DEG C and crackle does not the most occur, and the welding of invention is described Manufacturability is excellent, it is easy to welding.
Table 2 embodiment 4 welding point oblique Y groove result of the test
Note: full-argon gas shielded arc welding, thermal weld stress amount is 15kJ/cm.
For checking the welding point mechanical performance of invention steel plate, have employed two kinds of thermal weld stress of 15kJ/cm, 30kJ/cm Amount has carried out banjo fixing butt jointing welding and mechanical performance test, and result of the test is shown in Table 3.
Table 3 embodiment 4 welding butter joint mechanical properties results
From the point of view of table 3, the welding point satisfactory mechanical property of steel of the present invention, Technological adaptability is strong.

Claims (10)

1. an extremely simple composition high-strength structure steel plate, it is characterised in that its main chemical compositions percentage by weight is: C: 0.12～0.20%, Si:0.15～0.50%, Mn:1.30～1.80%, P≤0.020%, S≤0.010%, Al:0.020～ 0.050%, Ti:0.015～0.035%, Nb:0.020～0.060%, B:0.0015～0.0035%, remaining is Fe and can not The impurity avoided；Simultaneously the chemical composition of steel also meet carbon equivalent require: carbon equivalent: Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Cu/+Ni)/15≤0.50% (wherein, Cr, Mo, V, Cu, Ni are residual elements).
2. one as claimed in claim 1 extremely letter composition high-strength structure steel plate, it is characterised in that described steel plate thickness model Enclosing is 10～60mm, and its main Mechanical index is yield strength (Rp0.2) >=690MPa, tensile strength (Rm)770- 930MPa, elongation after fracture (A) >=14% ,-40 DEG C and above test temperature Charpy impact energy (KV2)≥47J。
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that its Technological process is: KR molten iron pretreatment → top and bottom combined blown converter smelting → CAS microalloying → LF+RH refine → slab casting → Heating → high-pressure water descaling → recrystallization zone rolling → Unhydrated cement rolling → aligning → cooling → ball blast → Quenching Treatment → Temper → aligning → finishing → spray mark → pick test.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that: use The inside steel billet quality that described manufacture method is obtained is C class segregation≤2.0, center porosity≤0.5, non-stop layer crackle.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that:
Described slab stacking enters heating furnace heating, heat time heating time after placing more than 48 hours after checking billet surface zero defect Not less than 4 hours, heating-up temperature 1120～1280 DEG C.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that:
Described high-pressure water descaling 2～3 times.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that:
Described recrystallization zone rolling mill practice is particularly as follows: become intermediate blank in austenite recrystallization district by billet rolling, and this stage is controlled System at least 2 more than reduction in pass 20mm, it is thus achieved that workpiece thickness is finished product thickness 2.0～2.5 times.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that: described Unhydrated cement rolling mill practice particularly as follows: intermediate blank is rolled into into before austenite Unhydrated cement generation ferrite transformation Product thickness steel plate, this stage control total reduction more than 50%, rolling temperature range 890～790 DEG C, roll air cooling after aligning.
9. the manufacture method of extremely letter composition high-strength structure steel plate as claimed in claim 3, it is characterised in that: described quenches Fire is processed as out-line quenching, and Shot Blasting before quenching, hardening heat is 900～930 DEG C.
A kind of manufacture method of extremely letter composition high-strength structure steel plate, it is characterised in that: institute The temper technique stated, temperature is 450～550 DEG C.
CN201610463631.6A 2016-06-23 2016-06-23 Extremely-simple component steel plate for high-strength structures and manufacture method thereof Pending CN106048408A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109112264A (en) * 2018-10-26 2019-01-01 山东钢铁集团日照有限公司 The high tough medium plate of micro alloying element quenching and tempering type and its manufacturing method on a small quantity
CN110205557A (en) * 2019-07-17 2019-09-06 贝斯山钢(山东)钢板有限公司 A kind of 350-380HBW hardness level thick-specification high-tenacity wear-resisting steel plate and preparation method
CN113235009A (en) * 2021-05-19 2021-08-10 宝武集团鄂城钢铁有限公司 Economical 690 MPa-grade high-strength steel plate and preparation method thereof

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CN102181794A (en) * 2011-04-14 2011-09-14 舞阳钢铁有限责任公司 Hardening and tempering high-strength steel plate for wood based panel equipment and production method of tempering high-strength steel plate
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CN102181794A (en) * 2011-04-14 2011-09-14 舞阳钢铁有限责任公司 Hardening and tempering high-strength steel plate for wood based panel equipment and production method of tempering high-strength steel plate
CN104451379A (en) * 2014-11-06 2015-03-25 南京钢铁股份有限公司 High-strength low-alloy niobium-vanadium structural steel and preparation method thereof

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Publication number Priority date Publication date Assignee Title
CN109112264A (en) * 2018-10-26 2019-01-01 山东钢铁集团日照有限公司 The high tough medium plate of micro alloying element quenching and tempering type and its manufacturing method on a small quantity
CN110205557A (en) * 2019-07-17 2019-09-06 贝斯山钢(山东)钢板有限公司 A kind of 350-380HBW hardness level thick-specification high-tenacity wear-resisting steel plate and preparation method
CN113235009A (en) * 2021-05-19 2021-08-10 宝武集团鄂城钢铁有限公司 Economical 690 MPa-grade high-strength steel plate and preparation method thereof
CN113235009B (en) * 2021-05-19 2022-05-13 宝武集团鄂城钢铁有限公司 Economical 690 MPa-grade high-strength steel plate and preparation method thereof

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Application publication date: 20161026