CN104630625A - Low-temperature-resistant hot-rolled H-shaped steel and preparation method thereof - Google Patents

Low-temperature-resistant hot-rolled H-shaped steel and preparation method thereof Download PDF

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CN104630625A
CN104630625A CN201510044714.7A CN201510044714A CN104630625A CN 104630625 A CN104630625 A CN 104630625A CN 201510044714 A CN201510044714 A CN 201510044714A CN 104630625 A CN104630625 A CN 104630625A
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steel
temperature
slag
hot rolled
cooling
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CN104630625B (en
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王中学
韩蕾蕾
于浩
宋成浩
李四军
张学民
杨栋
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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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    • 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
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/12Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/14Ferrous alloys, e.g. steel alloys containing titanium or zirconium

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The invention discloses a low-temperature-resistant hot-rolled H-shaped steel and a preparation method thereof. The hot-rolled H-shaped steel comprises the following chemical components in percentage by weight: 0.07-0.10% of C, 0.2-0.4% of Si, 1.30-1.60% of Mn, at most 0.020% of P, at most 0.015% of S, 0.015-0.070% of V, 0.010-0.030% of Ti, and the balance of Fe and inevitable impurities. The production method comprises the following steps: converter smelting, LF (ladle furnace) refining, continuous casting, rolling and the like. The structure of the H-shaped steel is a polygonal ferrite and pearlite structure, the yield strength is 350-450 MPa, the tensile strength is 480-600 MPa, the percentage elongation after fracture is greater than or equal to 22%, and the -40-DEG C V-notch Charpy impact energy is greater than or equal to 200J.

Description

A kind of low temperature resistant hot rolled H-shaped and preparation method thereof
Technical field
The invention belongs to the technical field of smelting of low temperature resistant H profile steel, particularly, the present invention relates to a kind of low temperature resistant hot rolled H-shaped and preparation method thereof.
Background technology
China starts from the eighties in 20th century offshore platform building oneself, and in marine oil, gas extraction, development rapidly, this also strong demand having promoted offshore oil drilling platform steel.The demand of high strength, low temperature resistant offshore platform steel is increasing, and China's technical capacity is in this respect also relatively backward, the high strength of independent intellectual property right, high tenacity offshore platform steel is had in the urgent need to researching and developing series, this is for making full use of China's sea area resources, and the energy strategy realizing country has profound significance.The impacts such as wind loading, wave loading, river load, ice load, earthquake load will be considered with hot rolled H-shaped in ocean, and this just determines the singularity of offshore platform steel, special requirement high strength, high tenacity.
Because offshore platform is built among sea, its Working environment is very severe.Therefore, offshore platform is very high to the specification of quality of steel, except to except requirement of strength, requires also very high to resistance to low temperature.For ensureing that Steels For Offshore Oil Platform has good over-all properties, the external main technological line adopting Nb or Nb-V microalloying, the Steels For Offshore Oil Platform such as A572/A572M and EH36, the BS4360-50D of Britain, the StE355 of Germany as the U.S. is Nb-V microalloyed steel.China's H profile steel production kind is more single compared with abroad, and intensity rank is at 235-345MPa, and wherein 235MPa accounts for most output.Microalloying is with hot rolled H-shaped development in the starting stage, and current production is high-strength low temperature resistant hot rolled H-shaped except the rolling that tightens control, and key still will introduce suitable micro-alloying technology.
Be used in the low temperature resistant hot rolled H-shaped patent of marine petroleum exploitation platform at published relevant microalloying, Chinese patent application CN103667910A describes a kind ofly has the hot rolled H-shaped of favorable low-temperature impact toughness and manufacture method thereof, by weight percentage, the chemical constitution of its molten steel is: C0.05 ~ 0.18, Si0.15 ~ 0.40, Mn1.0 ~ 1.5, V0.010 ~ 0.050, Nb0.015 ~ 0.050, Ti0.005 ~ 0.025, Al≤0.035, P≤0.020, S≤0.015, and surplus is Fe and trace impurity.This invention, mainly through low carbon content, applies niobium vanadium titanium-combined microalloying technique, low temperature resistant hot rolled H-shaped products production under achieving high finishing temperature condition.Although its problem is that this steel grade employs microalloy Nb, intensity rank is too not high, and the toughness of-40 DEG C neither be very high, adds the production cost after Nb and add.
Chinese patent application CN101760704A discloses a kind of economical high-strength and high-weather-resistance hot rolled H-shaped containing vanadium, wherein the content of V is 0.07% ~ 0.12%, but because it controls less in steelmaking and continuous casting process, its low-temperature flexibility is not very high, does not make full use of the effect of V in steel.
In sum, the hot rolled H-shaped research and development in microalloying ocean are produced on traditional process at home, from the kind of Composition Design to controlling of production process technology comparatively low level be in developmental stage.Q345E and other high-strength low temperature resistant hot rolled H-shaped Composition Design of higher level and technique at home and abroad be have not been reported.Because Q345E and other hot rolled H-shaped metallurgical process of higher level and technological process all have difference with traditional process, mainly easily occur that low-temperature flexibility is unstable or intensity is nonconforming, therefore need to take new design and processes route in metallurgically design and technology controlling and process, produce the low temperature resistant hot rolled H-shaped Q345E being suitable for ocean platform at lower cost, to meet the need of market.
Summary of the invention
The object of the invention is to, provide a kind of low temperature resistant hot rolled H-shaped, H profile steel prepared by the present invention be organized as polygonal ferrite and pearlitic structure, yield strength is 350 ~ 450MPa, tensile strength is 480 ~ 600MPa, elongation after fracture >=22% ,-40 DEG C of V-type Charpy-V impact power >=200J.
For reaching the object of foregoing invention, present invention employs following technical scheme:
A kind of low temperature resistant hot rolled H-shaped, described is hot rolled H-shaped, its chemical composition is by weight percentage: C0.07 ~ 0.10%, Si0.2 ~ 0.4%, Mn1.30 ~ 1.60%, P≤0.020%, S≤0.015%, V0.015 ~ 0.070%, Ti0.010 ~ 0.030%, and surplus is Fe and inevitable impurity.
The organization type of H profile steel of the present invention is polygonal ferrite tissue and a small amount of pearlitic structure, and do not need to heat-treat operation, yield strength is 350 ~ 450MPa, and tensile strength is 480 ~ 600MPa, elongation after fracture >=22% ,-40 DEG C of V-type Charpy-V impact power >=200J.
Below the effect of component contained in the present invention and the selection of consumption are made and having illustrated:
C: be soft steel tradition, economic strengthening element, the increase of the intensity carbon content of steel and improving, but it is very large on the impact of the welding property of steel, mechanical property and corrosion resisting property, the carbon equivalent Ceq specified from International Institude of Welding and crack-sensitivity indices P cm can find out that carbon affects a most responsive element of welding property, and impelling strength also can obviously decline with the increase of carbon content, adopt low carbon content design, toughness and the ductility of steel plate can be improved, and there is good weldability and corrosion resisting property.Therefore, for meeting the matched well of high strength and high tenacity, the most basic approach reduces carbon content, and improve intensity by other means, and the C content therefore in the present invention controls between 0.07 ~ 0.10%.
Si: be the fundamental element in steel, mainly play desoxydatoin in steelmaking process, generally, the Si content in killed steel is all more than 0.1%.But si content is higher in steel, the toughness of steel can be made, especially low-temperature flexibility is made obviously to reduce, and unfavorable to the welding property of steel during too high levels, the intensity of comprehensive steel, toughness, many considerations such as corrosion resistance nature and welding property, the Si content in the present invention controls between 0.2 ~ 0.4%.
Mn: as the essentially consist element of carbon steel and structural low alloy steel, it serves the effect of reductor in steelmaking process, in addition Mn plays solution strengthening effect in steel, due to steel will be made, there is good weldability and then require that it has lower carbon content, therefore usually its intensity is ensured by improving Fe content, but there have data to show Mn too high levels (> 1.5%) to be unfavorable to the welding property of steel, and may center segregation be increased the weight of, and the higher easy formation MnS of manganese element is mingled with, the solidity to corrosion of steel is had a negative impact, therefore the Mn content in the present invention controls between 1.30 ~ 1.60%.
P: be considered to cheap raising resistance to corrosion seawater element, but it can bring adverse influence to the low-temperature flexibility of mother metal and welding heat influence area toughness, consider, the P content of various countries' offshore platform steel has stricter upper line traffic control, generally be no more than 0.030%, the P content in the present invention is reached the standard grade and is decided to be 0.020%.
S: be the harmful element in steel, in steel, easily form MnS be mingled with, its lateral performance to steel, Z-direction performance, sea water corrosion resistant etc. are all harmful, should control at minimum content in actual production as far as possible, and the S content in the present invention is reached the standard grade location 0.015%.
V:V can improve the hardening capacity of steel, dissolves in ferrite and has strengthening effect, can form stable carbide, crystal grain thinning.But the obstruction effect of V to austenite recrystallization does not have Nb obvious.Just have retardation function to recrystallize when V is only below 900 DEG C, after austenitic transformation, V almost dissolves completely, and V only usually affects austenite to ferritic transformation as a unit.V can produce the precipitation strength of medium tenacity and more weak grain refining, and is proportional with the percentage ratio shared by it.N can strengthen the effect of V, in order to obtain larger strengthening effect, can utilize the method that the precipitation strength of V and the grain refining of Nb combine.After adding V in steel, can improve ductile-brittle transition temperature, affect low-temperature flexibility, general needs controls below 0.10%, and when V, Ti coexist, suitably improving V has good effect to raising welding seam toughness,
Ti: be micro alloying element, adds the intensity that a small amount of Ti can improve steel in steel, improves cold shaping performance and the welding property of steel, also can produce strong precipitation strength and moderate Grain Refinement Effect.The chemically reactive of Ti is very strong, C, N, O, S in Yi Yugang form compound, TiN effectively can stop austenite crystal growing up in heat-processed, play the effect of fining austenite grains, and the toughness of welded heat affecting zone can be improved, in addition, Ti also can be used as steel medium sulphide content modifying element and uses, to improve the performance difference in length and breadth of steel plate.But the interpolation of Ti is less than 0.005%, DeGrain, and addition too much easily produces slab defects.To sum up consider, the Ti content in the present invention controls between 0.010 ~ 0.030%.
Another object of the present invention is to, provide a kind of low temperature resistant hot rolled H-shaped preparation method, described method comprises converter smelting-LF refining-continuous casting-roll forming successively, wherein:
1) converter smelting:
A. Terminal Process Control: [S] <0.020%, [P] <0.015%;
B. slag-stopping tapping, thickness of slag layer≤70mm in bag;
C. deoxidation alloying;
2) LF refining:
A. refining cycle: be greater than 30 minutes (not comprising the soft blow time);
B. deoxidation and slag making operation: adopt high voltage low current slag, add lime 8 ~ 12kg/t steel; Add carbide of calcium 1.5 ~ 2.5kg/t steel, Si-Ca-Ba 2.0 ~ 3.0kg/t steel-deoxidizing adjust slag; Refining process slag and finishing slag basicity 2.0 ~ 3.0; Determine oxygen < 20ppm after getting first sample and then feed titanium wire 60 ~ 90m, wire-feeding velocity >=3m/s;
C. Calcium treatment and soft blow: before molten steel departures, get one, gas sample, and feed real core calcium line 100 ~ 150m according to aluminium content in steel and carry out calcification processing, carry out " soft blow " after line feeding, soft blow time >=10 minutes;
3) continuous casting process:
A. pouring basket liquid level >=800mm, whole process protection is poured into a mould, and tundish protection adopts " carbon-free alkaline covering agent+rice husk ";
B. covering slag uses soft steel mould flux: crystallizer inflow temperature >=25 DEG C; Crystallizer cooling, cooling twice adopt weak cold mode; Control the superheating temperature of molten steel, make it be less than 25 DEG C;
4) technique of rolling:
A. continuously cast bloom in process furnace the section of adding time >=120min, soaking time 30 ~ 50min, tapping temperature steel billet controls at 1160 ~ 1240 DEG C;
B. adopt recrystallization zone rolling, start rolling temperature controls at 1020 ~ 1060 DEG C, and finishing temperature control is at 850 ~ 1000 DEG C;
C. opening cold temperature after rolling controls at 850 ~ 950 DEG C, and final cooling temperature controls at 100 DEG C, and speed of cooling is 3 ~ 7 DEG C/s;
D. straightening temperature < 100 DEG C, laggard row stacking slow cooling.
Further, described step 1) deoxidation alloying in, first adopt aluminium manganese-ferro deoxidation, aluminium ferromanganese add-on is 2.5 ~ 4kg/t steel, secondly adopts manganese metal and ferrosilicon and vanadium nitrogen or vanadium iron to carry out alloying.
The present invention, owing to have employed above technical scheme, makes it compared with prior art, has the following advantages and positively effect:
(1) the invention provides a kind of low temperature resistant H profile steel can produced under traditional hot rolling technology and preparation method thereof, this method does not need controlled rolling and controlled cooling when rolling, by means of only suitable Composition Design and technology controlling and process, make yield strength 350 ~ 450MPa, the ballistic work > 200J of the Charpy impact test ﹣ 40 DEG C of employing;
(2) the present invention's produced steel plate organization type is two-phase polygonal ferrite tissue and a small amount of pearlitic structure, and the precipitate containing V, Ti, play the effect of precipitation strength, have employed this microalloying technique, steel making working procedure technology controlling and process is simple, and alloy recovery is stablized, and the operation of rolling does not need to carry out low temperature controlled rolling, do not need to carry out the cold and thermal treatment of control after rolling, complete Composition Design and the production of high level low temperature resistant (﹣ 40 DEG C) ballistic work H profile steel;
(3) the present invention's produced Plate Production cost is low, stable performance, there is excellent obdurability coupling and low temperature tolerance ability, resistance to low temperature is good, by composition and technique adjustment, solving original steel-making, steel rolling equipment is aging, be difficult to the difficult problem adapting to high added value shaped steel products production, laying the foundation for realizing the transformation of general carbon Section Steel Production alignment high-performance type steel production line.
The present invention adopts V, Ti microalloying, can improve the hardening capacity of steel, dissolve in ferrite and have strengthening effect, can form stable carbide, crystal grain thinning.N can strengthen the effect of V, in order to obtain larger strengthening effect, can utilize the method that the precipitation strength of V and the grain refining of N combine, and when V, Ti coexist, suitably improving V has good effect to raising welding seam toughness.In addition the present invention strictly controls the content of C element, because ductile-brittle transition temperature improves with the increase of C content, and reduction C content is also conducive to the welding property improving steel.And V can separate out at a lower temperature in a large number, play the effect improving intensity.
Accompanying drawing explanation
Fig. 1 is the metallograph of embodiment 1 gained H profile steel;
Fig. 2 is the TEM precipitate figure of embodiment 1 gained H profile steel;
Fig. 3 is embodiment 1 gained H profile steel M 3c type precipitate particle size distribution figure;
Fig. 4 is embodiment 1 gained H profile steel MC type precipitate particle size distribution figure.
Embodiment
With the drawings and specific embodiments, the present invention is further detailed explanation below.
Embodiment 1: according to the chemical composition requirement of steel in the present invention, the chemical composition of acquisition is in table 1:
The chemical composition (wt.%) of table 1 embodiment 1 steel
Converter smelting endpoint [S]: 0.020%, [P]: 0.010%.Slag-stopping tapping, thickness of slag layer 50mm in bag.Aluminium ferromanganese 4kg/t steel is added when putting steel.Add manganese metal, ferrosilicon, vanadium nitrogen carries out alloying.
Ladle enters the station and adds lime 8kg/t steel.Carbide of calcium 2.5kg/t steel, aluminum shot, Si-Ca-Ba 3.0kg/t steel carry out slag making deoxidation.Refining process slag and finishing slag basicity are 2.5.Oxygen 19ppm is determined, feeding titanium wire 90m, wire-feeding velocity >=3m/s after getting first sample.Refining time 31min.Before soft blow, the real core calcium line 150m of feeding carries out calcification processing, 10 minutes soft blow time.
Pouring basket liquid level: 810 ~ 815mm, tundish protection adopts " carbon-free alkaline covering agent+rice husk ".Covering slag uses soft steel mould flux.Crystallizer inflow temperature 25 ~ 26.5 DEG C.Crystallizer cooling, cooling twice adopt weak cold mode.Control the superheating temperature of molten steel, make it be less than 25 DEG C; Strict suppression casting process slag, becomes 275 × 380mm rectangular bloom by continuous casting of molten steel, carry out stacking slow cooling to room temperature.
Continuously cast bloom is heated to 1240 DEG C, time inside furnace 240min.Soaking time 30min, entrance finishing temperature is 1040 DEG C, and finish rolling final temperature is 1000 DEG C, and temperature on cooling table is 900 DEG C, and final cooling temperature is 100 DEG C, enters aligning, and laggard row stacking slow cooling, its mechanical property is in table 2.
The mechanical property of table 2 embodiment 1 steel plate
Adopt ordinary method to carry out metallographic structure and Sludge Analysis to the present embodiment gained H profile steel, concrete outcome is shown in Fig. 1-4; As can be seen from Figure 1 material is made up of ferrite and pearlite tissue, crystal grain arrangement in good order rule, for etc. shaft-like crystal grain, grain size is about 12 μm, and banded structure bandwidth is very tiny, and uniform crystal particles degree is very high, anti-ductile deformation's ability of material is very strong, tenacity excellent.
Can find out that from Fig. 2 (b Fig. 2 is the energy diagram of arrow indication precipitate in a) carbonitride that arrow is designated as vanadium titanium is pinned in dislocation, shape is trapezoidal, about size 30nm, several skewness can also be seen, size is at the precipitate of below 50nm, and shape has rectangle, spherical and irregularly shaped etc.Precipitate is pinned in dislocation, strongly hinders dislocation motion, improves the intensity of material.
As can be seen from Figure 3 precipitate is M 3the size-grade distribution of C type, wherein size improves obviously the intensity of material at the particle of below 20nm, can find out that the volume fraction of below 20nm is 0.15%, according to Ashby-Orowan correction model formula, can obtain M in figure 3c type precipitate can improve yield strength 296MPa.
As can be seen from Figure 4 precipitate is the size-grade distribution of MC type, and wherein size is 0.00625% in the volume fraction of below 20nm particle, according to Ashby-Orowan correction model formula, can obtain M 3c type precipitate can improve yield strength 58Mpa, illustrates that the raising of microalloying system to the strength of materials of V, Ti compound has and comparatively significantly acts on.
M can be found out in figure 3c type precipitate accounts for main, and its massfraction is 1.3508%, and M (C, N) type precipitate is less, only has 0.0363%.But the precipitate containing V, Ti can be greatly improved in the yield strength to material of below 20nm, precipitation strength mechanism can be utilized to calculate their reinforcement values of bringing, by calculating, M 3the theoretic precipitation strength of C can reach 296MPa, and the precipitation strength value of M (C, N) is 58MPa.And Fig. 1 also illustrate that the precipitate containing V is separated out, and serves the effect of precipitation strength after adding V.
Embodiment 2: according to the chemical composition requirement of steel in the present invention, the chemical composition of acquisition is in table 3:
The chemical composition (wt.%) of table 3 embodiment 2 steel
Converter smelting endpoint [S]: 0.0:15%, [P]: 0.012%.Slag-stopping tapping, thickness of slag layer 70mm in bag.When putting steel, aluminium ferromanganese add-on is 2.5kg/t steel.Add manganese metal, ferrosilicon, vanadium nitrogen carries out alloying.
Ladle enters the station and adds lime 12kg/t steel.Carbide of calcium 1.5kg/t steel, aluminum shot, Si-Ca-Ba 2.0kg/t steel carry out slag making deoxidation.Refining process slag and finishing slag basicity are 3.0.Oxygen 15ppm is determined, feeding titanium wire 80m, wire-feeding velocity >=3m/s after getting first sample.Refining time 31min.Before soft blow, the real core calcium line 120m of feeding carries out calcification processing, 11 minutes soft blow time.
Pouring basket liquid level: 803 ~ 810mm, tundish protection adopts " carbon-free alkaline covering agent+rice husk ".Covering slag uses soft steel mould flux.Crystallizer inflow temperature 26 ~ 27 DEG C.Crystallizer cooling, cooling twice adopt weak cold mode.Control the superheating temperature of molten steel, make it be less than 25 DEG C; Strict suppression casting process slag, becomes 275 × 380mm rectangular bloom by continuous casting of molten steel, carry out stacking slow cooling to room temperature.
Continuously cast bloom is heated to 1160 DEG C, time inside furnace 120min.Soaking time 50min, entrance finishing temperature is 1040 DEG C, and finish rolling final temperature is 850 DEG C, and temperature on cooling table is 840 DEG C, and final cooling temperature is 100 DEG C, enters aligning, and laggard row stacking slow cooling, its mechanical property is in table 4.
The mechanical property of table 4 embodiment 2 steel plate
Embodiment 3: according to the chemical composition requirement of steel in the present invention, the chemical composition of acquisition is in table 5:
The chemical composition (wt.%) of table 5 embodiment 3 steel
Converter smelting endpoint [S]: 0.016%, [P]: 0.010%.Slag-stopping tapping, thickness of slag layer 60mm in bag.When putting steel, aluminium ferromanganese add-on is 3.5kg/t steel.Add manganese metal, ferrosilicon, vanadium iron carry out alloying.
Ladle enters the station and adds lime 10kg/t steel.Carbide of calcium 2.0kg/t steel, aluminum shot, Si-Ca-Ba 2.5kg/t steel carry out slag making deoxidation.Refining process slag and finishing slag basicity are 2.1.Determine oxygen 9ppm after getting first sample and then feed titanium wire 60m, wire-feeding velocity >=3m/s.Refining time 31min.Before soft blow, the real core calcium line 120m of feeding carries out calcification processing, 12 minutes soft blow time.
Pouring basket liquid level: 805 ~ 810mm, tundish protection adopts " carbon-free alkaline covering agent+rice husk ".Covering slag uses soft steel mould flux.Crystallizer inflow temperature 25.5 ~ 27.0 DEG C.Crystallizer cooling, cooling twice adopt weak cold mode.Control the superheating temperature of molten steel, make it be less than 25 DEG C; Strict suppression casting process slag, becomes 275 × 380mm rectangular bloom by continuous casting of molten steel, carry out stacking slow cooling to room temperature.
Continuously cast bloom is heated to 1200 DEG C, time inside furnace 180min.Soaking time 40min, it is 1060 DEG C that roughing starts temperature, and finish rolling final temperature is 910 DEG C, and temperature on cooling table is 900 DEG C, and final cooling temperature is 100 DEG C, enters aligning, and laggard row stacking slow cooling, its mechanical property is in table 6.
The mechanical property of table 6 embodiment 3 steel plate
As fully visible, the steel plate in the present invention has excellent toughness and tenacity, and low-temperature impact work is stablized.
It should be noted last that, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted.Although with reference to embodiment to invention has been detailed description, will be understood by those skilled in the art that, modify to technical scheme of the present invention or equivalent replacement, do not depart from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.

Claims (4)

1. one kind low temperature resistant hot rolled H-shaped, it is characterized in that, described is hot rolled H-shaped, its chemical composition is by weight percentage: C 0.07 ~ 0.10%, Si 0.2 ~ 0.4%, Mn 1.30 ~ 1.60%, P≤0.020%, S≤0.015%, V 0.015 ~ 0.070%, Ti 0.010 ~ 0.030%, and surplus is Fe and inevitable impurity.
2. low temperature resistant hot rolled H-shaped according to claims 1, it is characterized in that, the organization type of described H profile steel is polygonal ferrite tissue and pearlitic structure, yield strength is 350 ~ 450MPa, tensile strength is 480 ~ 600MPa, elongation after fracture >=22% ,-40 DEG C of V-type Charpy-V impact power >=200J.
3. a low temperature resistant hot rolled H-shaped preparation method, described method comprises converter smelting-LF refining-continuous casting-roll forming successively, wherein:
1) converter smelting:
A. Terminal Process Control: [S] <0.020%, [P] <0.015%;
B. slag-stopping tapping, thickness of slag layer≤70mm in bag;
C. deoxidation alloying;
2) LF refining:
A. refining cycle: be greater than 30 minutes;
B. deoxidation and slag making operation: adopt high voltage low current slag, add lime 8 ~ 12kg/t steel; Add carbide of calcium 1.5 ~ 2.5kg/t steel, Si-Ca-Ba 2.0 ~ 3.0kg/t steel-deoxidizing adjust slag; Refining process slag and finishing slag basicity 2.0 ~ 3.0; Determine oxygen < 20ppm after getting first sample and then feed titanium wire 60 ~ 90m, wire-feeding velocity >=3m/s;
C. Calcium treatment and soft blow: before molten steel departures, get one, gas sample, and feed real core calcium line 100 ~ 150m according to aluminium content in steel and carry out calcification processing, carry out " soft blow " after line feeding, soft blow time >=10 minutes;
3) continuous casting process:
A. pouring basket liquid level >=800mm, whole process protection is poured into a mould, and tundish protection adopts " carbon-free alkaline covering agent+rice husk ";
B. covering slag uses soft steel mould flux: crystallizer inflow temperature >=25 DEG C; Crystallizer cooling, cooling twice adopt weak cold mode; Control the superheating temperature of molten steel, make it be less than 25 DEG C;
4) technique of rolling:
A. continuously cast bloom in process furnace the section of adding time >=120min, soaking time 30 ~ 50min, tapping temperature steel billet controls at 1160 ~ 1240 DEG C;
B. adopt recrystallization zone rolling, start rolling temperature controls at 1020 ~ 1060 DEG C, and finishing temperature control is at 850 ~ 1000 DEG C;
C. opening cold temperature after rolling controls at 850 ~ 950 DEG C, and final cooling temperature controls at 100 DEG C, and speed of cooling is 3 ~ 7 DEG C/s;
D. straightening temperature < 100 DEG C, laggard row stacking slow cooling.
4. low temperature resistant hot rolled H-shaped preparation method according to claim 3, it is characterized in that, described step 1) deoxidation alloying in, first adopt aluminium manganese-ferro deoxidation, secondly aluminium ferromanganese add-on is 2.5 ~ 4kg/t steel, adopts manganese metal and ferrosilicon and vanadium nitrogen or vanadium iron to carry out alloying.
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CN105018861A (en) * 2015-08-10 2015-11-04 山东钢铁股份有限公司 Low-cost normalizing rolling hot rolling H type steel and preparation method thereof
CN105714201A (en) * 2016-04-15 2016-06-29 山东钢铁股份有限公司 Hot-rolled H profile steel and preparation method thereof
CN105886961A (en) * 2016-06-07 2016-08-24 蒋南宁 High-performance hot-rolled H-shape steel capable of resisting marine atmospheric environment corrosion and preparation method thereof
CN106244926A (en) * 2016-09-28 2016-12-21 河钢股份有限公司承德分公司 A kind of containing vanadium steel used for vehicle transmission shaft and production method thereof
CN106756471A (en) * 2016-11-11 2017-05-31 攀钢集团攀枝花钢铁研究院有限公司 345MPa grades of vanadium titanium microalloying anti-seismic structure hot continuous rolling steel band and preparation method thereof
CN107299283A (en) * 2017-05-27 2017-10-27 内蒙古包钢钢联股份有限公司 Depth low temperature resistant hot rolled H-shaped and its production technology
CN107475494A (en) * 2017-07-21 2017-12-15 河钢股份有限公司邯郸分公司 A kind of control method of air-cooled bainitic steels bloom bending
CN108642381A (en) * 2018-05-16 2018-10-12 山东钢铁股份有限公司 Low temperature resistant H profile steel of a kind of yield strength 460MPa grades of hot rolled high-ductilities and preparation method thereof
CN110546295A (en) * 2018-03-23 2019-12-06 日本制铁株式会社 Rolled H-section steel and method for producing same
CN113604735A (en) * 2021-07-20 2021-11-05 山东钢铁股份有限公司 Hot-rolled low-temperature-resistant H-shaped steel with yield strength of 420MPa and preparation method thereof
JPWO2022185632A1 (en) * 2021-03-03 2022-09-09

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JP2002080938A (en) * 2000-09-08 2002-03-22 Nkk Corp Rolled shape steel having excellent soil corrosion resistance and earthquake resistance and its production method
CN102418037A (en) * 2011-12-02 2012-04-18 莱芜钢铁集团有限公司 Hot-rolled H-section steel with lamellar tearing resistance and manufacturing method thereof
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Cited By (18)

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Publication number Priority date Publication date Assignee Title
CN105018861B (en) * 2015-08-10 2017-07-14 山东钢铁股份有限公司 A kind of inexpensive normalizing rolling is hot rolled H-shaped and preparation method thereof
CN105018861A (en) * 2015-08-10 2015-11-04 山东钢铁股份有限公司 Low-cost normalizing rolling hot rolling H type steel and preparation method thereof
CN105714201A (en) * 2016-04-15 2016-06-29 山东钢铁股份有限公司 Hot-rolled H profile steel and preparation method thereof
CN105886961A (en) * 2016-06-07 2016-08-24 蒋南宁 High-performance hot-rolled H-shape steel capable of resisting marine atmospheric environment corrosion and preparation method thereof
CN106244926A (en) * 2016-09-28 2016-12-21 河钢股份有限公司承德分公司 A kind of containing vanadium steel used for vehicle transmission shaft and production method thereof
CN106756471B (en) * 2016-11-11 2018-07-10 攀钢集团攀枝花钢铁研究院有限公司 345MPa grades of vanadium titanium microalloying anti-seismic structure hot continuous rolling steel bands and preparation method thereof
CN106756471A (en) * 2016-11-11 2017-05-31 攀钢集团攀枝花钢铁研究院有限公司 345MPa grades of vanadium titanium microalloying anti-seismic structure hot continuous rolling steel band and preparation method thereof
CN107299283A (en) * 2017-05-27 2017-10-27 内蒙古包钢钢联股份有限公司 Depth low temperature resistant hot rolled H-shaped and its production technology
CN107475494A (en) * 2017-07-21 2017-12-15 河钢股份有限公司邯郸分公司 A kind of control method of air-cooled bainitic steels bloom bending
CN107475494B (en) * 2017-07-21 2019-04-23 河钢股份有限公司邯郸分公司 A kind of curved control method of air-cooled bainitic steels bloom
CN110546295A (en) * 2018-03-23 2019-12-06 日本制铁株式会社 Rolled H-section steel and method for producing same
CN108642381A (en) * 2018-05-16 2018-10-12 山东钢铁股份有限公司 Low temperature resistant H profile steel of a kind of yield strength 460MPa grades of hot rolled high-ductilities and preparation method thereof
CN108642381B (en) * 2018-05-16 2020-02-18 山东钢铁股份有限公司 Hot-rolled high-toughness low-temperature-resistant H-shaped steel with yield strength of 460MPa and preparation method thereof
JPWO2022185632A1 (en) * 2021-03-03 2022-09-09
WO2022185632A1 (en) * 2021-03-03 2022-09-09 Jfeスチール株式会社 H-shaped steel
JP7405246B2 (en) 2021-03-03 2023-12-26 Jfeスチール株式会社 H-shaped steel
CN113604735A (en) * 2021-07-20 2021-11-05 山东钢铁股份有限公司 Hot-rolled low-temperature-resistant H-shaped steel with yield strength of 420MPa and preparation method thereof
CN113604735B (en) * 2021-07-20 2022-07-12 山东钢铁股份有限公司 Hot-rolled low-temperature-resistant H-shaped steel with yield strength of 420MPa and preparation method thereof

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