CN104004957B - Oxides Metallurgy Technology is utilized to produce the method for small reduction ratio low temperature H profile steel - Google Patents
Oxides Metallurgy Technology is utilized to produce the method for small reduction ratio low temperature H profile steel Download PDFInfo
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- CN104004957B CN104004957B CN201410261664.3A CN201410261664A CN104004957B CN 104004957 B CN104004957 B CN 104004957B CN 201410261664 A CN201410261664 A CN 201410261664A CN 104004957 B CN104004957 B CN 104004957B
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Abstract
The invention discloses a kind of method utilizing Oxides Metallurgy Technology to produce small reduction ratio low temperature H profile steel, the method comprises hot metal pretreatment, converter smelting, LF refining, continuous beam blank casting, heating, rolling and refrigerating work procedure successively, wherein: in described converter smelting operation, before tapping, the content of Si composition is adjusted to 0.05-0.25wt%; In described LF refining procedure, namely ladle adds ferrozirconium, feeding titanium wire after entering refining station.The present invention is by rational Oxides Metallurgy Technology, control nonmetallic inclusionsin steel, improve homogeneity and the compactness of strand and product tissue when not changing original small reduction ratio low temperature H profile steel production technique, thus improve low-temperature performance and the poor even unqualified problem of mechanical property that Hot Metal in Beam Blank rolling small reduction ratio low temperature H profile steel often occurs.
Description
Technical field
The present invention relates to a kind of hot rolled H-shaped production technical field, particularly a kind of method utilizing Oxides Metallurgy Technology to produce small reduction ratio low temperature H profile steel.
Background technology
The distribution of H profile steel mechanics rationally, profile cross-section coefficient is large, supporting capacity large, is convenient to assembled and rivet welding, is that a kind of section area distributes optimization, the ratio of strength to weight more reasonably economic section high efficiency section bar more, is widely applied.Along with social progress and development in science and technology, various building, structure require also more and more higher to the properties of steel, particularly in the stability, security of guarantee structure, propose high requirement.Current low-temperature steel product mainly sheet material, for requiring that the H profile steel product with low-temperature impact-resistant performance takes welding process to obtain mostly, and in welding process, the reduction of the performance index of welded heat affecting zone and weld seam is can hardly be avoided, process welding process in addition and also will produce certain expense, the simultaneously performance measurement of position while welding, flaw detection all need expense, and the construction period has also been extended.
Modern H profile steel is produced as significantly improving production efficiency, improving recovery rate, normal employing casting for shaped blank continuous or near-net-shape casting for shaped blank continuous technology.Adopt Hot Metal in Beam Blank rolled section steel product can improve the rolling power of milling train thus improve output, but for production think gauge product, due to the impact by strand size, often compression ratio is on the low side, thus causes the defects such as strand segregation and center porosity to can not get effectively alleviating or improving.In addition, coldly effective means are still lacked because the complicacy of shaped steel shape of product will be controlled uniformly.Therefore, all there is unstable properties, defect that qualification rate is low in industry when producing the product of low-temperature impact-resistant shaped steel or small reduction ratio low-temperature impact-resistant shaped steel.
In order to solve the problem, industry proposes various solution, such as in metallurgical process, add Ni, B, made up the deficiency of performance by microalloying, but the program affects product surface quality because the interpolation of Ni makes the iron scale in course of hot rolling be difficult to remove; Yi You manufacturer sets up controlled cooling model equipment on a production line, improves tissue thus enhance product performance by controlled rolling and controlled cooling, but program investment is large, later maintenance cost is high.
Summary of the invention
For the deficiencies in the prior art, the object of the present invention is to provide a kind of method utilizing Oxides Metallurgy Technology to produce small reduction ratio low temperature H profile steel.
Production method of the present invention is for shaped steel products production feature, by choose reasonable and interpolation trace alloying element, control nonmetallic inclusionsin steel, make it as the core of cenotype heterogeneous nucleation or the effect playing pinning crystal boundary, thus utilize the non-metallic inclusion in steel to control tissue, the raising performance of steel.Be applied to by Oxides Metallurgy Technology and improve small reduction ratio low temperature H profile steel, the oxide compound kind needed for acquisition, size and distribution thereof are crucial, and the tiny and oxide compound particle of Dispersed precipitate is conducive to promoting cenotype forming core and pinning crystal boundary.Small reduction ratio low temperature H profile steel production technique comprises hot metal pretreatment-converter smelting-LF refining-Profiled Slab CCM etc. successively, the final product of oxide compound is relevant with C, O equal size in molten steel, wherein oxygen level can be reflected indirectly by converter control Si content, and relevant with deoxidant element, alloying element and order of addition.
To achieve these goals, the present invention is by the following technical solutions:
Utilize Oxides Metallurgy Technology to produce a method for small reduction ratio low temperature H profile steel, comprise hot metal pretreatment, converter smelting, LF refining, continuous beam blank casting, heating, rolling and refrigerating work procedure successively, wherein:
In described converter smelting operation, before tapping, the content of Si composition is adjusted to 0.05-0.25wt%;
In described LF refining procedure, namely ladle adds ferrozirconium, feeding titanium wire after entering refining station, the amount adding ferrozirconium controls at 0.07-0.1kg/ ton molten steel, and the amount of feeding titanium wire controls at 0.4-0.8m/ ton molten steel;
The H profile steel that described method obtains is made up of following chemical composition by weight percentage: C0.12-0.20%, Si0.10-0.30%, Mn1.15-1.70%, P≤0.025%, S≤0.010%, Nb≤0.02%, Cu≤0.02%, and all the other are Fe and inevitable impurity.
The present invention adopt converter by cast iron melting and before tapping by the composition adjustment of Si to 0.05wt%-0.25wt%, i.e. line feeding after ladle enters refining station, namely the complex inclusion of the tiny distribution of disperse is generated after feeding mentioned component, as shown in Figure 7, these tiny inclusiones, austenite forming core can be promoted on the one hand, can tissue be stoped to grow up by pinning crystal boundary on the other hand.The oxide type obtained by Oxide Metallurgy technique of the present invention is tiny and the oxide compound particle of Dispersed precipitate, be conducive to promoting cenotype forming core and pinning crystal boundary, for ensureing that Oxide Metallurgy technique obtains excellent results, in converter, refining procedure, production process need be implemented targetedly.In the present invention, owing to being Zr and Ti of trace, therefore when composition detection, requirement not done to the two, even cannot detect.
In the above-mentioned methods, as a kind of preferred implementation, in described hot metal pre process procedures, molten iron is delivered to desulfurization station, after desulfurization, ensure sulphur content≤0.008wt% (such as 0.005wt%, 0.006wt%, 0.007wt%) in molten iron.
In the above-mentioned methods, as a kind of preferred implementation, in described continuous beam blank casting operation, described continuously cast bloom edge of a wing thickness is 60-80mm, pulling rate is≤1.0m/min (such as 0.7m/min, 0.8m/min, 0.9m/min).
In the above-mentioned methods, as a kind of preferred implementation, in described heating process, the soaking temperature of described continuous casting steel billet is 1200 DEG C-1300 DEG C (such as 1210 DEG C, 1230 DEG C, 1250 DEG C, 1260 DEG C, 1280 DEG C, 1295 DEG C).
In the above-mentioned methods, as a kind of preferred implementation, in described rolling process, the start rolling temperature of split rolling method is more than 1150 DEG C (such as 1150 DEG C, 1180 DEG C, 1200 DEG C, 1240 DEG C, 1260 DEG C, 1280 DEG C), the start rolling temperature of universal rolling mill group is not less than 970 DEG C (such as 970 DEG C, 1000 DEG C, 1020 DEG C, 1050 DEG C, 1070 DEG C, 1090 DEG C), and finished product finishing temperature is not higher than 920 DEG C (such as 800 DEG C, 820 DEG C, 850 DEG C, 880 DEG C, 900 DEG C, 910 DEG C).More preferably, the start rolling temperature of described split rolling method is 1150-1250 DEG C, the start rolling temperature 970-1100 DEG C of universal rolling mill group, finished product finishing temperature 850-920 DEG C.
The present invention, by the comprehensive action of dispersion-strengthened and refined crystalline strengthening, improves steel performance especially low-temperature impact-resistant performance.
In the above-mentioned methods, as a kind of preferred implementation, described small reduction ratio refers to that compression ratio is not more than 3.5 (such as 2,2.5,3,3.4).
The processing step do not related in the present invention adopts this area common process.
Compared with prior art, the present invention is by rational Oxides Metallurgy Technology, control nonmetallic inclusionsin steel, improve homogeneity and the compactness of strand and product tissue when not changing original small reduction ratio low temperature H profile steel production technique, thus improve low-temperature performance and the poor even unqualified problem of mechanical property that Hot Metal in Beam Blank rolling small reduction ratio low temperature H profile steel often occurs.Especially make small reduction ratio low temperature H profile steel obtain excellent low-temperature impact-resistant performance compared with industry be the method solving the interpolation Ni alloy that problems often adopts have simple to operate, cost is low, do not affect product surface quality and do not increase the advantages such as rolling process de-scaling difficulty, be under existing weaponry and equipment technical qualification, Hot Metal in Beam Blank realizes the effective ways of stably manufactured small reduction ratio low temperature H profile steel.The present invention also has the following advantages: be easy to implement in production scene; Operating process is simple, direct; Alloying constituent controls accurately; Cost is lower.
Accompanying drawing explanation
Fig. 1 is the macrostructure photo of continuous casting special-shaped base described in embodiment;
Fig. 2 is the macrostructure photo of continuous casting special-shaped base described in comparative example;
Fig. 3 is the metallographic structure photo of continuous casting special-shaped base described in embodiment;
Fig. 4 is the metallographic structure photo of continuous casting special-shaped base described in comparative example;
Fig. 5 is the inclusion distribution figure of continuous casting special-shaped base described in embodiment;
Fig. 6 is the inclusion distribution figure of continuous casting special-shaped base described in comparative example;
Fig. 7 is the inclusion scanning electron microscope (SEM) photograph of continuous casting special-shaped base described in embodiment, wherein, and (a) inclusion distribution figure; (b) ZrO
2-TiO
x; (c) TiO
x-ZrO
2.
Embodiment
Below in conjunction with drawings and Examples, comparative example, the present invention will be further described, but be not limited thereto.
Embodiment
Adopt 120 tons of smelting equipments that this area is conventional, casting for shaped blank continuous equipment, by composition corresponding in table 1 and alloy content, Oxides Metallurgy Technology is adopted to smelt, and continuous casting is Hot Metal in Beam Blank, then obtain small reduction ratio low temperature H profile steel of the present invention through process furnace heating, rolling, cooling and aligning.Concrete production method is as follows:
1) hot metal pretreatment: molten iron is delivered to desulfurization station, ensures sulphur content≤0.008wt% in molten iron after desulfurization;
2) converter smelting: before tapping, the content of Si composition is adjusted to≤0.15wt%; Add carbide of calcium in converter tapping process and carry out deoxidation, and in converter tapping process, add manganeseirom, ferrocolumbium; Cu is added with steel scrap in converter;
3) LF refining: ladle enters the station, first connects tunger tube, after argon gas blows open, thermometric, determine oxygen after, add ferrozirconium 10KG/ stove, feed titanium wire 70m/ stove, wire-feeding velocity is 4m/s;
4) in continuous beam blank casting operation, continuous casting steel billet is of a size of 555 × 440 × 90 × 70 (web height × flange width × web thickness × edge of a wing thickness), pulling rate is 0.9m/min, acquisition Fig. 1 is shown in by continuous casting special-shaped base macrostructure, metallograph is shown in Fig. 3, inclusion overall distribution situation is shown in Fig. 5;
5) heat: the soaking temperature of continuous casting steel billet is 1250 DEG C, and heat-up time is 3h;
6) rolling: the start rolling temperature of described split rolling method is 1200 DEG C, the start rolling temperature of universal rolling mill group 1000 DEG C, finished product finishing temperature 900 DEG C;
7) cooling and aligning: deliver to after water-cooled on cold bed and carry out naturally cooling, product temperature is down to 80-120 DEG C of laggard straightener and is aligned, stocking trimmed size is H428 × 407 × 20 × 20 (units: mm), and compression ratio is 3.5, and mechanical property is in table 2.
As can be known from Fig. 7, the content containing Ti, Zr in complex inclusion, size is less than 1 μm, and pattern is spherical in shape, and complex inclusion is inner with ZrO
2be main, outside is then with TiO
xbe main.
Adopt the method for the present embodiment to produce 30 H profile steel finished products altogether, the low-temperature performance in its table 2 and mechanical property equal 100% qualified.
Comparative example
Adopt the smelting identical with embodiment, casting for shaped blank continuous equipment, by composition corresponding in table 1 and alloy content, industry is adopted to be solve the unstable Ni-B microalloying used of small reduction ratio low temperature H profile steel low-temperature impact-resistant performance to smelt scheme (specific as follows), continuous casting goes out the Hot Metal in Beam Blank identical with specification in embodiment, then heats through the process furnace identical with embodiment, rolling pattern and cooling and aligning operation.
In this comparative example smelt and refining procedure as follows:
1) hot metal pretreatment: molten iron is delivered to desulfurization station, ensures sulphur content≤0.008wt% in molten iron after desulfurization;
2) converter smelting: before tapping, the content of Si composition is adjusted to≤0.15wt%; Appropriate Ni alloy is added in tapping process;
3) LF refining: feed appropriate B line before soft blow;
4), in continuous beam blank casting operation, it is 0.9m/min that continuous casting steel billet is of a size of 555 × 440 × 90 × 70 (web height × flange width × web thickness × edge of a wing thickness) pulling rate.
The specification that the present embodiment obtains H profile steel finished product is identical with embodiment, and mechanical property is in table 2, and Fig. 2 is shown in by its continuously cast bloom macrostructure, metallograph is shown in Fig. 4, inclusion overall distribution situation is shown in Fig. 6.
The chemical composition of table 1 embodiment and comparative example steel
| Composition | C | Si | Mn | P | S | Nb | Ni | Cu | Ti | Zr | B |
| Embodiment | 0.12 | 0.13 | 1.25 | 0.011 | 0.008 | 0.015 | - | 0.02 | 0.007 | 0.004 | - |
| Comparative example | 0.14 | 0.14 | 1.24 | 0.014 | 0.005 | 0.018 | 0.437 | 0.019 | - | - | 0.006 |
The mechanical property of table 2 embodiment and comparative example steel
Wherein, the sample sampling position that in table 2, mechanical property is used is on the H profile steel edge of a wing, and by edge to heart portion 1/3, reference standard is GB/T2975-1998 " steel and product made from steel mechanical property test sample position and sample preparation "; The test method reference standard GB GB/T228-2010 of yield strength, tensile strength, unit elongation; Ballistic work test method reference standard GB GB/T229-2007.
Adopt the method for comparative example to produce 30 H profile steel finished products altogether, the low-temperature performance in its table 2 and mechanical property are only 60% qualified.
Known by the contrast of Fig. 1 and Fig. 2, by implementing zirconium titanium processing process, the strand center porosity of the embodiment of the present invention and segregation defects be improved significantly, homogeneity and compactness significantly improves.
Known by the contrast of Fig. 3 and Fig. 4, the product banded structure of the embodiment of the present invention obviously improves, and crystal grain is more tiny.
Known by the contrast of Fig. 5 and Fig. 6, the product inclusion size of the embodiment of the present invention is less, distribution disperse.
Comprehensive Correlation example and embodiment, the present invention can improve slab quality, crystal grain thinning tissue, and significantly improves H profile steel low-temperature impact-resistant performance.The problems such as low-temperature performance that section rolling especially Hot Metal in Beam Blank rolling, small reduction ratio or low temperature resistant H profile steel be difficult to overcome is unstable are overcome by rational Oxides Metallurgy Technology, be effective, convenient and the scheme of practicality, have great importance at H profile steel production field.
Claims (6)
1. utilize Oxides Metallurgy Technology to produce a method for small reduction ratio low temperature H profile steel, it is characterized in that, comprise hot metal pretreatment, converter smelting, LF refining, continuous beam blank casting, heating, rolling and refrigerating work procedure successively, wherein:
In described converter smelting operation, before tapping, the content of Si composition is adjusted to 0.05-0.25wt%;
In described LF refining procedure, namely ladle adds ferrozirconium, feeding titanium wire after entering refining station, the amount adding ferrozirconium controls at 0.07-0.1kg/ ton molten steel, and the amount of feeding titanium wire controls at 0.4-0.8m/ ton molten steel;
The H profile steel that described method obtains is made up of following chemical composition by weight percentage: C0.12-0.20%, Si0.10-0.30%, Mn1.15-1.70%, P≤0.025%, S≤0.010%, Nb≤0.015%, Cu≤0.02%, and all the other are Fe and inevitable impurity;
Described small reduction ratio refers to that compression ratio is less than 3.5.
2. method according to claim 1, is characterized in that, in described hot metal pre process procedures, molten iron is delivered to desulfurization station, ensures sulphur content≤0.008wt% in molten iron after desulfurization.
3. method according to claim 1, is characterized in that, in described continuous beam blank casting operation, described continuously cast bloom edge of a wing thickness is 60-80mm, pulling rate is≤1.0m/min.
4. method according to claim 1, is characterized in that, in described heating process, the soaking temperature of described continuous casting steel billet is 1200 DEG C-1300 DEG C.
5. method according to claim 1, is characterized in that, in described rolling process, the start rolling temperature of split rolling method is more than 1150 DEG C, and the start rolling temperature of universal rolling mill group is not less than 970 DEG C, and finished product finishing temperature is not higher than 920 DEG C.
6. method according to claim 5, is characterized in that, more preferably, the start rolling temperature of described split rolling method is 1150-1250 DEG C, the start rolling temperature 970-1100 DEG C of universal rolling mill group, finished product finishing temperature 850-920 DEG C.
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| CN111229827B (en) * | 2020-03-02 | 2021-07-23 | 马鞍山钢铁股份有限公司 | Hot-rolled H-shaped steel with yield strength of 450MPa and production method thereof |
| CN111304404B (en) * | 2020-03-31 | 2021-10-22 | 鞍钢股份有限公司 | Cored wire for oxide metallurgy of vacuum induction furnace and use method |
| CN112941411A (en) * | 2021-01-29 | 2021-06-11 | 中冶华天南京工程技术有限公司 | Ultra-low carbon bainite super-heavy H-shaped steel and manufacturing method thereof |
| CN115449700A (en) * | 2022-09-20 | 2022-12-09 | 西安建筑科技大学 | Method for improving low-carbon gear steel strip-shaped structure based on oxide metallurgy and low-carbon gear steel |
| CN116770017B (en) * | 2023-08-03 | 2024-01-23 | 昆明理工大学 | Method for modifying inclusions in Ti microalloyed high-strength steel |
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| WO2001075182A1 (en) * | 2000-04-04 | 2001-10-11 | Nippon Steel Corporation | Rolled h-shaped steel having uniform microstructure and uniform mechanical properties and method for producing the same |
| JP4980253B2 (en) * | 2008-01-15 | 2012-07-18 | 新日本製鐵株式会社 | High-strength hot-rolled steel sheet with excellent strength-ductility balance and punchability and method for producing the same |
| KR101205144B1 (en) * | 2010-06-28 | 2012-11-26 | 현대제철 주식회사 | H-steel for building structure and method for producing the same |
| CN102021475B (en) * | 2010-10-25 | 2013-03-13 | 山东钢铁股份有限公司 | Preparation method of hot-rolled H-shaped steel for low temperature-resisting structure |
| CN102418037B (en) * | 2011-12-02 | 2013-04-24 | 莱芜钢铁集团有限公司 | Hot-rolled H-section steel with lamellar tearing resistance and manufacturing method thereof |
| CN103540844B (en) * | 2013-10-28 | 2016-04-06 | 莱芜钢铁集团有限公司 | Low temperature resistant H profile steel and production method thereof |
| CN103834861A (en) * | 2014-03-20 | 2014-06-04 | 莱芜钢铁集团有限公司 | 320MPa low-temperature resistant hot-rolled H-shaped steel and preparation method thereof |
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