CN102400053B - Steel plate for building structure with yield strength of 460 MPa, and manufacturing method thereof - Google Patents
Steel plate for building structure with yield strength of 460 MPa, and manufacturing method thereof Download PDFInfo
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- CN102400053B CN102400053B CN201010276610.6A CN201010276610A CN102400053B CN 102400053 B CN102400053 B CN 102400053B CN 201010276610 A CN201010276610 A CN 201010276610A CN 102400053 B CN102400053 B CN 102400053B
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Abstract
The present invention discloses a steel plate for a building structure with yield strength of 460 MPa, and a manufacturing method thereof. Chemical components of the steel plate comprise, by weight, 0.05-0.10% of C, 0.2-0.3% of Si, 1.40-1.60% of Mn, 0.025-0.060% of Nb, 0.015-0.030% of Ti, 0.015-0.045% of Als, one selected from 0.2-0.4% of Cr, 0.10-0.30% of Mo and 0.0010-0.0020% of B, and the balance of Fe and other inevitable impurities, wherein the impurity elements are controlled, and comprise, by weight, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.0040% of [N], and less than or equal to 0.0020% of [O]. The manufacturing method comprises that: the steel billet heating temperature is 1180-1220 DEG C; at the first phase, the rolling starting temperature is 1040-1080 DEG C, and the rolling finishing temperature is 950-1000 DEG C; at the second phase, the rolling starting temperature is 920-870 DEG C, the rolling finishing temperature is controlled to 800-850 DEG C, the amount of the rolling accumulation and deformation in the recrystallization area is more than 60%; after hot rolling, a temperature waiting treatment is performed, and then a water cooling treatment is performed, wherein the temperature waiting time is more than 15 seconds, the water cooling starting temperature is 680-750 DEG C, the cooling rate is 5-9 DEG C per second, and the self-tempering temperature is 450-620 DEG C. The steel plate of the present invention has characteristics of simple chemical components, carbon equivalent less than 0.40, yield ratio less than 0.80 and simple production process.
Description
Technical field
The present invention relates to a kind of 460MPa rank high-performance steel plate for building structure and manufacture method thereof, belong to metal material field.
Background technology
In recent years, along with the steady-state growth of China's iron and steel output and going deep into of steel construction application technical research, steel construction is widely applied at construction field; Demand to high strength, high property constructional steels is more and more higher.
460MPa is the maximum intensity rank of the steel plate for building of current domestic use, and use 460MPa rank construction(al)steel can be than the 345MPa rank saving steel consumption 10%～20% generally adopting now, and market outlook are wide.In recent years, China has started to use 460MPa construction(al)steel in batches in the priority projects such as Bird's Nest, obtains good effect.
Other construction(al)steel of domestic this grade is produced the general Composition Design that adopts low-carbon (LC) to coordinate Nb, V, Ti microalloying, carries out normalizing treatment after controlled rolling, or in two-phase region, quenches and carry out the production method of temper again after hot rolling.
The patent of invention " a kind of super-thick steel plate for low yield ratio buildings with 460 MPa grade yield strength and manufacture method " that the publication number of Capital Iron & Steel General Co's application is CN101613828, steel plate composition weight percent is: C0.14%～0.18%, Si 0.35%-0.45%, Mn 1.40%～1.50%, Nb 0.025%～0.035%, V0.040%～0.050%, Ti 0.010%～0.020%, and all the other are iron Fe.Rolling technology: obtain >=80mm Plate Steel after the rolling of employing two-stage control.Thermal treatment process: quench in two-phase region, the steel plate after quenching carries out temper, finally obtains low yield strength ratio high-strength building steel plate.Be applicable to >=80mm of the method Plate Steel, and a large amount of in actual production what use is the steel plate below 80mm, and the method carbon equivalent is higher, and unfavorable to welding property, complex manufacturing, must quench and tempering two-phase region in addition, and cost is higher.
The patent of invention " a kind of manufacture method of 460 MPa grade yield strength low-alloy high-tensile structural steel sheet material " that the publication number of Northeastern University's application is CN1537968.Main chemical compositions: C, Si, Mn, Nb, Ti, Als and Fe assembly, its weight percent proportioning is: C 0.13%～0.20%, Si 0.2%～0.5%, Mn 1.30%～1.70%, Nb 0.01%～0.02%, Ti 0.005%～0.01%, and Als 0.005%～0.015%, and all the other are Fe; Rolling in two stages, after rolling, carry out cooling fast, obtain the heterogeneous structure of polygonal ferrite, perlite, acicular ferrite and a small amount of granular bainite, consumption and the cost of micro alloying element are lower, but this process example yield tensile ratio is all greater than 0.8, and low yield strength ratio is the important indicator of construction(al)steel; Embodiment rolls 10～18 ℃/s of rear cooling rate, and owing to will inevitably forming very large unrelieved stress from high temperature is cooling fast, and postwelding heat affected zone intensity can decline larger.
The patent of invention " high-intensity high-tenacity low yield strength ratio ultra-large linear energy input is Plate Steel and production method thereof for welding " that the publication number of Japan JFE company application is JP2005068478A, relate to chemical composition: C0.03%～0.15%, Si 0.05%～0.5%, Mn 0.5%～3.0%, Cu < 1.5%, Ni < 2.0%, B0.0005%～0.003%, Al 0.005%～0.01%, after hot rolling, adopt 700～750 ℃ of two-phase regions to quench, steel plate after quenching carries out 400～550 ℃ of temper, steel plate yield strength is greater than 440MPa tensile strength and is greater than 570MPa, can carry out the welding of 400KJ/cm super large energy, this patent composition and complex manufacturing, cost is higher.
From contrasting above patent, the production of 460MPa rank steel plate for building at present has the following disadvantages:
1. generally adopt to adopt after hot rolling normalizing or two-phase region to quench and add temper, complex manufacturing, cost is higher;
2. carbon equivalent is higher, welding difficulty;
3. control cold rear yield tensile ratio and be greater than 0.80.
Summary of the invention
In view of above-mentioned the deficiencies in the prior art, the object of the present invention is to provide a kind of 460 MPa grade yield strength steel plate for building structure and manufacture method thereof, its chemical composition is simple, and carbon equivalent is less than 0.40, is easy to welding; Production technique is simple, by optimizing cooling controlling and rolling controlling process, makes the yield tensile ratio of steel plate be less than 0.80; Do not need to use the thermal treatment process such as normalizing or two-phase region quenching, performance meets the related request of national standard completely.
It is essential characteristic that steel chemical composition of the present invention be take the compound interpolation Mo of the low Nb of low C or one of Cr, B, in the present invention, its chemical composition scope (Wt%) is: C0.05%～0.10%, Si0.2%～～0.3%, Mn1.40%～1.60%, Nb0.025%～0.060%, Cr0.2～0.4%, Mo0.10～0.30%, B0.0010～0.0020%, Ti0.015%～0.030%, Als0.015%～0.045%, surplus is Fe and inevitable impurity.Impurity element in steel is controlled at P≤0.015%, S≤0.005%, [N]≤0.0040%, [O]≤0.0020%.In order to guarantee that the intensity of steel and certain ferrite, content of pearlite in alloy need more than 0.05% C content, simultaneously in order to guarantee welding property and the low-temperature flexibility of steel, the content of C should not surpass 0.10%, the Main Function of Si, Mn is solution strengthening and deoxidation, in the time of too much, can make intensity too high, affect toughness simultaneously; Nb and Ti Main Function are grain growths when postponing recrystallization temperature and suppressing to heat simultaneously, also have the effect of solid solution and precipitation strength.Cr or Mo, B Main Function are the hardening capacity that improves steel, form a certain amount of bainite structure, guarantee that yield strength is more than 460MPa.
The concrete production technique feature of steel of the present invention is as follows:
The technological process of production: cooling-(the tempering)-finished product of steel-making-refining-casting-heating steel billet-two-stage controlled rolling-control.
Smelting technology feature: carry out hot metal pretreatment, adopt converter smelting, by top blast or top bottom blowing, carry out refining treatment, and carry out microalloying, control Impurities in steel in mentioned component scope; This patent is characterised in that if add B, will control molten steel [N]≤0.0040% during refining, [O] thereby≤0.0020% make effective B content 0.0010%～0.0020%; Add Ti microalloying, continuous casting adopts induction stirring, reduces element segregation.
Rolling technology feature: roll 1180～1220 ℃ of front Heating temperatures, control heat-up time and be according to steel plate thickness 60～110 seconds/centimetre; Adopt the controlled rolling of two stages, object is the tissue before abundant refinement phase transformation, 1040～1080 ℃ of first stage start rolling temperatures, and 950～1000 ℃ of finishing temperatures, subordinate phase rolling starts temperature and is controlled at 920～870 ℃; Finishing temperature is controlled at 800～850 ℃, and subordinate phase recrystallization zone rolling accumulation of distortion amount is greater than 60%; Roll rear water-cooled, water-cooled starts 680～750 ℃ of temperature, 5～9 ℃/S of cooling rate, 450～620 ℃ of red temperatures; Feature of the present invention is will be through being greater than the temperature for the treatment of of 15 second time after hot rolling, then water-cooled, to generate ferrite, perlite and Martensite-Bainite Mixed Microstructure, guarantee that the yield tensile ratio of steel is below 0.80, can control the yield strength of steel simultaneously in the scope of GB regulation.
Thermal treatment process feature: in order to obtain best effect, the invention is characterized in and can carry out 500～650 ℃ of temper to the steel plate after hot rolling, optimum tempering temperature is at 550～630 ℃.By drawing process, can adjust the intensity of steel, improve toughness and the plasticity of steel simultaneously.
The low yield strength ratio steel plate for building structure of producing by technique scheme has following beneficial effect:
1. yield strength is greater than 460N/mm
2;
2. yield tensile ratio is less than 0.80;
3. production technique is simple, cooling with 5～9 ℃/s after controlled rolling; As coordinate tempering can obtain better properties;
4. chemical composition is simple, and carbon equivalent is less than 0.40.
Embodiment
According to chemical composition of the present invention and production technique, smelt the actual chemical composition of steel grade of the present invention as table 1, the actual rolling technological parameter of steel example of the present invention is as table 2, and object performance assay of the present invention is as table 3, table 4.
The smelting composition example of table 1, steel grade of the present invention, Wt%
The actual process parameter of table 2, steel example of the present invention
The As rolled mechanical property of table 3 steel embodiment of the present invention
Table 4 steel of the present invention utilizes 1-1 test plate (panel) embodiment tempering experimental performance
Claims (3)
1. the manufacture method of a 460 MPa grade yield strength steel plate for building structure, mainly comprise smelting, continuous casting and billet rolling, it is characterized in that: the weight percent of steel billet chemical composition is: C0.059%～0.10%, Si0.2%～0.3%, Mn1.40%～1.60%, Nb0.025%～0.055%, Ti0.022%～0.030%, Als0.015%～0.045%, also contain Cr0.2%～0.4%, Mo0.10%～0.20%, a kind of in B0.0010%～0.0020%, surplus is Fe and inevitable impurity, impurity element in steel is controlled at P≤0.015%, S≤0.005%, [N]≤0.0040%, [O]≤0.0020%, steel billet rolls 1180～1220 ℃ of front Heating temperatures, 1040～1080 ℃ of first stage start rolling temperatures, 950～1000 ℃ of finishing temperatures, subordinate phase rolling starts temperature and is controlled at 918～870 ℃, finishing temperature is controlled at 800～850 ℃, subordinate phase recrystallization zone rolling accumulation of distortion amount is greater than 60%, will be through being greater than the temperature for the treatment of of 15 second time after hot rolling, then water-cooled, water-cooled starts 680～745 ℃ of temperature, 5～9 ℃/S of cooling rate, 450～620 ℃ of red temperatures.
2. the manufacture method of a kind of 460 MPa grade yield strength steel plate for building structure according to claim 1, is characterized in that the steel plate after hot rolling to carry out 500～650 ℃ of temper.
3. the manufacture method of a kind of 460 MPa grade yield strength steel plate for building structure according to claim 2, is characterized in that tempering temperature is controlled at 550～630 ℃.
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| CN201010276610.6A CN102400053B (en) | 2010-09-07 | 2010-09-07 | Steel plate for building structure with yield strength of 460 MPa, and manufacturing method thereof |
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| CN201010276610.6A CN102400053B (en) | 2010-09-07 | 2010-09-07 | Steel plate for building structure with yield strength of 460 MPa, and manufacturing method thereof |
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| CN102400053A CN102400053A (en) | 2012-04-04 |
| CN102400053B true CN102400053B (en) | 2014-03-12 |
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Families Citing this family (11)
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| CN104313468A (en) * | 2014-11-14 | 2015-01-28 | 武汉钢铁(集团)公司 | Steel plate for 460MPa grade low-alloy high-strength structure and production method of steel plate |
| CN105200329A (en) * | 2015-09-11 | 2015-12-30 | 武汉钢铁(集团)公司 | Tensile strength-700MPa level easy-to-weld low-internal-stress structural steel plate and manufacturing method thereof |
| CN106636937A (en) * | 2016-10-08 | 2017-05-10 | 武汉钢铁股份有限公司 | Easy-to-weld structural steel with tensile strength in 600 MPa level and production method thereof |
| CN106834919B (en) * | 2016-12-22 | 2019-06-28 | 南京钢铁股份有限公司 | A kind of 460MPa grade high ductility low-alloy high-strength structural steel plate and its production method |
| CN108220798B (en) * | 2018-03-22 | 2020-04-24 | 北京科技大学 | 460 MPa-level anti-seismic fireproof building steel and preparation method thereof |
| CN108374126B (en) * | 2018-04-17 | 2019-12-03 | 东北大学 | A kind of high intensity fine grain reinforcing bar and preparation method thereof |
| CN109913629B (en) * | 2019-01-02 | 2021-07-27 | 武汉钢铁有限公司 | Easily-welded structural steel with yield strength of 630MPa and preparation method thereof |
| CN110724875B (en) * | 2019-09-20 | 2021-10-26 | 南京钢铁股份有限公司 | Steel plate for railway and manufacturing method for improving yield strength of steel plate |
| CN111172465B (en) * | 2020-02-28 | 2021-07-20 | 鞍钢股份有限公司 | Low-carbon equivalent large-thickness Q390GJ steel plate for building structure and manufacturing method thereof |
| CN112251569A (en) * | 2020-09-11 | 2021-01-22 | 南京钢铁股份有限公司 | Method for improving yield strength of Q460 grade high-strength steel plate |
| CN114686776B (en) * | 2022-03-31 | 2022-10-18 | 鞍钢股份有限公司 | 460 MPa-grade high-toughness extra-thick plate and manufacturing method thereof |
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