CN101008065A - Production process of II-grade threaded steel bar - Google Patents

Production process of II-grade threaded steel bar Download PDF

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Publication number
CN101008065A
CN101008065A CN 200610031201 CN200610031201A CN101008065A CN 101008065 A CN101008065 A CN 101008065A CN 200610031201 CN200610031201 CN 200610031201 CN 200610031201 A CN200610031201 A CN 200610031201A CN 101008065 A CN101008065 A CN 101008065A
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steel
nitrogen
alloy
ladle
tapping
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CN 200610031201
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CN100420763C (en
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吴光亮
罗钢
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Hunan Valin Lianyuan Iron & Steel Co Ltd
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Hunan Valin Lianyuan Iron & Steel Co Ltd
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Abstract

The invention discloses a production process of a 20MnSi II-grade spiral steel bar, which utilizes extremely rich nitrogen resources in the nature as a strengthening element of the 20MnSi II-grade spiral steel, is supplemented with other trace nitride forming elements, and controls the manganese content in the 20MnSi steel to be 0.4-1.2%, the silicon content to be 0.20-0.60% and the carbon content to be 0.15-0.25%. Adding a nitrogen-containing alloy into a steel ladle in the tapping process to ensure that the nitrogen content in the steel is 0.5-0.025%, and simultaneously adding 0.1-3.0 kg/tSteelThe nitride forms an alloy of the elements. After tapping, carrying out ladle bottom argon blowing or top argon blowing operation, wherein the argon blowing intensity is 0.01-0.10 m3/min·tSteelArgon blowing time is 3-8 min, the initial rolling temperature is 1000-1300 ℃, and the cooling speed after rolling is 1.0-3.5 ℃/s. The grade II screw thread steel bar produced by the process has yieldThe strength is more than 345MPa, the tensile strength is more than 500MPa, the yield ratio is about 0.68, the elongation is more than 17%, and the comprehensive cost is reduced by 5-10 yuan per ton compared with the traditional 20MnSi II-grade spiral steel bar.

Description

A kind of production technique of II level Twisted Steel
Technical field
The present invention relates to a kind of production technique of low alloy steel, relate in particular to a kind of production technique of 20MnSi II level Twisted Steel for building.
Background technology
At present, China's building bar about 90% is a 20MnSi II level Twisted Steel.II level Twisted Steel belongs to carbon manganese steel series, generally by electric furnace or converter smelting, in tapping process, adopt manganeseirom or silicomanganese that molten steel is carried out Alloying Treatment, make and contain manganese [Mn]=1.2~1.6%, silicon [Si]=0.40~0.80%, carbon [C]=0.17~0.25%, yield strength 〉=335MPa, tensile strength (б in the steel b) 〉=490MPa, unit elongation (δ 5) 〉=16%.The performance of this steel grade is mainly strengthened by carbon, manganese and silicon in the steel, belongs to old trade mark steel grade, mature production technology, market recognition height.But the main drawback of this method is that the content of carbon in the invar (C), manganese (Mn), silicon (Si) is higher, the cost of alloy height of use.In addition, the manganese element segregation takes place easily in smelting process, the welding property instability also is prone to the not obvious phenomenon of surrender.Another method be with chemical Composition Control at lower limit, adopt cooling control after rolling promptly to wear water cooling and reach above-mentioned requirements to guarantee its performance index, this method production cost is low slightly, but following shortcoming is arranged: 1. increase and wear wetting system, thereby increase maintenance of the equipment.2. wear water reinforcement property instability, especially the welding property influence to steel is bigger, and traction is very low.
Summary of the invention
The object of the present invention is to provide a kind of before stablizing 20MnSi II level Twisted Steel over-all properties the topic under, suitably reduce manganese, silicon alloy constituent content in the 20MnSi II level Deformed Steel Bars, thus the II level Twisted Steel production technique that reduces production costs.
For achieving the above object, the technical solution used in the present invention is:
1. redesign the composition of II level Twisted Steel 20MnSi, reduce manganese, silicone content in the 20MnSi steel: between manganese in the steel (Mn) content is controlled at 0.40~1.20%, silicon (Si) content is controlled between 0.20~0.60%, carbon (C) content is controlled between 0.15~0.25%;
2. adopt oxygen coverter or electrosmelting.The smelting technology in its early stage and mid-term is identical with traditional technology, smelting the later stage, promptly tap and add reductive agent, manganese ore in the forward direction smelting furnace and carry out top blast or the electric furnace fire door blows 0.5~3min oxygen or nitrogen, bottom blowing 0~3min nitrogen or argon gas, [Mn] 〉=0.25%, [C] 〉=0.10% in the control endpoint molten steel, other composition satisfy smelts standard-required;
3. in tapping process, in ladle, add silicomanganese or manganeseirom and ferro-silicon, make [M in the molten steel n]=0.40~1.20%, [Si]=0.20~0.60% add nitrogen promoter and make nitrogen content in the molten steel [N]=0.005~0.025%;
4. add the alloy of nitrogenate forming element in tapping process in ladle, its add-on is 0.1~3.0kg/t Steel
5. Argon (Ar) processing is carried out to the molten steel in the ladle in the tapping back, and blowing argon gas intensity is 0.01~0.10m 3/ mint Steel, the blowing argon gas time is controlled at 3~8min;
6. according to the nominal diameter and the scale requirement of rolling II level Twisted Steel, molten steel casting is become the continuously cast bloom of different section;
7. process furnace adds hot continuously cast material, and start rolling temperature is controlled at 1000~1300 ℃, rolls the postcooling speed control at 1.0~3.5 ℃/second.
Adopt the production technique of a kind of 20MnSi II level Twisted Steel that as above technical scheme provides to compare with traditional technology, its beneficial effect is:
1. silicomanganese or ferromanganese and ferrosilicon consumption can reduce by 20~50%, and the ferrosilicon consumption can reduce by 20~50%, reduce alloy consumption, can reduce the Twisted Steel production cost.
2. the technical performance index of II level Twisted Steel is constant, can satisfy needs for building.
3. technological operation is constant, need not drop into by increase equipment.
Embodiment
Below in conjunction with embodiment the specific embodiment of the present invention is described in further detail.
The production technique of described a kind of II level Twisted Steel can adopt oxygen coverter to smelt---continuous casting---rolling technology,---continuous casting---rolling technology that also can adopt electrosmelting.The present invention smelts with oxygen coverter---continuous casting---, and rolling technology is implemented.
Be added in the converter blast-melted, add steel scrap simultaneously, the oxygen blast melting, and add slag making materials such as lime, before [C] in the converter molten steel, [P], [S] reach the smelting code requirement, prepare tapping, adding 1.0~5.0kg/t in the tapping forward direction stove SteelReductive agent, 2.0~8.0kg/t SteelManganese ore, and top blast oxygen or nitrogen 0.5~3min, bottom blowing nitrogen 0.5~3min makes manganese content [Mn] 〉=0.25% in the endpoint molten steel, carbon content [C] 〉=0.10%, tapping.Described reductive agent is selected from a kind of in carbon dust, silicon carbide, the class graphite.
In tapping process, in ladle, add silicomanganese (Mn-Si) or manganeseirom (Fe-Mn) and ferro-silicon (Fe-Si), control its add-on, make manganese content [Mn]=0.40~1.20%, silicone content [Si]=0.20~0.60%, carbon content [C]=0.15~0.25% in the molten steel.
In tapping process, in ladle, add nitrogen-containing alloy, control its add-on, make the nitrogen content [N]=0.005~0.025% in the molten steel.Described nitrogen-containing alloy can be selected from one or more the combination in silicon nitrogen alloy, manganese nitrogen alloy, the titanium nitrogen alloy, and combination is than being selected from 1: 1 or 1: 1: 1 etc., and they can buy product for market.Add the alloy of nitrogenate forming element adding nitrogen-containing alloy in ladle when in ladle, its add-on is controlled at 0.1~3.0kg/t steel.The alloy of described nitrogenate forming element can be selected from ferro-vanadium (Fe-V), ferrocolumbium (Fe-Nb), ferro-titanium (Fe-Ti), the ferro-boron (Fe-B) one or more combination, combination is than being selected from 1: 1 or 1: 1: 1 etc., the purpose that adds nitrogenate forming element alloy is to eliminate the deleterious effect of nitrogen, the reinforced concrete-bar effect that improves nitrogen.Ferro-vanadium, ferrocolumbium, ferro-titanium, ferro-boron are prior art, and product can be bought in market.
Carry out the operation of ladle argon-blown gas after the tapping, operating method can be selected from steel ladle bottom argon blowing or ladle top blast argon.The blowing argon gas intensity control is at 0.01~0.10m 3/ mint steel, the blowing argon gas time is controlled at 3~8min.
According to rolling II level Twisted Steel nominal diameter and scale requirement, be cast into the continuously cast bloom of different section size.
To continuously cast bloom heating, treat that the strand temperature reaches requirement after, stocking, start rolling temperature is 1000~1300 ℃, rolling postcooling speed is 1.0~3.5 ℃/second, evenly cooling.
Embodiment 1
Smelt 20MnSi II level Deformed Steel Bars on 100 tons of oxygen top and bottom combined blown converters, blast-melted and steel scrap are added in the converter, the oxygen blast melting adds slag making material such as lime, treats that [C] in the molten steel, [P] [S] reach adding 5.0kg/t in the smelting code requirement forward direction steel melting furnace SteelReductive agent such as carbon dust add 8.0kg/t SteelManganese ore, top blast 2.0min oxygen, bottom blowing 2.5min nitrogen, sampling analysis makes carbon in the endpoint molten steel [C]=0.12%, [Mn]=0.20% o'clock tapping.In tapping process, in ladle, add Fe-Mn alloy, Fe-Si alloy, control its add-on and make manganese in the steel [Mn]=1.0%, silicon [Si]=0.40%, in tapping process, in ladle, add silicon nitrogen alloy simultaneously, and control its add-on and make nitrogen in steel [N]=0.015%, when in ladle, adding silicon nitrogen alloy, in ladle, adding 0.1kg/t SteelThe alloy of nitrogenate forming element such as ferro-vanadium (Fe-V); The BOTTOM ARGON BLOWING operation is carried out to ladle in the tapping back, and blowing argon gas intensity is 0.04m 3/ mint Steel, the blowing argon gas time is 5min, stocking, and start rolling temperature is 1200 ℃, rolling postcooling speed is 2.5 ℃/second.With the 20MnSi II level Twisted Steel of this explained hereafter, yield strength (б s) be 370MPa, tensile strength (б b) be 540MPa, unit elongation (δ 5) be 32%, the steel comprehensive cost reduces by 5 yuan of/ton steel.
Embodiment 2
Smelt 20MnSi II level Deformed Steel Bars on 60 tons of oxygen top and bottom combined blown converters, 50 tons of molten iron and 8 tons of steel scraps are added in the converter, the oxygen blast melting adds slag making work stone ash, treats that [C] in the molten steel, [P], [S] reach adding 1.0kg/t in the smelting code requirement forward direction steel melting furnace SteelReductive agent such as silicon carbide add 2.0kg/t SteelManganese ore, top blast 0.5min oxygen, bottom blowing 0.5min nitrogen, sampling analysis makes carbon in the endpoint molten steel [C]=0.10%, [Mn]=0.25% o'clock tapping.In tapping process, in ladle, add silicomanganese (Mn-Si) and ferro-silicon (Fe-Si), control its add-on and make manganese in the steel [Mn]=0.40%, silicon [Si]=0.60%, in tapping process, in ladle, add manganese nitrogen alloy simultaneously, and control its add-on and make nitrogen in steel [N]=0.025%, when in ladle, adding manganese nitrogen alloy, in ladle, adding 0.10kg/t SteelThe alloy of nitrogenate forming element such as ferrocolumbium (Fe-Nb), the operation of top blast argon is carried out to ladle in the tapping back, and blowing argon gas intensity is 0.01m 3/ mint Steel, the blowing argon gas time is 8min, stocking, and start rolling temperature is 1000 ℃, rolling postcooling speed is 1.5 ℃/second.With the 20MnSiII level Twisted Steel of this explained hereafter, its yield strength (б s)=360MPa, tensile strength (б b)=545MPa, unit elongation (δ 5)=25%, the steel comprehensive cost reduces by 10 yuan of/ton steel.
Embodiment 3
Smelt 20MnSi II level Deformed Steel Bars on 100 tons of oxygen top and bottom combined blown converters, blast-melted and steel scrap are added in the converter, the oxygen blast operation adds slag making material such as lime, treats that [C] in the molten steel, [P], [S] reach the smelting code requirement and add 4.5kg/t to steel melting furnace SteelReductive agent such as class graphite add 8.0kg/t SteelManganese ore, top blast 3min oxygen, bottom blowing 3min nitrogen, sampling analysis makes carbon content in the endpoint molten steel [C]=0.15%, manganese content [Mn]=0.36% o'clock tapping.In tapping process, in ladle, add silicomanganese [Si-Mn] and manganeseirom (Fe-Mn), control its add-on and make manganese in the molten steel [Mn]=1.2%, silicon [Si]=0.20%, in tapping process, in ladle, add simultaneously titanium nitrogen alloy, and control its add-on and make nitrogen in steel (N)=0.005%, when in ladle, adding titanium nitrogen alloy, in ladle, adding 2.8kg/t SteelThe alloy of nitrogenate forming element such as ferro-titanium (Fe-Ti), the operation of top blast argon is carried out to ladle in the tapping back, and blowing argon gas intensity is 0.10m 3/ mint Steel, the blowing argon gas time is 3min, stocking, and start rolling temperature is 1300 ℃, rolling postcooling speed is 3.5 ℃/second.With the 20MnSi II level Twisted Steel of this explained hereafter, its yield strength (б s)=395MPa, tensile strength (б b)=580MPa, unit elongation (δ 5)=35%, the steel comprehensive cost reduces by 8 yuan/ton.

Claims (1)

1, a kind of production technique of II level Twisted Steel is added in the converter oxygen blast melting with blast-melted and steel scrap, add the slag making material, before treating that [C] in the converter molten steel, [P], [S] reach the smelting code requirement, prepare tapping, it is characterized in that: in tapping forward direction steel melting furnace, add 1.0~5.0kg/t SteelReductive agent adds 2.0~8.0kg/t SteelManganese ore, top blast 0.5~3.0min oxygen or nitrogen, bottom blowing 05~3min nitrogen makes [C] 〉=0.10% in the endpoint molten steel, [Mn] 〉=0.25% tapping; In tapping process, in ladle, add silicomanganese or manganeseirom and ferro-silicon, make manganese content [Mn]=0.40~1.20% in the molten steel, silicone content [Si]=0.20~0.60%, carbon content [C]=0.15~0.25%; In tapping process, in ladle, add nitrogen-containing alloy, make nitrogen content in the molten steel [N]=0.005~0.025%, when in ladle, adding nitrogen-containing alloy, in ladle, add 0.1~3.0kg/t SteelThe alloy of nitrogenate forming element; Carry out the operation of ladle top blast argon gas or argon bottom-blowing after the tapping, blowing argon gas intensity is 0.01~0.10m 3/ mint Steel, the blowing argon gas time is controlled at 3~8min; Start rolling temperature is 1000~1300 ℃, and rolling postcooling speed is 1.0~3.5 ℃/second, wherein
Nitrogen-containing alloy is selected from: a kind of in silicon nitrogen alloy, manganese nitrogen alloy, the titanium nitrogen alloy,
The alloy of nitrogenate forming element is selected from: a kind of in ferro-vanadium, ferrocolumbium, ferro-titanium, the ferro-boron,
Reductive agent is selected from: a kind of in carbon dust, silicon carbide, the class graphite.
CNB2006100312013A 2006-01-23 2006-01-23 Production process of II-grade threaded steel bar Expired - Fee Related CN100420763C (en)

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Cited By (11)

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CN101775538A (en) * 2010-03-24 2010-07-14 中南大学 Technique for producing 500MPa level high-strength quake-proof reinforcing steel bar
CN103643086A (en) * 2013-11-21 2014-03-19 江苏天舜金属材料集团有限公司 Nickel-chromium alloy powder-coated steel bar manufacturing method
CN104673971A (en) * 2015-02-05 2015-06-03 河北钢铁股份有限公司承德分公司 Method for increasing nitrogen content in vanadium-containing steel bar
CN105401070A (en) * 2015-12-18 2016-03-16 首钢水城钢铁(集团)有限责任公司 Production method of finish rolling twisted steel for prestressed concrete
CN106319139A (en) * 2016-08-30 2017-01-11 唐山钢铁集团有限责任公司 Smelting method for increasing nitrogen content of screw-thread steel
CN107400831A (en) * 2017-08-19 2017-11-28 广州广钢新材料有限公司 A kind of screw-thread steel and its quenching technical
CN109201748A (en) * 2018-08-27 2019-01-15 合肥东方节能科技股份有限公司 A kind of cooling intelligent control technology of screw-thread steel fine grain rolling rolling stock
CN109576433A (en) * 2019-01-09 2019-04-05 山东莱钢永锋钢铁有限公司 A kind of V-Ti composite alloy reinforcing hot rolled ribbed bars processing method
CN110106446A (en) * 2019-06-24 2019-08-09 新余钢铁股份有限公司 A kind of 400MPa grades of hot rolled ribbed bars containing Ti and its production technology
CN113265584A (en) * 2021-05-13 2021-08-17 大冶特殊钢有限公司 Medium-carbon boron-containing steel and rolling and cooling control method for online normalizing treatment
CN115627410A (en) * 2022-10-31 2023-01-20 南京钢铁股份有限公司 Control method for designing vanadium-nitrogen alloy to meet requirement of deformed steel bar for nuclear power building

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GB1281203A (en) * 1968-08-13 1972-07-12 Uralsky Inst Chernykh Metall Method for refining molten iron alloys
CN1098439A (en) * 1994-06-19 1995-02-08 付德成 20MnSi hot rolling ribbed steel bar SINGLE-SLAG PROCESS TO ELECTRIC ARC FURNACE MELTING

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101775538A (en) * 2010-03-24 2010-07-14 中南大学 Technique for producing 500MPa level high-strength quake-proof reinforcing steel bar
CN103643086A (en) * 2013-11-21 2014-03-19 江苏天舜金属材料集团有限公司 Nickel-chromium alloy powder-coated steel bar manufacturing method
CN103643086B (en) * 2013-11-21 2015-10-28 江苏天舜金属材料集团有限公司 A kind of manufacture method of nichrome powder cladding reinforcing steel bar
CN104673971A (en) * 2015-02-05 2015-06-03 河北钢铁股份有限公司承德分公司 Method for increasing nitrogen content in vanadium-containing steel bar
CN105401070A (en) * 2015-12-18 2016-03-16 首钢水城钢铁(集团)有限责任公司 Production method of finish rolling twisted steel for prestressed concrete
CN106319139A (en) * 2016-08-30 2017-01-11 唐山钢铁集团有限责任公司 Smelting method for increasing nitrogen content of screw-thread steel
CN107400831A (en) * 2017-08-19 2017-11-28 广州广钢新材料有限公司 A kind of screw-thread steel and its quenching technical
CN109201748A (en) * 2018-08-27 2019-01-15 合肥东方节能科技股份有限公司 A kind of cooling intelligent control technology of screw-thread steel fine grain rolling rolling stock
CN109201748B (en) * 2018-08-27 2019-09-06 合肥东方节能科技股份有限公司 A kind of cooling intelligent control method of screw-thread steel fine grain rolling rolling stock
CN109576433A (en) * 2019-01-09 2019-04-05 山东莱钢永锋钢铁有限公司 A kind of V-Ti composite alloy reinforcing hot rolled ribbed bars processing method
CN110106446A (en) * 2019-06-24 2019-08-09 新余钢铁股份有限公司 A kind of 400MPa grades of hot rolled ribbed bars containing Ti and its production technology
CN110106446B (en) * 2019-06-24 2021-04-13 新余钢铁股份有限公司 400 MPa-grade Ti-containing hot-rolled ribbed steel bar and production process thereof
CN113265584A (en) * 2021-05-13 2021-08-17 大冶特殊钢有限公司 Medium-carbon boron-containing steel and rolling and cooling control method for online normalizing treatment
CN113265584B (en) * 2021-05-13 2022-05-06 大冶特殊钢有限公司 Medium-carbon boron-containing steel and rolling and cooling control method for online normalizing treatment
CN115627410A (en) * 2022-10-31 2023-01-20 南京钢铁股份有限公司 Control method for designing vanadium-nitrogen alloy to meet requirement of deformed steel bar for nuclear power building

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