CN102398003A - Crystallizer covering slag for continuous casting and method for continuously casting medium and low-carbon steel round billets - Google Patents
Crystallizer covering slag for continuous casting and method for continuously casting medium and low-carbon steel round billets Download PDFInfo
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- CN102398003A CN102398003A CN2010102871831A CN201010287183A CN102398003A CN 102398003 A CN102398003 A CN 102398003A CN 2010102871831 A CN2010102871831 A CN 2010102871831A CN 201010287183 A CN201010287183 A CN 201010287183A CN 102398003 A CN102398003 A CN 102398003A
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Abstract
The invention provides crystallizer covering slag for continuous casting. The covering slag is characterized by containing CaO, SiO2, Al2O3, Na2O, F<-> and C, wherein the alkalinity of the covering slag is 1.05-1.15, the viscosity at 1,300 DEG C is 0.30-0.40 Pa.S, and the melting point is 1,120-1,160 DEG C. The invention further provides a method for continuously casting medium and low-carbon steel by using large crystallizer taper billets in the presence of the crystallizer covering slag for continuous casting, provided by the invention. By controlling the alkalinity of the covering slag as well as the viscosity and the melting point at 1,300 DEG C, the surface quality of a casting blank can be ensured in the continuous casting process of large crystallizer taper medium and low-carbon steel round billets, lubrication between a blank shell of the casting blank at the lower port of a crystallizer and a crystallizer wall can be enhanced, the friction resistance is reduced, and the risks of blank shell pull crack and bleed-out are lowered.
Description
Technical field
The present invention relates to a kind of crystallizer protecting cinder for continuous casting, and the method for using the middle low carbon steel round billet continuous casting of said crystallizer protecting cinder for continuous casting.
Background technology
Continuous cast round billets is because its unfavorable factor in shape is prone to produce blemish; Can cause the bleed-out accident when serious; And the performance of covering slag has material impact to cc billet surface quality in the crystallizer, and the covering slag that performance is suitable is to produce surperficial flawless high-quality continuous cast round billets and guarantee one of ordinary production essential condition.Because the content of carbon is positioned at the peritectic reaction district in the middle low carbon steel steel; When continuous cast round billets solidifies at crystallizer,, cause in the crystallizer base shell inequality of catching a cold very easily because of the solidification shrinkage velocity jump; The growth of base shell is inhomogeneous, thereby cracks or pit defect at base shell weakness.In addition; The microalloy element such as Al, V, Ti that generally contains high level in the middle low carbon steel continuous cast round billets composition; Because the existence of these microalloy elements; In continuous casting production process, at high temperature solid molten Al, V, Ti are at austenite grain boundary with AlN, TiN, V forms such as (CN) when temperature reduces and dynamically separate out or static state is separated out, and have further increased crack sensitivity.Therefore; Adopt rational continuous casting process; Improving the continuous cast round billets surface quality is the key link of production high-quality middle low carbon steel continuous cast round billets, and the continuous casting covering slag that research and development and middle low carbon steel continuous cast round billets adapt is to alleviate and eliminates one of core technology of surperficial lobe defective of middle low carbon steel continuous cast round billets and pit defect.
Conical degree of crystallizer is an important parameter of crystallizer, and is very big to the influence of continuous casting operation and continuous cast round billets quality.For adapt to the thermal contraction that produces when molten steel solidifies in crystallizer; Crystallizer internal cavity is back draught, to reduce air gap, improves cooling condition; Increase shell thickness; Be beneficial to improve pulling rate and improve cc billet surface quality, can also eliminate or reduce base shell temperature recovery phenomenon simultaneously, help preventing that strand from cracking and distortion etc.Conical degree of crystallizer is bigger, help guaranteeing that the casting machine pulling rate improves after, the cooling of strand, but can increase the wearing and tearing of resistance of billet withdrawal and crystallizer wall is prone to cause that strand shakes, even drawing crack base shell, causes bleed-out.Therefore, for the bigger round billet continuous casting machine of conical degree of crystallizer, how guaranteeing low defective and high pulling rate simultaneously, is the key that continuous casting production is carried out smoothly.
CN 101658907A discloses a kind of protective slag of large-profile round billet continuous-casting crystallizer and preparation method thereof, and the weight percent of wherein said covering slag is formed as follows: SiO
2For 27-33%, CaO are that 24-30%, MgO are 1-3%, Fe
2O
3For be not more than 2%, Al
2O
3Be 5-10%, Na
2O is that 4-9%, F are that 1-4%, MnO are 0.5-2.5%, C
GuBe 15-20%.The composition of said continuous crystallizer protecting slag is according to CaO-SiO
2-Al
2O
3Pseudo-wollastonite zone in the ternary system selects each to become to be grouped into, and CaO is as main basic matterial, SiO in the component that constitutes covering slag
2As main acid material, Na
2O, CaF
2, Li
2O is as main flux, and carbonaceous components is as framework material and molten speed control preparation.In this patent documentation, said covering slag is difficult to guarantee the uniformly transfer heat of middle low carbon steel base shell in the crystallizer, is easy to generate crack defect; Also be difficult to guarantee required the lubricating of circle base high casting speed continuous casting, be unfavorable for preventing bonding bleed-out accident.
" iron and steel " magazine (the 37th volume the 9th phase 23-25 page or leaf in 2002; The covering slag performance is to the influence of continuous cast round billets surface quality; Works such as Cheng Zewei) reported on the basis of round billet continuous casting actual production data; Analysis-by-synthesis the influence of covering slag viscosity, fusion temperature, molten speed to circle base surface lobe and pit, produce blemish for preventing the circle base, must the covering slag performance be adjusted to suitable scope.The suitable covering slag viscosity of Φ 210mm circle base is 0.6-1.1PaS, and fusion temperature is 1130-1230 ℃, and molten speed is 40-50s; The suitable covering slag viscosity of Φ 270mm circle base is 0.6-1.0PaS, and fusion temperature is 120-1270 ℃, and molten speed is 60-80s.In the document, for circle base covering slag the influence of cc billet surface quality is analyzed, but do not analyzed of the influence of covering slag basicity slab quality, do not combine the casting machine appointed condition especially not consider the influence of conical degree of crystallizer simultaneously to the covering slag consumption yet.
In above-mentioned bibliographical information, said round billet continuous casting covering slag only considers that all certain several aspect has the improvement effect to the surface quality of continuous cast round billets, and fails conditions such as covering slag basicity, viscosity, fusing point and conical degree of crystallizer are taken all factors into consideration.
Summary of the invention
The purpose of this invention is to provide a kind of middle low carbon steel circle blank surface defects of can either effectively eliminating and to satisfy the crystallizer protecting residue that the high pulling rate of big conical degree of crystallizer circle base is produced again.
Another object of the present invention provides a kind of method of middle low carbon steel round billet continuous casting.
The invention provides a kind of crystallizer protecting cinder for continuous casting, wherein, said covering slag contains CaO, SiO
2, Al
2O
3, Na
2O, F
-And C, and the basicity of said covering slag is 1.05-1.15, and the viscosity under 1300 ℃ is 0.30-0.40PaS, and fusing point is 1120-1160 ℃.
Crystallizer protecting cinder for continuous casting provided by the invention is through viscosity and fusing point under the basicity, 1300 ℃ of the said covering slag of control; In the process of big conical degree of crystallizer middle low carbon steel round billet continuous casting; Not only can guarantee cc billet surface quality; And can improve lubricated that crystallizer end opening place's casting blank shell and crystallizer wall ask, the resistance of reducing friction reduces the risk of base shell drawing crack and bleed-out.
The specific embodiment
Crystallizer protecting cinder for continuous casting provided by the invention contains CaO, SiO
2, Al
2O
3, Na
2O, F-and C, and the basicity of said covering slag is 1.05-1.15, the viscosity under 1300 ℃ is 0.30-0.40PaS, fusing point is 1120-1160 ℃.Under the preferable case, the basicity of said covering slag is 1.08-1.11, and the viscosity under 1300 ℃ is 0.34-0.38PaS, and fusing point is 1130-1150 ℃.
In the present invention, said basicity is meant CaO and SiO in the said covering slag
2Weight ratio, therefore, content that can be through increasing CaO or reduce SiO
2Content improve the basicity of said covering slag, content that also can be through reducing CaO or increase SiO
2Content reduce the basicity of said covering slag.Said viscosity can be through routine method for example the hang spring method under 1300 ℃, record the viscosity of said covering slag and F wherein
-, Na
2O and Al
2O
3Composition is relevant, works as Al
2O
3Content when increasing relatively, the viscosity of said covering slag increases, and works as F
-, Na
2When the content of O increased relatively, the viscosity of said covering slag reduced.Said fusing point can be through routine method for example hemisphere point method record the fusing point of said covering slag and Na wherein
2O and Al
2O
3Composition is relevant, works as Al
2O
3Content when increasing relatively, the fusing point of said covering slag increases, and works as Na
2When the content of O increased relatively, the fusing point of said covering slag reduced.
In said crystallizer protecting cinder for continuous casting, under the situation of the parameter area that satisfies above-mentioned basicity, viscosity, fusing point, each components contents does not have special qualification.In order further to improve lubricating between crystallizer end opening place's casting blank shell and crystallizer wall; The resistance of reducing friction; Guarantee that simultaneously the base shell conducts heat evenly in the crystallizer, can satisfy the crystallizer protecting residue that the high pulling rate of big conical degree of crystallizer circle base is produced again thereby can either effectively eliminate middle low carbon steel circle blank surface defects.Each components contents in the said covering slag is satisfied: the gross weight with said covering slag is a benchmark, and the content of CaO is 30-40 weight %, SiO
2Content be 28-38 weight %, Al
2O
3Content be 2-8 weight %, Na
2The content of O is 4-8 weight %, F
-Content be 1-5 weight %, the content of C is 8-18 weight %; Further preferred satisfied: the gross weight with said covering slag is a benchmark, and the content of CaO is 32-38 weight %, SiO
2Content be 30-35 weight %, Al
2O
3Content be 4-6 weight %, Na
2The content of O is 5-7 weight %, F
-Content be 3-4 weight %, the content of C is 10-16 weight %.
Can also contain Fe in the crystallizer protecting cinder for continuous casting according to the invention
2O
3And/or MnO, and be benchmark with the total amount of said covering slag, said Fe
2O
3Can be 0.5-8 weight % with the total content of MnO, be preferably 1-6 weight %.
Because under the condition of identical component and constituent content, pre-melted type hollow bead slag can improve the uniformity of covering slag fusion process.Therefore; Said crystallizer protecting cinder for continuous casting provided by the invention is preferably pre-melted type hollow bead slag; Further the particle diameter of preferred said pre-melted type hollow bead slag can be the 0.1-1 millimeter, and the particle diameter of the said pre-melted type hollow bead slag more than the 80 weight % is the 0.1-0.8 millimeter.
In the present invention; When said covering slag is pre-melted type hollow bead slag; Said covering slag can prepare through following method: the raw material except that carbonaceous material in the said covering slag is evenly mixed and fusion, the product that obtains after the fusion is evenly mixed with carbonaceous material, carry out granulation then; Said raw material except that carbonaceous material comprises the raw material of calcium containing compound, the raw material of silicon-containing compound, the raw material of aluminum contained compound, the raw material of compounds containing sodium and the raw material of fluorochemical.
Said carbonaceous material can be the conventional various carbonaceous materials that use in this area, for example can be in carbon black, graphite and the coke at least a.
The raw material of said calcium containing compound can be for containing the raw material that can generate CaO after CaO or the fusion, for example can be in pre-melted slag, wollastonite and the clinker at least a, be preferably pre-melted slag and/or clinker, further be preferably pre-melted slag; The raw material of said silicon-containing compound can be for containing SiO
2Perhaps can generate SiO after the fusion
2Raw material, for example can be in pre-melted slag, wollastonite, clinker, quartz sand and the feldspar at least a, be preferably pre-melted slag and/or quartz sand, further be preferably pre-melted slag; The raw material of said aluminum contained compound can be for containing Al
2O
3Perhaps can generate Al after the fusion
2O
3Raw material, for example can be in pre-melted slag, bauxite, clinker and the white clay at least a, be preferably pre-melted slag and/or white clay; The raw material of said compounds containing sodium can be for containing Na
2Can generate Na after O or the fusion
2The raw material of O for example can be preferably sodium carbonate for pre-melted slag and/or sodium carbonate; The raw material of said fluorochemical can be for containing F
-Perhaps can generate F after the fusion
-Raw material, for example can be preferably fluorite for pre-melted slag and/or fluorite.
In the present invention, said pre-melted slag contains the CaO of 35-45 weight %, the SiO of 35-45 weight %
2, 2-5 weight % Al
2O
3, 2-5 weight % Na
2The F of O and 2-5 weight %
-Said wollastonite contains the CaO of 35-45 weight % and the SiO of 40-60 weight %
2Said clinker contains the CaO of 60-70 weight %, the SiO of 20-30 weight %
2Al with 4-10 weight %
2O
3Said quartz sand contains the SiO of 85-98 weight %
2Said feldspar contains the SiO of 60-70 weight %
2Said fluorite contains the F of 45-50 weight %
-Said bauxite contains the Al of 60-90 weight %
2O
3Said white clay contains the Al of 30-50 weight %
2O
3
In most preferred embodiment of the present invention; In the method for the said covering slag of above-mentioned preparation; With respect to the said covering slag of 100 weight portions, use pre-melted slag, 2-5 weight parts of sodium carbonate, the fluorite of 0.5-5 weight portion, the quartz sand of 1-5 weight portion, the white clay of 0.5-5 weight portion, the clinker of 5-10 weight portion, the carbon black of 1-5 weight portion and the graphite of 8-12 weight portion of 60-80 weight portion.To make said pre-melted type hollow bead slag.
In the method for the said covering slag of above-mentioned preparation, said fusion and process for granulating all can be for well known to a person skilled in the art the whole bag of tricks.For example, said fusion can adopt electric furnace or furnace cupola to implement, and commonly used is electric furnace.Said process for granulating is preferably the prilling process that can form the hollow spheres particle; For example can adopt mist projection granulating; The method of said mist projection granulating has been conventionally known to one of skill in the art, comprises that the covering slag raw material is added water processes slurry, through compression pump slurry is delivered to and is carried out granulating and drying in the spray granulating and drying tower; Promptly obtain the covering slag that the particle diameter scope is the 0.1-1.0 millimeter through screening again, and the hollow spheres particle grain size more than the 80 weight % is in 0.1-0.8 millimeter scope.Parameter during mist projection granulating is following: slurry concentration is that 20-80 weight %, pressure are that 1-3 MPa, EAT are that 600-900 ℃, exhaust gas temperature are that 100-300 ℃, spray sheet diameter are the 1.5-2.5 millimeter.Under preferable case; Raw material in said covering slag except that carbonaceous material evenly mixes after the also fusion; Make molten mixture through water-cooled, fragmentation and fine grinding, thereby obtain particle diameter, be preferably the intermediate particle slag of 5-60 micron below 80 microns; And then said intermediate particle slag is evenly mixed with carbonaceous material, carry out granulation then.The said method that makes molten mixture water-cooled, fragmentation and fine grinding repeats no more at this for conventionally known to one of skill in the art.
The present invention also provides a kind of method of big tapering middle low carbon steel round billet continuous casting, and said method comprises carries out round billet continuous casting with the molten steel that obtains after smelting in the presence of covering slag, and wherein, said covering slag is an above-mentioned crystallizer protecting cinder for continuous casting provided by the invention.
The cross section diameter of the used round base casting machine of said round billet continuous casting can be 200-250mm, further is preferably 200-230mm.
Said conical degree of crystallizer can be 1.2-1.8%/m, further is preferably 1.2-1.6%/m.
In the process of said middle low carbon steel round billet continuous casting; The pulling rate of said round base does not have special qualification, can carry out well known to a person skilled in the art technological parameter, under the preferable case; The pulling rate of said round base is 1.6-2.0m/min, further is preferably 1.6-1.8m/min.
According to method provided by the invention, the interior covering slag liquid slag layer thickness of crystallizer can be 10-15mm when the addition of said covering slag made round billet continuous casting, further was preferably 11-13mm.
According to method provided by the invention, with respect to said molten steel per ton, the addition of said covering slag can be the 0.30-0.45 kilogram, further is preferably the 0.35-0.45 kilogram.
In said method, the chemical composition of the molten steel that in said crystallizer, adds can for: the gross weight with said molten steel is a benchmark, and the content of carbon is 0.05-0.40 weight % in the said molten steel; The content of silicon is 0.05-0.50 weight %; The content of manganese is 0.50-1.80 weight %, and the content of sulphur is smaller or equal to 0.020 weight %, and the content of phosphorus is smaller or equal to 0.025 weight %; The content of titanium is 0.02-0.04 weight %; The content of vanadium is 0.01-0.5 weight %, and the content of chromium is 0.05-1.30 weight %, and the content of iron is 95.5-99.0 weight %.
In addition, all be conventionally known to one of skill in the art for other operating parameter in the middle low carbon steel round billet continuous casting process and concrete implementation method, repeat no more at this.
Below through embodiment and Comparative Examples the present invention is done further detailed explanation.In following examples, said pre-melted slag contains the CaO of 43 weight %, the SiO of 41 weight %
2, 5 weight % Al
2O
3, 5 weight % Na
2The F of O and 4 weight %
-Said fluorite contains the F of 47 weight %
-Said quartz sand contains the SiO of 98 weight %
2Said white clay contains the Al of 37 weight %
2O
3Said clinker contain 68 weight % CaO, 21 weight % SiO
2Al with 10 weight %
2O
3
Embodiment 1
Present embodiment is used to explain crystallizer protecting cinder for continuous casting provided by the invention.
After 740 kilograms pre-melted slags, 40 kilograms sodium carbonate, 15 kilograms fluorite, 70 kilograms clinker, 20 kilograms quartz sand and 25 kilograms of white claies are evenly mixed; With electric furnace with its fusion; Pass through water-cooled, fragmentation and fine grinding then, thereby make the intermediate particle slag that particle diameter is the 5-60 micron.Then carbon black and the double centner graphite of said intermediate particle slag with 20 kilograms is mixed; Mix with mixer then; Add entry again; And adopt ball mill that the gained mixture is processed the slurry that concentration is 20 weight %; Be that 2 MPas, EAT are that 800 ℃, exhaust gas temperature are that 200 ℃, spray sheet diameter are under 2 millimeters the condition at last, through compression pump slurry delivered to and carried out granulating and drying in the spray granulating and drying tower that promptly obtaining particle size range through screening again is the 0.1-1.0 millimeter at pressure; And the pre-melted type hollow bead slag of the particle diameter of 95 weight % in 0.1-0.8 millimeter scope, (said covering slag contains the CaO of 36.23 weight %, the SiO of 32.78 weight % to crystallizer protecting cinder for continuous casting A1 promptly provided by the invention
2, 5.17 weight % Al
2O
3, 5.86 weight % Na
2The F of O, 3.56 weight %
-With the C of 11.65 weight %, all the other are Fe
2O
3And MnO), the basicity of said covering slag is CaO/SiO
2Be 1.11, the fusing point that uses hemisphere point method to record said covering slag is 1141 ℃, uses the hang spring method to be 0.36PaS 1300 ℃ of viscosity that record said continuous casting covering slag.
Embodiment 2
Present embodiment is used to explain crystallizer protecting cinder for continuous casting provided by the invention.
After 620 kilograms pre-melted slags, 35 kilograms sodium carbonate, 25 kilograms fluorite, 80 kilograms clinker, 32 kilograms quartz sand and 45 kilograms of white claies are evenly mixed; With electric furnace with its fusion; Pass through water-cooled, fragmentation and fine grinding then, thereby make the intermediate particle that particle diameter is the 5-60 micron.Then said intermediate particle slag carbon black and 115 kilograms of graphite with 35 kilograms are mixed; Mix with mixer then; Add entry again; And adopt ball mill that the gained mixture is processed the slurry that concentration is 20 weight %; Be that 2 MPas, EAT are that 800 ℃, exhaust gas temperature are that 200 ℃, spray sheet diameter are under 2 millimeters the condition at last, through compression pump slurry delivered to and carried out granulating and drying in the spray granulating and drying tower that promptly obtaining particle size range through screening again is the 0.1-1.0 millimeter at pressure; And the pre-melted type hollow bead slag of the particle diameter of 88 weight % in 0.1-0.8 millimeter scope, (said covering slag contains the CaO of 33.15 weight %, the SiO of 30.63 weight % to crystallizer protecting cinder for continuous casting A2 promptly provided by the invention
2, 5.64 weight % Al
2O
3, 5.21 weight % Na
2The F of O, 3.70 weight %
-With the C of 15.70 weight %, all the other are Fe
2O
3And MnO), the basicity of said covering slag is CaO/SiO
2Be 1.08, the fusing point that uses hemisphere point method to record said covering slag is 1150 ℃, uses the hang spring method to be 0.38PaS 1300 ℃ of viscosity that record said continuous casting covering slag.
Embodiment 3
Present embodiment is used to explain crystallizer protecting cinder for continuous casting provided by the invention.
After 1000 kilograms pre-melted slags, 60 kilograms sodium carbonate, 5 kilograms fluorite, 110 kilograms clinker, 41 kilograms quartz sand and 5 kilograms of white claies are evenly mixed; With electric furnace with its fusion; Pass through water-cooled, fragmentation and fine grinding then, thereby make the intermediate particle that particle diameter is the 5-60 micron.Then said intermediate particle slag carbon black and 115 kilograms of graphite with 20 kilograms are mixed; Mix with mixer then; Add entry again; And adopt ball mill that the gained mixture is processed the slurry that concentration is 20 weight %; Be that 2 MPas, EAT are that 800 ℃, exhaust gas temperature are that 200 ℃, spray sheet diameter are under 2 millimeters the condition at last, through compression pump slurry delivered to and carried out granulating and drying in the spray granulating and drying tower that promptly obtaining particle size range through screening again is the 0.1-1.0 millimeter at pressure; And the pre-melted type hollow bead slag of the particle diameter of 85 weight % in 0.1-0.8 millimeter scope, (said covering slag contains the CaO of 37.96 weight %, the SiO of 34.85 weight % to crystallizer protecting cinder for continuous casting A3 promptly provided by the invention
2, 4.63 weight % Al
2O
3, 6.27 weight % Na
2The F of O, 3.11 weight %
-With the C of 10.01 weight %, all the other are Fe
2O
3And MnO), the basicity of said covering slag is CaO/SiO
2Be 1.09, the fusing point that uses hemisphere point method to record said covering slag is 1130 ℃, uses the hang spring method to be 0.34PaS 1300 ℃ of viscosity that record said continuous casting covering slag.
Comparative Examples 1
Method according to embodiment 1 prepares crystallizer protecting cinder for continuous casting; Different is; Replace the raw material among the embodiment 1 with 600 kilograms pre-melted slags, 20 kilograms sodium carbonate, 30 kilograms fluorite, 30 kilograms clinker, 80 kilograms quartz sand, double centner white clay, 10 kilograms carbon black and 90 kilograms graphite, (said covering slag contains the CaO of 29.0 weight %, the SiO of 34.45 weight % thereby obtain crystallizer protecting cinder for continuous casting D1
2, 7.29 weight % Al
2O
3, 4.34 weight % Na
2The F of O, 3.97 weight %
-, 10.42 weight % C, all the other are Fe
2O
3And MnO), the basicity of said covering slag is CaO/SiO
2Be 0.84, the fusing point that uses hemisphere point method to record said covering slag is 1165 ℃, uses the hang spring method to be 0.56PaS 1300 ℃ of viscosity that record said continuous casting covering slag.
Comparative Examples 2
Method according to embodiment 1 prepares crystallizer protecting cinder for continuous casting; Different is; Replace the raw material among the embodiment 1 with the sodium carbonate of 600 kilograms pre-melted slags, double centner, 40 kilograms fluorite, the clinker of double centner, 5 kilograms quartz sand, 15 kilograms of white claies, 20 kilograms carbon black and the graphite of double centner, (said covering slag contains the CaO of 33.27 weight %, the SiO of 27.13 weight % thereby obtain crystallizer protecting cinder for continuous casting D2
2, 4.65 weight % Al
2O
3, 9.03 weight % Na
2The F of O, 4.38 weight %
-, 12.24 weight % C, all the other are Fe
2O
3And MnO), the basicity of said covering slag is CaO/SiO
2Be 1.23, the fusing point that uses hemisphere point method to record said covering slag is 1082 ℃, uses the hang spring method to be 0.21PaS 1300 ℃ of viscosity that record said continuous casting covering slag.
Embodiment 4-6
Present embodiment is used to explain the method for said middle low carbon steel round billet continuous casting provided by the invention.
Respectively in the presence of said covering slag A1-A3; Under the casting machine pulling rate is 1.8 meters/minute, the condition of circle base casting machine cross section diameter 200mm and conical degree of crystallizer 1.6%/rice, the cast molten steel of composition as described in Table 1; And with respect to said molten steel per ton; The consumption of said covering slag is respectively 0.35 kilogram, 0.39 kilogram and 0.45 kilogram, thereby obtains middle low carbon steel strand S1-S3 respectively.
Detect the casting billet surface defective and statistics bonding steel leakage number of times of middle low carbon steel strand S1-S3.
The detection method of casting billet surface defective: the casting billet surface to producing carries out hand inspection (naked eyes detection), and the strand quantity that has defective is as molecule, and checked strand total quantity is as denominator, and both percentage is ratio of defects.
The statistical method of bonding bleed-out number of times: owing to reasons such as the covering slag performance are not good, cause the molten steel in mold solidified shell crack defect to occur, the molten steel of solidified shell parcel, causes and stops watering by spilling in the crystallizer along crackle, so then counts the bleed-out accident one time.
Comparative Examples 3-4
Produce the middle low carbon steel strand according to the method for embodiment 4-6, different is, uses said covering slag D1 that Comparative Examples 1 and 2 prepares and D2 as crystallizer protecting cinder for continuous casting respectively, thereby obtains middle low carbon steel strand SD1-SD2.Likewise, according to the method rolled steel finished product of embodiment 4-6 and surface defect rate and the bonding steel leakage number of times that detects strand, its result is as shown in table 2.
Table 1
| C | Si | Mn | P | S | Ti | V | Cr | Fe |
| 0.38 | 0.20 | 1.35 | 0.02 | 0.02 | 0.03 | 0.25 | 0.95 | 96.8 |
Table 2
Can find out by table 2, in big tapering crystallizer round billet continuous casting production process, adopt crystallizer protecting cinder for continuous casting A1-A3 continuous casting provided by the invention to produce middle low carbon steel circle base S1-S3; The covering slag consumption is normal; The covering slag thickness of slag layer can guarantee in the casting process between the base shell and crystallizer wall required lubricated, prevents bonding and bleed-out, and because the covering slag behaviour in service is good; Effectively ensured cc billet surface quality, the casting billet surface ratio of defects is lower than 1%.
The covering slag D1 basicity that makes in the Comparative Examples 1 is lower, and viscosity and fusing point are very high, uses in the Comparative Examples 3 of D1 as covering slag; The covering slag consumption is lower, is difficult to guarantee lubricate in the crystallizer, and the bleed-out accident has taken place 1 time; And there is blemish in casting billet surface, and ratio of defects reaches 20%.
The covering slag D2 viscosity and the fusing point that make in the Comparative Examples 2 are lower, and basicity is too high, use in the Comparative Examples 4 of D2 as covering slag; The covering slag consumption is very big; And all be molten state and float on molten steel top, the melt cinder thickness of slag layer of formation is lower, and the bleed-out accident has also taken place 1 time; And there is blemish in casting billet surface, and ratio of defects reaches 22%.
This shows that covering slag provided by the invention has significantly improved lubricating between interior base shell of crystallizer and the crystallizer wall, has guaranteed the direct motion of cast, has improved cc billet surface quality, has eliminated the casting billet surface defective.
Claims (13)
1. a crystallizer protecting cinder for continuous casting is characterized in that, said covering slag contains CaO, SiO
2, Al
2O
3, Na
2O, F
-And C, and the basicity of said covering slag is 1.05-1.15, and the viscosity under 1300 ℃ is 0.30-0.40PaS, and fusing point is 1120-1160 ℃.
2. covering slag according to claim 1, wherein, the basicity of said covering slag is 1.08-1.11, and the viscosity under 1300 ℃ is 0.34-0.38PaS, and fusing point is 1130-1150 ℃.
3. covering slag according to claim 1 wherein, is a benchmark with the gross weight of said covering slag, and the content of CaO is 30-40 weight %, SiO
2Content be 28-38 weight %, Al
2O
3Content be 2-8 weight %, Na
2The content of O is 4-8 weight %, F
-Content be 1-5 weight %, the content of C is 8-18 weight %.
4. covering slag according to claim 3 wherein, is a benchmark with the gross weight of said covering slag, and the content of CaO is 32-38 weight %, SiO
2Content be 30-35 weight %, Al
2O
3Content be 4-6 weight %, Na
2The content of O is 5-7 weight %, F
-Content be 3-4 weight %, the content of C is 10-16 weight %.
5. covering slag according to claim 1, wherein, said covering slag is a pre-melted type hollow bead slag, the particle diameter of said covering slag is the 0.1-1 millimeter, and the particle diameter of the said covering slag particle more than the 80 weight % is the 0.1-0.8 millimeter.
6. covering slag according to claim 5, wherein, the preparation method of said covering slag comprises: the raw material except that carbonaceous material in the said covering slag is evenly mixed and fusion, the product that obtains after the fusion is evenly mixed with carbonaceous material, carry out granulation then; Said raw material except that carbonaceous material comprises the raw material of calcium containing compound, the raw material of silicon-containing compound, the raw material of aluminum contained compound, the raw material of compounds containing sodium and the raw material of fluorochemical; Said carbonaceous material is at least a in carbon black, graphite and the coke.
7. covering slag according to claim 6, wherein, the raw material of said calcium containing compound is to contain the raw material that can generate CaO after CaO or the fusion; The raw material of said silicon-containing compound is for containing SiO
2Perhaps can generate SiO after the fusion
2Raw material; The raw material of said aluminum contained compound is for containing Al
2O
3Perhaps can generate Al after the fusion
2O
3Raw material; The raw material of said compounds containing sodium is for containing Na
2Can generate Na after O or the fusion
2The raw material of O; The raw material of said fluorochemical is for containing F
-Perhaps can generate F after the fusion
-Raw material.
8. covering slag according to claim 7, wherein, the raw material of said calcium containing compound is at least a in pre-melted slag, wollastonite and the clinker; The raw material of said silicon-containing compound is at least a in pre-melted slag, wollastonite, clinker, quartz sand and the feldspar; The raw material of said aluminum contained compound is at least a in pre-melted slag, bauxite, clinker and the white clay; The raw material of said compounds containing sodium is pre-melted slag and/or sodium carbonate; The raw material of said fluorochemical is pre-melted slag and/or fluorite.
9. the method for a middle low carbon steel round billet continuous casting, said method comprise carries out round billet continuous casting with the molten steel that obtains after smelting in the presence of covering slag, it is characterized in that said covering slag is any described covering slag among the claim 1-8.
10. method according to claim 9, wherein, the interior covering slag liquid slag layer thickness of crystallizer was 10-15mm when the addition of said covering slag made round billet continuous casting.
11. method according to claim 10, wherein, with respect to said molten steel per ton, the addition of said covering slag is the 0.3-0.45 kilogram.
12. according to any described method among the claim 9-11, wherein, the used round base casting machine cross section diameter of said round billet continuous casting is 200-250mm, conical degree of crystallizer is 1.2-1.8%/rice, pulling rate be 1.6-2 rice/minute.
13. method according to claim 9 wherein, is a benchmark with the gross weight of the molten steel that obtains after the said smelting; The content of carbon is 0.05-0.4 weight % in the said molten steel, and the content of silicon is 0.05-0.5 weight %, and the content of manganese is 0.50-1.8 weight %; The content of sulphur is smaller or equal to 0.02 weight %; The content of phosphorus is smaller or equal to 0.025 weight %, and the content of titanium is 0.02-0.04 weight %, and the content of vanadium is 0.01-0.5 weight %; The content of chromium is 0.05-1.3 weight %, and the content of iron is 95.5-99 weight %.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103785804A (en) * | 2013-10-19 | 2014-05-14 | 河南通宇冶材集团有限公司 | Round-billet continuous-casting crystallizer covering slag and production method thereof |
| CN106216622A (en) * | 2016-08-29 | 2016-12-14 | 山东钢铁股份有限公司 | A kind of method of quick-replaceable tundish in molten steel casting process |
| CN106345976A (en) * | 2016-11-16 | 2017-01-25 | 攀钢集团攀枝花钢铁研究院有限公司 | Continuous casting crystallizer casting powder and continuous casting method of wide and thick slab micro-carbon steel |
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| CN111440923A (en) * | 2020-04-24 | 2020-07-24 | 芜湖新兴铸管有限责任公司 | Covering slag for high-carbon high-alloy wear-resistant steel and preparation method thereof |
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| CN113996771A (en) * | 2021-11-12 | 2022-02-01 | 江苏嘉耐高温材料股份有限公司 | Pre-melted crystallizer casting powder for non-oriented silicon steel and preparation method thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1260740A (en) * | 1997-06-19 | 2000-07-19 | 阿奇亚斯佩丝阿里特尔尼公司 | Continuous casting process for producing low carbon steel strips and strips obtained with good as cast mechanical properties |
| CN1911559A (en) * | 2006-08-25 | 2007-02-14 | 重庆大学 | Protective slag for ultralow carbon steel continuous casting |
| CN101036939A (en) * | 2007-04-20 | 2007-09-19 | 攀枝花钢铁(集团)公司 | Method for controlling the cross crack of blank angle of high nitrogen steel casting board containing vanadium |
| CN101658907A (en) * | 2009-09-16 | 2010-03-03 | 河南通宇冶材集团有限公司 | Protective slag of large-profile round billet continuous-casting crystallizer and method for preparing same |
| CN102039386A (en) * | 2009-10-15 | 2011-05-04 | 攀钢集团研究院有限公司 | Crystallizer mold powder for continuous casting and continuous casting method of low-alloy steel slab |
-
2010
- 2010-09-16 CN CN201010287183.1A patent/CN102398003B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1260740A (en) * | 1997-06-19 | 2000-07-19 | 阿奇亚斯佩丝阿里特尔尼公司 | Continuous casting process for producing low carbon steel strips and strips obtained with good as cast mechanical properties |
| CN1911559A (en) * | 2006-08-25 | 2007-02-14 | 重庆大学 | Protective slag for ultralow carbon steel continuous casting |
| CN101036939A (en) * | 2007-04-20 | 2007-09-19 | 攀枝花钢铁(集团)公司 | Method for controlling the cross crack of blank angle of high nitrogen steel casting board containing vanadium |
| CN101658907A (en) * | 2009-09-16 | 2010-03-03 | 河南通宇冶材集团有限公司 | Protective slag of large-profile round billet continuous-casting crystallizer and method for preparing same |
| CN102039386A (en) * | 2009-10-15 | 2011-05-04 | 攀钢集团研究院有限公司 | Crystallizer mold powder for continuous casting and continuous casting method of low-alloy steel slab |
Non-Patent Citations (2)
| Title |
|---|
| 蔡开科等: "《连铸结晶器》", 31 October 2008 * |
| 陈天明等: "空心颗粒连铸保护渣的研制与应用", 《钢铁钒钛》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103785804A (en) * | 2013-10-19 | 2014-05-14 | 河南通宇冶材集团有限公司 | Round-billet continuous-casting crystallizer covering slag and production method thereof |
| CN103785804B (en) * | 2013-10-19 | 2016-05-11 | 河南通宇冶材集团有限公司 | A kind of protecting slag of round blank continuous-casting crystallizer and production method thereof |
| CN106216622A (en) * | 2016-08-29 | 2016-12-14 | 山东钢铁股份有限公司 | A kind of method of quick-replaceable tundish in molten steel casting process |
| CN106345976A (en) * | 2016-11-16 | 2017-01-25 | 攀钢集团攀枝花钢铁研究院有限公司 | Continuous casting crystallizer casting powder and continuous casting method of wide and thick slab micro-carbon steel |
| CN106513605A (en) * | 2016-11-16 | 2017-03-22 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for improving low-carbon aluminum killed steel cold-rolled plate coil peeling |
| CN111440923A (en) * | 2020-04-24 | 2020-07-24 | 芜湖新兴铸管有限责任公司 | Covering slag for high-carbon high-alloy wear-resistant steel and preparation method thereof |
| CN114472836A (en) * | 2020-11-13 | 2022-05-13 | 上海梅山钢铁股份有限公司 | Method for preventing slab continuous casting high-carbon steel from casting and breakout |
| CN112828254A (en) * | 2020-12-30 | 2021-05-25 | 芜湖新兴铸管有限责任公司 | Method for controlling liquid level fluctuation of peritectic steel continuous casting crystallizer |
| CN113996771A (en) * | 2021-11-12 | 2022-02-01 | 江苏嘉耐高温材料股份有限公司 | Pre-melted crystallizer casting powder for non-oriented silicon steel and preparation method thereof |
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