JP3119999B2 - Mold powder for continuous casting - Google Patents
Mold powder for continuous castingInfo
- Publication number
- JP3119999B2 JP3119999B2 JP06140858A JP14085894A JP3119999B2 JP 3119999 B2 JP3119999 B2 JP 3119999B2 JP 06140858 A JP06140858 A JP 06140858A JP 14085894 A JP14085894 A JP 14085894A JP 3119999 B2 JP3119999 B2 JP 3119999B2
- Authority
- JP
- Japan
- Prior art keywords
- mold powder
- powder
- present
- range
- raw material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Continuous Casting (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は、鋼の連続鋳造時に、
鋳型内の溶鋼に添加される連続鋳造用モールドパウダー
に関するものであり、特に、連続鋳造操業が安定して行
われ、品質の優れた鋳片を連続鋳造することができる連
続鋳造用モールドパウダーに関するものである。BACKGROUND OF THE INVENTION The present invention relates to a method for continuously casting steel.
The present invention relates to a mold powder for continuous casting added to molten steel in a mold, and more particularly to a mold powder for continuous casting capable of continuously performing a continuous casting operation and continuously casting high-quality slabs. It is.
【０００２】[0002]
【従来の技術】鋼の連続鋳造操業において、鋳型内の溶
鋼に添加されるモールドパウダーは、鋳型内における溶
鋼表面の酸化防止、溶鋼の保温、浮上介在物の吸収等の
ほか、鋳型と鋳片との間に流入するスラグフィルムによ
る潤滑作用および抜熱制御作用を有している。2. Description of the Related Art In a continuous casting operation of steel, mold powder added to molten steel in a mold is used to prevent oxidation of the surface of the molten steel in the mold, heat retention of the molten steel, absorption of floating inclusions, etc. Has a lubricating action and a heat removal controlling action due to the slag film flowing between them.
【０００３】従来のモールドパウダーの化学成分組成
は、化学分析の換算値で例えば下記表１に示す通りであ
る。[0003] The chemical composition of a conventional mold powder is, for example, as shown in Table 1 below in terms of chemical analysis.
【表１】
（wt.%） [Table 1]
(Wt.%)
【０００４】上記のような化学成分組成を有するモール
ドパウダーの原料としては、セメント、ケイ酸カルシウ
ム、珪藻土、物性調整剤としてのアルカリ金属の炭酸塩
およびフッ化物または他の金属酸化物としての合成物等
が使用され、必要に応じ、溶融速度調整剤として２〜10
wt.%の炭素粉末が上記組成物に添加される。The raw materials of the mold powder having the above-mentioned chemical composition include cement, calcium silicate, diatomaceous earth, carbonates of alkali metals as physical property modifiers and compounds as fluorides or other metal oxides. Etc. are used, and if necessary, 2-10
wt.% carbon powder is added to the composition.
【０００５】近年、連続鋳造の高速化に伴って、ブレー
クアウトなどの鋳造事故が生ずることなく、表面性状の
優れた鋳片を安定して鋳造し得る連続鋳造用モールドパ
ウダーの研究開発が進められており、例えば、特公昭64
-6859 号公報には、迅速溶融および高潤滑特性を得るた
めに、CaO −Ba0 −SiO2−F 系組成物からなる基材と、
アルカリ金属・アルカリ土類金属の炭酸塩と、アルカリ
金属・アルカリ土類金属の弗化物とそして炭素とが各々
所定量配合された連続鋳造用モールドパウダー（以下、
先行技術１という）が開示されている。In recent years, with the speeding up of continuous casting, research and development of mold powder for continuous casting which can stably cast slabs having excellent surface properties without causing a casting accident such as breakout has been promoted. For example,
The -6859 discloses, in order to obtain a rapid melting and high lubricating properties, a substrate made of CaO -Ba0 -SiO 2 -F-based composition,
A mold powder for continuous casting in which a predetermined amount of alkali metal / alkaline earth metal carbonate, alkali metal / alkaline earth metal fluoride, and carbon are blended, respectively
Prior art 1) is disclosed.
【０００６】また、日本金属学会会報第２５巻第６号
（1986）には、溶鋼上に添加後、直ちに安定した均一プ
ールが形成され、溶融速度および粘度の適正設計によ
り、メニスカス部より均一フィルムとして鋳型と鋳片と
の間に流入し、鋳片の均一冷却に寄与し、健全な鋳片を
安定して製造し得る、溶融型連続鋳造用パウダー（以
下、先行技術２という）が開示されている。In addition, in the Bulletin of the Japan Institute of Metals, Vol. 25, No. 6, (1986), a stable uniform pool is formed immediately after addition to molten steel, and a uniform film is formed from the meniscus portion by appropriate design of the melting rate and viscosity. A powder for continuous casting of a molten mold (hereinafter referred to as prior art 2) which flows between a mold and a slab, contributes to uniform cooling of the slab, and can stably produce a sound slab. ing.
【０００７】[0007]
【発明が解決しようとする課題】先行技術１のように、
迅速溶融および高潤滑特性を付与するための調整剤とし
て、Na2CO3およびLi2CO3等のような、加熱時に分解反応
を伴う炭酸塩系原料を、モールドパウダー中に多量に含
有させると、モールドパウダー中のイグニッションロス
が増加する。その結果、モールド内でのパウダー溶融時
に多量のガスが発生し、溶融状態が乱れて不均一になる
ため、保温性が低下し、且つ、不均一溶融による溶鋼表
面上のパウダー溶融層の厚さおよび成分の乱れに起因す
る鋳片欠陥が発生する問題がある。SUMMARY OF THE INVENTION As in the prior art 1,
As a modifier for imparting rapid melting and high lubricating properties, a large amount of carbonate-based raw materials, such as Na 2 CO 3 and Li 2 CO 3 , that undergo a decomposition reaction when heated, is contained in the mold powder. As a result, ignition loss in the mold powder increases. As a result, a large amount of gas is generated when the powder is melted in the mold, and the molten state is disturbed and uneven, so that the heat retention is reduced and the thickness of the powder melt layer on the molten steel surface due to the uneven melting. In addition, there is a problem that a slab defect occurs due to disorder of components.
【０００８】また、先行技術２のように、パウダー中に
おける溶融型原料の比率が極端に高いと、高速用パウダ
ーとしての必須要件である保温性と湯面追従性の良い粉
末形態の場合に嵩比重が大になり、拡がり性が悪く、ガ
ス抜けも不良になって、連続鋳造用モールドパウダーと
しての機能が劣化する問題が生ずる。Further, as in the prior art 2, when the ratio of the melt-type raw material in the powder is extremely high, the volume of the powder in the form of a powder having good heat retaining properties and good ability to follow the surface of the molten metal, which are essential requirements for a high-speed powder, is high. The specific gravity becomes large, the spreadability is poor, the outgassing is poor, and the function as a mold powder for continuous casting deteriorates.
【０００９】従って、この発明の目的は、上述した問題
を解決し、溶融過程でのガス発生量が少なく、保温性に
富み、鋳型内における溶鋼の表面上に、安定した溶融モ
ールドパウダー層を形成することができて、連続鋳造操
業が安定化し、品質の優れた鋳片を連続鋳造することが
できる連続鋳造用モールドパウダーを提供することにあ
る。Accordingly, an object of the present invention is to solve the above-mentioned problems, to form a stable molten mold powder layer on the surface of molten steel in a mold, which has a small amount of gas generated during the melting process, has a high heat retention property, and has a high heat retention property. It is an object of the present invention to provide a continuous casting mold powder capable of stabilizing a continuous casting operation and continuously casting a high-quality slab.
【００１０】本発明者等は、上述した問題を解決し、連
続鋳造の操業を安定化し、品質の優れた鋳片を製造する
ことができる、連続鋳造用モールドパウダーを開発すべ
く鋭意研究を重ねた。その結果、次の知見を得た。即
ち、モールドパウダー主原料を、CaO/SiO2が 0.6〜1.8
の範囲内であり、２〜10wt.%のフッ素、および、Al2O3
を含有する珪酸カルシウムの製造時に、アルカリ金属・
アルカリ土類金属の炭酸塩を溶解させることによって調
製する。The present inventors have conducted intensive studies to solve the above-mentioned problems, stabilize the operation of continuous casting, and produce a mold powder for continuous casting capable of producing high quality cast slabs. Was. As a result, the following findings were obtained. That is, the main material of the mold powder, CaO / SiO 2 is 0.6 to 1.8
2 to 10 wt.% Of fluorine and Al 2 O 3
When manufacturing calcium silicate containing
It is prepared by dissolving the alkaline earth metal carbonate.
【００１１】そして、モールドパウダーを、上記により
調製されたモールドパウダー主原料が、70〜95wt.%の割
合で配合され、且つ、溶融調整剤として、0.5 〜５wt.%
の量の炭素分以外の原料例えばフッ化物、金属酸化物、
アルカリ金属炭酸塩、アルカリ土類金属炭酸塩等から混
入する炭酸等のイグニッションロスの量を７wt.%以下に
抑制した構成にすれば、分解ガスによる発泡や、炭酸塩
等の低融点原料および珪酸カルシウムのような高融点原
料の融解反応による溶融の遅れがなく、パウダーの融解
を円滑に行うことができる。Then, the mold powder is mixed with the main raw material of the mold powder prepared as described above at a ratio of 70 to 95 wt.%, And 0.5 to 5 wt.
Raw materials other than the amount of carbon, such as fluorides, metal oxides,
If the ignition loss of carbonic acid and the like mixed from alkali metal carbonates and alkaline earth metal carbonates is suppressed to 7 wt.% Or less, foaming by decomposition gas, low melting point materials such as carbonates and silica There is no delay in melting due to the melting reaction of the high melting point raw material such as calcium, and the powder can be smoothly melted.
【００１２】[0012]
【課題を解決するための手段】この発明は、上記知見に
基づいてなされたものであって、この発明の連続鋳造用
モールドパウダーは、CaO/SiO2が 0.6〜1.8 の範囲内で
あり、２〜10wt.%のフッ素、および、Al2O3 を含有する
珪酸カルシウムの製造用原料と、アルカリ金属・アルカ
リ土類金属の炭酸塩とを、1200〜1700℃の範囲内の温度
で溶融し、炭酸ガスを分解除去した後、急冷し水砕しそ
して粉砕することによって得られたモールドパウダー主
原料が、70〜95wt.%の割合で配合され、そして、炭素分
以外の原料中から混入する炭酸等のイグニッションロス
を７wt.%以下となしたことに特徴を有するものである。DISCLOSURE OF THE INVENTION The present invention has been made on the basis of the above findings, and the mold powder for continuous casting according to the present invention has CaO / SiO 2 within the range of 0.6 to 1.8. 1010 wt.% Fluorine, and a raw material for producing calcium silicate containing Al 2 O 3 and an alkali metal / alkaline earth metal carbonate at a temperature in the range of 1200 to 1700 ° C., After decomposing and removing the carbon dioxide gas, the mold powder main raw material obtained by quenching, granulating and pulverizing is blended at a ratio of 70 to 95 wt.%, And carbonic acid mixed from the raw material other than the carbon content is mixed. It is characterized by having an ignition loss of 7 wt.% Or less.
【００１３】[0013]
【作用】この発明におけるモールドパウダー主原料は、
上述したように、CaO/SiO2が 0.6〜1.8 の範囲内であ
り、２〜10wt.%のフッ素、および、Al2O3 を含有する珪
酸カルシウムの製造用原料と、Na, Li, Ba, Mg, Sr, Ca
等のアルカリ金属・アルカリ土類金属の炭酸塩とを、12
00〜1700℃の範囲内の温度で溶融し、炭酸ガスを分解除
去した後、急冷し水砕しそして粉砕することによって調
製される。The main raw material of the mold powder in the present invention is:
As described above, in the range of CaO / SiO 2 is 0.6 to 1.8, 2 to 10 wt.% Of fluorine, and the raw material for the production of calcium silicate containing Al 2 O 3, Na, Li , Ba, Mg, Sr, Ca
And alkali metal and alkaline earth metal carbonates
It is prepared by melting at a temperature in the range of 00 to 1700 ° C., decomposing and removing carbon dioxide gas, quenching, granulating and crushing.
【００１４】上記珪酸カルシウムの製造用原料として
は、例えば、珪石、石灰、蛍石、ボ−キサイト等が使用
される。このような珪酸カルシウムの塩基度即ちCaO/Si
O2は、0.6〜1.8 の範囲内に限定すべきである。即ち、C
aO/SiO2が 0.6未満では、珪酸カルシウムの粘性が高く
なり、一方、CaO/SiO2が1.8 を超えると、珪酸カルシウ
ムが結晶しやすくなって、何れの場合も、珪酸カルシウ
ムの流動性が悪化する結果、パウダーの製造が困難にな
る。As a raw material for producing the above-mentioned calcium silicate, for example, silica stone, lime, fluorite, bauxite and the like are used. The basicity of such calcium silicate, ie CaO / Si
O 2 should be limited within the range of 0.6-1.8. That is, C
When aO / SiO 2 is less than 0.6, the viscosity of calcium silicate increases, while when CaO / SiO 2 exceeds 1.8, calcium silicate tends to crystallize, and in any case, the fluidity of calcium silicate deteriorates. As a result, powder production becomes difficult.
【００１５】上記珪酸カルシウム中のフッ素含有量は、
２〜10wt.%の範囲内に限定すべきである。フッ素含有量
が２wt.%未満では、モールドパウダーの粘性や融点等の
物性を調整する効果が得られない。一方、フッ素含有量
が10wt.%を超えると、浸漬ノズル等の耐火物の溶損が激
しくなる。The content of fluorine in the calcium silicate is as follows:
It should be limited to the range of 2-10 wt.%. If the fluorine content is less than 2 wt.%, The effect of adjusting physical properties such as viscosity and melting point of the mold powder cannot be obtained. On the other hand, if the fluorine content exceeds 10 wt.%, Erosion of refractories such as immersion nozzles becomes severe.
【００１６】アルカリ金属・アルカリ土類金属の炭酸塩
としては、例えば、炭酸ナトリウム(NaCO3),炭酸リチウ
ム(Li2CO3)等が使用される。このようなアルカリ金属・
アルカリ土類金属の炭酸塩および珪酸カルシウム製造用
原料の、電気炉における溶融温度は、1200〜1700℃の範
囲内に限定すべきである。上記溶融温度が1200℃未満で
は未溶解物が残存し、一方、上記溶融温度が1700℃を超
えると、アルカリ成分の歩留りが低下する。As carbonates of alkali metals and alkaline earth metals, for example, sodium carbonate (NaCO 3 ), lithium carbonate (Li 2 CO 3 ) and the like are used. Such an alkali metal
The melting temperature of the raw materials for the production of alkaline earth metal carbonates and calcium silicate in an electric furnace should be limited to the range of 1200 to 1700 ° C. If the melting temperature is lower than 1200 ° C., undissolved matter remains, while if the melting temperature exceeds 1700 ° C., the yield of alkali components decreases.
【００１７】炭素分以外の原料中から混入する炭酸等の
イグニッションロスの量は７wt.%以下に限定すべきであ
る。イグニッションロスの量が７wt.%を超えると、モー
ルド内における溶融時に多量のガスが発生して溶融状態
が乱れ、不均一になる結果、保温性が低下し、更に、不
均一溶融による溶鋼表面上のパウダー層の厚さおよび成
分の乱れのために、鋳片に欠陥が発生しやすくなる。The amount of ignition loss such as carbonic acid mixed from the raw materials other than the carbon content should be limited to 7 wt.% Or less. If the ignition loss exceeds 7 wt.%, A large amount of gas is generated at the time of melting in the mold and the molten state is disturbed, resulting in non-uniformity. Due to the disorder of the thickness and composition of the powder layer, defects are likely to occur in the cast slab.
【００１８】珪酸カルシウムの製造用原料とアルカリ金
属・アルカリ土類金属の炭酸塩とを溶融することによっ
て調製されたモールドパウダー主原料の、全原料中にお
ける配合割合は、70〜95wt.%の範囲内に限定すべきであ
る。モールドパウダー主原料の配合割合が70wt.%未満で
は、上記イグニッションロス量を７wt.%以下にすること
が困難になり、更に、連続鋳造時における溶融スラグの
成分が不均一になって、鋳片幅方向の粘度および初晶晶
出温度が変動し、均一な潤滑および抜熱作用が発揮され
ない。一方、モールドパウダー主原料の配合割合が95w
t.%を超えると、モールドパウダーの嵩比重が0.95超に
なり、保温性の低下、散布時の拡がり性の低下および溶
鋼中に吹き込まれているアルゴンガスのガス抜け不良等
が発生する。The mixing ratio of the main raw material of the mold powder prepared by melting the raw material for producing calcium silicate and the carbonate of the alkali metal / alkaline earth metal is in the range of 70 to 95 wt.%. Should be limited to If the mixing ratio of the main raw material of the mold powder is less than 70 wt.%, It is difficult to reduce the ignition loss amount to 7 wt.% Or less, and further, the components of the molten slag at the time of continuous casting become non-uniform. The viscosity in the width direction and the primary crystallization temperature fluctuate, and uniform lubrication and heat removal cannot be achieved. On the other hand, the mixing ratio of the main raw material of the mold powder is 95w
When the content exceeds t.%, the bulk specific gravity of the mold powder exceeds 0.95, which causes a decrease in heat retention, a decrease in spreadability during spraying, and a defect in outgassing of argon gas blown into molten steel.
【００１９】粉末状のモールドパウダーの嵩比重は、0.
60〜0.95の範囲内であることが好ましい。上記嵩比重が
0.60未満では溶融速度が遅くなり、一方、上記嵩比重が
0.95を超えると、保温性の低下、散布時の拡がり性の低
下および溶鋼中に吹き込まれるアルゴンガスのガス抜け
不良等が発生する。従って、モールドパウダーの嵩比重
を上記範囲内に調整するために、比重の低い珪藻土、金
属酸化物、および、アルカリ金属・アルカリ土類金属の
炭酸塩の添加が必要になる。よって、この観点からも、
モールドパウダー主原料の配合割合は、95wt.%以下にす
べきである。The bulk specific gravity of the powdery mold powder is 0.
Preferably it is in the range of 60 to 0.95. The bulk specific gravity is
If it is less than 0.60, the melting rate becomes slow, while the bulk specific gravity is
If it exceeds 0.95, a decrease in heat retention, a decrease in spreadability at the time of spraying, and a defect in outgassing of argon gas blown into molten steel may occur. Therefore, in order to adjust the bulk specific gravity of the mold powder within the above range, it is necessary to add diatomaceous earth, metal oxides and alkali metal / alkaline earth metal carbonates having low specific gravities. So from this point of view,
The mixing ratio of the mold powder main raw material should be 95 wt.% Or less.
【００２０】[0020]
【実施例】次に、この発明を実施例により、比較例と対
比しながら説明する。珪石、石灰、蛍石およびボ−キサ
イト等のフッ素を含有する珪酸カルシウムの製造用原料
と、アルカリ金属・アルカリ土類金属の炭酸塩としての
炭酸ナトリウム(NaCO3) および炭酸リチウム(Li2CO3)と
を、電気炉において、1400〜1500℃の温度で溶融し、炭
酸ガスを分解除去した後、急冷し水砕しそして粉砕する
ことによって、表２に示す成分組成のモールドパウダー
主原料を調製した。EXAMPLES Next, the present invention will be described with reference to examples and comparative examples. Raw materials for the production of fluorine-containing calcium silicates such as silica stone, lime, fluorite and bauxite, and sodium carbonate (NaCO 3 ) and lithium carbonate (Li 2 CO 3 ) as carbonates of alkali metals and alkaline earth metals Is melted at a temperature of 1400 to 1500 ° C. in an electric furnace, carbon dioxide gas is decomposed and removed, quenched, water-granulated, and pulverized to prepare a mold powder main raw material having a component composition shown in Table 2. did.
【００２１】[0021]
【表２】 [Table 2]
【００２２】上記によって得られたモールドパウダー主
原料と、表３に示す種類および品位の副原料とを、本発
明範囲内の割合で配合し、そして、イグニッションロス
が本発明の範囲内に抑制されたモールドパウダーの供試
体（以下、本発明供試体という）No. １および２を調製
した。比較のために、イグニッションロスまたはイグニ
ッションロスおよびモールドパウダー主原料の配合割合
が本発明の範囲外であるモールドパウダーの供試体（以
下、比較用供試体という）No. １〜３を調製した。The main raw material of the mold powder obtained above and the auxiliary raw materials of the kind and grade shown in Table 3 are blended at a ratio within the range of the present invention, and ignition loss is suppressed within the range of the present invention. Specimens (hereinafter, referred to as specimens of the present invention) No. 1 and 2 of the prepared mold powder were prepared. For comparison, ignition loss or mold powder specimens (hereinafter referred to as comparative specimens) Nos. 1 to 3 in which the mixing ratio of the ignition loss and the main ingredient of the mold powder were out of the range of the present invention were prepared.
【００２３】[0023]
【表３】 [Table 3]
【００２４】表４に、本発明供試体No. １、２および比
較用供試体No. １〜３の化学成分組成、イグニッション
ロス、融点、粘性、結晶化温度等を示す。表４におい
て、本発明供試体No. １は、モールドパウダー主原料が
75wt.%配合され且つイグニッションロスが3.5wt.% に抑
制され、フッ化物および珪藻土で成分の微調整と粉体の
物性調整が行われた中炭素鋼用のモールドパウダーであ
る。本発明供試体No. ２は本発明供試体No. １とほぼ同
じ主原料が配合され、化学成分組成および物性において
若干炭酸塩の配合が多く、イグニッションロスが6.2wt.
% に抑制されたモールドパウダーである。Table 4 shows the chemical composition, ignition loss, melting point, viscosity, crystallization temperature, etc. of the test samples Nos. 1 and 2 of the present invention and the test samples Nos. 1 to 3 for comparison. In Table 4, the test sample No. 1 of the present invention has a main mold powder material.
This is a mold powder for medium carbon steel in which 75 wt.% Is blended, ignition loss is suppressed to 3.5 wt.%, And fine adjustment of components and physical properties of powder are performed with fluoride and diatomaceous earth. Specimen No. 2 of the present invention contains substantially the same main raw materials as Specimen No. 1 of the present invention, and has a slightly higher content of carbonate in chemical composition and physical properties, and an ignition loss of 6.2 wt.
% Of the mold powder.
【００２５】[0025]
【表４】 [Table 4]
【００２６】比較用供試体No. １は、本発明供試体No.
１とほぼ同じ割合で主原料が配合されているが、化学成
分組成および物性において本発明供試体No. ２よりも炭
酸塩の配合量が多く、イグニッションロスが8.1wt.% で
あって本発明の範囲を超えて多い。比較用供試体No. ２
は、主原料の配合割合が57wt.%であって本発明の範囲を
外れて少なく、そして、イグニッションロスが11.0wt.%
であって本発明の範囲を超えて多い中炭素鋼用のモール
ドパウダーである。そして、比較用供試体No.３は、比
較用供試体No. ２と同様に、主原料の配合割合が50wt.%
であって本発明の範囲を外れて少なく、そして、イグニ
ッションロスが12.0wt.%であって本発明の範囲を超えて
多い低炭素鋼用のモールドパウダーである。The specimen No. 1 for comparison was the specimen No. 1 of the present invention.
Although the main raw material is blended in almost the same ratio as that of No. 1, the amount of carbonate is larger than that of the test sample No. 2 of the present invention and the ignition loss is 8.1 wt. Many beyond the range. Specimen No. 2 for comparison
Is less than the range of the present invention is a compounding ratio of the main raw material is 57 wt.%, And the ignition loss is 11.0 wt.%
This is a mold powder for medium carbon steel which is more than the scope of the present invention. In addition, the comparative sample No. 3 has the same mixing ratio of the main raw material as 50 wt.% Like the comparative sample No. 2.
Therefore, the present invention is a low-carbon steel mold powder having a small amount outside the range of the present invention and having an ignition loss of 12.0 wt.% And exceeding the range of the present invention.
【００２７】上述した本発明供試体No. １および２並び
に比較用供試体No. １〜３の各々を使用し、鋳造速度を
1.6m/minまたは1.8m/minとして、割れ感受性の大きい中
炭素鋼を連続鋳造したときの、鋼中炭素濃度、モールド
パウダー消費量、鋳片の縦割れ発生指数および作業性を
調べ、その結果を表５に示した。Using each of the above-described specimens Nos. 1 and 2 of the present invention and comparative specimens Nos. 1-3, the casting speed was reduced.
At 1.6m / min or 1.8m / min, when continuously casting medium carbon steel with high crack sensitivity, the carbon concentration in the steel, mold powder consumption, vertical cracking index of slab and workability were investigated. Are shown in Table 5.
【００２８】[0028]
【表５】 [Table 5]
【００２９】表４および表５から明らかなように、主原
料の配合割合は本発明の範囲内であるが、イグニッショ
ンロスが本発明の範囲を超えて多い比較用供試体No. １
は、鋳片の縦割れ指数および作業性が悪かった。主原料
の配合割合が本発明の範囲を外れて少なく、且つ、イグ
ニッションロスが本発明の範囲を超えて多い比較用供試
体No. ２は、粉末層全体が赤熱し、鋳造状況の確認が困
難であって、断熱性も悪く、鋳造操業を継続して行うこ
とが困難であった。そして、主原料の配合割合が本発明
の範囲を外れて少なくそしてイグニッションロスが本発
明の範囲を超えて多い比較用供試体No. ３は、縦割れ指
数が著しく悪かった。As is clear from Tables 4 and 5, the mixing ratio of the main raw materials is within the range of the present invention, but the ignition loss is larger than the range of the present invention.
Was poor in the vertical crack index and workability of the slab. In Comparative Sample No. 2 in which the mixing ratio of the main raw material is small outside the range of the present invention and ignition loss is large beyond the range of the present invention, the entire powder layer glows red, making it difficult to confirm the casting status. However, the heat insulation was poor, and it was difficult to continue the casting operation. Comparative Sample No. 3 in which the mixing ratio of the main raw materials was small outside the range of the present invention and the ignition loss was large beyond the range of the present invention, had a significantly poor longitudinal crack index.
【００３０】これに対して、本発明供試体No. １および
２は、縦割れ発生指数が非常に低く、作業性が良好であ
り、従来困難であった中炭素鋼の高速鋳造を容易に行う
ことができた。On the other hand, the specimens Nos. 1 and 2 of the present invention have a very low index of occurrence of longitudinal cracks, have good workability, and easily perform high-speed casting of medium carbon steel, which has been difficult in the past. I was able to.
【００３１】次に、モールドパウダーの溶融性を評価す
るために、本発明供試体No. １および比較用供試体No.
２および３について、そのパウダー成形体の加熱温度に
対する高さの変化を測定した。図２は、上記測定のため
のパウダー均一溶融性の評価概念図である。図２の(a)
に示すように、断面長方形で高さＨのパウダー圧縮成形
体１を調製し、電気炉内において、５℃／分の炉温上昇
速度でこれを加熱し、温度に対する成形体１の高さ変化
を、同図(b) のＨ1 、同図(c) のＨ2 、同図(d) のＨ3
のように連続的に測定し、その測定結果をグラフ化して
図１に示した。Next, in order to evaluate the melting property of the mold powder, the specimen No. 1 of the present invention and the specimen No. 1 for comparison were evaluated.
With respect to 2 and 3, the change in height with respect to the heating temperature of the powder compact was measured. FIG. 2 is a conceptual diagram of the evaluation of powder uniform melting property for the above measurement. FIG. 2 (a)
As shown in Fig. 5, a powder compression-molded body 1 having a rectangular cross section and a height H is prepared and heated in an electric furnace at a furnace temperature rising rate of 5 ° C / min. Is H 1 in FIG. 3B, H 2 in FIG. 3C, and H 3 in FIG.
As shown in FIG. 1, the measurement results were continuously graphed.
【００３２】図１はモールドパウダーの溶融性を評価す
るグラフであって、縦軸はパウダー成形体の高さ変化
(%) であり、横軸は温度である。図１から明らかなよう
に、主原料の配合割合が本発明の範囲を外れて少なく、
且つ、イグニッションロスが本発明の範囲を超えて多い
比較用供試体No. ２および３は、加熱の途中において溶
融遅滞部や発泡部が発生した。これに対し、本発明供試
体No. １は、極めて円滑な溶融状態を示した。FIG. 1 is a graph for evaluating the meltability of a mold powder, and the vertical axis indicates a change in height of a powder molded body.
(%), And the horizontal axis is temperature. As is clear from FIG. 1, the blending ratio of the main raw material is small outside the range of the present invention,
In addition, in Comparative Sample Nos. 2 and 3 in which the ignition loss exceeded the range of the present invention, a melt-delayed portion and a foamed portion occurred during heating. On the other hand, Sample No. 1 of the present invention showed a very smooth molten state.
【００３３】[0033]
【発明の効果】以上述べたように、この発明によれば、
溶融過程でのガス発生量が少なく、保温性に富み、鋳型
内における溶鋼の表面上に、安定した溶融モールドパウ
ダー層を形成することができて、連続鋳造操業が安定化
し、品質の優れた鋳片を連続鋳造することができる、工
業上有用な効果がもたらされる。As described above, according to the present invention,
The amount of gas generated during the melting process is small, the heat retention is high, and a stable molten mold powder layer can be formed on the surface of the molten steel in the mold, the continuous casting operation is stabilized, and excellent quality casting is achieved. An industrially useful effect that the pieces can be continuously cast is provided.
【図面の簡単な説明】[Brief description of the drawings]
【図１】モールドパウダーの溶融性を評価するグラフで
ある。FIG. 1 is a graph for evaluating the meltability of a mold powder.
【図２】パウダー均一溶融性の評価概念図である。FIG. 2 is a conceptual diagram of evaluation of powder uniform melting property.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 豊田 剛治 東京都千代田区丸の内一丁目１番２号 日本鋼管株式会社内 (72)発明者 内野 薫 東京都千代田区丸の内一丁目１番２号 日本鋼管株式会社内 (72)発明者 酒井 英典 東京都千代田区丸の内二丁目３番２号 鋼管鉱業株式会社内 (72)発明者 清水 正明 東京都千代田区丸の内二丁目３番２号 鋼管鉱業株式会社内 (72)発明者 和泉 洋 東京都千代田区丸の内二丁目３番２号 鋼管鉱業株式会社内 (56)参考文献 特開 平１−212714（ＪＰ，Ａ) 特開 平１−104452（ＪＰ，Ａ) 特開 昭59−27753（ＪＰ，Ａ) 特開 昭56−109148（ＪＰ，Ａ) 特開 昭60−72653（ＪＰ，Ａ) 特開 昭60−234752（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B22D 11/108 C21C 7/076 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Goji Toyoda 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Kaoru Uchino 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan (72) Inventor Hidenori Sakai 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Steel Pipe Mining Co., Ltd. (72) Inventor Masaaki Shimizu 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Steel Pipe Mining Co., Ltd. 72) Inventor Hiroshi Izumi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Kokan Mining Co., Ltd. (56) References JP-A-1-212714 (JP, A) JP-A-1-104452 (JP, A) JP-A-59-27753 (JP, A) JP-A-56-109148 (JP, A) JP-A-60-72653 (JP, A) JP-A-60-2344752 (JP, A) (58) Int.Cl. 7 , DB name) B22D 11/108 C21C 7/076
Claims (1)
２〜10wt.%のフッ素、および、Al2O3 を含有する珪酸カ
ルシウムの製造用原料と、アルカリ金属・アルカリ土類
金属の炭酸塩とを、1200〜1700℃の範囲内の温度で溶融
し、炭酸ガスを分解除去した後、急冷し水砕しそして粉
砕することによって調製されたモールドパウダー主原料
が、70〜95wt.%の割合で配合され、そして、炭素分以外
の原料中から混入する炭酸等のイグニッションロスの量
が７wt.%以下に限定されていることを特徴とする連続鋳
造用モールドパウダー。(1) CaO / SiO 2 is in the range of 0.6 to 1.8,
2 to 10 wt.% Of fluorine, and a raw material for producing calcium silicate containing Al 2 O 3 and an alkali metal / alkaline earth metal carbonate are melted at a temperature in the range of 1200 to 1700 ° C. After decomposing and removing carbon dioxide, the mold powder main raw material prepared by quenching, granulating and pulverizing is blended in a ratio of 70 to 95 wt.%, And mixed from raw materials other than carbon content. A mold powder for continuous casting, wherein the amount of ignition loss such as carbonic acid is limited to 7 wt.% Or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06140858A JP3119999B2 (en) | 1994-05-31 | 1994-05-31 | Mold powder for continuous casting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06140858A JP3119999B2 (en) | 1994-05-31 | 1994-05-31 | Mold powder for continuous casting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07323354A JPH07323354A (en) | 1995-12-12 |
| JP3119999B2 true JP3119999B2 (en) | 2000-12-25 |
Family
ID=15278384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06140858A Expired - Fee Related JP3119999B2 (en) | 1994-05-31 | 1994-05-31 | Mold powder for continuous casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3119999B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4751283B2 (en) * | 2006-02-01 | 2011-08-17 | 新日本製鐵株式会社 | Continuous casting powder and steel continuous casting method |
| JP5226423B2 (en) * | 2008-08-12 | 2013-07-03 | 日鐵住金建材株式会社 | Powder for continuous casting of steel |
| JP5342296B2 (en) * | 2009-03-27 | 2013-11-13 | 品川リフラクトリーズ株式会社 | Mold powder for continuous casting of steel |
| CN106493321A (en) * | 2016-11-08 | 2017-03-15 | 凯诺斯(中国)铝酸盐技术有限公司 | Steel-making tundish covering flux and preparation method thereof |
-
1994
- 1994-05-31 JP JP06140858A patent/JP3119999B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07323354A (en) | 1995-12-12 |
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