JPH09164460A - Powdery pre-melt flux for continuous casting of steel - Google Patents
Powdery pre-melt flux for continuous casting of steelInfo
- Publication number
- JPH09164460A JPH09164460A JP34705595A JP34705595A JPH09164460A JP H09164460 A JPH09164460 A JP H09164460A JP 34705595 A JP34705595 A JP 34705595A JP 34705595 A JP34705595 A JP 34705595A JP H09164460 A JPH09164460 A JP H09164460A
- Authority
- JP
- Japan
- Prior art keywords
- flux
- sio
- amorphous
- powder
- continuous casting
- 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.)
- Granted
Links
- 230000004907 flux Effects 0.000 title claims abstract description 43
- 238000009749 continuous casting Methods 0.000 title claims abstract description 16
- 229910000831 Steel Inorganic materials 0.000 title abstract description 15
- 239000010959 steel Substances 0.000 title abstract description 15
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 5
- 239000000843 powder Substances 0.000 claims description 34
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 29
- 229910018068 Li 2 O Inorganic materials 0.000 claims description 9
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 5
- 125000001475 halogen functional group Chemical group 0.000 claims description 4
- 229910052708 sodium Inorganic materials 0.000 claims description 4
- 150000002642 lithium compounds Chemical class 0.000 claims description 2
- 239000000203 mixture Substances 0.000 abstract description 13
- 229910000954 Medium-carbon steel Inorganic materials 0.000 abstract description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 8
- 238000001816 cooling Methods 0.000 abstract description 8
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- JHLNERQLKQQLRZ-UHFFFAOYSA-N calcium silicate Chemical compound [Ca+2].[Ca+2].[O-][Si]([O-])([O-])[O-] JHLNERQLKQQLRZ-UHFFFAOYSA-N 0.000 abstract description 7
- 239000000377 silicon dioxide Substances 0.000 abstract description 4
- 230000007547 defect Effects 0.000 abstract description 3
- 229910052681 coesite Inorganic materials 0.000 abstract 2
- 229910052906 cristobalite Inorganic materials 0.000 abstract 2
- 235000012239 silicon dioxide Nutrition 0.000 abstract 2
- 229910052682 stishovite Inorganic materials 0.000 abstract 2
- 229910052905 tridymite Inorganic materials 0.000 abstract 2
- 229910018404 Al2 O3 Inorganic materials 0.000 abstract 1
- 229910011763 Li2 O Inorganic materials 0.000 abstract 1
- 229910004742 Na2 O Inorganic materials 0.000 abstract 1
- 230000035945 sensitivity Effects 0.000 abstract 1
- 239000002994 raw material Substances 0.000 description 16
- 239000000378 calcium silicate Substances 0.000 description 9
- 229910052918 calcium silicate Inorganic materials 0.000 description 9
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 9
- 238000005266 casting Methods 0.000 description 9
- 238000002441 X-ray diffraction Methods 0.000 description 7
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 238000002425 crystallisation Methods 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000002585 base Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 238000005336 cracking Methods 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 239000011575 calcium Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000004575 stone Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 229910000288 alkali metal carbonate Inorganic materials 0.000 description 2
- 150000008041 alkali metal carbonates Chemical class 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 238000005280 amorphization Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 239000010436 fluorite Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、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
（以下単にモールドパウダー又はパウダーという）の主
原料として用いられるプリメルトフラックスに関するも
のである。TECHNICAL FIELD The present invention relates to a premelt flux used as a main raw material of a mold powder for continuous casting (hereinafter simply referred to as mold powder or powder) added to molten steel in a mold during continuous casting of steel. is there.
【０００２】[0002]
【従来の技術】鋼の連続鋳造においてモールドパウダー
は溶鋼上面において溶鋼の酸化を防止し、溶鋼面の保温
及び湯面に浮上してきた介在物を吸収する作用がある。
また、溶鋼面で溶融したパウダーは鋳型と鋳片間に流入
してスラグフィルム層を形成し、鋳型と鋳片間の潤滑剤
として作用し、更に、鋳型と鋳片間の抜熱を制御してい
る。2. Description of the Related Art In continuous casting of steel, mold powder has an effect of preventing oxidation of molten steel on the upper surface of molten steel, keeping the temperature of the molten steel surface and absorbing inclusions floating on the molten metal surface.
Further, the powder melted on the molten steel surface flows between the mold and the slab to form a slag film layer, acts as a lubricant between the mold and the slab, and further controls heat removal between the mold and the slab. ing.
【０００３】従来のモールドパウダーを化学分析すると
以下の様な成分組成になっている。ＳｉＯ2 ：２０〜４
０ｗｔ％、 ＣａＯ：２０〜４０ｗｔ％、Ａｌ
2 Ｏ3 ：１〜１０ｗｔ％、 Ｎａ：１〜３０ｗｔ％、
Ｆ：１〜２０ｗｔ％、 Ｌｉ：０〜２０ｗｔ
％、ＭｇＯ：１〜１０ｗｔ％、 ＺｒＯ2 ：０〜
２０ｗｔ％、Ｂ：０〜１０ｗｔ％[0003] Chemical analysis of a conventional mold powder has the following composition. SiO 2 : 20-4
0 wt%, CaO: 20-40 wt%, Al
2 O 3 : 1 to 10 wt%, Na: 1 to 30 wt%,
F: 1 to 20 wt%, Li: 0 to 20 wt
%, MgO: 1-10 wt%, ZrO 2 : 0
20 wt%, B: 0-10 wt%
【０００４】上記モールドパウダーを製造する場合に
は、基材としてセメント、珪酸カルシウムの他、焼石
灰、珪石等の原料を電気炉で溶融し、水滓化して得られ
る所謂プリメルトされた珪酸カルシウムが使われてお
り、物性調整剤としてアルカリ金属の炭酸塩やフッ素化
合物等の低融点化合物が配合され、更に、溶融速度調整
剤として炭素粉末が配合されている。In the case of producing the above-mentioned mold powder, so-called pre-melted calcium silicate obtained by melting raw materials such as cement, calcium silicate, calcined lime and silica stone in an electric furnace as a base material and water-casting It is used, and a low melting point compound such as an alkali metal carbonate or a fluorine compound is blended as a physical property adjusting agent, and carbon powder is further blended as a melting rate adjusting agent.
【０００５】ところで、鋼の炭素濃度が０．０８〜０．
１６ｗｔ％の中炭素鋼（以下、中炭素鋼という）の連続
鋳造においては、鋼が液相から固相に変化する際の凝固
収縮率が大きく、鋳片表面に割れ欠陥が発生し易く、高
速鋳造が困難とされてきた。[0005] By the way, when the carbon concentration of steel is 0.08-0.
In continuous casting of 16 wt% medium carbon steel (hereinafter referred to as medium carbon steel), the solidification shrinkage when the steel changes from a liquid phase to a solid phase is large, cracks are easily generated on the slab surface, and high speed Casting has been difficult.
【０００６】そこで、材料とプロセス、第４巻、第４号
（１９９１年、１２４７頁）には、前記中炭素鋼の割れ
欠陥対策として鋳型と鋳片表面間の熱流束を低下させる
ため、塩基度（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ％）を１．
３以上とし、冷却時における結晶による体積収縮により
接触熱抵抗の増大を図り、更にＺｒＯ2 を３．０ｗｔ％
以上添加することでパウダーフィルムを不透明化し、輻
射伝熱の低減を行い、良好な鋳片の製造が可能であるこ
とを開示している（従来技術１）。[0006] Therefore, in Materials and Processes, Vol. 4, No. 4 (1991, p. 1247), in order to reduce the cracking defect of the medium carbon steel, the heat flux between the mold and the surface of the slab is lowered, so that the base The degree (CaO wt% / SiO 2 wt%) is 1.
3 or more to increase the contact thermal resistance due to the volume shrinkage of the crystal during cooling, and further ZrO 2 3.0 wt%
It is disclosed that the addition of the above makes the powder film opaque, reduces radiant heat transfer, and enables good production of cast pieces (prior art 1).
【０００７】また、品川技報第３２号（１９８９年、１
４７頁）には前記中炭素鋼を鋳造する際、問題となる鋳
片の縦割れを防止するため、鋳型内の抜熱速度とパウダ
ーの特性を調査し、溶融したパウダーの凝固過程におけ
る結晶化温度を高めることにより、モールド内抜熱を緩
和し、縦割れ発生を減少させ得ることを見いだしたこと
を報告している。さらに、高塩基度パウダーほど結晶化
温度が高くなる傾向があると記載されている（従来技術
２）。Further, Shinagawa Technical Report No. 32 (1989, 1
On page 47), in order to prevent vertical cracking of the slab, which is a problem when casting the medium carbon steel, the heat removal rate in the mold and the characteristics of the powder were investigated, and crystallization of the molten powder during the solidification process was conducted. It is reported that the heat removal in the mold can be relaxed and the occurrence of vertical cracks can be reduced by raising the temperature. Furthermore, it is described that the higher the basicity powder, the higher the crystallization temperature tends to be (prior art 2).
【０００８】上記において結晶化とは、溶融したパウダ
ーが鋳型と鋳片表面の間に流入し、凝固する際に溶融体
の一部が結晶体として析出する現象である。また、鋳造
パウダーの基材であるプリメルトフラックスが凝固する
際にも生ずる。[0008] In the above, crystallization is a phenomenon in which a molten powder flows between a mold and a slab surface, and a part of a molten material precipitates as crystals when solidifying. It also occurs when the premelt flux, which is the base material of the casting powder, solidifies.
【０００９】近年、連続鋳造の高速化に伴い、パウダー
の迅速かつ均一溶融を図るために、モールドパウダーの
基材としては前述のプリメルトタイプの珪酸カルシウム
フラックスが主流となっている。プリメルトタイプの珪
酸カルシウムフラックスは従来、以下の組成となってい
る。In recent years, with the speeding up of continuous casting, the above-mentioned premelting type calcium silicate flux has become the mainstream as a base material for mold powder in order to achieve rapid and uniform melting of powder. The pre-melt type calcium silicate flux conventionally has the following composition.
【００１０】ＳｉＯ2 ：３０〜５０ｗｔ％、 Ｃａ
Ｏ：４０〜５５ｗｔ％、Ａｌ2 Ｏ3 ：１〜１０ｗｔ％、
Ｎａ：１〜２０ｗｔ％、Ｆ：１〜４ｗｔ％、
Ｌｉ：０〜５ｗｔ％、ＭｇＯ：０〜３ｗｔ％SiO 2 : 30 to 50 wt%, Ca
O: 40~55wt%, Al 2 O 3: 1~10wt%,
Na: 1 to 20 wt%, F: 1 to 4 wt%,
Li: 0-5 wt%, MgO: 0-3 wt%
【００１１】プリメルト珪酸カルシウムフラックスは、
通常、パウダーに５０％以上配合されており、モールド
パウダー自体の塩基度（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ
％）と同程度の塩基度を有するプリメルト珪酸カルシウ
ムを用いることが一般的である。例えば、中炭素鋼用の
パウダー原料として、塩基度１．３以上の高塩基度プリ
メルトフラックスを用いる。The premelted calcium silicate flux is
Usually, 50% or more of powder is mixed, and the basicity of the mold powder itself (CaOwt% / SiO 2 wt)
%), It is common to use premelted calcium silicate having the same basicity as the (%). For example, as a powder raw material for medium carbon steel, a high basicity premelt flux having a basicity of 1.3 or more is used.
【００１２】[0012]
【発明が解決しようとする課題】前記従来技術が結晶化
した珪酸カルシウムをフラックスが望ましいと考えてい
るが、しかし、本発明においては、この珪酸カルシウム
は、本来、非晶質であることが望ましいと考える。The above-mentioned prior art considers that a flux of crystallized calcium silicate is desirable, but in the present invention, it is desirable that this calcium silicate is originally amorphous. I think.
【００１３】この理由は、珪酸カルシウムが結晶質であ
ると、ミクロ的には組成の不均一な変化が生じ、また製
造時において原料の飛散等があって目標とする成分組成
を有する均質な組成状態が得難いからである。従って、
このような結晶化したフラックスを多量に配合したモー
ルドパウダーは、溶融する際に、成分組成が不均一なた
め溶融特性の著しい不均一性を生じるからである。The reason for this is that if the calcium silicate is crystalline, the composition changes microscopically in a non-uniform manner, and the raw materials are scattered during the production, so that a homogeneous composition having a target composition is obtained. This is because it is difficult to obtain the condition. Therefore,
This is because such a mold powder containing a large amount of crystallized flux has an inhomogeneous melting property when it is melted due to an inhomogeneous component composition.
【００１４】更に、前記従来技術においては、モールド
パウダーが鋳片と鋳型間において結晶化すると鋳片の割
れを防止して良好な鋳片が得られるとしている。しか
し、この結晶化が部分的に発生するとかえって不均一な
冷却が生じ、鋳片の表面性状が悪くなる。Further, in the above-mentioned prior art, when the mold powder is crystallized between the slab and the mold, cracking of the slab is prevented and a good slab is obtained. However, if this crystallization partially occurs, uneven cooling occurs, and the surface quality of the cast piece deteriorates.
【００１５】前述の通り、中炭素鋼用モールドパウダー
の主原料となるプリメルトフラックスは通常、塩基度
１．３以上のものが使われる。さらに連続鋳造の高速化
に伴い、迅速溶融、高潤滑特性を得るためにＬｉ2 ＣＯ
3 に代表されるアルカリ炭酸塩原料がフラックス原料と
して多用されている。As described above, the premelt flux, which is the main raw material of the mold powder for medium carbon steel, usually has a basicity of 1.3 or more. Furthermore, with the speeding up of continuous casting, Li 2 CO
Alkali carbonate raw materials represented by 3 are often used as flux raw materials.
【００１６】しかし、上記のように、上記リチウムの原
料をＬｉ2 Ｏとして１％以上含み、Ｃａのｗｔ％から換
算したＣａＯのｗｔ％とＳｉのｗｔ％から換算したＳｉ
Ｏ2のｗｔ％との比である塩基度が１．４以上になる
と、水滓条件を強冷却化しても、冷却過程で結晶が生成
しやすくなり、結晶相としてβ−２ＣａＯ・ＳｉＯ
2 （Ｌａｒｎｉｔｅ）が生成する。However, as described above, the lithium raw material contains 1% or more as Li 2 O, and wt% of CaO converted from wt% of Ca and Si converted from wt% of Si.
If the basicity, which is the ratio with respect to the wt% of O 2 , is 1.4 or more, crystals are likely to be generated in the cooling process even if the water slag condition is strongly cooled, and β-2CaO · SiO as a crystal phase.
2 (Larnite).
【００１７】プリメルトフラックス中にβ−２ＣａＯ・
ＳｉＯ2 が生成するとβ−２ＣａＯ・ＳｉＯ2 自体が経
時変化（風化）していくためにフラックスの粉体特性が
経時的に変質し、パウダー基材としては不適である。さ
らに電気炉から排出する際に、結晶化するため、湯流れ
が悪くなる等の操業上の問題が発生する。Β-2CaO
When SiO 2 is produced, β-2CaO · SiO 2 itself changes with time (weathering), and the powder characteristics of the flux change over time, which is unsuitable as a powder base material. Furthermore, when discharged from the electric furnace, crystallization occurs, which causes operational problems such as poor flow of molten metal.
【００１８】[0018]
【課題を解決するための手段】本発明者らは、上記問題
について種々検討を重ねた結果、従来のプリメルトフラ
ックスの基本成分において、プリメルトフラックス原料
中にリチウム原料をＬｉ2 Ｏとして１％以上配合し、更
に全Ｃａｗｔ％から換算したＣａＯと全Ｓｉｗｔ％から
換算したＳｉＯ2 とのｗｔ％比である塩基度（ＣａＯｗ
ｔ％／ＳｉＯ2ｗｔ％）が１．４以上の時、Ｆｗｔ％≧
２４×塩基度−３１となるようにＣａＦ2 を添加するこ
とによって、プリメルトフラックスに要求される成分組
成範囲内において、β−２ＣａＯ・ＳｉＯ2 の生成を抑
え、非晶質化を達成し、さらに安定した操業を行えると
の知見を得て、下記の発明をするに至った。Means for Solving the Problems As a result of various studies on the above problems, the present inventors have found that, in the basic component of the conventional premelt flux, the lithium raw material is 1% as Li 2 O in the premelt flux raw material. The basicity (CaOw) which is the wt% ratio of CaO converted from the total Cawt% and converted to SiO 2 converted from the total Siwt% is added.
t% / SiO 2 wt%) is 1.4 or more, Fwt% ≧
By adding CaF 2 so as to be 24 × basicity −31, in the component composition range required for the premelt flux, the production of β-2CaO · SiO 2 is suppressed, and amorphization is achieved, With the knowledge that stable operation can be performed, the inventors have made the following inventions.
【００１９】第１の発明は、ＣａＯ：４０〜６０ｗｔ
％、ＳｉＯ2 ：３０〜４０ｗｔ％、Ａｌ2 Ｏ3 ：１〜７
ｗｔ％、ＭｇＯ＜１．５ｗｔ％、Ｎａ2 Ｏ：１〜４ｗｔ
％、Ｌｉ2 Ｏ：１〜５ｗｔ％、Ｆ：２〜８ｗｔ％を含有
し，かつ、非晶質であることを特徴とする連続鋳造用モ
ールドパウダーのプリメルトフラックスを提供する。良
好な鋳片表面を得る為には、高速鋳造用のモールドパウ
ダーのプリメルトフラックスは少なくとも上記の様な成
分組成を有し、且つ非晶質であることが必要だからであ
る。The first invention is CaO: 40-60 wt.
%, SiO 2: 30~40wt%, Al 2 O 3: 1~7
wt%, MgO <1.5 wt%, Na 2 O: 1 to 4 wt
%, Li 2 O: 1 to 5 wt%, F: 2 to 8 wt%, and a pre-melt flux of a mold powder for continuous casting, which is amorphous. This is because the premelt flux of the mold powder for high-speed casting must have at least the above-described component composition and be amorphous in order to obtain a good slab surface.
【００２０】第２の発明は、第１の発明において、
（ａ）リチウム化合物をＬｉ2 Ｏとして１％以上含み、
（ｂ）Ｃａのｗｔ％から計算したＣａＯのｗｔ％とＳｉ
のｗｔ％から計算したＳｉＯ2 のｗｔ％との比である塩
基度（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ％）が１．４以上
で、（ｃ）ＣａＦ2 を、Ｆｗｔ％≧２４×（塩基度）−
３１となるように含有している連続鋳造用パウダーのプ
リメルトフラックスを提供する。上記の条件を備えたプ
リメルトフラックスは、製造後使用するまでの間に風化
するβ−２ＣａＯ・ＳｉＯ2 （Ｌａｒｎｉｔｅ）の生成
を抑え、冷却時において非晶質となり、鋳型と鋳片間の
冷却を抑制することができるためである。The second invention is the same as the first invention,
(A) contains 1% or more of a lithium compound as Li 2 O,
(B) wt% of CaO calculated from wt% of Ca and Si
The basicity (CaOwt% / SiO 2 wt%), which is the ratio with the SiO 2 wt% calculated from the wt% of 1.4, is 1.4 or more, and (c) CaF 2 is Fwt% ≧ 24 × (basicity) −
A premelt flux of powder for continuous casting, which is contained so as to be 31, is provided. The pre-melt flux with the above conditions suppresses the formation of β-2CaO · SiO 2 (Larnite) that is weathered after manufacturing and becomes amorphous during cooling, and cools between the mold and the slab. This is because it is possible to suppress
【００２１】第３の発明は、第１及び第２の発明におい
て、前記プリメルトフラックスが、Ｃｕターゲット、管
電圧４０ＫＶ、管電流３０ｍＡの条件でＸ線回折を行な
ったとき、無定形ハローパターンが検出され、最強度ピ
ークが５００カウント／秒以下であることを特徴とする
連続鋳造用プリメルトフラックスを提供する。この様な
プリメルトフラックスは冷却時において確実に非晶質と
なっており、鋳型と鋳片間の均一な冷却を実現させるこ
とができるためである。In a third aspect based on the first and second aspects, when the premelt flux is subjected to X-ray diffraction under the conditions of a Cu target, a tube voltage of 40 KV and a tube current of 30 mA, an amorphous halo pattern is obtained. Provided is a pre-melting flux for continuous casting, which is detected and has a maximum intensity peak of 500 counts / second or less. This is because such a pre-melt flux is definitely amorphous during cooling and can realize uniform cooling between the mold and the slab.
【００２２】[0022]
【発明の実施の形態】プリメルトフラックス基本成分は
下記の通りである。ＣａＯ：４０〜６０ｗｔ％、ＳｉＯ
2 ：３０〜４０ｗｔ％、Ａｌ2 Ｏ3 ：１〜７ｗｔ％、Ｍ
ｇＯ＜１．５％、Ｎａ2 Ｏ：１〜４ｗｔ％、Ｌｉ2 Ｏ：
１〜５ｗｔ％、Ｆ：２〜８ｗｔ％、高速鋳造用のモール
ドパウダーのプリメルトフラックスは少なくとも上記の
様な成分組成を有する場合に非晶質となる得るためであ
る。BEST MODE FOR CARRYING OUT THE INVENTION The premelt flux basic components are as follows. CaO: 40-60 wt%, SiO
2 : 30-40 wt%, Al 2 O 3 : 1-7 wt%, M
gO <1.5%, Na 2 O : 1~4wt%, Li 2 O:
1 to 5 wt%, F: 2 to 8 wt%, because the premelt flux of the mold powder for high-speed casting can become amorphous when it has at least the above-mentioned component composition.
【００２３】更に、プリメルトフラックス原料中にリチ
ウム原料をＬｉ2 Ｏとして１％以上配合し、全Ｃａのｗ
ｔ％から換算したＣａＯと全Ｓｉのｗｔ％から換算した
ＳｉＯ2 と比である塩基度（ＣａＯｗｔ％／ＳｉＯ2 ｗ
ｔ％）を１．４以上にし、ＣａＦ2 の量をＦｗｔ％≧２
４×（塩基度）−３１となるように添加すれば、風化す
るβ−２ＣａＯ・ＳｉＯ2 （Ｌａｒｎｉｔｅ）の生成を
抑え、フラックスは全体として非晶質であるプリメルト
フラックスを製造することができる。Further, 1% or more of a lithium raw material is added as Li 2 O in the premelt flux raw material to obtain w of all Ca.
The basicity (CaO wt% / SiO 2 w) which is the ratio of CaO calculated from t% and SiO 2 converted from wt% of all Si
t%) is 1.4 or more, and the amount of CaF 2 is Fwt% ≧ 2
If it is added so as to be 4 × (basicity) −31, it is possible to suppress the formation of weathered β-2CaO · SiO 2 (Larnite), and to manufacture a premelt flux in which the flux as a whole is amorphous. .
【００２４】さらに、より完全に非晶質であることが中
炭素鋼高速鋳造パウダー用の主原料として望ましい。望
ましい非晶質とは、Ｃｕターゲット、管電圧４０ＫＶ、
管電流３０ｍＡのＸ線回折条件において、無定形ハロー
パターンが検出されるものであり、最強度ピークが５０
０カウント／秒以下である場合である。Further, it is desirable that it be more completely amorphous as a main raw material for medium carbon steel high speed casting powder. A desirable amorphous material is a Cu target, a tube voltage of 40 KV,
An amorphous halo pattern is detected under the X-ray diffraction condition of a tube current of 30 mA, and the maximum intensity peak is 50.
This is the case when the count is 0 count / second or less.
【００２５】リチウム原料については、Ｌｉ2 Ｏとして
１％未満であれば、迅速溶融性が期待できず、５％を超
える配合は連鋳パウダーの結晶化温度が低くなりすぎ、
中炭素鋼を鋳造する際に良好な鋳片が得られにくい。Regarding the lithium raw material, if Li 2 O is less than 1%, rapid melting property cannot be expected, and if it exceeds 5%, the crystallization temperature of the continuous casting powder becomes too low,
It is difficult to obtain a good slab when casting medium carbon steel.
【００２６】また、全Ｃａｗｔ％から換算したＣａＯと
全Ｓｉｗｔ％から換算したＳｉＯ2とのｗｔ％比の比で
ある塩基度が１．４未満の時はβ−２ＣａＯ・ＳｉＯ2
（Ｌａｒｎｉｔｅ）の生成が少なく、ＣａＦ2 を添加し
なくても非晶質化しやすい。しかし、上記塩基度が１．
４以上の場合にはＣａＦ2 の量をＦｗｔ％≧２４×（塩
基度）−３１となるように添加しないと、風化するβ−
２ＣａＯ・ＳｉＯ2 （Ｌａｒｎｉｔｅ）の生成を抑える
ことができず、フラックスは全体として非晶質となりに
くい。When the basicity, which is the ratio of the wt% ratio of CaO converted from total Cawt% to SiO 2 converted from total Siwt%, is less than 1.4, β-2CaO · SiO 2
There is little (Larnite) formation, and it tends to become amorphous even without adding CaF 2 . However, when the basicity is 1.
When it is 4 or more, CaF 2 is weathered unless it is added so that Fwt% ≧ 24 × (basicity) -31.
The formation of 2CaO.SiO 2 (Larnite) cannot be suppressed, and the flux is unlikely to be amorphous as a whole.
【００２７】次に、ＭｇＯは中炭素鋼用連鋳パウダー成
分として、適正な粘性を維持するために１．５％未満に
することが必要であり、プリメルトフラックス成分とし
ても、１．５％未満にすることが経験上望ましい。Next, MgO must be less than 1.5% as a continuous casting powder component for medium carbon steel in order to maintain an appropriate viscosity, and also as a premelt flux component, 1.5%. It is desirable from experience that it is less than.
【００２８】[0028]
【実施例】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、石炭石、螢石、ガラス粉、アルカ
リ金属炭酸塩、アルカリ土類炭酸塩等を本発明範囲内の
成分組成になるように配合した原料を三相アーク炉にお
いて溶融し、溶融物をジェット水流によって急冷・水滓
化し、乾燥後、粉砕したものをプリメルトフラックス
（以下発明体という）１〜４とした。比較のため、本発
明の範囲外にあるプリメルトフラックス（以下、比較体
という）を調製した。EXAMPLES The present invention will be described with reference to examples and comparison with comparative examples. A raw material prepared by blending silica stone, coal stone, fluorite, glass powder, alkali metal carbonate, alkaline earth carbonate, etc. to have a composition within the scope of the present invention is melted in a three-phase arc furnace, and the melt is jetted. Premelt fluxes (hereinafter referred to as invention bodies) 1 to 4 were obtained by rapidly cooling and slagging with a water stream, drying and pulverizing. For comparison, a premelt flux outside the scope of the present invention (hereinafter referred to as a comparative body) was prepared.
【００２９】表１に発明体１〜４および比較体１〜４の
成分組成、Ｘ線回折（ＸＲＤ）における最強ピークカウ
ント数を示す（Ｘ線回折条件：Ｃｕターゲット、管電圧
４０ＫＶ、管電流３０ｍＡ）。表１から明らかなように
塩基度（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ％）およびＦｗｔ
％が本発明の範囲内にある発明体１〜４はＸＲＤ結果か
ら最強度ピークカウント数が５００カウント／秒以下で
あり、望ましい非晶質であることが分かる。Table 1 shows the component compositions of Inventions 1-4 and Comparatives 1-4, and the strongest peak count number in X-ray diffraction (XRD) (X-ray diffraction conditions: Cu target, tube voltage 40 KV, tube current 30 mA. ). As is clear from Table 1, basicity (CaO wt% / SiO 2 wt%) and Fwt
Inventive bodies 1 to 4 whose% is within the range of the present invention have the maximum intensity peak count number of 500 counts / second or less from the XRD result, which shows that they are desirable amorphous.
【００３０】これに対し、Ｆｗｔ％が本発明の範囲を超
えている比較体１〜４はＸＲＤ結果からβ−２ＣａＯ・
Ｓｉ2 （Ｌａｒｎｉｔｅ）の生成が顕著であった。On the other hand, Comparatives 1 to 4 in which Fwt% exceeds the range of the present invention show β-2CaO.
The production of Si 2 (Larnite) was remarkable.
【００３１】図１に各発明体および比較体の塩基度（Ｃ
ａＯｗｔ％／ＳｉＯ2 ｗｔ％）とＦｗｔ％を示す。この
図から、Ｆｗｔ％≧２４×（ＣａＯ／ＳｉＯ2 ）−３１
を満たすものが非晶質であることを示している。また、
図２に発明体１、２、比較体４のＸＲＤチャートを示
す。FIG. 1 shows the basicity (C
aOwt% / SiO 2 wt%) and Fwt% are shown. From this figure, Fwt% ≧ 24 × (CaO / SiO 2 ) -31
Those satisfying the condition are shown to be amorphous. Also,
FIG. 2 shows XRD charts of Invention bodies 1 and 2 and Comparative body 4.
【００３２】[0032]
【表１】 [Table 1]
【００３３】[0033]
【発明の効果】以上述べたように、この発明によれば中
炭素鋼高速鋳造用モールドパウダーの主原料であるプリ
メルトフラックスの要求される成分組成範囲内におい
て、β−２ＣａＯ・ＳｉＯ2 の生成を抑え、非晶質のプ
リメルトフラックスを得ることができ、さらに安定して
フラックスの製造が実施できるようになった。これによ
って、割れ感受性の大きい中炭素鋼においても割れ欠陥
のない品質の優れた鋼を連続鋳造することができるよう
になった。As described above, according to the present invention, β-2CaO.SiO 2 is produced within the required composition range of the premelt flux which is the main raw material of the mold powder for medium carbon steel high speed casting. It was possible to obtain an amorphous premelted flux by suppressing the above, and it became possible to more stably manufacture the flux. As a result, it has become possible to continuously cast a high-quality steel having no cracking defects even in a medium carbon steel having a high cracking susceptibility.
【図１】プリメルトフラックスの塩基度とＦｗｔ％との
関係において定まる結晶化・非晶化の状態を示す図であ
る。FIG. 1 is a diagram showing a crystallized / amorphized state determined by a relationship between a basicity of a premelt flux and Fwt%.
【図２】発明体と比較体のＸＲＤチャートを示す図であ
る。FIG. 2 is a diagram showing an XRD chart of an invention body and a comparison body.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 川島 健 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 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 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ken Kawashima Ken 3-2, Marunouchi, Chiyoda-ku, Tokyo Steel tube mining Co., Ltd. (72) Hidenori Sakai 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Steel Tube Mining Co., Ltd. (72) Inventor Masaaki Shimizu 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Steel Tube Mining Co., Ltd.
Claims (3)
３０〜４０ｗｔ％、Ａｌ2 Ｏ3 ：１〜７ｗｔ％、ＭｇＯ
＜１．５ｗｔ％、Ｎａ2 Ｏ：１〜４ｗｔ％、Ｌｉ2 Ｏ：
１〜５ｗｔ％、Ｆ：２〜８ｗｔ％を含有し，かつ、非晶
質であることを特徴とする連続鋳造用パウダーのプリメ
ルトフラックス。1. CaO: 40-60 wt%, SiO 2 :
30~40wt%, Al 2 O 3: 1~7wt%, MgO
<1.5 wt%, Na 2 O: 1 to 4 wt%, Li 2 O:
A pre-melt flux for a powder for continuous casting, characterized by containing 1 to 5 wt% and F: 2 to 8 wt% and being amorphous.
１％以上含み、（ｂ）Ｃａのｗｔ％から計算したＣａＯ
のｗｔ％と，Ｓｉのｗｔ％から計算したＳｉＯ2 のｗｔ
％との比である塩基度（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ
％）が１．４以上で、（ｃ）ＣａＦ2 を、Ｆｗｔ％≧２
４×（ＣａＯｗｔ％／ＳｉＯ2 ｗｔ％）−３１となるよ
うに含有している請求項１に記載された連続鋳造用パウ
ダーのプリメルトフラックス。2. A CaO containing (a) a lithium compound as Li 2 O in an amount of 1% or more, and (b) calculated from the wt% of Ca.
Wt% of SiO 2 and wt% of SiO 2 calculated from wt% of Si
% Is the ratio of basicity (CaO wt% / SiO 2 wt
%) Is 1.4 or more, and (c) CaF 2 is Fwt% ≧ 2
The premelt flux of the powder for continuous casting according to claim 1, which is contained so as to be 4 × (CaO wt% / SiO 2 wt%)-31.
流３０ｍＡのＸ線回折条件において無定形ハローパター
ンが検出され、最強度ピークが５００カウント／秒以下
であることを特徴とする請求項１又は２に記載された連
続鋳造用プリメルトフラックス。3. An amorphous halo pattern is detected under a Cu target, a tube voltage of 40 KV, and a tube current of 30 mA, and an amorphous halo pattern is detected, and the maximum intensity peak is 500 counts / second or less. The pre-melt flux for continuous casting described in.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07347055A JP3107739B2 (en) | 1995-12-15 | 1995-12-15 | Premelt flux of powder for continuous casting of steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07347055A JP3107739B2 (en) | 1995-12-15 | 1995-12-15 | Premelt flux of powder for continuous casting of steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09164460A true JPH09164460A (en) | 1997-06-24 |
| JP3107739B2 JP3107739B2 (en) | 2000-11-13 |
Family
ID=18387619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP07347055A Expired - Fee Related JP3107739B2 (en) | 1995-12-15 | 1995-12-15 | Premelt flux of powder for continuous casting of steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3107739B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001047200A (en) * | 1999-08-04 | 2001-02-20 | Nippon Steel Metal Prod Co Ltd | Powder for continuously casting steel |
| KR20010112886A (en) * | 2000-06-15 | 2001-12-22 | 이구택 | A front flux for continuous casting of medium carbon steel |
| KR100455812B1 (en) * | 2002-07-23 | 2004-11-06 | 스톨베르그 앤드 삼일 주식회사 | Synthetic calcium aluminium silicate composite for mold flux and mold flux manufactured therefrom |
| JP2006247744A (en) * | 2005-09-29 | 2006-09-21 | Jfe Steel Kk | Continuous casting method for steel |
| CN103128240A (en) * | 2011-11-28 | 2013-06-05 | 上海梅山钢铁股份有限公司 | Low carbon steel continuous casting crystallizer casting powder |
| JP2015205281A (en) * | 2014-04-17 | 2015-11-19 | 品川リフラクトリーズ株式会社 | Powder for ingot making |
-
1995
- 1995-12-15 JP JP07347055A patent/JP3107739B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001047200A (en) * | 1999-08-04 | 2001-02-20 | Nippon Steel Metal Prod Co Ltd | Powder for continuously casting steel |
| KR20010112886A (en) * | 2000-06-15 | 2001-12-22 | 이구택 | A front flux for continuous casting of medium carbon steel |
| KR100455812B1 (en) * | 2002-07-23 | 2004-11-06 | 스톨베르그 앤드 삼일 주식회사 | Synthetic calcium aluminium silicate composite for mold flux and mold flux manufactured therefrom |
| JP2006247744A (en) * | 2005-09-29 | 2006-09-21 | Jfe Steel Kk | Continuous casting method for steel |
| CN103128240A (en) * | 2011-11-28 | 2013-06-05 | 上海梅山钢铁股份有限公司 | Low carbon steel continuous casting crystallizer casting powder |
| CN103128240B (en) * | 2011-11-28 | 2015-06-03 | 上海梅山钢铁股份有限公司 | Low carbon steel continuous casting crystallizer casting powder |
| JP2015205281A (en) * | 2014-04-17 | 2015-11-19 | 品川リフラクトリーズ株式会社 | Powder for ingot making |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3107739B2 (en) | 2000-11-13 |
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