JPS63143216A - Melting method for extremely low carbon and low nitrogen steel - Google Patents
Melting method for extremely low carbon and low nitrogen steelInfo
- Publication number
- JPS63143216A JPS63143216A JP28903686A JP28903686A JPS63143216A JP S63143216 A JPS63143216 A JP S63143216A JP 28903686 A JP28903686 A JP 28903686A JP 28903686 A JP28903686 A JP 28903686A JP S63143216 A JPS63143216 A JP S63143216A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- gas
- steel
- carbon
- concn
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 60
- 239000010959 steel Substances 0.000 title claims abstract description 60
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims abstract description 36
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 27
- 229910052757 nitrogen Inorganic materials 0.000 title claims abstract description 18
- 238000000034 method Methods 0.000 title description 10
- 238000002844 melting Methods 0.000 title description 5
- 230000008018 melting Effects 0.000 title description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000001301 oxygen Substances 0.000 claims abstract description 41
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 41
- 239000007789 gas Substances 0.000 claims abstract description 39
- 238000006243 chemical reaction Methods 0.000 claims abstract description 25
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 48
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 29
- 229910052786 argon Inorganic materials 0.000 claims description 24
- 238000005261 decarburization Methods 0.000 claims description 16
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000007664 blowing Methods 0.000 abstract description 10
- 229910045601 alloy Inorganic materials 0.000 abstract description 6
- 239000000956 alloy Substances 0.000 abstract description 6
- 229910001209 Low-carbon steel Inorganic materials 0.000 abstract description 3
- 238000005262 decarbonization Methods 0.000 abstract description 3
- 238000007670 refining Methods 0.000 abstract description 2
- 238000009849 vacuum degassing Methods 0.000 description 14
- 239000001257 hydrogen Substances 0.000 description 11
- 229910052739 hydrogen Inorganic materials 0.000 description 11
- 238000007872 degassing Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000010992 reflux Methods 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 229910000616 Ferromanganese Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、極低炭素・低窒素鋼の溶製方法に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing ultra-low carbon and low nitrogen steel.
近年、炭素並びに窒素含有量の極めて少ない、良加工性
鋼板製造のため、極低炭素・低窒素鋼を溶製する必要が
生じている。一方、極低炭素鋼の溶製のためには、真空
脱ガス装置において、酸素或いは、二酸化炭素等のガス
、又は、酸化鉄等の粉末を添加する事により溶鋼中の溶
解酸素を富化し、脱炭反応を促進する試みがなされてい
る（例えば、特開昭４９−３４４１４号公報、特開昭５
１−１５１２１１号公報、特開昭５１−１５１２１２号
公報）。しかし、これらの方法は、真空脱炭後の脱酸に
より、大量の脱酸生成物が発生し、非金属介在物の増加
という良加工性鋼板製造上好ましくない結果を引き起こ
す。更に、溶鋼の脱窒反応は、溶鋼中の溶存酸素濃度を
高める事により、著しく遅くなる。一般に、真空脱ガス
処理により脱窒反応を行う場合の反応速度式は次式のよ
うに表される。In recent years, in order to manufacture steel sheets with extremely low carbon and nitrogen content and good workability, it has become necessary to produce extremely low carbon and low nitrogen steel. On the other hand, in order to melt ultra-low carbon steel, dissolved oxygen in the molten steel is enriched by adding gases such as oxygen or carbon dioxide, or powders such as iron oxide in a vacuum degassing device. Attempts have been made to accelerate the decarburization reaction (for example, Japanese Patent Laid-Open No. 49-34414, Japanese Patent Laid-open No. 5
1-151211, JP-A-51-151212). However, in these methods, a large amount of deoxidation products are generated due to deoxidation after vacuum decarburization, resulting in an increase in nonmetallic inclusions, which is undesirable in terms of manufacturing a steel sheet with good workability. Furthermore, the denitrification reaction of molten steel is significantly slowed down by increasing the dissolved oxygen concentration in molten steel. Generally, the reaction rate equation when performing a denitrification reaction by vacuum degassing treatment is expressed as the following equation.
Ｎ＋Ｎ →Ｎ ｚ （ｉ）〔Ｎ〕 ：溶鋼
バルク中の窒素濃度、（Ｎ）、：平衡窒素濃度、Ａ：反
応界面積、Ｖ：溶鋼の体積、に：反応速度定数
ここで、脱窒反応速度定数には、例えば、鉄と鋼Ｖｏ１
．６４（１９７８）ｐ７０２より第１図に引用して示す
如く、溶存酸素濃度が増大することにより、著しく小さ
くなる。これは、酸素等の表面活性元素はガスー溶綱界
面に吸着し、（１）式の化学反応を起こすために有効な
界面積を減少させるためと考えられている。従って、溶
鋼中の溶存酸素濃度を高めても、脱炭反応は促進されて
も、脱窒反応が進行しないという問題があった。N+N → N z (i) [N]: Nitrogen concentration in the bulk of molten steel, (N): Equilibrium nitrogen concentration, A: Reaction interfacial area, V: Volume of molten steel, N: Reaction rate constant Here, denitrification reaction For example, the rate constant includes iron and steel Vo1
．． 64 (1978) p. 702, it becomes significantly smaller as the dissolved oxygen concentration increases. This is thought to be because surface active elements such as oxygen are adsorbed at the gas-molten metal interface and reduce the effective interfacial area for causing the chemical reaction of formula (1). Therefore, even if the dissolved oxygen concentration in molten steel is increased, the denitrification reaction does not progress even though the decarburization reaction is promoted.
脱炭反応を進行させる他の方法として、溶鋼を真空脱炭
処理するに際し、水素含有物質を添加し、溶鋼中の水素
濃度を高めた後、脱水素する事により、水素ガス気泡を
鋼浴内部に生成せしめ、脱炭反応を促進する方法が特開
昭５７−１９４２０６号公報の中に述べられている。し
かし、転炉等の一次精錬炉にて精錬された溶鋼中の溶存
酸素濃度は、一般に３００〜６００ｐｐｍ程度であり、
上記理由により脱窒反応が進行しないという問題があっ
た。Another method for advancing the decarburization reaction is to add hydrogen-containing substances to increase the hydrogen concentration in the molten steel when vacuum decarburizing the molten steel, and then dehydrogenate the molten steel to remove hydrogen gas bubbles from inside the steel bath. JP-A-57-194206 discloses a method for producing carbon dioxide and promoting the decarburization reaction. However, the dissolved oxygen concentration in molten steel refined in a primary refining furnace such as a converter is generally about 300 to 600 ppm.
Due to the above reasons, there was a problem that the denitrification reaction did not proceed.
一方、特開昭５２−５６１４号公報に見るように、大量
のガスを吹き込み、反応界面積を増大させる事により脱
ガス反応を促進する試みがある。この方法は、脱炭、脱
窒反応の両者を促進するに有効な方法ではあるが、真空
槽内の溶鋼飛散の増大による鋼のロス、及び、地金付着
、温度低下による操業上の障害を招くばかりでなく、真
空度を保つために、大型の排気装置が必要になり、設備
費の増加等の問題を生ずる。On the other hand, as seen in JP-A-52-5614, there has been an attempt to promote the degassing reaction by blowing in a large amount of gas to increase the reaction interfacial area. This method is effective in promoting both decarburization and denitrification reactions, but it also causes steel loss due to increased molten steel scattering in the vacuum chamber, as well as operational problems due to metal adhesion and temperature drop. In addition to this, a large exhaust system is required to maintain the degree of vacuum, resulting in problems such as an increase in equipment costs.
（発明が解決しようとする問題点）
本発明は、上記問題点を解決し、効率的、かつ安価に極
低炭素・低窒素鋼を溶製しうる方法を提供しようとする
ものである。(Problems to be Solved by the Invention) The present invention aims to solve the above-mentioned problems and provide a method for efficiently and inexpensively producing extremely low carbon and low nitrogen steel.
（問題点を解決するための手段）
本発明の要旨とするところは、鋼を真空脱炭処理するに
際し、炭素濃度０．０１０％以下、酸素濃度０．００５
０〜０．０２０％の領域で、水素ガスとアルゴンガスを
吹き込み、その溶存酸素濃度を保持しながら、脱炭と脱
窒反応を進行させることを特徴とする極低炭素・低窒素
鋼の溶製方法にある。(Means for Solving the Problems) The gist of the present invention is that when vacuum decarburizing steel, the carbon concentration is 0.010% or less and the oxygen concentration is 0.005%.
A melting method for ultra-low carbon and low nitrogen steel characterized by blowing hydrogen gas and argon gas in the range of 0 to 0.020% to advance decarburization and denitrification reactions while maintaining the dissolved oxygen concentration. It's in the manufacturing method.
水素ガスとアルゴンガスのそれぞれ独立の吹き込み、及
び、水素とアルゴンの混合ガスを吹き込む場合のいずれ
も同様の効果があり、極低炭素・低窒素鋼の溶製上、有
利に実施されるものである。Both the independent injection of hydrogen gas and argon gas and the injection of a mixed gas of hydrogen and argon have the same effect, and are advantageous in producing ultra-low carbon and low nitrogen steel. be.
さて、本発明者らは、極低炭素・低窒素鋼の溶製方法に
ついて種々の検討を行った結果、溶鋼を真空脱炭素処理
するに際しては、第２図に示す如く、炭素濃度０．０１
０％以下では、溶鋼中の溶存酸素濃度が５０ｐｐｍ以上
あれば、それ以上の溶存酸素濃度が存在する場合と比較
して、実操業上、脱炭素速度に差は認められない事を見
出した。ここに、第２図の横軸は、溶鋼中の溶存酸素濃
度を示し、縦軸は、次式で定義される脱炭反応の容量係
数ｋ （Ａ／Ｖ）である。Now, as a result of various studies conducted by the present inventors regarding the melting method of ultra-low carbon/low nitrogen steel, we found that when vacuum decarbonizing the molten steel, the carbon concentration is 0.01 as shown in Fig. 2.
It has been found that when the dissolved oxygen concentration in the molten steel is 0% or less, there is no difference in the decarbonization rate in actual operation when the dissolved oxygen concentration is 50 ppm or more, compared to when the dissolved oxygen concentration is higher than 50 ppm. Here, the horizontal axis in FIG. 2 shows the dissolved oxygen concentration in the molten steel, and the vertical axis shows the capacity coefficient k (A/V) of the decarburization reaction defined by the following equation.
ｄｔ Ｖ
また、第３図に示す如く、溶存酸素濃度が２００ｐｐｍ
以下の溶鋼に水素とアルゴンの混合ガスを吹き込めば脱
窒速度はアルゴンガスと比較して、格段に向上すること
を見出した。dt V Also, as shown in Figure 3, the dissolved oxygen concentration is 200 ppm.
We have found that by blowing a mixed gas of hydrogen and argon into the following molten steel, the denitrification rate can be significantly improved compared to argon gas.
アルゴンガスと比較して、水素とアルゴンの混合ガスの
場合が大きな脱窒速度を示す理由は、吹き込まれた水素
ガスが溶鋼−ガス界面に吸着している酸素を除去するた
め先に述べた酸素の毒作用を低減するからであると考え
られる。The reason why a mixed gas of hydrogen and argon exhibits a higher denitrification rate than argon gas is because the injected hydrogen gas removes oxygen adsorbed at the molten steel-gas interface. This is thought to be because it reduces the toxic effects of
次に本発明を第４図に従って詳細に説明する。Next, the present invention will be explained in detail with reference to FIG.
転炉等で一次精錬した未脱酸溶鋼に合金を添加した溶鋼
１を取鍋２に受鋼する。この場合、合金としては薄板鋼
板に必要とするフェロマンガン等を添加するが、ここで
は溶鋼中の溶存酸素濃度が高いために、合金元素が溶存
酸素と反応し、合金歩留が低下する。従って、ここでは
、リミングアクションによる溶鋼のボイリングを抑える
ために必要な最小限の合金だけを添加し、真空脱ガス処
理により、溶存酸素濃度を低減したのち、最終製品成分
となるよう、残りの合金を添加するのが望ましい。次に
取鍋自溶ａ２に真空脱ガス装置の浸漬管３を浸漬し、排
気管４を介して真空槽内を減圧し、真空槽５内に溶鋼を
導入する。その後、アルゴンガスのバルブ６を開き、ア
ルゴンガスホルダー７から還流ガス吹き込み羽口８を介
してアルゴンガスを溶鋼中に吹き込み、溶鋼の真空脱炭
処理を行う、脱炭処理中、炭素濃度を分析し、炭素濃度
が０．０１０％以下になった時点で、？８鋼中の溶存酸
素濃度を測定し、溶存酸素濃度が５０〜２００ｐｐｍに
なるようにマンガン、アルミニウム等で酸素濃度をコン
トロールする。さらに、水素バルブ９を開き、吹き込み
羽口８を介し、水素ガスホルダー１０からの水素ガスを
溶鋼中に吹き込み、脱炭、脱窒を同時に進行させ、最終
目標の炭素、窒素濃度とする。ただし、例えば、真空脱
ガス処理前の初期溶存酸素濃度が、３００ｐｐｍ程度の
場合には脱炭の進行とともに、溶存酸素濃度が低下し、
炭素濃度が０．０１０％以下に達した時、既に５０〜２
００ｐｐｍの範囲にあることもある。この場合には、脱
酸剤の添加を行う必要は無い。Molten steel 1, which is obtained by adding an alloy to undeoxidized molten steel that has been primarily refined in a converter or the like, is received in a ladle 2. In this case, ferromanganese and the like required for the thin steel sheet are added to the alloy, but since the dissolved oxygen concentration in the molten steel is high, the alloying elements react with the dissolved oxygen, reducing the alloy yield. Therefore, only the minimum amount of alloy necessary to suppress boiling of molten steel due to rimming action is added, the dissolved oxygen concentration is reduced by vacuum degassing treatment, and then the remaining alloy is added to form the final product component. It is desirable to add Next, the immersion tube 3 of the vacuum degassing device is immersed in the self-melting ladle a2, the pressure inside the vacuum chamber is reduced through the exhaust tube 4, and molten steel is introduced into the vacuum chamber 5. After that, the argon gas valve 6 is opened, and argon gas is blown into the molten steel from the argon gas holder 7 through the reflux gas blowing tuyere 8 to perform vacuum decarburization treatment of the molten steel. During the decarburization treatment, the carbon concentration is analyzed. However, when the carbon concentration becomes 0.010% or less,? Measure the dissolved oxygen concentration in the 8 steel, and control the oxygen concentration with manganese, aluminum, etc. so that the dissolved oxygen concentration is 50 to 200 ppm. Further, the hydrogen valve 9 is opened, and hydrogen gas from the hydrogen gas holder 10 is blown into the molten steel through the tuyere 8 to simultaneously advance decarburization and denitrification to reach the final target carbon and nitrogen concentrations. However, for example, if the initial dissolved oxygen concentration before vacuum degassing treatment is about 300 ppm, the dissolved oxygen concentration will decrease as decarburization progresses.
When the carbon concentration reached 0.010% or less, it was already 50~2
It may be in the range of 00 ppm. In this case, there is no need to add a deoxidizing agent.
なお、水素ガスは、炭素濃度ｏ、ｏｉｏ％以上の領域で
吹き込みを開始しても特に問題はないが、水素ガスはア
ルゴンガスに比して高価であり、脱窒に有効に作用させ
るには、溶存酸素濃度を５０〜２００ｐｐｍに調整した
後に吹き込みを開始することが望ましい、また、水素ガ
スとアルゴンガスの混合比は水素ガスが５〜２０％で十
分な効果が得られた。Note that there is no particular problem when hydrogen gas starts blowing in a region where the carbon concentration is o or oio% or higher, but hydrogen gas is more expensive than argon gas, and it is difficult to make it work effectively for denitrification. It is desirable to start blowing after adjusting the dissolved oxygen concentration to 50 to 200 ppm, and a sufficient effect was obtained when the mixing ratio of hydrogen gas and argon gas was 5 to 20%.
以上、本発明法を環流式真空脱ガス装置に用いる場合を
例に説明したが、末法は、他の真空脱ガス装置を用いる
場合にも適用可能である。また、環流式真空脱ガス装置
を用いて脱ガス処理する場合、水素ガスとアルゴンガス
を吹き込むにあたっては、既に第４図に示したように、
環流ガス中に水素ガスを混合することが最も面側ではあ
るが、第５図に示すように、吹き込みランス１８を用い
て取鍋内に吹き込むことも可能である。また、第６図に
示すように、取鍋底に設けたポーラスプラグ２８等を用
いても良く、また、第７図に示すように、水素ガスとア
ルゴンガスをそれぞれを独立に吹き込んでも良く、本発
明により容易に、極低炭素・低窒素鋼の溶製が可能にな
った。Although the method of the present invention has been described above using an example of a reflux type vacuum degassing device, the method can also be applied to a case of using other vacuum degassing devices. In addition, when degassing using a recirculation vacuum degassing device, when blowing hydrogen gas and argon gas, as shown in Figure 4,
Although hydrogen gas is best mixed into the reflux gas, it is also possible to blow it into the ladle using a blow lance 18, as shown in FIG. Further, as shown in Fig. 6, a porous plug 28 provided at the bottom of the ladle may be used, or as shown in Fig. 7, hydrogen gas and argon gas may be blown into each independently. The invention has made it possible to easily produce ultra-low carbon and low nitrogen steel.
（実施例）
表１に本発明の実施例及び比較例を示す。溶鋼は、いず
れも２５０を転炉により溶製されたものである。脱ガス
装置としては、Ｒ８式真空脱ガス装置を用いた。実施例
１は、真空脱ガス処理開始から１０％の水素を混合した
アルゴンガスを吹き込んだ場合である。処理開始後７分
後に溶鋼中の炭素濃度を分析し、更に、８分後に溶存酸
素濃度を測定し、溶存酸素濃度が５０〜２００ｐｐｍに
なるように、Ａｌを添加した例である。(Example) Table 1 shows examples and comparative examples of the present invention. The molten steel was 250 molten steel made in a converter. As a degassing device, an R8 type vacuum degassing device was used. Example 1 is a case where argon gas mixed with 10% hydrogen was blown from the start of the vacuum degassing process. This is an example in which the carbon concentration in the molten steel was analyzed 7 minutes after the start of treatment, and the dissolved oxygen concentration was measured 8 minutes later, and Al was added so that the dissolved oxygen concentration was 50 to 200 ppm.
実施例２は、真空脱ガス処理開始後、８分まで還流ガス
としてアルゴンを吹き込み、溶存酸素濃度、及び炭素濃
度の測定を行ったのち、溶存酸素濃度を５０〜２００ｐ
ｐｍになるよう、所定量の＾！を添加し、引き続き、環
流ガス中に水素ガスを１０％混合して吹き込んだ場合で
ある。In Example 2, after the start of vacuum degassing treatment, argon was blown in as a reflux gas for 8 minutes, dissolved oxygen concentration and carbon concentration were measured, and then the dissolved oxygen concentration was reduced to 50 to 200 p.
A predetermined amount to make it pm ^! This is the case where 10% hydrogen gas was mixed and blown into the reflux gas.
実施例３は、真空脱ガス処理前の溶存酸素濃度が３２０
ｐｐｍと低く、脱ガス開始より８分が経過した段階で、
溶存酸素濃度が１４０ｐｐｍであったため、特に脱酸剤
を添加せず水素とアルゴンの混合ガスを吹き込み開始し
た場合である。In Example 3, the dissolved oxygen concentration before vacuum degassing treatment was 320
ppm is as low as 8 minutes after the start of degassing.
Since the dissolved oxygen concentration was 140 ppm, this was the case when blowing a mixed gas of hydrogen and argon was started without adding a deoxidizing agent.
比較例１は、通常の真空脱炭素処理を行い、溶存酸素濃
度をコントロールする、水素ガスを混合するという操作
を行わなかった場合である。この場合には、溶損酸素濃
度が高いまま推移するため、脱窒反応はほとんど進行し
ていない。Comparative Example 1 is a case in which ordinary vacuum decarbonization treatment was performed, and operations such as controlling the dissolved oxygen concentration and mixing hydrogen gas were not performed. In this case, the denitrification reaction hardly progresses because the dissolved oxygen concentration remains high.
比較例２は、環流ガス量を通常の１０ ＯＮｍ’／ｈｒ
から１５０ Ｎｍｊ／ｈｒに増加し、浸漬管径を通常の
６０（Ｊから７３ｃＩｌに拡大し、環流量の増大及び、
ガスー溶鋼間反応界面積の増大を狙ったものである。こ
の場合には、若干の炭素濃度の低減に若干の効果が認め
られるものの、酸素濃度が４００ ｐｐｍ以上という高
い濃度であったため、脱窒反応が進行しなかった例であ
る。In Comparative Example 2, the amount of recirculated gas was reduced to the usual 10 ONm'/hr.
to 150 Nmj/hr, and the immersion pipe diameter was expanded from the usual 60 (J) to 73 cIl, increasing the recirculation flow rate and
The aim is to increase the reaction interface area between gas and molten steel. In this case, although some effect was observed in reducing the carbon concentration, the denitrification reaction did not proceed because the oxygen concentration was as high as 400 ppm or more.
（発明の効果）
本発明によれば、溶解炉設備、脱ガス設備の大幅な改造
、もしくは、溶融金属の移し換え設備の新設等は殆ど必
要無く、従来の極低炭素鋼にくらべ、更に炭素濃度の低
く、かつ窒素濃度も十分に低い鋼が安定して得られ、時
効性、延性に優れた鋼を安定かつ容易に溶製可能になっ
た。(Effects of the Invention) According to the present invention, there is almost no need for major modification of melting furnace equipment and degassing equipment, or new installation of molten metal transfer equipment, etc., and compared to conventional ultra-low carbon steel, Steel with low concentration and sufficiently low nitrogen concentration was stably obtained, and steel with excellent aging properties and ductility could be produced stably and easily.
第１図は、脱窒反応速度定数に及ぼす溶鋼中の溶存酸素
濃度の影響を示す図、第２図は、炭素濃度０．０１０％
以下での脱炭反応速度に及ぼす溶存酸素濃度の影響を示
す図（ここに、ｋ （Ａ／Ｖ）は、（３）式で表される
脱炭反応の容量係数である。）、第３図は、環流式真空
脱ガス装置においてアルゴンガス及び１０％の水素ガス
を混合したアルゴンガスを溶鋼中に吹き込んだ場合の窒
素濃度の経時変化を示す図、第４図は、本実施例に示す
試験を行った際に真空脱ガス設備の概要を示す説明図、
第５図は、水素とアルゴンの混合ガスを、取鍋内にラン
スを介して吹き込む設備例の概略を示す説明図、第６図
は、水素とアルゴンの混合ガスを、取鍋の底に設けたポ
ーラスプラグを介して吹き込む設備例の概略を示す説明
図、第７図は、水素ガスとアルゴンガスをそれぞれ独立
に吹き込むための設備例の概要を示す説明図である。
１：溶鋼、２：取鍋、３：浸漬管、
４：排気管、５：真空槽、６：バルブ、７：アルゴンガ
スホルダー、８：羽口、９：水素バルブ、１０：水素ガ
スホルダー。
第１図
；３存酸素−１受（ｐｐｒｎ）
第２図
溶存酸ｆ濃液（８２ｍ）
第３図
脱力゛ヌ又り埋」千間 （介）
第４図
第５図
第６図Figure 1 shows the influence of the dissolved oxygen concentration in molten steel on the denitrification rate constant, and Figure 2 shows the carbon concentration of 0.010%.
The following diagram shows the influence of dissolved oxygen concentration on the decarburization reaction rate (here, k (A/V) is the capacity coefficient of the decarburization reaction expressed by equation (3)). The figure shows the change in nitrogen concentration over time when argon gas mixed with argon gas and 10% hydrogen gas is blown into molten steel in a recirculation vacuum degassing device. An explanatory diagram showing the outline of the vacuum degassing equipment when testing was carried out,
Figure 5 is an explanatory diagram showing an outline of an example of equipment for blowing a mixed gas of hydrogen and argon into the ladle through a lance, and Figure 6 is an explanatory diagram showing the outline of an example of equipment in which a mixed gas of hydrogen and argon is blown into the bottom of the ladle. FIG. 7 is an explanatory diagram showing an outline of an example of equipment for injecting hydrogen gas and argon gas independently through a porous plug. 1: Molten steel, 2: Ladle, 3: Immersion tube, 4: Exhaust pipe, 5: Vacuum tank, 6: Valve, 7: Argon gas holder, 8: Tuyere, 9: Hydrogen valve, 10: Hydrogen gas holder. Figure 1; 3 existing oxygen - 1 receptor (pprn) Figure 2 Dissolved acid f concentrated solution (82m) Figure 3 Weakness ゛ Nu Mata Buried' Sengen (Intermediate) Figure 4 Figure 5 Figure 6
Claims (1)
下、酸素濃度０．００５０〜０．０２０％の領域で、水
素ガスとアルゴンガスを吹き込み、その溶存酸素濃度を
保持しながら、脱炭と脱窒反応を進行させることを特徴
とする極低炭素・低窒素鋼の溶製方法。When performing vacuum decarburization treatment on steel, hydrogen gas and argon gas are blown in at a carbon concentration of 0.010% or less and an oxygen concentration of 0.0050 to 0.020%, and decarburization is carried out while maintaining the dissolved oxygen concentration. A method for producing ultra-low carbon and low nitrogen steel characterized by advancing a denitrification reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28903686A JPS63143216A (en) | 1986-12-05 | 1986-12-05 | Melting method for extremely low carbon and low nitrogen steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28903686A JPS63143216A (en) | 1986-12-05 | 1986-12-05 | Melting method for extremely low carbon and low nitrogen steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63143216A true JPS63143216A (en) | 1988-06-15 |
Family
ID=17737996
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28903686A Pending JPS63143216A (en) | 1986-12-05 | 1986-12-05 | Melting method for extremely low carbon and low nitrogen steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63143216A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04333512A (en) * | 1990-10-03 | 1992-11-20 | Kawasaki Steel Corp | Method for melting extremely low carbon steel |
| CN100457949C (en) * | 2007-03-26 | 2009-02-04 | 攀枝花钢铁(集团)公司 | Method of controlling carbon content in ultralow carbon high strength high toughness steel |
| KR20160063096A (en) * | 2014-11-26 | 2016-06-03 | 현대제철 주식회사 | Degassing apparatus and method |
| CN109182657A (en) * | 2018-08-29 | 2019-01-11 | 唐山钢铁集团有限责任公司 | A kind of method of RH dry-type mechanical pump control carbon control nitrogen |
| WO2019054577A1 (en) * | 2017-09-18 | 2019-03-21 | 주식회사 포스코 | Vacuum degassing equipment and refining method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58117817A (en) * | 1982-01-07 | 1983-07-13 | Nippon Kokan Kk <Nkk> | Manufacture of extra-low nitrogen steel |
-
1986
- 1986-12-05 JP JP28903686A patent/JPS63143216A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58117817A (en) * | 1982-01-07 | 1983-07-13 | Nippon Kokan Kk <Nkk> | Manufacture of extra-low nitrogen steel |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04333512A (en) * | 1990-10-03 | 1992-11-20 | Kawasaki Steel Corp | Method for melting extremely low carbon steel |
| JPH0798972B2 (en) * | 1990-10-03 | 1995-10-25 | 川崎製鉄株式会社 | Ultra low carbon steel melting method |
| CN100457949C (en) * | 2007-03-26 | 2009-02-04 | 攀枝花钢铁(集团)公司 | Method of controlling carbon content in ultralow carbon high strength high toughness steel |
| KR20160063096A (en) * | 2014-11-26 | 2016-06-03 | 현대제철 주식회사 | Degassing apparatus and method |
| WO2019054577A1 (en) * | 2017-09-18 | 2019-03-21 | 주식회사 포스코 | Vacuum degassing equipment and refining method |
| CN109182657A (en) * | 2018-08-29 | 2019-01-11 | 唐山钢铁集团有限责任公司 | A kind of method of RH dry-type mechanical pump control carbon control nitrogen |
| CN109182657B (en) * | 2018-08-29 | 2020-07-31 | 唐山钢铁集团有限责任公司 | Carbon and nitrogen control method for RH dry type mechanical pump |
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