JPH03191004A - Manufacture of atomized iron powder - Google Patents
Manufacture of atomized iron powderInfo
- Publication number
- JPH03191004A JPH03191004A JP32966189A JP32966189A JPH03191004A JP H03191004 A JPH03191004 A JP H03191004A JP 32966189 A JP32966189 A JP 32966189A JP 32966189 A JP32966189 A JP 32966189A JP H03191004 A JPH03191004 A JP H03191004A
- Authority
- JP
- Japan
- Prior art keywords
- tundish
- molten steel
- iron powder
- molten metal
- atomized iron
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 239000002184 metal Substances 0.000 claims abstract description 16
- 229910052751 metal Inorganic materials 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 11
- 239000011261 inert gas Substances 0.000 claims abstract description 10
- 239000012530 fluid Substances 0.000 claims abstract description 4
- 238000007664 blowing Methods 0.000 claims description 7
- 229910000831 Steel Inorganic materials 0.000 abstract description 59
- 239000010959 steel Substances 0.000 abstract description 59
- 239000002893 slag Substances 0.000 abstract description 26
- 239000000843 powder Substances 0.000 abstract description 6
- 230000000694 effects Effects 0.000 description 8
- 239000002245 particle Substances 0.000 description 7
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 239000007921 spray Substances 0.000 description 6
- 230000003749 cleanliness Effects 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000007667 floating Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000012733 comparative method Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 238000005206 flow analysis Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000008775 paternal effect Effects 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明はアトマイズ鉄粉の製造方法に関し、非金属介
在物の混入量を低減し高品質のアトマイズ鉄粉を製造し
ようとするものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing atomized iron powder, and aims to reduce the amount of nonmetallic inclusions and produce high-quality atomized iron powder.
（従来の技術）
アトマイズ鉄粉は粉末冶金用材料の中では比較的に歴史
の浅い材料であるが、量産に適しており品質のばらつき
も少ない等の利点を有するところから、最近注目されて
いる。(Conventional technology) Atomized iron powder is a material with a relatively short history among materials for powder metallurgy, but it has recently attracted attention because it has advantages such as being suitable for mass production and having little variation in quality. .
その製造は電気炉又は転炉等で溶製した溶鋼をタンディ
ツシュノズルから流下させ、この流れに窒素ガス等の高
圧ガスまたは高圧水を当て溶鋼を噴霧化した後象、冷凝
固させる方法によるのが一般的である。It is manufactured by a method in which molten steel made in an electric furnace or converter flows down from a tundish nozzle, and then high-pressure gas such as nitrogen gas or high-pressure water is applied to the flow to atomize the molten steel, followed by cooling and solidification. is common.
この製造方法で問題となるのは、非金属介在物の混入に
よって鉄粉の品質が著しく損われる点である。すなわち
アトマイズ鉄粉の場合、溶鋼を噴霧化した後急冷凝固さ
せるため、非金属介在物を浮上分離して除去することは
できない。したがって非金属介在物の混入を未然に防止
した上で、溶鋼のタンディツシュへの注入及び噴霧化を
行う必要がある。A problem with this manufacturing method is that the quality of the iron powder is significantly impaired by the inclusion of nonmetallic inclusions. That is, in the case of atomized iron powder, since molten steel is atomized and then rapidly solidified, nonmetallic inclusions cannot be removed by flotation. Therefore, it is necessary to prevent non-metallic inclusions before injecting the molten steel into the tundish and atomizing it.
一般にアトマイズ鉄粉中への非金属介在物の混入は、電
気炉又は転炉等で溶製される際における精錬工程での脱
酸生成物及びＣａＯやＣａＦｚ等の造滓剤が出鋼時に混
入すること、取鍋からタンディツシュへ溶鋼を注入する
際の空気酸化及びタンディツシュ内溶鋼表面に浮遊して
存在するスカム（スラグ）の巻込み、等が主たる原因で
ある。In general, non-metallic inclusions in atomized iron powder are caused by deoxidation products during the refining process and slag-forming agents such as CaO and CaFz that are mixed in during tapping when the iron powder is melted in an electric furnace or converter. The main causes include air oxidation when pouring molten steel from the ladle into the tundish, and entrainment of scum floating on the surface of the molten steel in the tundish.
このような非金属介在物の混入を防止する方法として特
公昭５８−４８６０３号公報には、タンディツシュ内に
筒体を立設するとともに、筒体内にはタンディツシュ内
のスラブが流入しない構造とし、この筒体を介して溶鋼
をタンディツシュ内に注入することが開示されている。As a method for preventing such nonmetallic inclusions from entering, Japanese Patent Publication No. 58-48603 discloses that a cylindrical body is installed upright within the tundish, and a structure is adopted in which the slab inside the tundish does not flow into the cylindrical body. Injecting molten steel into a tundish through a cylinder is disclosed.
この方法は、タンディツシュ内溶鋼の表面に浮遊してい
るスラグやスカムの取鍋からの注入流による巻き込みを
防止することに主眼があり、取鍋内溶鋼中に懸濁してい
るスラグやスカム、あるいはタンディツシュ内の溶鋼内
に混入したスラグやスカムの除去には効果がなく、従っ
て得られる鉄粉の品質向上には限界があった。The main purpose of this method is to prevent slag and scum floating on the surface of the molten steel in the tundish from being entrained by the injection flow from the ladle. It was ineffective in removing slag and scum mixed into the molten steel in the tundish, and therefore there was a limit to the quality improvement of the obtained iron powder.
（発明が解決しようとする課題）
この発明は、タンディツシュ内溶鋼中に混入したスラグ
やスカム等の非金属介在物の分離を達成し、よってタン
ディツシュから流下する？８ｍ中への非金属介在物の混
入を防止し得る方法について提案することを目的とする
。(Problems to be Solved by the Invention) Does the present invention achieve the separation of non-metallic inclusions such as slag and scum mixed into the molten steel in the tundish, and therefore flow down from the tundish? The purpose of this study is to propose a method for preventing non-metallic inclusions from being mixed into 8m.
（課題を解決するための手段）
発明者らは、コンピュータによる溶鋼の流動解析シミュ
レーションを行った結果、タンディツシュ内の溶鋼に水
平回転を付与することが、以下の２点で有利であるとの
知見を得た。(Means for Solving the Problems) As a result of performing a flow analysis simulation of molten steel using a computer, the inventors found that imparting horizontal rotation to molten steel in a tundish is advantageous in the following two points. I got it.
１）水平回転流を付与すると、溶鋼に働く遠心力と非金
属介在物に働く遠心力との差によって非金属介在物は回
転中心部に集中する。1) When a horizontal rotational flow is applied, the nonmetallic inclusions are concentrated at the center of rotation due to the difference between the centrifugal force acting on the molten steel and the centrifugal force acting on the nonmetallic inclusions.
２）水平回転の付与によって溶融金属の上面は放物面状
になっているため、タンディツシュ注入口からの溶鋼の
注入主流は、タンディツシュ底部に向かわずに、直ちに
タンディツシュの上部に達し、注入後に直ちに流出口に
向かう、いわゆるショートサーキットを防止できる。2) Due to the horizontal rotation, the top surface of the molten metal has a parabolic shape, so the main flow of molten steel from the tundish injection port does not go to the bottom of the tundish, but immediately reaches the top of the tundish, and immediately after injection. A so-called short circuit towards the outlet can be prevented.
又、水モデル実験において、
３）水平回転を与えられた液体中に不活性ガスを吹込む
と、気泡の液体滞留時間が回転を与えない場合に比較し
て長くなり、また気泡が回転中心部に集まり、さらに液
の回転によって生成したガス気泡は回転流による剪断力
で微細気泡になることが、すなわち水平回転流によりバ
ブリングの撹拌効果が増加することが、確認された。In addition, in a water model experiment, 3) When an inert gas is blown into a liquid subjected to horizontal rotation, the residence time of bubbles in the liquid becomes longer than when rotation is not applied, and the bubbles stay at the center of rotation. It was confirmed that the gas bubbles collected by the liquid and generated by the rotation of the liquid became fine bubbles due to the shear force caused by the rotational flow, that is, the agitation effect of bubbling was increased by the horizontal rotational flow.
この発明は上記の知見に基いてなされたものである。This invention was made based on the above findings.
すなわちこの発明は、溶湯をタンディツシュに供給し、
このタンディツシュから流下させた溶湯流に高圧流体を
衝突させて溶湯を粉粒化するに当たり、タンディツシュ
の外側に配設した回転磁界発生装置により、タンディツ
シュ内熔湯に水平回転を与えるとともに、溶湯のタンデ
ィツシュ内での平均滞留時間を１００〜３００秒に調整
することを特徴とするアトマイズ鉄粉の製造方法及びさ
らにタンディツシュ内の溶湯中に不活性ガスを吹き込む
ことを特徴とするアトマイズ鉄粉の製造方法である。That is, this invention supplies molten metal to a tandish,
When high-pressure fluid collides with the molten metal flowing down from the tundish to pulverize the molten metal, a rotating magnetic field generator installed outside the tundish gives horizontal rotation to the molten metal inside the tundish, and the molten metal flows into the tundish. A method for producing atomized iron powder characterized by adjusting the average residence time in the tundish to 100 to 300 seconds, and a method for producing atomized iron powder characterized by further blowing an inert gas into the molten metal in the tundish. be.
さて第１図にこの発明に使用する装置を示す。Now, FIG. 1 shows the apparatus used in this invention.
図中１は溶鋼２を装入した取鍋、３は取鍋１からの溶鋼
２を注入ノズル１ａを介して受けるクンデインシュ、４
はタンディツシュ３内の溶鋼２に水平回転を与えるため
の回転磁界発生装置、５はタンディッシュ３内に不活性
ガスを吹き込むためのパイプ、６はタンディツシュ３か
ら流下する溶鋼２に高圧ガス又は高圧水を吹き付ける噴
霧ノズル、７は粉粒化した７１〜マイズ鉄粉、そして８
は噴霧槽である。In the figure, 1 is a ladle charged with molten steel 2, 3 is a kundeinshu that receives molten steel 2 from the ladle 1 through the injection nozzle 1a, and 4
is a rotating magnetic field generator for giving horizontal rotation to the molten steel 2 in the tundish 3; 5 is a pipe for blowing inert gas into the tundish 3; 6 is a high-pressure gas or high-pressure water supply to the molten steel 2 flowing down from the tundish 3; 7 is pulverized 71~mize iron powder, and 8 is a spray nozzle that sprays
is a spray tank.
図示のタンディッシュ３は溶鋼２の取鍋１からの注入及
び噴霧槽８への流出を同時に行うもので、このタンディ
ツシュ３の外側から回転磁界発生装置４によって溶鋼２
に水平回転を与え、溶鋼２と非金属介在物とを分離し、
浮遊した非金属介在物を水平回転流の中心付近に集める
。なお溶！１ｉ１２はタンディツシュ３の中心部へ注入
し、一方塊出口はタンディツシュ３底部の溶鋼回転中心
から離間した位置に設けることが好ましい。The illustrated tundish 3 simultaneously injects the molten steel 2 from the ladle 1 and discharges it into the spray tank 8. The molten steel 2 is fed from the outside of the tundish 3 by a rotating magnetic field generator 4.
horizontal rotation is applied to separate the molten steel 2 and the non-metallic inclusions,
Floating nonmetallic inclusions are collected near the center of the horizontal rotational flow. In addition, it melts! 1i12 is preferably injected into the center of the tundish 3, while the lump outlet is provided at a position spaced from the molten steel rotation center at the bottom of the tundish 3.
またタンディツシュ３内における？容量２の平均滞留時
間は１００秒以上３００秒以下に調整する。Also in Tanditshu 3? The average residence time of capacity 2 is adjusted to 100 seconds or more and 300 seconds or less.
さらに溶鋼２に水平回転を与えるとともに、溶鋼２中に
パイプ５から不活性ガスを吹き込むと、非金属介在物と
溶鋼との分離をより一層促進することができる。Furthermore, when the molten steel 2 is given horizontal rotation and an inert gas is blown into the molten steel 2 from the pipe 5, separation of nonmetallic inclusions and the molten steel can be further promoted.
（作 用）
タンディツシュ３内の溶鋼２に水平回転を与えていない
場合、この溶鋼２へ新たに、非金属介在物（以下スラグ
と示す）が混入した溶鋼を注入すると、第２図（ａ）に
矢印で示すような流れに従って、注入流はスラグが浮上
しないまま流出される（ショートサーキット）。(Function) When the molten steel 2 in the tundish 3 is not given horizontal rotation, if molten steel mixed with non-metallic inclusions (hereinafter referred to as slag) is newly injected into the molten steel 2, the result will be as shown in Fig. 2 (a). Following the flow shown by the arrow in , the injected flow is discharged without the slag rising to the surface (short circuit).
これに対して水平回転を与えた溶鋼２へ新たに、スラグ
が混入した溶鋼を注入すると、同図（ｂ）に矢印で示す
ような流れに従って、注入流は浴面に沿って一旦拡がり
、この過程でスラグが浴面に浮上分離される。さらに溶
銅浴面上に浮上しない微細なスラグ粒は溶鋼とスラグと
の遠心力の差によって、溶鋼回転流の中心部へ集まる。On the other hand, when molten steel mixed with slag is newly injected into the molten steel 2 which has been given horizontal rotation, the injected flow temporarily spreads along the bath surface, following the flow shown by the arrow in Figure (b). During the process, slag floats to the bath surface and is separated. Furthermore, fine slag particles that do not float on the surface of the molten copper bath gather at the center of the rotating flow of molten steel due to the difference in centrifugal force between the molten steel and the slag.
なお上記のスラグ分割をはかるには、クンデイツシュ内
溶鋼に２Ｏｒ、ｐ、ｍ、以上の水平回転を与えることが
好ましい。すなわち溶鋼に与える水平回転が２Ｏｒ、ｐ
、ｍ、未満であると、注入流の落下エネルギが水平回転
エネルギーより大きくなり、その結果第２図（ｂ）に示
したようなショートサーキットの防止効果がなくなる。In addition, in order to achieve the above-mentioned slag division, it is preferable to give horizontal rotation of 2 Or, p, m or more to the molten steel in the kundish. In other words, the horizontal rotation given to the molten steel is 2Or,p
, m, the falling energy of the injected flow becomes greater than the horizontal rotational energy, and as a result, the effect of preventing short circuits as shown in FIG. 2(b) is lost.
一方１００ ｒ、ｐ、ｍ、をこえるとタンディツシュ耐
火物の溶損量が増加することに加えて、回転による溶銅
の凹深さが増大し、その結果フリーボードの大きなタン
ディッシュが必要となり設備費の増大、熱的条件の不利
を招くため、上限は１００ ｒ、ｐ、ｍ、とすることが
好ましい。On the other hand, when the temperature exceeds 100 r, p, m, the amount of corrosion of the tundish refractory increases, and the depth of the concavity of the molten copper due to rotation increases, resulting in the need for a large tundish with freeboard, which requires equipment. The upper limit is preferably set to 100 r, p, m, since this results in increased costs and disadvantageous thermal conditions.
次にススラグを有利に分離する条件としての、タンディ
ツシュ内溶鋼の平均滞留時間（タンディツシュ容量／１
秒当たりにクンデイツシュから流出する）容鋼量）に関
して行った実機実験の結果について説明する。Next, the average residence time of molten steel in the tundish (tundish volume/1
We will explain the results of an actual machine experiment regarding the amount of steel flowing out of Kundeitshu per second).
平均滞留時間とタンディツシュからのスラグ流出率との
関係について、直径が６００ ｍｍのタンディッシュ内
に装入した溶鋼に３Ｑｒ、ｐ、ｍ、の水平回転を与えた
場合及び同様のタンディツシュ内溶鋼に回転を与えない
場合をそれぞれ調べた。その結果を第３図に示すように
、溶鋼に回転を与えない場合は平均滞留時間を５００〜
６００秒以上にしなければスラグ流出を防止できないの
に対し、溶鋼に水平回転を与えた場合は１００秒間の滞
留でスラグ流出を防止できることが判明した。Regarding the relationship between the average residence time and the slag outflow rate from the tundish, when molten steel charged in a tundish with a diameter of 600 mm is given horizontal rotation of 3 Qr, p, m, and when molten steel in a similar tundish is rotated, We examined the cases in which . The results are shown in Figure 3, where the average residence time is 500~500mm when the molten steel is not rotated.
It has been found that slag outflow cannot be prevented unless the retention period is 600 seconds or longer, whereas slag outflow can be prevented by retaining for 100 seconds when molten steel is given horizontal rotation.
しかしながら溶鋼に水平回転を与えた場合であっても、
平均滞留時間が１００秒未満ではスラブ流出率が高くな
る。これはタンディツシュ内への注入流の一部が第２図
（ａ）に示したショートサーキットを構成するためと推
測され、そこで平均滞留時間は１００秒以上とすること
が肝要となる。また平均滞留時間が３００秒をこえると
、スラグ流出防止には効果的であるが、タンディツシュ
からの溶鋼流出量（スループット量）を小さくせねばな
らず、（当然タンディッシュに供給する量も小さくする
）その結果注入ノズル径は小さくなり、ノズル詰まり等
のトラブル発生の原因となる。さらに、アトマイズ製造
においては粉末径のバラツキを非常に嫌うため溶鋼流出
量は高圧水、尚圧ガスにマツチングした量に決められて
おり、その結果、滞留時間の増加はタンディツシュ容量
を必要以上に大きくする原因となり得策でない。However, even when horizontal rotation is applied to molten steel,
When the average residence time is less than 100 seconds, the slab outflow rate becomes high. It is assumed that this is because a part of the flow injected into the tundish forms a short circuit as shown in FIG. 2(a), and therefore it is important that the average residence time is 100 seconds or more. Furthermore, if the average residence time exceeds 300 seconds, although it is effective in preventing slag outflow, the amount of molten steel flowing out from the tundish (throughput amount) must be reduced (naturally, the amount supplied to the tundish must also be reduced). ) As a result, the diameter of the injection nozzle becomes smaller, causing problems such as nozzle clogging. Furthermore, in atomization manufacturing, variations in powder diameter are extremely difficult to handle, so the flow rate of molten steel is determined to match the amount of high-pressure water and still-pressure gas. It is not a good idea to do so.
なお第３図におけるスラグ流出率とは、取鍋内湾鋼中の
スラグ系介在物量に対するタンディッシュから流出する
溶鋼中のスラグ系介在物量の比で表わす。The slag outflow rate in FIG. 3 is expressed as the ratio of the amount of slag inclusions in the molten steel flowing out from the tundish to the amount of slag inclusions in the bay steel in the ladle.
このように溶鋼に水平回転を与えた場合は平均滞留時間
として１００秒以上を確保できればよく、従来のように
、５００〜６００秒以上の滞留時間を確保するために大
容量のタンディツシュを用いる必要はない。When horizontal rotation is applied to molten steel in this way, it is sufficient to ensure an average residence time of 100 seconds or more, and there is no need to use a large-capacity tundish to ensure a residence time of 500 to 600 seconds or more, as in the past. do not have.
なお平均滞留時間は、タンディツシュの径及び／又は深
さを注入及び流出する溶鋼量によって選択することで調
整できる。Note that the average residence time can be adjusted by selecting the diameter and/or depth of the tundish depending on the amount of molten steel injected and outflowed.
また溶鋼の水平回転流の中心部に集積するスラグは、水
平回転数や平均滞留時間によって粒子径が異なる。すな
わち微細スラグ粒の分離効果を上げるには回転数が大、
平均滞留時間が長いほど有効である。しかしながら回転
数の増加はタンディツシュの内張り耐火物等の溶損によ
る外来系介在物の増加をまねき、一方滞留時間を延ばす
のはタンディツシュの大型化が必要となり、どちらも得
策ではない。そこで耐火物の溶損を回避するには回転に
よって生じる非金属介在物の最大求心力が重力より小さ
い回転数とすることが望ましい。この場合遠心力の差に
よるスラグが回転中心部に集中して分離する効果は低減
されるが、溶鋼中への不活性ガス吹きを併用することに
よってその効果の不足分を補うことができる。Furthermore, the particle size of the slag that accumulates at the center of the horizontally rotating flow of molten steel differs depending on the horizontal rotational speed and average residence time. In other words, in order to increase the separation effect of fine slag particles, the rotation speed is high.
The longer the average residence time, the more effective it is. However, increasing the rotational speed will lead to an increase in foreign inclusions due to erosion of the refractory lining of the tundish, while increasing the residence time will require increasing the size of the tundish, neither of which is a good idea. Therefore, in order to avoid melting and damage of the refractory, it is desirable to set the rotation speed to such that the maximum centripetal force of the nonmetallic inclusions generated by rotation is smaller than the gravity. In this case, the effect of the slag concentrating on the center of rotation and separating due to the difference in centrifugal force is reduced, but the lack of this effect can be compensated for by also using inert gas blowing into the molten steel.
すなわち溶鋼中に吹き込んだ気泡はスラグに比べて密度
が小さく、同一回転数であれば最大求心力はスラグに比
較して大きく、回転中心部への集中分離は容易で、この
気泡の集中分離の際に溶鋼中に懸濁している微細スラグ
粒子が捕捉されて分離がはかられる。従って、非金属介
在物の最大求心力が重力より大きい回転数の場合と同等
な効果が得られる。なお回転数が小さくても、第２図（
ｂ）に示したようなショートサーキットを防止する効果
は十分である。In other words, bubbles blown into molten steel have a lower density than slag, and at the same rotation speed, the maximum centripetal force is greater than that of slag, and it is easy to concentrate and separate them at the center of rotation. The fine slag particles suspended in the molten steel are captured and separated. Therefore, the same effect as in the case where the maximum centripetal force of the nonmetallic inclusion is greater than the gravity can be obtained. Note that even if the rotational speed is small, Fig. 2 (
The effect of preventing short circuits as shown in b) is sufficient.
なお不活性ガス吹き込み量は、２１／ｍｉｎ未満ては微
細スラグ粒子の捕捉が不十分であり、又、１０１／ｍｉ
ｎ以上になるとスプラシュが増加し操業上のトラブル発
生の原因となる。この理由から、２〜１０１／ｍｉｎ
とすることが好ましい。Note that if the inert gas blowing rate is less than 21/min, the capture of fine slag particles will be insufficient;
If it exceeds n, the amount of splash will increase and cause operational troubles. For this reason, 2~101/min
It is preferable that
（実施例）
第１図に示したタンディツシュ（直径６００ ｍｍ、高
さ１０００ｍｍ、浴深さ４００ ｍｍ）内に注入した溶
鋼に３０ｒ、ｐ、ｍ、の水平回転を与えかつ平均滞留時
間を２４０秒に調整した上で、タンディツシュから、電
炉溶製された溶鋼（５ｔｏｎ）を、２００ ｋｇ／ｍｉ
ｎの流量で流下させて噴霧処理し、アトマイズ鉄粉を製
造した（適合例１）。次いで同アトマイズ鉄粉を原料粉
末として、通常の粉末鍛造品を作製し、その清浄度およ
び介在物の粒径分布を調べた。また同様に、さらに溶鋼
中にアルゴンガス（５１／ｍ１ｎ）吹き込みを行う方法
（適合例２）及び水平回転を与えない方法（比較例）に
ついても、それぞれ同条件で得られた鍛造品の清浄度及
び介在物の粒度分布を調べた。(Example) The molten steel injected into the tundish (diameter 600 mm, height 1000 mm, bath depth 400 mm) shown in Fig. 1 was given horizontal rotation of 30 r, p, m, and the average residence time was 240 seconds. After adjusting to
The atomized iron powder was produced by spraying it down at a flow rate of n (Compatible Example 1). Next, a regular powder forged product was produced using the same atomized iron powder as a raw material powder, and its cleanliness and particle size distribution of inclusions were examined. Similarly, for the method of injecting argon gas (51/m1n) into the molten steel (Compatible Example 2) and the method of not applying horizontal rotation (Comparative Example), the cleanliness of the forged products obtained under the same conditions. and the particle size distribution of inclusions.
表１にその結果を示すように、比較法で得たアトマイズ
鉄粉の清浄度の値は極めて高く、かつ介在物の足も多く
、しかも５０μｍ以上の大型介在物が認められる。As shown in Table 1, the cleanliness value of the atomized iron powder obtained by the comparative method was extremely high, and there were many inclusions, and large inclusions of 50 μm or more were observed.
これに対しこの発明に従う適合例１（不活性ガス吹き込
み無し）では清浄度の値は比較例対比で約１７３になり
、又５０μｍ以上の大型介在物は全く認められず、その
他の介在物の減少も顕著である。On the other hand, in Compatible Example 1 according to the present invention (without inert gas blowing), the cleanliness value was approximately 173 compared to the comparative example, and no large inclusions of 50 μm or more were observed, and other inclusions were reduced. is also remarkable.
さらに不活性ガス吹き込みを併用した適合例２では清浄
度がさらに減少し、介在物の量、特に２０μｍ以下の小
型介在物の減少をはかることができた。Furthermore, in Compatible Example 2, which also used inert gas blowing, the cleanliness was further reduced, and the amount of inclusions, especially small inclusions of 20 μm or less, could be reduced.
表 １
（発明の効果）
以上のようにこの発明は、鋼中の非金属介在物の分離能
力を強化することによりすくれた品質のアトマイズ鉄粉
を容易かつ短時間で製造することができる。Table 1 (Effects of the Invention) As described above, the present invention enables the production of atomized iron powder of excellent quality easily and in a short time by strengthening the ability to separate nonmetallic inclusions in steel.
第１図はこの発明に用いる装置の模式図、第２図（ａ）
及び（ｂ）は溶鋼の注入流の動きを説明する模式図、
第３図は平均滞留時間とスラグ流出率との関係を示すグ
ラフである。
１・・・取鍋 １ａ・・・注入ノズル２・
・・７容ＫＡ ３ ・・・タンディツシ
ュ４・・・回転磁界発生父方 ５・・・バイブロ・・・
噴霧ノズル ７・・・アトマイズ銖粉８・・・噴
霧槽
（ａ）
ｒｂ）
第３図Figure 1 is a schematic diagram of the device used in this invention, Figure 2 (a)
FIG. 3 is a graph showing the relationship between average residence time and slag outflow rate. 1... Ladle 1a... Injection nozzle 2.
...7 volume KA 3 ...Tandish 4...Rotating magnetic field generation paternal side 5...Vibro...
Spray nozzle 7... Atomized powder 8... Spray tank (a) rb) Fig. 3
Claims (1)
ュから流下させた溶湯流に高圧流体を衝突させて溶湯を
粉粒化するに当たり、 タンディッシュの外側に配設した回転磁界 発生装置により、タンディッシュ内溶湯に水平回転を与
えるとともに、溶湯のタンディッシュ内での平均滞留時
間を１００〜３００秒に調整することを特徴とするアト
マイズ鉄粉の製造方法。 ２、請求項１に記載の方法において、さらにタンディッ
シュ内の溶湯に不活性ガスを吹き込むことを特徴とする
アトマイズ鉄粉の製造方法。 ３、溶湯に与える水平回転は２０〜１００ｒ．ｐ．ｍ．
である請求項１または２に記載の方法。[Claims] 1. When supplying molten metal to a tundish and colliding a high-pressure fluid with the molten metal stream flowing down from the tundish to pulverize the molten metal, a rotating magnetic field provided outside the tundish is used. A method for producing atomized iron powder, which comprises applying horizontal rotation to the molten metal in the tundish using a generator, and adjusting the average residence time of the molten metal in the tundish to 100 to 300 seconds. 2. A method for producing atomized iron powder according to claim 1, further comprising blowing an inert gas into the molten metal in the tundish. 3. Horizontal rotation given to the molten metal is 20 to 100 rpm. p. m.
The method according to claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32966189A JPH03191004A (en) | 1989-12-21 | 1989-12-21 | Manufacture of atomized iron powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32966189A JPH03191004A (en) | 1989-12-21 | 1989-12-21 | Manufacture of atomized iron powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03191004A true JPH03191004A (en) | 1991-08-21 |
Family
ID=18223847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32966189A Pending JPH03191004A (en) | 1989-12-21 | 1989-12-21 | Manufacture of atomized iron powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03191004A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5779102A (en) * | 1980-09-08 | 1982-05-18 | Asea Ab | Metal powder producing method and device |
| JPS6431907A (en) * | 1987-07-27 | 1989-02-02 | Nippon Kokan Kk | Apparatus for producing metal powder |
-
1989
- 1989-12-21 JP JP32966189A patent/JPH03191004A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5779102A (en) * | 1980-09-08 | 1982-05-18 | Asea Ab | Metal powder producing method and device |
| JPS6431907A (en) * | 1987-07-27 | 1989-02-02 | Nippon Kokan Kk | Apparatus for producing metal powder |
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