JPH09170002A - Iron powder finish heat-treating method and device therefor - Google Patents
Iron powder finish heat-treating method and device thereforInfo
- Publication number
- JPH09170002A JPH09170002A JP8270750A JP27075096A JPH09170002A JP H09170002 A JPH09170002 A JP H09170002A JP 8270750 A JP8270750 A JP 8270750A JP 27075096 A JP27075096 A JP 27075096A JP H09170002 A JPH09170002 A JP H09170002A
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- Japan
- Prior art keywords
- heat treatment
- raw material
- magnetic field
- acid
- powder
- 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.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、焼結部品、磁性材
料等の焼結製品の原料粉として使用される鉄粉や、粉末
のままで使用される鉄粉の脱酸、脱炭および脱窒等の仕
上げ熱処理方法およびそれに使用する装置に関する。TECHNICAL FIELD The present invention relates to an iron powder used as a raw material powder of a sintered product such as a sintered part and a magnetic material, and an iron powder used as a powder, for deoxidation, decarburization and deoxidation. The present invention relates to a finishing heat treatment method such as nitrification and an apparatus used for the method.
【０００２】[0002]
【従来の技術】例えば、粗還元したミルスケール還元鉄
粉やアトマイズしたままの鉄粉（以下原料粉という）等
は、その用途に応じて脱酸、脱炭、脱窒あるいは脱硫等
の熱処理が１種以上行われる。これらの仕上げ熱処理
は、移動床と呼ばれる連続的に移動するベルト上に原料
粉を積層し、温度および雰囲気が制御された水平炉（連
続式移動床炉という）内を連続的に通過させることで、
この原料粉が雰囲気中の水蒸気ないし水素と反応し、下
記の反応式で示されるように脱酸、脱炭ないし脱窒が行
われる。2. Description of the Related Art For example, roughly reduced mill-scale reduced iron powder or as-atomized iron powder (hereinafter referred to as raw material powder) is subjected to heat treatment such as deoxidation, decarburization, denitrification or desulfurization depending on the application. One or more types are performed. These finishing heat treatments consist of stacking raw material powder on a continuously moving belt called a moving bed, and continuously passing it through a horizontal furnace whose temperature and atmosphere are controlled (called a continuous moving bed furnace). ,
This raw material powder reacts with water vapor or hydrogen in the atmosphere to perform deoxidation, decarburization or denitrification as shown in the following reaction formula.
【０００３】 ＦｅＯ（ｓ）＋Ｈ2 （ｇ）＝Ｆｅ（ｓ）＋Ｈ2 Ｏ Ｃ（in Ｆｅ）＋Ｈ2 Ｏ（ｇ）＝ＣＯ（ｇ）＋Ｈ
2 （ｇ） Ｎ（in Ｆｅ）＋３／２Ｈ2 （ｇ）＝ＮＨ3 （ｇ） これらの仕上げ熱処理を効率良く行うため、従来種々の
提案がなされている。例えば、特公昭57−58401 号公報
には移動床炉を用いて水蒸気を含む水素中で脱炭と脱酸
を行う方法が開示されており、また、特公昭58−482 号
公報には移動床炉を用いて水素中の水蒸気量を変えて脱
炭あるいは脱酸を優先的に行う方法が提案されている。
また、特開昭59−35601 号公報には脱炭、脱酸の後、 9
00〜550℃で徐冷して脱窒を積極的に行う方法が開示さ
れている。さらに、特開昭61−110701号公報には連続式
移動床炉内を進行方向に分割して各処理工程を独立させ
た上で、移動床上の原料粉が焼結する位置以降で雰囲気
ガスをファンで撹拌して炉内の反応生成ガスが原料粉上
に滞留する（よどむ）ことを防止することにより反応を
促進する方法が開示されている。FeO (s) + H 2 (g) = Fe (s) + H 2 O C (in Fe) + H 2 O (g) = CO (g) + H
2 (g) N (in Fe) + 3 / 2H 2 (g) = NH 3 (g) Various proposals have heretofore been made in order to efficiently perform these finishing heat treatments. For example, Japanese Patent Publication No. 57-58401 discloses a method of decarburizing and deoxidizing in hydrogen containing steam using a moving bed furnace, and Japanese Patent Publication No. 58-482 discloses moving bed. A method of preferentially performing decarburization or deoxidation by changing the amount of water vapor in hydrogen using a furnace has been proposed.
Further, in Japanese Patent Laid-Open No. 59-35601, after decarburization and deoxidation,
A method of positively performing denitrification by gradually cooling at 00 to 550 ° C is disclosed. Furthermore, in JP-A-61-110701, the inside of a continuous moving bed furnace is divided in the direction of travel to make each processing step independent, and after the position where raw material powder on the moving bed is sintered, atmospheric gas is supplied. A method is disclosed in which a reaction is promoted by stirring with a fan to prevent the reaction product gas in the furnace from staying (stagnation) on the raw material powder.
【０００４】[0004]
【発明が解決しようとする課題】しかし、これらの方法
はいずれも原料粉の上にある雰囲気に関するものであ
り、原料粉層の表面にある原料粉と雰囲気中の水素ない
し水蒸気との反応は促進されるが、原料粉層の内部にあ
る原料粉との反応は遅くなり、結果的に生産性は不十分
であった。However, these methods are all related to the atmosphere above the raw material powder, and the reaction between the raw material powder on the surface of the raw material powder layer and hydrogen or water vapor in the atmosphere is promoted. However, the reaction with the raw material powder inside the raw material powder layer was delayed, resulting in insufficient productivity.
【０００５】ここにおいて本発明者らは、原料粉の脱
酸、脱炭、脱窒が上記反応式で示される反応で進行する
ことから、水素ないし水蒸気が原料粉層を容易に通過し
て供給される必要があることに着目し、当該層のガスの
通気性を改善することで熱処理の効率を向上させんとの
観点から、当該層の通気性改善手段を鋭意検討した結
果、本発明をなすに至った。Here, since the deoxidation, decarburization, and denitrification of the raw material powder proceed in the reaction represented by the above reaction formula, the present inventors can easily supply hydrogen or water vapor through the raw material powder layer. Focusing on the need to be performed, from the viewpoint of improving the efficiency of heat treatment by improving the gas permeability of the layer, as a result of diligent study of the gas permeability improving means of the layer, the present invention It came to eggplant.
【０００６】[0006]
【課題を解決するための手段】本発明は、脱酸、脱炭お
よび脱窒の各熱処理のうち１種または２種以上の熱処理
を行う鉄粉の仕上げ熱処理方法において、原料粉に磁場
を印加したまま水分、好ましくは酸を溶解させた水分、
を含有させた後、当該原料粉の熱処理を行うことを特徴
とする鉄粉の仕上げ熱処理方法である。According to the present invention, a magnetic field is applied to a raw material powder in a finishing heat treatment method for iron powder, wherein one or more heat treatments of deoxidation, decarburization and denitrification are performed. Water as it is, preferably water in which an acid is dissolved,
Is a finishing heat treatment method for iron powder, characterized in that the raw material powder is subjected to heat treatment after the addition of.
【０００７】前記酸は、例えば炭酸，ぎ酸，酢酸，安息
香酸，シュウ酸等の、Ｃ，Ｏ，Ｈのみからなる酸である
ことが好ましく、また、水分中の酸濃度は 0.10wt ％以
上20wt％未満であることが好ましい。前記鉄粉の仕上げ
熱処理は、連続式移動床炉で連続的に行われることが好
ましい。The acid is preferably an acid consisting of only C, O and H, such as carbonic acid, formic acid, acetic acid, benzoic acid and oxalic acid, and the acid concentration in water is 0.10 wt% or more. It is preferably less than 20 wt%. It is preferable that the finish heat treatment of the iron powder is continuously performed in a continuous moving bed furnace.
【０００８】また、本発明は、脱酸、脱炭および脱窒の
各熱処理のうち１種または２種以上の熱処理を行う鉄粉
の仕上げ熱処理装置において、原料粉の供給部と熱処理
部の間に、原料粉の移動方向に原料粉に磁場を印加する
ための磁場発生装置と、磁場を印加された原料粉に水分
を含有させる水分供給装置とをこの順序で近接して配設
したことを特徴とする鉄粉の仕上げ熱処理装置である。
前記鉄粉の仕上げ熱処理装置は、連続式移動床炉である
ことが好ましい。Further, the present invention is a finishing heat treatment apparatus for iron powder, which performs one or more heat treatments of deoxidation, decarburization and denitrification, between a raw material powder supply section and a heat treatment section. In addition, a magnetic field generator for applying a magnetic field to the raw material powder in the moving direction of the raw material powder, and a moisture supply device for containing moisture in the raw material powder to which the magnetic field is applied are arranged close to each other in this order. This is a characteristic iron powder finishing heat treatment device.
The iron powder finishing heat treatment apparatus is preferably a continuous moving bed furnace.
【０００９】[0009]
【発明の実施の形態】上述のように、脱酸、脱炭ないし
脱窒は以下の反応で進行することが知られている。 ＦｅＯ（ｓ）＋Ｈ2 （ｇ）＝Ｆｅ（ｓ）＋Ｈ2 Ｏ Ｃ（in Ｆｅ）＋Ｈ2 Ｏ（ｇ）＝ＣＯ（ｇ）＋Ｈ
2 （ｇ） Ｎ（in Ｆｅ）＋３／２Ｈ2 （ｇ）＝ＮＨ3 （ｇ） いずれも水素あるいは水蒸気が原料粉層に供給される必
要があり、当該層の通気性に依存する。すなわち、層厚
が厚いほど反応にとって不利であり、逆に層の厚みを薄
くすると反応にとっては有利であるが、生産性から考え
ると限界がある。そこで、原料粉層のガス通気性を良く
する手段を種々検討した結果、原料粉層に磁場をかける
と磁力線の方向に原料粉が配列し、充填密度が低下して
通気性が良くなることが判明した。BEST MODE FOR CARRYING OUT THE INVENTION As described above, it is known that deoxidation, decarburization and denitrification proceed by the following reactions. FeO (s) + H 2 (g) = Fe (s) + H 2 O C (in Fe) + H 2 O (g) = CO (g) + H
2 (g) N (in Fe) + 3 / 2H 2 (g) = NH 3 (g) In either case, hydrogen or water vapor needs to be supplied to the raw material powder layer and depends on the air permeability of the layer. That is, the thicker the layer, the more unfavorable to the reaction, and conversely, the thinner the layer, the better to the reaction, but there is a limit in view of productivity. Therefore, as a result of various studies on means for improving the gas permeability of the raw material powder layer, when a magnetic field is applied to the raw material powder layer, the raw material powder is arranged in the direction of the magnetic lines of force, and the packing density is lowered and the air permeability is improved. found.
【００１０】しかしながら、この状態では磁場を取り去
ると原料粉層は再び元の充填状態に戻ってしまうため、
さらに検討した結果、磁場をかけた状態で水分を含ませ
ると、磁場を除いても低充填密度の配列構造を保持する
ことが可能であることがわかった。この場合、水分とし
ては、蒸留水、純水、工場内環水等いずれでも構わな
い。さらに、この水分として酸を溶解させた水（酸水溶
液）を用いると、上記配列構造がより強固に保たれるこ
とが判明した。However, in this state, when the magnetic field is removed, the raw material powder layer returns to the original filling state again.
As a result of further study, it was found that by including water under a magnetic field, it is possible to maintain an array structure with a low packing density even if the magnetic field is removed. In this case, the water content may be any of distilled water, pure water, in-plant circulating water, and the like. Furthermore, it has been found that the use of water (acid aqueous solution) in which an acid is dissolved as this water makes it possible to maintain the above-mentioned array structure more firmly.
【００１１】なお、加熱するに従い水分が蒸発除去され
ても充填密度が上がることはない。これは加熱により原
料粉間の接触点において焼結が起こり、原料粉間の配列
構造が弱いながらも維持されるためと考えられる。さら
に、水分として酸水溶液を用いると、その酸が原料粉表
面の酸化を促進するので、水単体の場合よりも原料粉相
互の間に酸化物が促進して形成され、この酸化物が結合
剤として作用し、磁場印加でもたらされた原料粉間の配
列構造を磁場除去状態でも保持する保持力の強化に寄与
するものと考えられる。It should be noted that the filling density does not increase even if the water content is evaporated and removed by heating. It is considered that this is because the heating causes sintering at the contact points between the raw material powders and the arrangement structure between the raw material powders is maintained even though it is weak. Furthermore, when an aqueous acid solution is used as water, the acid accelerates the oxidation of the surface of the raw material powder, so that an oxide is formed between the raw material powders more than in the case of water alone. Is considered to contribute to strengthening the coercive force that holds the array structure between the raw material powders brought about by the magnetic field application even in the magnetic field removed state.
【００１２】水分に溶かし込む酸の種類は、鉄粉中に微
量残っても有害となるＢ，Ｐ，Ｓ等の成分を含まないも
のであること、排気ガスにＮＯx ，ＳＯx ，塩素ガス等
の環境汚染物質が含まれないものであることが望まし
く、それゆえＣ，Ｏ，Ｈのみから構成される酸、例え
ば、炭酸，ぎ酸，酢酸，安息香酸，シュウ酸等のうちか
ら選定するのが好ましい。The type of acid that dissolves in water is that it does not contain components such as B, P, and S that are harmful even if a trace amount remains in the iron powder, and the exhaust gas contains NOx, SOx, chlorine gas, and the like. It is desirable that it does not contain environmental pollutants, and therefore it is preferable to select an acid composed only of C, O, and H, such as carbonic acid, formic acid, acetic acid, benzoic acid, and oxalic acid. preferable.
【００１３】また、酸水溶液の酸濃度が0.10wt％未満で
あると、磁場除去後の原料粉の配列構造保持効果が水単
体の場合とほとんど変わらないので、酸水溶液は0.10wt
％以上の酸濃度に調整するのが好ましい。また、酸濃度
が20wt％以上であると、酸が強すぎて炉内付帯設備を浸
食する等の悪影響が大きくなるので、酸濃度は20wt％未
満に調整するのが好ましい。Further, if the acid concentration of the aqueous acid solution is less than 0.10 wt%, the effect of maintaining the array structure of the raw material powder after removal of the magnetic field is almost the same as in the case of water alone.
It is preferable to adjust the acid concentration to at least%. Further, when the acid concentration is 20 wt% or more, the acid is too strong and the adverse effects such as erosion of the auxiliary equipment in the furnace become large, so it is preferable to adjust the acid concentration to less than 20 wt%.
【００１４】連続式移動床炉の場合、磁場を印加する場
所すなわち磁場発生装置と、その直後に置かれる原料粉
に水分を含有させる場所すなわち水分供給装置の設置場
所としては、原料粉の供給部（供給装置）と熱処理部の
間でなければならない。磁場発生装置と水分供給装置と
が近接していない場合、原料粉に印加される磁場が小さ
くなり、十分な通気性の得られない状態で水分が供給さ
れることになる。また、原料粉が熱処理部に挿入された
後で磁場を印加する場合、原料粉の温度が上昇して原料
粉に磁力が生じない可能性があるばかりか、磁場発生装
置の設置自体が困難である。In the case of a continuous moving bed furnace, the place where the magnetic field is applied, that is, the magnetic field generator, and the place where the raw material powder placed immediately after that contains moisture, that is, the installation place of the moisture supply device, are the raw material powder supply section. It must be between the (feeding device) and the heat treatment section. When the magnetic field generator and the water supply device are not in close proximity to each other, the magnetic field applied to the raw material powder becomes small, and the water is supplied in a state where sufficient air permeability is not obtained. Also, when applying a magnetic field after the raw material powder is inserted into the heat treatment section, the temperature of the raw material powder may rise and magnetic force may not occur in the raw material powder, and it is difficult to install the magnetic field generator itself. is there.
【００１５】磁場発生装置の磁石としては永久磁石、電
磁石のどちらでも必要な磁場が得られるものであれば良
い。磁場発生装置の構造としては必要な磁場が得られる
限り制限されるものではないが、均一な磁場のためには
原料粉層の上下に磁石の対極が位置するものが好まし
い。The magnet of the magnetic field generator may be either a permanent magnet or an electromagnet as long as the required magnetic field is obtained. The structure of the magnetic field generator is not limited as long as a necessary magnetic field can be obtained, but for a uniform magnetic field, a structure in which the counter electrodes of the magnets are located above and below the raw material powder layer is preferable.
【００１６】必要な磁場の大きさは原料粉層の厚みに依
存するが、いずれの部分においても50ガウス以上印加さ
れれば十分である。連続式移動床炉の場合、原料粉層の
厚みが20mmから100mm であれば 100〜2000ガウスが好ま
しい。磁場を取り除いた後の原料粉の配列構造を磁場を
印加した状態と同じに維持するのに必要な水分量は、原
料粉に対して重量％で３〜25wt％が好ましい。３wt％未
満であると配列構造を維持するのが難しくなり、25wt％
を超えると原料粉層がスラリー化してしまう恐れがあ
り、また水分を過度に蒸発させる必要があるので熱収支
の上でも、経済的にも好ましくない。The magnitude of the required magnetic field depends on the thickness of the raw material powder layer, but it is sufficient to apply 50 gauss or more to any portion. In the case of a continuous moving bed furnace, if the raw material powder layer has a thickness of 20 mm to 100 mm, 100 to 2000 Gauss is preferable. The amount of water required to maintain the array structure of the raw material powder after removing the magnetic field in the same state as when the magnetic field is applied is preferably 3 to 25 wt% in weight% with respect to the raw material powder. If it is less than 3 wt%, it becomes difficult to maintain the array structure, and 25 wt%
If it exceeds, the raw material powder layer may be slurried, and it is necessary to evaporate water excessively, which is not preferable in terms of heat balance and economically.
【００１７】なお、磁場除去後の原料粉の配列構造を強
固に維持したい場合には、酸に代えて水溶性のビニル系
樹脂（ポリビニルアルコール、酢酸ビニルアルコール
等）を添加剤として水に加えてもよい。When it is desired to firmly maintain the array structure of the raw material powder after removing the magnetic field, a water-soluble vinyl resin (polyvinyl alcohol, vinyl acetate alcohol, etc.) is added to water as an additive instead of the acid. Good.
【００１８】[0018]
＜第１実施例＞表１のＡに示すアトマイズ生粉を50cm×
50cm×厚み10cmに積層して原料粉層を形成し、図３(a)
に模式図で示す実験装置における磁場発生装置12によ
り、この原料粉層21の表面に1000ガウス、中央に 200ガ
ウスの磁場を印加した状態で原料粉に対して５wt％の水
分を添加した。磁場除去後、原料粉層21を積層状態のま
ま図３(b) に示す実験装置における雰囲気炉22に装入
し、昇温速度20℃／分で 950℃まで昇温後、この温度に
て０〜60分保持し、炉冷した。炉内はＨ2 を80体積％、
Ｈ2 Ｏを１体積％含むAr雰囲気に維持した。<First Example> 50 cm of atomized raw flour shown in A of Table 1
50 cm x 10 cm thick is laminated to form a raw material powder layer, as shown in Fig. 3 (a)
5 wt% of water was added to the raw material powder in a state where a magnetic field of 1000 gauss was applied to the surface of the raw material powder layer 21 and 200 gauss was applied to the center by the magnetic field generator 12 in the experimental apparatus shown in the schematic diagram. After removing the magnetic field, the raw material powder layer 21 in the laminated state was charged into the atmosphere furnace 22 in the experimental apparatus shown in Fig. 3 (b), and the temperature was raised to 950 ° C at a heating rate of 20 ° C / min. It was kept for 0 to 60 minutes and cooled in the furnace. 80% by volume of H 2 in the furnace,
An Ar atmosphere containing 1% by volume of H 2 O was maintained.
【００１９】このようにして得られた熱処理時の鉄粉
（実施例１）中の酸素および窒素の含有量の変化のグラ
フを図４に示す。磁場の印加と水分の添加がないほかは
実施例１と同一とした比較例の熱処理時の鉄粉（比較例
１）中の酸素および窒素の含有量の変化を図４に併せて
示す。実施例１と比較例１との比較から明らかなよう
に、原料粉に磁場を印加した状態で水分を加えた後に熱
処理した場合には、脱酸および脱窒に要する時間は大幅
に低減できる。 ＜第２実施例＞表１のＢに示すミルスケール粗還元粉を
50cm×50cm×厚み10cmに積層して原料粉層を形成し、図
３（ａ）に示す磁場発生装置12により、表面 700、中央
200ガウスの磁場を印加した状態で原料粉に対して20wt
％の水分を添加した。磁場除去後、積層状態のまま図３
（ｂ）に示す雰囲気炉22に挿入し、昇温速度15℃／分で
930℃まで昇温後、この温度にて０〜80分保持し、炉冷
した。炉内はＨ2 Ｏを 3.5体積％、Ｈ2 を50体積％含む
Ar雰囲気に維持した。FIG. 4 is a graph showing changes in the oxygen and nitrogen contents in the iron powder (Example 1) during the heat treatment thus obtained. FIG. 4 also shows changes in the oxygen and nitrogen contents in the iron powder (Comparative Example 1) during the heat treatment of the Comparative Example which was the same as Example 1 except that no magnetic field was applied and no water was added. As is clear from the comparison between Example 1 and Comparative Example 1, the time required for deoxidation and denitrification can be significantly reduced when heat treatment is performed after adding water in a state where a magnetic field is applied to the raw material powder. <Second Embodiment> A mill scale crude reduced powder shown in B of Table 1 was used.
The raw material powder layer is formed by stacking 50 cm × 50 cm × thickness 10 cm, and the magnetic field generator 12 shown in FIG.
20 wt with respect to the raw material powder with a magnetic field of 200 Gauss applied
% Water was added. Figure 3
Insert into the atmosphere furnace 22 shown in (b), and raise the temperature at 15 ° C / min.
After the temperature was raised to 930 ° C., the temperature was maintained for 0 to 80 minutes, and the furnace was cooled. The furnace contains 3.5% by volume of H 2 O and 50% by volume of H 2.
Maintained in Ar atmosphere.
【００２０】熱処理時の鉄粉（実施例２）中の炭素の含
有量の変化のグラフを図５に示す。比較例として磁場の
印加と水分の添加がないほかは実施例２と同一とした場
合の熱処理時の鉄粉（比較例２）中の炭素の含有量の変
化を図５に併せて示す。実施例２と比較例２との比較か
ら明らかなように、原料粉に磁場を印加した状態で水分
を加えた後熱処理した場合には、脱炭に要する時間は大
幅に低減できる。FIG. 5 is a graph showing changes in the carbon content in the iron powder (Example 2) during heat treatment. As a comparative example, FIG. 5 also shows changes in the carbon content in the iron powder (Comparative Example 2) during heat treatment when the same as Example 2 except that no magnetic field was applied and no water was added. As is clear from the comparison between Example 2 and Comparative Example 2, the time required for decarburization can be significantly reduced when heat treatment is performed after adding water to the raw material powder while applying a magnetic field.
【００２１】[0021]
【表１】 [Table 1]
【００２２】＜第３実施例＞表１のＢに示すミルスケー
ル粗還元粉をステンレス（SUS304）製容器内に50cm×50
cm×厚み10cmのサイズで充填し、図３（ａ）に示す磁場
発生装置12により、表面 700、中央 200ガウスの磁場を
印加した状態で原料粉に対して20wt％の量の酢酸水溶液
（酢酸濃度を表２に示すように0.00〜20wt％に変化させ
た）を添加した。磁場除去後、充填状態のまま図３
（ｂ）に示す雰囲気炉22に挿入し、昇温速度15℃／分で
930℃まで昇温後、この温度にて０〜80分保持し、炉冷
した。炉内はＨ2 Ｏを 3.5体積％、Ｈ2 を50体積％含む
Ar雰囲気に維持した。<Third Embodiment> Mill scale coarse reduced powder shown in B of Table 1 was placed in a stainless steel (SUS304) container and 50 cm × 50.
cm × thickness 10 cm, and a magnetic field generator 12 shown in FIG. 3 (a) applied a magnetic field of surface 700, central 200 gauss to the raw material powder in an amount of 20 wt% acetic acid aqueous solution (acetic acid The concentration was varied from 0.00 to 20 wt% as shown in Table 2) was added. Figure 3
Insert into the atmosphere furnace 22 shown in (b), and raise the temperature at 15 ° C / min.
After the temperature was raised to 930 ° C., the temperature was maintained for 0 to 80 minutes, and the furnace was cooled. The furnace contains 3.5% by volume of H 2 O and 50% by volume of H 2.
Maintained in Ar atmosphere.
【００２３】熱処理後の鉄粉充填層の配列構造に関し、
層表面の目視観察から保形状態を、酢酸濃度０wt％（水
単体）の場合を基準として、良（○），同等（△），劣
（×）で評価し、また、鉄粉を充填した容器の厚みを計
測して酸による浸食を評価した結果を表２に示す。濃度
0.10wt ％以上の酢酸水溶液添加で磁場除去後の原料粉
の配列構造がより強固に維持され、熱処理後の保形状態
が水単体添加の場合より良化するが、濃度20wt％以上で
は充填容器への酸浸食が激化することがわかる。Regarding the arrangement structure of the iron powder packing layer after heat treatment,
From the visual observation of the layer surface, the shape retention state was evaluated as good (○), equivalent (△), poor (x) based on the case of acetic acid concentration of 0 wt% (water alone), and filled with iron powder. Table 2 shows the results of evaluation of acid erosion by measuring the thickness of the container. concentration
When 0.10 wt% or more of acetic acid aqueous solution is added, the array structure of the raw material powder after magnetic field removal is more firmly maintained, and the shape retention after heat treatment is better than when water alone is added, but at a concentration of 20 wt% or more, the filling container It can be seen that the acid erosion on the steel is intensified.
【００２４】また、熱処理時の鉄粉中の炭素含有量の変
化のグラフを図６に示す。水分に 0.10wt ％以上の酢酸
を溶解させると、水単体の場合に比べ鉄粉の配列構造が
より強固に維持されることから鉄粉充填層内の反応がよ
り促進され、図示のように脱炭所要時間がさらに短縮す
る。FIG. 6 is a graph showing changes in carbon content in iron powder during heat treatment. When 0.10 wt% or more of acetic acid is dissolved in water, the arrangement structure of the iron powder is maintained more firmly than in the case of water alone, so that the reaction in the iron powder packed bed is further promoted and the desorption is performed as shown in the figure. The time required for charcoal is further reduced.
【００２５】[0025]
【表２】 [Table 2]
【００２６】＜第４実施例＞第３実施例において、酢酸
水溶液に代えて表３に第４実施例として示す酸（ぎ酸、
炭酸、安息香酸、シュウ酸）の水溶液（酸濃度 5.0wt
％）としたほかは第３実施例と同様の熱処理を行い、同
様の調査を行った結果を表３に示す。酢酸の場合と同様
の結果である。なお、熱処理時の鉄粉中の炭素含有量の
変化についても調査したが、図６の酢酸濃度 0.10wt ％
以上の場合のカーブに重なった。<Fourth Embodiment> In the third embodiment, the acid (formic acid,
Carbonic acid, benzoic acid, oxalic acid) aqueous solution (acid concentration 5.0 wt
%), The same heat treatment as in Example 3 was performed, and the results of the same investigation are shown in Table 3. The result is similar to that of acetic acid. The change in the carbon content in the iron powder during heat treatment was also investigated. The acetic acid concentration in Fig. 6 was 0.10 wt%.
The curve overlapped in the above cases.
【００２７】[0027]
【表３】 [Table 3]
【００２８】＜第５実施例＞図１は連続式移動床炉を用
いた本発明の仕上げ熱処理装置の概念図である。熱処理
炉20を仕切壁１により脱炭ゾーン２、脱酸ゾーン３、脱
窒ゾーン４に分け、ガス吹き込み管51、52を設置し、脱
炭ゾーン２にはガス吹き込み管52により水蒸気を含む雰
囲気ガスを導入し、脱酸ゾーン３、脱窒ゾーン４にはガ
ス吹き込み管51により水素を含む雰囲気ガスを導入し、
反応後の生成ガスを含む雰囲気ガスは脱炭ゾーン２に設
置された排ガス管６から排気できるようにした。<Fifth Embodiment> FIG. 1 is a conceptual diagram of a finishing heat treatment apparatus of the present invention using a continuous moving bed furnace. The heat treatment furnace 20 is divided into a decarburizing zone 2, a deoxidizing zone 3 and a denitrifying zone 4 by a partition wall 1, gas blowing pipes 51 and 52 are installed, and the decarburizing zone 2 has an atmosphere containing water vapor through the gas blowing pipe 52. A gas is introduced, and an atmosphere gas containing hydrogen is introduced into the deoxidizing zone 3 and the denitrifying zone 4 through a gas blowing pipe 51,
The atmosphere gas containing the product gas after the reaction was allowed to be exhausted from the exhaust gas pipe 6 installed in the decarburization zone 2.
【００２９】原料粉７は原料ホッパ８からベルト９に供
給され、熱処理炉20に送られる。ベルト９は熱処理炉20
の両端にあるホイール10で駆動され、熱処理炉20の加熱
にはラジアントチューブ11を用いた。熱処理部である熱
処理炉20と原料供給部である原料ホッパ８の間にベルト
９の上下に対極の磁石を有する磁場発生装置12を設置
し、その直後に磁場を印加されている状態の原料粉７に
水分を供給する配管13（水分供給装置）を設けた。図２
は磁場発生装置12近辺の拡大図である。The raw material powder 7 is supplied from the raw material hopper 8 to the belt 9 and sent to the heat treatment furnace 20. Belt 9 is heat treatment furnace 20
The radiant tube 11 was used to heat the heat treatment furnace 20 driven by the wheels 10 at both ends of the. A magnetic field generator 12 having magnets of opposite poles is installed above and below a belt 9 between a heat treatment furnace 20 which is a heat treatment section and a raw material hopper 8 which is a raw material supply section, and immediately after that, a raw material powder in a state where a magnetic field is applied. A pipe 13 (moisture supply device) for supplying water to 7 was provided. FIG.
FIG. 3 is an enlarged view of the vicinity of the magnetic field generator 12.
【００３０】この装置を用いた場合の実施例（実施例
３）を以下に述べる。原料粉７としては表１のＢに示す
ミルスケール粗還元粉を用いた。熱処理炉20の炉温は 9
50℃に設定し、脱窒ゾーン４へはガス吹き込み管51から
水素を200Nm3／hr導入し、脱炭ゾーン２へはガス吹き込
み管52から水蒸気を 70Nm3／hr導入した。An example (Example 3) using this apparatus will be described below. As the raw material powder 7, the mill scale crude reduced powder shown in B of Table 1 was used. The furnace temperature of the heat treatment furnace 20 is 9
The temperature was set to 50 ° C., 200 Nm 3 / hr of hydrogen was introduced into the denitrification zone 4 from the gas blowing pipe 51, and 70 Nm 3 / hr of steam was introduced into the decarburizing zone 2 from the gas blowing pipe 52.
【００３１】原料粉に印加する磁場は、原料粉層の底部
で1000ガウス、表面で 200ガウス程度となるように設定
した。また、原料粉に添加した水分量は原料粉に対して
15wt％程度になるようコントロールした。仕上げ熱処理
後の鉄粉の炭素、酸素、窒素の含有量は表４のとおり
0.002wt％Ｃ，0.27wt％Ｏ，0.0015wt％Ｎである。この
場合の生産量は 5.5ｔ／hrであった。The magnetic field applied to the raw material powder was set so that the bottom portion of the raw material powder layer was about 1000 gauss and the surface was about 200 gauss. Also, the amount of water added to the raw material powder is
It was controlled to be about 15 wt%. Table 4 shows the carbon, oxygen, and nitrogen contents of the iron powder after the finishing heat treatment.
It is 0.002 wt% C, 0.27 wt% O, 0.0015 wt% N. The production amount in this case was 5.5 t / hr.
【００３２】比較例として、磁場を印加することなく同
程度の炭素、酸素、窒素含有量が得られるように、ベル
トの移動速度を低下させた他は実施例３と同様にして操
業を行った（比較例３）。この場合の仕上げ熱処理後の
鉄粉の炭素、酸素、窒素の含有量は表４のとおり 0.003
wt％Ｃ，0.29wt％Ｏ，0.0018wt％Ｎであるが、生産量は
3.1ｔ／hrであった。As a comparative example, the operation was carried out in the same manner as in Example 3 except that the moving speed of the belt was lowered so that the carbon, oxygen and nitrogen contents were almost the same without applying a magnetic field. (Comparative example 3). In this case, the content of carbon, oxygen and nitrogen in the iron powder after finishing heat treatment is 0.003 as shown in Table 4.
wt% C, 0.29 wt% O, 0.0018 wt% N
It was 3.1 t / hr.
【００３３】すなわち本発明により、鉄粉の仕上げ熱処
理の生産性は約 1.8倍となった。That is, according to the present invention, the productivity of finish heat treatment of iron powder is increased by about 1.8 times.
【００３４】[0034]
【表４】 [Table 4]
【００３５】＜第６実施例＞原料粉に添加する水分とし
て表５に示す酢酸水溶液（酢酸濃度も同表に示す）を使
用し、酢酸濃度0.10wt％以上の場合に酢酸濃度0.00wt％
（水単体：上記第５実施例の実施例３に対応）の場合と
同程度の酸素、炭素、窒素含有量が得られるように、ベ
ルトの移動速度を増大させた以外は前記実施例３と同じ
設備・原料粉・操業条件で熱処理を行った。この場合の
仕上げ熱処理後の鉄粉の炭素、酸素、窒素の含有量は表
５のとおり0.0015〜0.0020wt％Ｃ，0.25〜0.27wt％Ｏ，
0.0012〜0.0015wt％Ｎであり、生産量は、酢酸濃度0.10
wt％未満の場合に実施例３と同じ 5.5ｔ／hrであるのに
対し、酢酸濃度0.10wt％以上の場合には 6.1〜6.2 ｔ／
hrと向上した。<Sixth Embodiment> The acetic acid aqueous solution shown in Table 5 (acetic acid concentration is also shown in the table) is used as the water content added to the raw material powder, and when the acetic acid concentration is 0.10 wt% or more, the acetic acid concentration is 0.00 wt%.
The same as Example 3 except that the moving speed of the belt was increased so that the oxygen, carbon, and nitrogen contents of the same degree as in the case of (water alone: corresponding to Example 3 of the fifth example above) were obtained. Heat treatment was performed using the same equipment, raw material powder, and operating conditions. In this case, the contents of carbon, oxygen, and nitrogen of the iron powder after the finish heat treatment are 0.0015 to 0.0020 wt% C, 0.25 to 0.27 wt% O, as shown in Table 5.
0.0012 to 0.0015 wt% N, the production amount is acetic acid concentration 0.10
When it is less than wt%, it is 5.5 t / hr, which is the same as in Example 3, whereas when the concentration of acetic acid is 0.10 wt% or more, it is 6.1 to 6.2 t / hr.
improved with hr.
【００３６】[0036]
【表５】 [Table 5]
【００３７】＜第７実施例＞原料粉に添加する水分とし
て表６に示す各種酸の水溶液（酸濃度 5.0wt％）を使用
した以外は上記第６実施例と同じ設備・原料粉・操業条
件（ベルト移動速度についても同様）で熱処理を行っ
た。この場合の仕上げ熱処理後の鉄粉の炭素、酸素、窒
素の含有量は表６のとおり0.0015〜0.0018wt％Ｃ，0.25
〜0.26wt％Ｏ，0.0012〜0.0013wt％Ｎであり、生産量
は、第６実施例における酢酸濃度0.10wt％以上の場合と
同程度の 6.1〜6.2 ｔ／hrに達し、水単体の場合の 5.5
ｔ／hrよりも向上した。<Seventh Embodiment> The same equipment, raw material powder, and operating conditions as those of the above sixth embodiment except that the aqueous solutions of various acids shown in Table 6 (acid concentration 5.0 wt%) were used as the water added to the raw material powder. (The same applies to the belt moving speed). In this case, the content of carbon, oxygen, and nitrogen of the iron powder after the finish heat treatment is 0.0015 to 0.0018 wt% C, 0.25 as shown in Table 6.
.About.0.26 wt% O, 0.0012 to 0.0013 wt% N, and the production amount reaches 6.1 to 6.2 t / hr, which is about the same as the case where the acetic acid concentration is 0.10 wt% or more in the sixth embodiment, and in the case of water alone. 5.5
Improved than t / hr.
【００３８】[0038]
【表６】 [Table 6]
【００３９】[0039]
【発明の効果】本発明によれば、原料粉の脱酸、脱炭あ
るいは脱窒熱処理における原料粉層の水素ガスないし水
蒸気ガスの通気性が改善されるので、熱処理の効率が格
段に向上する。According to the present invention, the permeability of hydrogen gas or water vapor gas in the raw material powder layer in the deoxidation, decarburization or denitrification heat treatment of the raw material powder is improved, so that the heat treatment efficiency is remarkably improved. .
【図１】連続式移動床炉を用いた本発明の仕上げ熱処理
装置の概念図である。FIG. 1 is a conceptual diagram of a finishing heat treatment apparatus of the present invention using a continuous moving bed furnace.
【図２】磁場発生装置近辺の拡大図である。FIG. 2 is an enlarged view of the vicinity of the magnetic field generator.
【図３】実験装置の模式図である。FIG. 3 is a schematic diagram of an experimental device.
【図４】第１実施例における熱処理時の鉄粉中の酸素お
よび窒素の含有量の変化のグラフである。FIG. 4 is a graph showing changes in oxygen and nitrogen contents in iron powder during heat treatment in the first example.
【図５】第２実施例における熱処理時の鉄粉中の炭素の
含有量の変化のグラフである。FIG. 5 is a graph showing changes in carbon content in iron powder during heat treatment in the second example.
【図６】第３実施例における熱処理時の鉄粉中の炭素の
含有量の変化のグラフである。FIG. 6 is a graph showing changes in carbon content in iron powder during heat treatment in the third example.
【符号の説明】 １ 仕切壁 ２ 脱炭ゾーン ３ 脱酸ゾーン ４ 脱窒ゾーン 51，52 ガス吹き込み管 ６ 排ガス管 ７ 原料粉 ８ 原料ホッパ ９ ベルト 10 ホイール 11 ラジアントチューブ 12 磁場発生装置 13 配管 20 熱処理炉 21 原料粉層 22 雰囲気炉[Explanation of symbols] 1 partition wall 2 decarburization zone 3 deoxidation zone 4 denitrification zone 51,52 gas injection pipe 6 exhaust gas pipe 7 raw material powder 8 raw material hopper 9 belt 10 wheel 11 radiant tube 12 magnetic field generator 13 pipe 20 heat treatment Furnace 21 Raw material powder layer 22 Atmosphere furnace
Claims (7)
１種または２種以上の熱処理を行う鉄粉の仕上げ熱処理
方法において、原料粉に磁場を印加したまま水分を含有
させた後、当該原料粉の熱処理を行うことを特徴とする
鉄粉の仕上げ熱処理方法。1. A finishing heat treatment method for iron powder, wherein one or more heat treatments of deoxidation, decarburization and denitrification are carried out, and after the raw material powder is made to contain water while a magnetic field is applied. A method for finishing heat treatment of iron powder, which comprises subjecting the raw material powder to heat treatment.
１種または２種以上の熱処理を行う鉄粉の仕上げ熱処理
方法において、原料粉に磁場を印加したまま、酸を溶解
させた水分を含有させ、しかる後に当該原料粉の熱処理
を行うことを特徴とする鉄粉の仕上げ熱処理方法。2. In a finishing heat treatment method for iron powder, wherein one or more heat treatments of deoxidation, decarburization and denitrification are carried out, the acid is dissolved while applying a magnetic field to the raw material powder. A finishing heat treatment method for iron powder, which comprises containing water and then heat-treating the raw material powder.
からなる酸であり、該溶解によって生じた酸水溶液の酸
濃度が0.10wt％以上20wt％未満である請求項２記載の鉄
粉の仕上げ熱処理方法。3. The iron according to claim 2, wherein the acid dissolved in water is an acid consisting of only C, O and H, and the acid concentration of the acid aqueous solution produced by the dissolution is 0.10 wt% or more and less than 20 wt%. Finish heat treatment method for powder.
酸，酢酸，安息香酸，シュウ酸の少なくともいずれかで
ある請求項３記載の鉄粉の仕上げ熱処理方法。4. The finishing heat treatment method for iron powder according to claim 3, wherein the acid consisting of only C, O and H is at least one of carbonic acid, formic acid, acetic acid, benzoic acid and oxalic acid.
で連続的に行われることを特徴とする請求項１〜４のい
ずれかに記載の鉄粉の仕上げ熱処理方法。5. The finishing heat treatment method for iron powder according to claim 1, wherein the finishing heat treatment for iron powder is continuously performed in a continuous moving bed furnace.
１種または２種以上の熱処理を行う鉄粉の仕上げ熱処理
装置において、原料粉の供給部と熱処理部の間に、原料
粉の移動方向に原料粉に磁場を印加するための磁場発生
装置と、磁場を印加された原料粉に水分を含有させる水
分供給装置とを近接して配設したことを特徴とする鉄粉
の仕上げ熱処理装置。6. A finishing heat treatment apparatus for iron powder, which performs one or more heat treatments among deoxidation, decarburization, and denitrification heat treatments, wherein a raw material powder is provided between a raw material powder supply section and a heat treatment section. Of iron powder characterized by arranging a magnetic field generator for applying a magnetic field to the raw material powder in the moving direction of and a water supply device for containing water in the raw material powder to which the magnetic field is applied close to each other. Heat treatment equipment.
床炉であることを特徴とする請求項６記載の鉄粉の仕上
げ熱処理装置。7. The finishing heat treatment apparatus for iron powder according to claim 6, wherein the finishing heat treatment apparatus for iron powder is a continuous moving bed furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8270750A JPH09170002A (en) | 1995-10-19 | 1996-10-14 | Iron powder finish heat-treating method and device therefor |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7-271037 | 1995-10-19 | ||
| JP27103795 | 1995-10-19 | ||
| JP8270750A JPH09170002A (en) | 1995-10-19 | 1996-10-14 | Iron powder finish heat-treating method and device therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09170002A true JPH09170002A (en) | 1997-06-30 |
Family
ID=26549350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8270750A Pending JPH09170002A (en) | 1995-10-19 | 1996-10-14 | Iron powder finish heat-treating method and device therefor |
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| Country | Link |
|---|---|
| JP (1) | JPH09170002A (en) |
Cited By (6)
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| WO2017043090A1 (en) * | 2015-09-11 | 2017-03-16 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| WO2017043095A1 (en) * | 2015-09-11 | 2017-03-16 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| WO2017056510A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| WO2017056509A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| WO2017056512A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| WO2017056511A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
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1996
- 1996-10-14 JP JP8270750A patent/JPH09170002A/en active Pending
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| JP6112278B1 (en) * | 2015-09-11 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
| WO2017043095A1 (en) * | 2015-09-11 | 2017-03-16 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| KR20180022904A (en) * | 2015-09-11 | 2018-03-06 | 제이에프이 스틸 가부시키가이샤 | Production method for alloy steel powder for powder metallurgy |
| WO2017043090A1 (en) * | 2015-09-11 | 2017-03-16 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| JP6112277B1 (en) * | 2015-09-11 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
| WO2017056509A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
| JP6112283B1 (en) * | 2015-09-30 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
| JP6112281B1 (en) * | 2015-09-30 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
| JP6112282B1 (en) * | 2015-09-30 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
| WO2017056511A1 (en) * | 2015-09-30 | 2017-04-06 | Ｊｆｅスチール株式会社 | Production method for alloy steel powder for powder metallurgy |
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| JP6112280B1 (en) * | 2015-09-30 | 2017-04-12 | Ｊｆｅスチール株式会社 | Method for producing alloy steel powder for powder metallurgy |
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