JPH111701A - Finish heat treatment for iron powder - Google Patents

Finish heat treatment for iron powder

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Publication number
JPH111701A
JPH111701A JP9153489A JP15348997A JPH111701A JP H111701 A JPH111701 A JP H111701A JP 9153489 A JP9153489 A JP 9153489A JP 15348997 A JP15348997 A JP 15348997A JP H111701 A JPH111701 A JP H111701A
Authority
JP
Japan
Prior art keywords
acid
heat treatment
raw material
material powder
water
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
Application number
JP9153489A
Other languages
Japanese (ja)
Inventor
Kuniaki Ogura
邦明 小倉
Keiichi Maruta
慶一 丸田
Hiroyuki Ishikawa
博之 石川
Yoshikazu Suzuki
良和 鈴木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
Kawasaki Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Priority to JP9153489A priority Critical patent/JPH111701A/en
Publication of JPH111701A publication Critical patent/JPH111701A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To improve the productivity of a finish heat treatment of raw material powder. SOLUTION: In the finish heat treatment of iron powder using one or more kinds of the heat treatments among each heat treatment of deoxidation, decarburization and denitrification, after adding the moisture by 0.5-20 wt.% to the raw material before adding the moisture. As the moisture, acid solution containing 0.1 wt.% to <=20 wt.% acid can be used. As the acid, the acid (carbonic acid, formic acid, acetic acid, benzoic acid, oxalic acid, etc.), constituted of only C, O and H, is used.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【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
上げ熱処理方法に関する。
The present invention relates to the deoxidation, decarburization and decarburization of iron powder used as raw material powder for sintered products such as sintered parts and magnetic materials and iron powder used as powder. It relates to a finishing heat treatment method such as nitriding.

【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, rough-reduced mill-scale reduced iron powder and as-atomized iron powder (hereinafter referred to as "raw material powder") are subjected to heat treatment such as deoxidation, decarburization, denitrification or desulfurization depending on the application. One or more types are performed. In these finishing heat treatments, the raw material powder is laminated on a continuously moving belt called a moving bed, and continuously passed through a horizontal furnace (referred to as a continuous moving bed furnace) whose temperature and atmosphere are controlled. ,
This raw material powder reacts with water vapor or hydrogen in the atmosphere, and deoxidation, decarburization or denitrification is performed as shown by 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よく行うため、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。
[0003] FeO (s) + H 2 (g) = Fe (s) + H 2 OC (in Fe) + H 2 O (g) = CO (g) + H
2 (g) N (in Fe) + 3 / 2H 2 (g) = NH 3 (g) Various proposals have conventionally been made to efficiently perform these finishing heat treatments. For example, Japanese Patent Publication No. 57-58401 discloses a method of performing decarburization and deoxidation in hydrogen containing steam using a moving bed furnace, and Japanese Patent Publication No. 58-482 discloses a moving bed furnace. A method has been proposed in which decarburization or deoxidation is preferentially performed by changing the amount of water vapor in hydrogen using a furnace.
JP-A-59-35601 also discloses that after decarburization and deacidification, 9
A method of positively performing denitrification by gradually cooling at 00 to 550 ° C. is disclosed. Further, JP-A-61-110701 discloses that the inside of a continuous moving bed furnace is divided in the traveling direction to make each processing step independent, and then the atmosphere gas is supplied from the position on the moving bed where the raw material powder sinters. 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 (stagnating) 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 all relate 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】この点に鑑み、本発明は、原料粉の仕上げ
熱処理の生産性を向上させることを目的とする。
In view of this point, an object of the present invention is to improve the productivity of the finishing heat treatment of raw material powder.

【0006】[0006]

【課題を解決するための手段】本発明者らは、原料粉の
脱酸、脱炭、脱窒が上記反応式に従って進行することか
ら、熱処理前に予め原料粉層内部まで水分を浸透させて
おけばこれらの反応が促進されると洞察し、この点を実
験により確認し、その結果得られた知見に基づいて本発
明を完成した。
Means for Solving the Problems Since the deoxidation, decarburization and denitrification of the raw material powder proceed according to the above-mentioned reaction formula, the present inventors infiltrate moisture into the raw material powder layer in advance before the heat treatment. It was insighted that these reactions would be accelerated, and this point was confirmed by experiments, and the present invention was completed based on the obtained knowledge.

【0007】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、原料粉に水分を添加した後、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。水分の添加量は、添加前の原料粉に
対する重量%にて0.5 〜20wt%とするのがよい。また、
水分として酸を0.1 wt%以上20wt%未満の濃度範囲で含
む酸水溶液を使用するといっそう効果的である。酸とし
ては、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、シュウ酸等を使用するのが
好ましい。
The present invention provides a method for finishing heat treatment of iron powder in which one or more heat treatments among deoxidation, decarburization and denitrification heat treatments are carried out. A finishing heat treatment method for iron powder. The amount of water to be added is preferably 0.5 to 20% by weight based on the weight of the raw material powder before addition. Also,
It is more effective to use an aqueous acid solution containing an acid as water in a concentration range of 0.1 wt% or more and less than 20 wt%. As the acid, it is preferable to use an acid composed only of C, O and H, for example, carbonic acid, formic acid, acetic acid, benzoic acid, oxalic acid and the like.

【0008】[0008]

【発明の実施の形態】上述のように、脱酸、脱炭ないし
脱窒は以下の反応式に従って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) 本発明によれば、熱処理時間を短縮できて生産性が向上
するが、その理由は、熱処理前の原料粉に水分を添加す
ることで、原料粉層の内部まで水分が浸透して、熱処理
中に層内部の原料粉の脱炭反応が促進され、この反応で
生成した水素がさらに脱酸および/または脱窒反応を促
進することにあると考えられる。
DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, it is known that deoxidation, decarburization or denitrification proceeds according to the following reaction formula. 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) According to the present invention, the heat treatment time can be shortened and the productivity is improved. By adding moisture to the raw material layer, the moisture penetrates into the raw material powder layer, thereby promoting the decarburization reaction of the raw material powder inside the layer during the heat treatment, and the hydrogen generated by this reaction further deoxidizes and / or deoxidizes. It is thought to be to promote the nitridation reaction.

【0009】水分添加量を0.5 〜20wt%としたのは、0.
5 wt%未満では脱炭が不足し、20wt%超では脱酸が不足
するためである。水分の添加方法は、熱処理炉に装入す
る前の原料粉末に添加するだけでよい。例えば、図1に
示す仕上げ熱処理装置(連続式移動床炉)20で熱処理を
行う場合には、例えば炉の入側に散水手段(散水管)31
を設けてホッパ8内の原料粉7に散水する等の方法が好
適である。なお、図1において、1は仕切壁、2は脱炭
ゾーン、3は脱酸ゾーン、4は脱窒ゾーン、6は排ガス
管、9はベルト、10はホイール、11はラジアントチュー
ブ、51、52はガス吹き込み管である。無論、炉内に水蒸
気吹き込みを行う前記従来法との併用も可能である。
The reason why the amount of water added is 0.5 to 20% by weight is as follows.
If it is less than 5 wt%, decarburization is insufficient, and if it exceeds 20 wt%, deoxidation is insufficient. As for the method of adding water, it is only necessary to add water to the raw material powder before charging into the heat treatment furnace. For example, when heat treatment is performed in the finishing heat treatment apparatus (continuous moving bed furnace) 20 shown in FIG. 1, for example, watering means (watering pipe) 31 is provided on the inlet side of the furnace.
And spraying water on the raw material powder 7 in the hopper 8 is suitable. 1, 1 is a partition wall, 2 is a decarburization zone, 3 is a deoxidation zone, 4 is a denitrification zone, 6 is an exhaust gas pipe, 9 is a belt, 10 is a wheel, 11 is a radiant tube, 51 and 52. Is a gas injection pipe. Of course, it is also possible to use the conventional method in which steam is blown into the furnace.

【0010】水分としては、蒸留水、純水、工場内環水
等のいずれを使用してもかまわない。また、本発明者ら
の実験によれば、水分として酸を0.1 wt%以上20wt%未
満の濃度範囲で含む酸水溶液を使用するといっそう効果
的である。酸濃度が0.1 wt%未満であると水単体の場合
と効果に差がなく、20wt%以上であると熱処理炉付帯設
備の侵食が無視できなくなる。酸としては、鉄粉中に微
量残っても有害となるB、P、S等の成分を含まず、か
つ排気ガスにNOx 、SOx 、塩素ガス等の環境汚染物
質を含まないものが望ましく、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、シュウ酸等を使用するのが好ましい。
As the water, any of distilled water, pure water, factory ring water, etc. may be used. According to experiments by the present inventors, it is more effective to use an acid aqueous solution containing an acid as a water in a concentration range of 0.1 wt% or more and less than 20 wt%. If the acid concentration is less than 0.1 wt%, there is no difference in effect from the case of water alone, and if it is 20 wt% or more, erosion of the heat treatment furnace auxiliary equipment cannot be ignored. It is desirable that the acid does not contain components such as B, P, and S that are harmful even if a trace amount remains in the iron powder, and that the exhaust gas does not contain environmental pollutants such as NOx, SOx, and chlorine gas. Therefore, it is preferable to use an acid composed only of C, O and H, for example, carbonic acid, formic acid, acetic acid, benzoic acid, oxalic acid and the like.

【0011】[0011]

【実施例】 (実施例1)表1に示すミルスケール粗還元粉A、Bを
50cm×50cm×厚み10cmに積層して原料粉層を形成した。
この際、ミルスケール粗還元粉に該粗還元粉の重量に対
して0.5 〜20wt%の水分を予め均一に混合添加(水分添
加量は表2参照)した。そして図2に示すように、この
原料粉層21を積層状態のまま、炉内を100 体積%のH 2
雰囲気に維持した雰囲気炉22に装入し、昇温速度15℃/
分で 930℃まで昇温後、この温度にて80分保持し、炉冷
するという条件で熱処理を行い実施例とした。
EXAMPLES (Example 1) Mill scale coarse reduced powders A and B shown in Table 1 were prepared.
The raw material powder layer was formed by laminating 50 cm × 50 cm × 10 cm in thickness.
At this time, the mill scale coarse reduced powder is added to the weight of the coarse reduced powder.
And uniformly add 0.5 to 20 wt% of water in advance (water addition
The amount added is shown in Table 2). And as shown in FIG.
While the raw material powder layer 21 is in a laminated state, the inside of the furnace is 100 volume% H Two
It was charged into an atmosphere furnace 22 maintained in an atmosphere, and was heated at a rate of 15 ° C /
After heating to 930 ° C in a minute, hold at this temperature for 80 minutes and cool
The heat treatment was performed under the condition that the heat treatment was performed, and the example was performed.

【0012】また、ミルスケール粗還元粉B、Cに0wt
%(水分無添加)、25wt%の水分を添加し実施例と同一
条件で熱処理を行ってそれぞれ従来例、比較例とした。
熱処理後の鉄粉の成分含有量を表2に示す。
Also, 0 wt.
% (Without addition of water) and 25 wt% of water, and heat-treated under the same conditions as in the example, to obtain a conventional example and a comparative example, respectively.
Table 2 shows the component contents of the iron powder after the heat treatment.

【0013】[0013]

【表1】 [Table 1]

【0014】[0014]

【表2】 [Table 2]

【0015】表2より、実施例ではいずれもC、O、N
が十分に低下したのに対し、水分無添加の従来例は脱炭
が、水分25wt%添加の比較例は脱酸が、それぞれ不足
し、本発明の効果が明らかである。 (実施例2)図1に示した連続式移動床炉20を用いて表
1のミルスケール粗還元粉Bを仕上げ熱処理した。炉温
を950 ℃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/h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35Nm3/h 導入した。この際、表3
に示す各条件でホッパ8内の原料粉7に散水管31より水
分を散布添加(水分無添加の従来例も含む)し、仕上げ
熱処理後の鉄粉の成分含有量がC≦0.003 wt%、O≦0.
30wt%、N≦0.0015wt%となるようにベルト9の移動速
度を調整した。
From Table 2, it can be seen that C, O, N
However, the conventional example without addition of water lacks decarburization, and the comparative example with addition of 25 wt% moisture lacks deoxidation, and the effect of the present invention is apparent. (Example 2) Using the continuous moving bed furnace 20 shown in Fig. 1, the mill scale coarse reduced powder B shown in Table 1 was subjected to a finish heat treatment. The furnace temperature was set to 950 ° C, and a gas injection pipe 51
And 200 Nm 3 / h introducing hydrogen from the decarburization zone 2 was introduced 35 Nm 3 / h of water vapor from the gas blowing tube 52. At this time, Table 3
Water is sprinkled and added to the raw material powder 7 in the hopper 8 from the water sprinkling tube 31 (including the conventional example in which no water is added) under the following conditions, and the iron powder after the finish heat treatment has a component content of C ≦ 0.003 wt%, O ≦ 0.
The moving speed of the belt 9 was adjusted so that 30 wt% and N ≦ 0.0015 wt%.

【0016】各条件での生産量(t/h )の従来例との比
と熱処理後の鉄粉の成分含有量を表3に示す。
Table 3 shows the ratio of the production amount (t / h) to the conventional example under each condition and the component content of the iron powder after the heat treatment.

【0017】[0017]

【表3】 [Table 3]

【0018】表3より、熱処理後の成分含有量はいずれ
の場合も目標範囲に達したが、水分無添加の従来例より
も水分添加の実施例のほうが生産性が高く、さらに水分
として酸水溶液を用いた実施例が最も生産性が高いとい
う結果であり、本発明の効果が明らかである。
From Table 3, it can be seen that the content of the components after the heat treatment reached the target range in each case. However, the productivity was higher in the embodiment in which water was added than in the conventional example in which no water was added. Are the results of the highest productivity, and the effect of the present invention is clear.

【0019】[0019]

【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内部の反応が促進さ
れて、熱処理の生産性が向上するという効果を奏する。
According to the present invention, the reaction inside the raw material powder layer in the deoxidizing, decarburizing or denitrifying heat treatment of the raw material powder is promoted, and the productivity of the heat treatment is improved.

【図面の簡単な説明】[Brief description of the drawings]

【図1】連続式移動床炉入側での水分添加方法の説明図
である。
FIG. 1 is an explanatory diagram of a method of adding water at a continuous moving bed furnace entrance side.

【図2】実施例1の熱処理方法の説明図である。FIG. 2 is an explanatory diagram of a heat treatment method of Example 1.

【符号の説明】[Explanation of symbols]

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 ホッパ 9 ベルト 10 ホイール 11 ラジアントチューブ 20 仕上げ熱処理装置(連続式移動床炉) 21 原料粉層 22 雰囲気炉 31 散水手段(散水管) DESCRIPTION OF SYMBOLS 1 Partition wall 2 Decarburization zone 3 Deoxidation zone 4 Denitrification zone 51,52 Gas injection pipe 6 Exhaust pipe 7 Raw material powder 8 Hopper 9 Belt 10 Wheel 11 Radiant tube 20 Finishing heat treatment equipment (continuous moving bed furnace) 21 Raw material powder Layer 22 Atmosphere furnace 31 Watering means (watering pipe)

───────────────────────────────────────────────────── フロントページの続き (72)発明者 石川 博之 千葉県千葉市中央区川崎町1番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 鈴木 良和 千葉県千葉市中央区川崎町1番地 川崎製 鉄株式会社千葉製鉄所内 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Ishikawa 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside the Chiba Works of Kawasaki Steel Corporation (72) Inventor Yoshikazu Suzuki 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Inside the Chiba Works

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 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、原料粉に水分を添加した後、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。
Claims: 1. A method for finishing heat treatment of iron powder in which one or more heat treatments of deoxidation, decarburization and denitrification are performed, after adding water to the raw material powder, heat treating the raw material powder. Finishing heat treatment method for iron powder.
【請求項2】 水分の添加量が、添加前の原料粉に対す
る重量%にて0.5 〜20wt%である請求項1記載の方法。
2. The method according to claim 1, wherein the amount of water added is 0.5 to 20% by weight in terms of% by weight based on the raw material powder before addition.
【請求項3】 水分が酸を0.1 wt%以上20wt%未満の濃
度範囲で含む酸水溶液である請求項1または2に記載の
方法。
3. The method according to claim 1, wherein the water is an aqueous acid solution containing an acid in a concentration range of 0.1 wt% or more and less than 20 wt%.
【請求項4】 酸がC、O、Hのみから構成される酸で
ある請求項3記載の方法。
4. The method according to claim 3, wherein the acid is an acid composed only of C, O and H.
JP9153489A 1997-06-11 1997-06-11 Finish heat treatment for iron powder Pending JPH111701A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9153489A JPH111701A (en) 1997-06-11 1997-06-11 Finish heat treatment for iron powder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9153489A JPH111701A (en) 1997-06-11 1997-06-11 Finish heat treatment for iron powder

Publications (1)

Publication Number Publication Date
JPH111701A true JPH111701A (en) 1999-01-06

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JP9153489A Pending JPH111701A (en) 1997-06-11 1997-06-11 Finish heat treatment for iron powder

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