JPS5881901A - Method of making atomized iron powder having excellent formability and low apparent density for use in powder metallurgy - Google Patents

Abstract

PURPOSE:To obtain atomized iron powder having low apparent density equal to that of reduced iron powder and excellent formability, by reduction-annealing atomized green iron powder having defined apparent density while increasing sintering-coagulation between particles, and controlling impulsive force to crush and disintegrate sintered cake. CONSTITUTION:Atomized green iron powder having the relationship between its apparent density chi(g/cm<3>) and its particle size di(mum) represented by the arithmetic means of two meshes d1 and d2 of Tyler Standard screen scale which satisfies the formulaIand II (a and b are the constants of particle size with b<=1.5) as for a part having a particle size exceeding 150mum and a part having a particle size below 150mum, respectively, is used. Said green iron powder, directly or after subjected to the treatment to accelerate the coagulation of particles, is reduction-annealed at 800-1,100 deg.C in a reducing decarburizing atmosphere to accomplish sufficient reduction-annealing and sintering-coagulation between particles. The obtained sintered cake is crushed and disintegrated by applying impulsive force below 1X10<5>kgf.m/S<2> to it, so as to obtain iron powder containing more than 80wt% particles having a particle size below 150mum and having apparent density of 2.00-2.60g/cm<3>.

Description

【発明の詳細な説明】 この発明は１、成形性に優れ、見掛密度の低い粉末冶金
用噴霧鉄粉の製造方法に関し、とくに、液体噴霧法によ
る生鉄粉の粒形すなわち見掛密度を規定し、またはさら
にその粒子相互の凝集を促進させる処理を施した上で還
元焼鈍するとと°によ）、粒子相互の焼結・凝集を高め
、ことにその焼結ケーキを粉砕解粒（以下矯解砕−と記
す）する費撃力を限定することによって、成形性に優れ
見掛密度の低い粉末冶金用噴霧鉄粉の有利な製造方法を
提案しようとするものである〇 一般に粉末冶金用の水噴霧鉄粉は、見掛密度が通常２３
０〜Ｊ、−〇ｔ４１５程度に高く圧縮性に優れるため、
高密度鉄系焼結材用の原料鉄粉として適用されているが
、ラトラー値や圧粉体抗折力で評価される成形性はむし
ろ悪く、高密度の割に焼結材の機械的強度も弱いため、
中、低密度鉄系焼結材への適用は不如意であって、上記
用途に限定されているのが現状である＠ こ＼に曳好、な圧縮性を保持したｔま、優れた成形性を
も兼ね備える噴霧鉄粉が要望され、成形性を高めるぺ〈
開発が進められている＠ 例えば、特開昭！ダー／／参ヂ１７号公報に記載されて
いる如く、高圧水の逆円錐状噴射角度ｔ−１０〜を吸引
し逆噴射を防止し乍ら噴霧して生鉄粉中の微粉量を増加
させ、１０００，１２００℃の温度の還元雰囲気中で焼
鈍し念の気中鉄粉の粒度分布に比べより大きい粒度分布
べなるよう焼結ケーキを解砕する方法が提案されている
。また、特開昭１０−／／！／ぶ１号公報によれば、粒
度分布ｙ　ｐｓｃ値すなわち米国規格による１００．２
００．コＪＯおよび３コｊメツシユの各線につき粒子の
篩上の累積量と受皿量とｔ針側して各累積重ｊ１割合を
合計し、イ。。を乗じ九値がｉ、ｏ−コ、７の範囲であ
る水噴霧化鉄粉を、７６０〜／／４ＩＹ℃の温度で還元
焼鈍しその焼結ケーキをミルギャップ０．Ｊ参ｊ−２，
＠Ｊ　ｆｎｍ　、回転数Ｊ００〜！０００ｒ、ｐ６ｍの
ディスクンルで解砕して、見掛密度がλ、ｔｏ　ｔ４ｓ
以下の鉄粉を製造する方法も提案されている。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to (1) a method for producing atomized iron powder for powder metallurgy with excellent formability and low apparent density; The sintering and agglomeration of the particles can be enhanced, and the sintered cake can be pulverized and agglomerated (hereinafter referred to as pulverization and agglomeration). This paper aims to propose an advantageous manufacturing method for atomized iron powder for powder metallurgy, which has excellent formability and low apparent density, by limiting the cost and impact of the process (denoted as straightening and crushing). Water-sprayed iron powder usually has an apparent density of 23
0~J, -〇t415, which has excellent compressibility,
It is used as a raw material iron powder for high-density iron-based sintered materials, but the formability evaluated by Rattler value and compact transverse rupture strength is rather poor, and the mechanical strength of sintered materials is poor despite its high density. is also weak,
Its application to medium- and low-density iron-based sintered materials is inadvertent and is currently limited to the above-mentioned applications. There is a demand for atomized iron powder that also has the following properties:
Development is progressing @ For example, Tokkai Sho! As described in Dar // Sanji No. 17, high-pressure water is sprayed at an inverted conical jet angle t-10 to prevent reverse jetting while increasing the amount of fine powder in raw iron powder. A method has been proposed in which a sintered cake is annealed in a reducing atmosphere at a temperature of 1,000 or 1,200 degrees Celsius to obtain a particle size distribution larger than that of airborne iron powder. Also, Tokkai Showa 10-//! According to Publication No. 1, the particle size distribution y psc value is 100.2 according to the American standard.
00. For each line of Ko JO and 3 Ko J Meshes, add up the cumulative amount of particles on the sieve, the amount of the saucer, and the cumulative weight j1 ratio on the t needle side, and a. . Water atomized iron powder whose 9 value is in the range of i, o-co, 7 is reduced annealed at a temperature of 760 to //4 IY°C, and the sintered cake is prepared with a mill gap of 0. J reference j-2,
@J fnm, rotation speed J00~! 000r, crushed with p6m discuncle, apparent density is λ, to t4s
The following method for producing iron powder has also been proposed.

しかしこれらはいずれも、ただ単に生鉄粉中の微粉量割
合を高くして、還元焼鈍時に粒子相互を焼結凝集させ、
その焼結ケーキを比較的軽い（低い）負荷で解砕してｔ
Ｗ密度化と成形性の改轡を図るものである。However, all of these methods simply increase the proportion of fine powder in the raw iron powder and cause the particles to sinter and agglomerate each other during reduction annealing.
The sintered cake is crushed under a relatively light (low) load.
The aim is to improve W density and formability.

一般に、水噴霧鉄粉の微粉量を増す程、ま九還元焼鈍温
度を高くする程、粒子相互の焼結が促進するため、解砕
した鉄粉の見掛密度は低下する＠従って成形性の向上を
図れるわけであるが、次の様表技幇的間■が伴われる。In general, as the amount of fine powder in the water-sprayed iron powder increases and as the reduction annealing temperature increases, sintering between particles is promoted, and the apparent density of the crushed iron powder decreases. Although it is possible to improve one's performance, it is accompanied by the following problems.

すなわち、還元焼鈍温度が／　１００℃を超えて高過ぎ
ると、その焼結ケ゛−キは解砕され難く、高負荷解砕し
て生産性を上げようとすると、加工を受けることＫより
かえって見掛密度が高くな夛成形性の向上が計れないば
かりでなく、圧縮性も劣化し、また還元焼鈍温度が１１
００℃以下の場合でも、蝋終製品鉄粉の見掛密度に対応
して相応に低い見掛密度の生鉄粉を用いないと、成形性
の向上が計れないばかシでなく、安定し良性状の低見掛
密度鉄粉の製造が困難である◎なお還元焼鈍温度が１０
０℃未満のように低く過ぎると、脱酸、脱炭、焼鈍およ
び再結晶が不十分で十分な圧縮性を確保することができ
ない。In other words, if the reduction annealing temperature is too high (over 100°C), the sintered cake will be difficult to crush, and if you try to increase productivity by crushing it under high load, it will be more difficult to process it. Not only is it impossible to improve the formability due to the high hanging density, but the compressibility is also deteriorated, and the reduction annealing temperature is 11.
Even if the temperature is below 00℃, it is not foolish to use raw iron powder with a lower apparent density corresponding to the apparent density of the finished wax product iron powder, which is stable and benign. It is difficult to produce iron powder with a low apparent density.
If the temperature is too low, such as less than 0°C, deoxidation, decarburization, annealing, and recrystallization will be insufficient, making it impossible to ensure sufficient compressibility.

そこでこの発明の目的は、噴霧鉄粉生来の優れ大圧縮性
金備える＃１か、とくに中、低密度鉄系焼結材への適用
を拡大すべく、還元鉄粉（（ルスケール還元鉄粉、鉱石
還元鉄粉）と同等の２．００〜コ、４０１１５の見掛密
度でしかも流動性に富み、遺− 元鉄粉より屯曳好な成形性をあわせ有する噴霧鉄粉を安
価に提供するところにある・ との発明は、最終製品である噴霧鉄粉の見掛密度に対応
した相応の低い見掛密度の噴霧生鉄粉、または、さらに
低見掛密賓化と成形性の向上を計るため粒子相互の凝集
を促進する処理を施し九噴−生鉄粉を原料に用いること
、十分な還元焼鈍と粒子相互の焼結凝集を達成する還元
焼鈍温変範囲にすること、および焼結ケーキの解砕にお
いて、鉄粉が液体Ｉ！ＪｔＩｌ生来の不規則粒形と焼結
凝集した集合不規則粒形とを保つ衝撃力によることの諸
条件の適合により上記目的を有利゛に充足し得ることを
究明したものである０ さて第１図に示すように、水噴霧化鉄粉の見掛密度８．
ｘ（ｆ／、１３〕と、その単一粒径！　ｄｉ（＃ｔｌ）
　トノ関には、 ｉｚｏｐｍを超える粒径においてχ＝は埋一定、ｌ！０
＃講以下の粒径においては、（ｌｌ−１６−”χこζに
ａ、ｂＪ粒形定数、ｅは自然対数の底なる関係があり、
そしてこの関係は還元焼鈍し丸焼結ケーキを、とくに／
　ｘ　１０５峙ｆ−ｍ／　　２以下の龜ｅｃ 衝撃力で解砕した水噴霧鉄粉においても同様に成立する
ことを発明者らは知見した。Therefore, the purpose of this invention is to expand the application of sprayed iron powder to #1, which has excellent high compressibility by nature, and especially to medium and low density iron-based sintered materials. To provide inexpensively atomized iron powder which has an apparent density of 2.00 to 40115, which is the same as that of reduced iron powder (reduced iron powder), is rich in fluidity, and has moldability superior to that of original iron powder. However, the invention of ``Sprayed Iron Powder'' is to produce atomized raw iron powder with a correspondingly low apparent density corresponding to the apparent density of the final product, atomized iron powder, or to further reduce the apparent density and improve formability. In order to achieve this, it is necessary to perform a treatment that promotes the agglomeration of particles and use raw iron powder as a raw material, to achieve sufficient reduction annealing and sintering agglomeration of particles, and to achieve reduction annealing temperature range that achieves sintering and sintering. In crushing the cake, the above object is advantageously achieved by satisfying the conditions that the iron powder maintains the irregular grain shape inherent in liquid I!JtIl and the aggregate irregular grain shape formed by sintering and agglomeration. As shown in Figure 1, the apparent density of water atomized iron powder is 8.
x(f/, 13] and its single particle size! di(#tl)
For grain sizes exceeding izopm, χ= is constant and l! 0
For grain sizes less than or equal to
And this relationship is especially true for reduction annealed round sintered cakes.
The inventors have found that the same holds true for water-sprayed iron powder crushed by an impact force of x 105 f-m/2 or less.

仁の知見によれば嘴轡生鉄粉の見掛密度によって、還元
焼鈍した鉄粉の見掛密度が限定される。According to Jin's knowledge, the apparent density of reduction annealed iron powder is limited by the apparent density of raw iron powder.

すなわち、／ｊＯｆｉｍを超える粒径において、還元焼
鈍し九鉄粉の見掛密度を噴霧生鉄粉の見掛密度よりも低
くすることは困難であシ、強解砕する程、高見掛密度化
することになる・一方／Ｊａｐａｎ以下の粒径において
、還元焼鈍した鉄粉の見掛密度は、粒子相互が焼結凝集
して集合不規則粒形となるため噴霧生鉄粉の見掛密度よ
り低くなるが、粒形足数；ｂは正の値を持ち、負の値の
工業的実現は困―である。In other words, it is difficult to make the apparent density of the reduction-annealed nine-iron powder lower than the apparent density of the atomized raw iron powder at a particle size exceeding /jOfim, and the harder the crushing, the higher the apparent density. On the other hand, for particle sizes smaller than Japan, the apparent density of reduction-annealed iron powder is lower than that of atomized raw iron powder because the particles sinter and agglomerate each other to form irregular grain shapes. However, the grain size index b has a positive value, and it is difficult to realize a negative value industrially.

よって、還元焼鈍して見掛密度が２．ｔｏｔ７ｓ以Ｃ目 下の噴霧鉄粉を製造するためには、ｉｚｏｐｍを超える
粒径において見掛密度（ｆ／ｓ）、χ≦ココ。０゜Ｃπ ／＃ｆｉｆ’ｌ＆以下の粒径におりてｄ　巨９６−ｂＸ
　　ただしｄ１ｇタイラー標準鋳の２つの篩目の平均径
（ｄａ−リ曳）（μｍ）、＠、ｂ５粒径定数でｂ≧／、
ｊの関係を満足する噴霧生鉄粉を原料に用いなければな
らないわけである・ ／ｊＯｕｒｎ以下の粒径において、粒子相互を焼結凝集
して集合不規則粒形となし一段と低見掛密麿化を促進せ
しめるには粒度別と、液体の混合と、帯磁が回れも次の
ような理由のもとで有効である仁とを見い出した。Therefore, after reduction annealing, the apparent density was 2. In order to produce atomized iron powder of tot7s or less, the apparent density (f/s), χ≦here, is required at a particle size exceeding izopm. 0゜Cπ /#fif'l&d giant 96-bX
However, d1g Tyler standard casting average diameter of two sieves (da-rihiki) (μm) @, b5 particle size constant b≧/,
It is necessary to use raw atomized iron powder that satisfies the relationship j as a raw material.In the particle size of /jOwn or less, the particles are sintered and agglomerated together to form an irregular grain shape, which further reduces the apparent density. We have found that particle size, mixing of liquids, and magnetization are effective for promoting magnetization for the following reasons.

噴霧生鉄粉は、まず粒度別に締分けすることにより、微
粉相互の焼結凝集による集合粗粒化を効率よくでき、縮
分作業性を考慮すると、２００メッシ：Ｌを境にするの
が実際的で、必要に応じ還元焼鈍後プレノドするとよい
。Sprayed raw iron powder can be efficiently aggregated into coarse particles by sintering and agglomerating the fine powders by first sorting them by particle size, and considering reduction workability, it is actually best to use 200 mesh:L as the boundary. If necessary, it is recommended to perform pre-throwing after reduction annealing.

噴霧生鉄粉充填層の粒子間空隙を満し喪液体は気化蒸発
するにつれ、液面が移動してその表面張力により粒子を
移動せしめ、とくに粗粉の局ＦＭＫ微粉を凝集する作用
がｉｂシ、ここに混合す、５液体として、水や油、アル
コール等の有機化合物〉よびそれらの混合物が用いら−
れる。Ｊ〜Ｊ１７重量−の範ｆ！が効果的で実用的であ
る・ 液体噴霧生鉄粉は高圧液体により急冷され格子が歪んで
いるため容易に帯磁して残留磁気を持ち、とくに水噴霧
生鉄粉において著しく、との九め粒子相互が吸引し合っ
て凝集するからである・次に還元、脱炭性雰囲気中での
還元焼鈍温度と、焼結ケーキの解砕衝撃力とけ解砕鉄粉
の見掛密度を決定する重要な要因である＠ 還元焼鈍温度が１００℃より低い場合、還元、焼鈍、粒
子相互の焼結凝集が不十分で、見掛密度の低下と圧縮性
の確保ができない・ 還元焼鈍温度が７１００℃より高い場合、解砕が困穣と
なシ、強引に高負荷をかけて解砕すると、平滑多面粒と
なシ高見掛密度化し、同時に加工硬化を受けて圧縮性を
劣化する。As the liquid fills the interparticle spaces in the packed bed of atomized raw iron powder and evaporates, the liquid level moves and its surface tension causes the particles to move, and the effect of agglomerating local FMK fine powder, especially coarse powder, is caused by the ib system. , water, oil, organic compounds such as alcohol, and mixtures thereof are used as the 5 liquids mixed here.
It will be done. J~J17 weight range f! is effective and practical. Liquid-sprayed raw iron powder is rapidly cooled by high-pressure liquid and the lattice is distorted, so it is easily magnetized and has residual magnetism, which is especially noticeable in water-sprayed raw iron powder. This is because they attract each other and agglomerate.Next, there are important factors that determine the reduction annealing temperature in a reducing and decarburizing atmosphere, the crushing impact force of the sintered cake, and the apparent density of the crushed iron powder. The cause @ If the reduction annealing temperature is lower than 100℃, the reduction, annealing, and mutual sintering agglomeration of particles are insufficient, resulting in a decrease in apparent density and failure to ensure compressibility.・Reduction annealing temperature higher than 7100℃ In such cases, it is difficult to crush the grains, and if the grains are forcibly crushed under a high load, they become smooth polyhedral grains with a high apparent density, and at the same time undergo work hardening and deteriorate their compressibility.

よって還元焼鈍温度はｔｏｏ　−１ｉｏｏ℃の範囲が適
ｉであ抄ただ保持均熱する時間は、上記熱処理に十分な
時間を適宜選定すれば良くとくに限定の必要はない。Therefore, the reduction annealing temperature is suitably in the range of too -1ioo°C, and the time for holding and soaking after papermaking is not particularly limited as long as the time sufficient for the above-mentioned heat treatment is appropriately selected.

焼結ケーキの解砕機としては、粒子を切断し九シ、粒子
表面を平坦な多面体化あるいは平板体化し′＃−り、丸
めつぶす様な機械は避けるべきで、例えば反発式あるい
は衝撃式のハンマーオル、デイメインテグレーター（ケ
ージでルーなどの様緘を採用する。As a crusher for sintered cakes, machines that cut the particles, make the surface of the particles into flat polyhedrons or flat plates, and crush them into balls should be avoided; for example, machines that use repulsion type or impact type hammers Ol, Demain Integrator (adopts various forms such as roux in a cage.

その衝撃力と解砕された鉄粉の見掛密度の関係について
調べ九結果、衝撃力−の増加にともない粒度全域に渡っ
て見掛密度は高くな９、ｔｏ　　］＃ｆ−ｍ／Ｓ＠ζを
超えると原料噴霧性鉄粉の見掛密度よシ高くなってしま
う・よって、衝撃力は１０”　ｋｙ、／’　＃　ｍ／＠
　＠ζ２　　　□を上限とする。なお、例えばハンマー
ミルに取り付けるロスドル間隙あるいはスクリーン穴径
は液・体噴霧生鉄粉生来の不規則状と焼結凝集による集
合不規則状を失うことのない様、配慮する必要があるが
、見掛密度へおよぼす要因寄与率は小さいので限定する
必要はない・ 仁の発明による噴霧鉄粉の化学組成については、透光鉄
粉（建ルスケール還元鉄粉、鉱石還元鉄物）と同等以上
すなわち、／−Ｚａ・８ｔ　（ステアリン酸亜鉛ｉｆり
重量１１Ｆ・混合粉において！ｔ／２の成Ｃ暉 形圧力における圧粉密度が４．７０１７５以上の確保０
胃 は最低限必要であ夛、この観点から、重量−で、ｏ　：
　ｏ、Ｊｓ以下、ｃ　３　ｏ、ｏｒ以下、Ｎ　ｊ　００
０１以下、８１　ｆ　００１０以下、Ｍｎ　ｉ　００８
０以下、Ｐ　；　０．０１以下、８　Ｊ　００１０以下
、８口５　ｏ、ｔｏ以下で、かつ残部が実質的に鉄とよ
シ成るものにつき、もちろん不可避的に混入する不純物
は許容される〇ま九粒度については鉄系焼結材において
粗粒が多過ぎ、ると、不規則状粗大空孔が多くなシ機械
的強度の脆化を招き、シ九がって粉末冶金用鉄粉の一般
的範囲、すなわち／１０　＃ｍ以下の粒度を１０重量慢
以上含む鉄粉に限定される。We investigated the relationship between the impact force and the apparent density of the crushed iron powder and found that as the impact force increases, the apparent density increases over the entire particle size range. If it exceeds ζ, the apparent density of the raw material atomized iron powder becomes higher. Therefore, the impact force is 10"ky, /'# m/@
@ζ2 □ is the upper limit. For example, it is necessary to take into consideration the diameter of the Rossdol gap or screen hole installed in a hammer mill so as not to lose the inherent irregularity of liquid/body sprayed raw iron powder and the aggregated irregularity due to sintered agglomeration. There is no need to limit the factor contribution rate to the coating density because it is small. The chemical composition of the sprayed iron powder invented by Jin is equal to or higher than that of transparent iron powder (building scale reduced iron powder, ore reduced iron powder), i.e. , /-Za・8t (zinc stearate if weight 11F・Mixed powder! Ensure green density at t/2 molding pressure is 4.70175 or more 0
The stomach is minimally necessary, from this point of view, the weight - o:
o, below Js, c 3 o, below or, N j 00
01 or less, 81 f 0010 or less, Mn i 008
0 or less, P: 0.01 or less, 8 J 0010 or less, 8 mouths 5 o, to or less, and the remainder is substantially composed of iron, of course unavoidable impurities are allowed. Regarding grain size, if there are too many coarse grains in iron-based sintered materials, there will be many irregularly shaped coarse pores, which will lead to embrittlement of mechanical strength, which will eventually lead to poor iron powder for powder metallurgy. It is limited to the general range, i.e. iron powder containing at least 10 particles with a particle size of /10 #m or less.

次に、実施例に基すき本発明の詳細な説明する。Next, the present invention will be described in detail based on examples.

特許第ｆＰＪｊｊＦ号に係る特会昭！コー／り！参〇号
公報に記載された溶解金属の霧化粉砕装置によシ、被数
のジェット衝流の集束角度αと、ガイドで複数のジェッ
ト衝流を偏向した膜状流の集束角度βと４ｏ、水圧を４
ｃＯ−／１０ｋｇｆ／　２Ｇ　Ｏ範囲、溶湯／　ス＃ａ
糞 口径をＩ−／参ｍＷＬφの範囲でそれすれ適宜調整し、
かつ水量が２７０７７ｍＩｎの水噴霧条件で、第１図中
ｄ、＋ｄ２ と単一粒径−ｄｉ　−（μｍ〕の関係ｔｓ有するＪ種類
の水噴霧生鉄粉を製造した。Special meeting regarding patent No. fPJjjF! Ko/ri! According to the molten metal atomization and crushing device described in Publication No. , water pressure 4
cO-/10kgf/2G O range, molten metal/S#a
Adjust the diameter of the feces appropriately within the range of I-/mWLφ,
Under water spraying conditions in which the amount of water was 27,077 mIn, type J water-sprayed raw iron powder having the relationship ts between d and +d2 in FIG. 1 and the single particle diameter -di-(μm) was produced.

次に、タイラー標準線で−１００とし、アンモニア分解
ガス中で７００〜／／１０℃の温度で１０〜／２０分間
均熱して還元焼鈍を行ない、大気中で再醗化を生じない
温度、すなわちｉｒｏ℃以下に炉中冷却した後、大気中
に取り出した焼結ケーキをハンマーミルにより解砕し、
ｒｏｍ鋳で篩分した。Next, the Tyler standard line is set to -100, and reduction annealing is performed by soaking for 10 to 20 minutes at a temperature of 700 to 10 degrees Celsius in ammonia decomposition gas, and the temperature is set to a temperature that does not cause re-distillation in the atmosphere, i.e. After cooling in the furnace to below iro℃, the sintered cake was taken out into the atmosphere and crushed with a hammer mill.
It was sieved using a ROM caster.

また、第１図中め記号：Ｉで示す見掛密度と単一粒径の
関係を有する水噴霧生鉄粉については、１０重量鴫の水
の混合、最大磁力／１００ガウスの磁選機による帯磁、
および１０〜−〇〇メツシュと一〃０メツシュとに篩分
たコ粒壇別の処理をそれぞれ施して、上記と同様の条件
で還元焼鈍し、解砕して粒子相互の焼結凝集効果ｔｎぺ
九。In addition, for water-sprayed raw iron powder having the relationship between apparent density and single particle size indicated by the middle symbol I in Figure 1, it is mixed with 10 weight drops of water and magnetized by a magnetic separator with a maximum magnetic force of 100 Gauss. ,
Then, the 10 to -00 mesh and the 100 mesh were subjected to different treatments for the sieved particles, and then reduced annealed under the same conditions as above and crushed to create a sintering agglomeration effect between the particles. Peku.

焼結ケーキの解砕は回転数：　ｊＩｏｏｔ、ｐ、ｍ、　
ｅ主′シャフト軸から７１ンｉ−先端までの距離ｉ　／
ｊＯｖｍ。The rotation speed for crushing the sintered cake is: jIoot, p, m,
e Distance from the main shaft axis to the tip of the 71 inch i/
jOvm.

ハンマーの数；ＪＯ本、ノ１ンマーの単重；　ｚｏｏｆ
ｔｆの機械仕様のノ１ンマー電ルにより、先ずＪｔＭｎ
φの穴径のスクリーンを取り付けて解砕し、１０メツシ
エ鋳により鋳分けたＯ 次に、この＋１０メツシユ鉄粉について／　ｍｍ−の穴
径のスクリーンを取如付けて解砕し、ｆＯメツシ為締に
よシ締分は九′Ｏ 同様にして順次Ｏ０お一φ、　０．３ｍｍφの穴径のス
クリーンを取り付けて解砕−篩分を繰返し、計参回分の
一１０メツシュ鉄粉ｔそれぞれブレンドしたＯなお、ｊ
ＯＮコＯＯメツシエと−ＪＯＯメツシュの一粒度別に還
元焼鈍した焼結ケーキはそれぞれ上記と同様の条件およ
び手順で計参回解砕−鋳分して一旦ブレンドし、水噴霧
生鉄粉のｔＯ〜−〇〇メツシュと一一〇〇メツシュの粒
度割合、すなわち１０．ｍＯメツシュを５／１ｏ、−一
〇〇メツシュを乞０の割合で再ブレンドした０ 以上に記述し九本噴霧生鉄粉の粉体特性、還元焼鈍した
鉄粉の粉体特性および圧粉体特性を粒子凝集処理および
還元焼鈍条件を付して、一括して第１表に示す。Number of hammers; JO book, unit weight of hammer; zoof
First, JtMn
Attach a screen with a hole diameter of φ and crush it, and cast it by 10 mesh casting. For tightening, the amount of tightening is 9'O. In the same way, attach a screen with a hole diameter of 0.3mmφ to O0 and 1φ, repeat the crushing and sieving process, and blend each batch of 110 mesh iron powder. I did O, j
The sintered cakes reduced and annealed according to grain size of ON CoOO Metsushi and -JOO Metsushi are respectively crushed, cast and blended under the same conditions and procedures as above, and water-sprayed raw iron powder tO ~ - Particle size ratio of 〇〇 mesh and 1100 mesh, that is, 10. The mO mesh was re-blended at a ratio of 5/1o and -100 mesh at a ratio of 0. Powder properties of the nine-sprayed raw iron powder described above, powder properties of reduction annealed iron powder, and green compact The properties are shown in Table 1 together with the particle agglomeration treatment and reduction annealing conditions.

第１表に示した如＜、ｆａ／図中の記号；■、すなわち
１１０μｍを超える粒径においてχ＝１．４０゜／ｊＯ
ａｍ以下の粒径において（ＩＩ　ｓｅ　４　ｘ　１０”
ｅ　−””なる関係を有する水噴霧生鉄粉を還元焼鈍し
た一１０メツシュの鉄粉（試験番号１）は、同表（２）
のように見掛密度がコ、１０　ｔ／　３で、第７図中の
記号０胃 ；！で示す如く、／ｊＯμｍを超える粒径においてχツ
２．４０．１１０μｍ以下の粒径においてｄ最＝ｉ、ｚ
ｘ、、７．−４，４７１なる関係を有する程度までにし
かならず、粒子相互の焼結凝集による低見掛密度化には
限度があって、コＣｕ−０ｊＣ−／Ｚｎ・８ｔ−５’ぶ
、２重量１１　Ｐａ混合粉の成形性が比較材（ミルスケ
ール還元鉄粉）に比べ劣っていることがわかる。As shown in Table 1, χ = 1.40°/jO for particle diameters exceeding 110 μm.
In particle sizes below am (II se 4 x 10”
110 mesh iron powder (test number 1) obtained by reduction annealing of water-sprayed raw iron powder having the relationship e - "" is shown in the same table (2).
As shown in Figure 7, the apparent density is 10 t/3, and the symbol 0 stomach;! As shown in , for particle diameters exceeding /jOμm, χ2.40.For particle diameters less than 110μm, dmax = i, z
x,,7. -4,471, and there is a limit to the reduction in apparent density due to mutual sintering and agglomeration of particles. It can be seen that the formability of the mixed powder is inferior to that of the comparative material (mill scale reduced iron powder).

一方、第１図中の記号；Ｉおよび厘、すなわち／ｊＯｐ
ｍを超える粒径においてχ≦２．４０．　／！ａｓ漢以
下の粒径においてｄｌ　＝　ａ６−”　、　ｂ　’）　
／、ｊなる関係を有する水噴霧生鉄粉をこの発明に従う
適当な温度で均熱して還元焼鈍した−１０メツシユの鉄
粉（試験番号！５．４．６．７．８．、９および１０）
は、同表（２）のように見掛密度が１．ぶＱ　ｆ／　Ｂ
以下の低い０■ 値を示し、Ｊ　Ｃｕ−０，ｔＣ−／　Ｚｎ　・８ｔ−タ
ｔ、２重量−□Ｆｅ混合粉の圧縮性および成形性は比較
材（ミルスケール還元鉄粉；試験番号１１．１２）に比
べ、同等かもしくはそれらより優れていることがわかる
・なお、記号；冨の噴霧生鉄粉に粒子凝集処理を細して
還元焼鈍した鉄粉（試験番号６，７および８）は見掛密
度がさらに低下し、成形性も向上していることがわかる
。On the other hand, the symbols in FIG.
χ≦2.40 for particle sizes exceeding m. /! dl = a6-'', b')
-10 mesh iron powder (test number! 5.4.6.7.8., 9 and 10 )
As shown in Table (2), the apparent density is 1. BuQ f/B
The compressibility and formability of the J Cu-0,tC-/Zn・8t-tat,2wt-□Fe mixed powder were as low as the comparative material (mill scale reduced iron powder; Test No. 11). It can be seen that it is equivalent to or better than .12) ・In addition, the symbol: Iron powder obtained by applying a particle agglomeration treatment to the atomized raw iron powder and reducing annealing (Test numbers 6, 7 and 8) It can be seen that the apparent density is further reduced and the moldability is improved.

これらに対し、還元焼鈍温度が７′ＯＯ℃のように低温
過ぎる場合（試験番号２）は、脱醗、焼鈍および粒子相
互の焼結が不十分なため、還元焼鈍したーｔｏメツシュ
の鉄粉の見掛密度は低下しきれず、圧縮性、成形性とも
に比較材（ミルスケール還元鉄粉；試験番号１ｊ、１２
）の水準に達していない・壕九還元焼鈍温度が１１１０
℃と高温過ぎる場合（。On the other hand, when the reduction annealing temperature is too low, such as 7'OO℃ (test number 2), the reduction annealed -to-mesh iron powder is The apparent density did not decrease completely, and both the compressibility and formability of
) has not reached the level of trench 9 reduction annealing temperature of 1110
If the temperature is too high (℃).

試験番号５）は、粒°子相互の焼結が進み焼結ケーキの
解砕が困−な九め、亭滑な多面化粒子となシ、還元焼鈍
し九鉄粉の見掛密Ｉ！ＩＦｉｊ１噴霧生鉄粉よシ上昇し
、解砕時に加工硬化して比較材（ミルスケール還元鉄粉
１試験番号１１，１２１に比べ、圧縮性、成形性ともに
劣化している。Test No. 5) is the apparent density of reduction annealed nine-iron powder, which is difficult to break up the sintered cake due to sintering between the particles, resulting in smooth, multifaceted particles. IFij1 sprayed raw iron powder rose and hardened during crushing, resulting in poor compressibility and formability compared to comparative materials (Mill Scale Reduced Iron Powder 1 Test Nos. 11 and 121).

第一図は第１図中の記号；Ｉの水噴霧生鉄粉をアンモニ
ア分解ガス中でり！０℃ｘ４Ａｊｒｒｔｉｎ均熱して還
元焼鈍した焼結ケーキをハンマーミルで解砕した時の衝
撃力と一１０メツシュ鉄粉の見掛密度の関係を調べた結
果である。これから明らかな様に、衝撃力は解砕した鉄
粉の見掛密度に影譬をおよぼし、ｉｏ５呻ｆ−ｍ／ｓｅ
ｃ　を超え九衝撃力を採用すると噴鐸生鉄粉の見掛密度
より本高くなってしまう。Figure 1 shows water-sprayed raw iron powder with symbol I in Figure 1 in ammonia decomposition gas! These are the results of investigating the relationship between the impact force when a sintered cake soaked at 0°C x 4Ajrrtin and reduction annealed is crushed in a hammer mill and the apparent density of 110 mesh iron powder. As is clear from this, the impact force affects the apparent density of the crushed iron powder, and the io5f-m/se
If an impact force exceeding c is adopted, the apparent density will be higher than the apparent density of raw iron powder.

以上の実施例では水噴霧生鉄粉を例にして説明・したが
、噴霧媒に液体を用いて製造し友還元あるいは焼鈍を必
要とする生鉄粉総てについてこの発明を適用する仁とが
できる。Although the above embodiments have been explained using water-sprayed raw iron powder as an example, the present invention can be applied to all raw iron powders that are produced using a liquid as the spray medium and require atomization or annealing. can.

以上のべ丸ようにこの発明によって、成形性に優れ、見
掛密度がコ、ＱＯ〜コ、ｔｏｅ／ｓ＠度に低い粉・Ｃ奪 末冶金用噴霧鉄粉の製造技術が確立され九のであシ、か
ような低見掛密度噴霧鉄粉は中、低密度鉄系焼結材の原
料として有利に適用でき、還元鉄物（ミルスケール還元
鉄粉、鉱石還元鉄粉）との代替が可能であるばかりでな
く、高い圧縮性も確保も使用できる・As described above, with this invention, a manufacturing technology for atomized iron powder for powder and carbon removal metallurgy, which has excellent formability and an apparent density as low as , QO ~ , and toe/s, has been established. Such low apparent density sprayed iron powder can be advantageously used as a raw material for medium to low density iron-based sintered materials, and can be used as a substitute for reduced iron materials (mill scale reduced iron powder, ore reduced iron powder). Not only is it possible, but it can also be used to ensure high compressibility.

【図面の簡単な説明】[Brief explanation of the drawing]

＃Ｉ１図は水噴霧生鉄粉と還元焼鈍し解砕した製品鉄粉
の見掛密度と単一粒径の関係を示すグラフ、第一図は第
１図中の記号ＪＩＩの水噴霧生鉄粉を還元焼鈍した焼結
ケーキをハンマーミルで解砕した時のハンマーミルの衝
撃力と−ｔｏメツシュ製品鉄粉の見掛密度の関係を示す
グラフである〇特許出願人　川崎製鉄株式会社Figure #I1 is a graph showing the relationship between the apparent density and single particle size of water-sprayed raw iron powder and reduction annealed and crushed product iron powder, and Figure 1 is a graph showing the relationship between water-sprayed raw iron powder with symbol JII in Figure 1. This is a graph showing the relationship between the impact force of the hammer mill and the apparent density of -to mesh product iron powder when a sintered cake obtained by reduction annealing the powder is crushed with a hammer mill.〇Patent applicant Kawasaki Steel Corporation

Claims (1)

【特許請求の範囲】 １、′見掛密度χ（４ｓ）と、タイラー標準締の１つの
＠Ｉ（１，ｄ、の算術平均ｄ１（＃祠であられし九粒程
との関係が、下記式（す、（２）の両条件を満たす・液
体噴霧法による生鉄粉を直接、または該生鉄粉に粒子凝
集処理を施し九のち、還元、脱炭性雰囲気中、１００〜
１ｔｏｏ℃の範囲の温度で還元焼鈍し、得られた焼結ク
ー中にｉ　ｘ　ｔｏ　ｋｙ／−ｍ７ｇ２以下の衝撃力を
加えて粉砕、解粒し、粒径ｔｚｏｓｔｎ以下の粒子１　
ｇｏ重量優以上を含み見掛密度コ、００−ｗ２，４０　
ｆ／、−の鉄粉を得ることから成る、成形性に優れ、見
掛密度の低い粉末冶金用噴霧鉄粉の製造方法０記 粒子径ｔｚｏｔｔｍを超える粒子につき　χ≦Ｘ、ｔＯ
・・・（り粒子径／ＩＯａ惧以下の粒子につき　ｄＩ！
１＃ｃ！　　　・・・（２）こ＼に１．ｂＨ粒形定数で
ｂ≧／、ｊ ２、還元焼鈍に供する噴霧生鉄粉が、粒度別に゛予め締
分けした分級粉である特許請求の範囲１記載の方法。 ５、焼結ケーキの粉砕、解粒のあと、ブレンドを行う特
許請求の範Ｉ！１２記載の方法０４、　粒子凝集処理が
、液体の添加、混合である特許請求の範８１．２またＦ
ｉｓ記載の方法０５、　粒子凝集処理が、帯磁である特
許請求の範囲１．２または３記載の方法０ ６、還元焼鈍を経た噴霧鉄粉が、重量嗟で酸素θ、コ！
以Ｔ１炭素０．０ｊ以下、窒素ｏ、ｏｉ以下、けい素θ
、・１０以下、マンガン０．ｆ−０以下、少ん０、＃以
下、およびいおう０．１０以下、もしくはさらに錫Ｏ０
！θ以下を含有する組成でやる特許請求の範囲１．２．
３．４ま九は５記載の方法。[Claims] 1. The relationship between the apparent density χ(4s) and the arithmetic mean d1 of one @I(1, d) of the Tyler standard density (#9 grains in the shrine) is as follows. Both conditions of formula (2) are met. Raw iron powder is directly processed by liquid spraying, or the raw iron powder is subjected to particle aggregation treatment, and then heated to 100 to 100% in a reducing and decarburizing atmosphere.
Reduction annealing is carried out at a temperature in the range of 1 too°C, and the resulting sintered coo is crushed and disintegrated by applying an impact force of ix to ky/-m7g2 or less to obtain particles 1 with a particle size of tzostn or less.
Apparent density, including go weight or higher, 00-w2,40
A method for producing atomized iron powder for powder metallurgy with excellent formability and low apparent density, comprising obtaining iron powder with f/, -.
...(dI for particles smaller than particle diameter/IOa)!
1#c! ...(2) Here 1. 2. The method according to claim 1, wherein bH grain shape constant is b≧/, j2, and the atomized raw iron powder to be subjected to reduction annealing is classified powder classified in advance according to particle size. 5. Claim I in which blending is performed after crushing and disintegrating the sintered cake! Method 04 according to claim 12, wherein the particle aggregation treatment is addition and mixing of a liquid, or claim 81.2;
Method 05 according to IS, the particle aggregation treatment is magnetization. Method 0 according to claim 1.2 or 3, in which the atomized iron powder that has undergone reduction annealing has oxygen θ, CO!
Below T1 carbon 0.0j or less, nitrogen o, oi or less, silicon θ
,・10 or less, manganese 0. f-0 or less, a little 0, # or less, and sulfur 0.10 or less, or even tin O0
! Claim 1.2.
3.4 is the method described in 5.