JPH07118705A - Method for controlling carbon content of metal powder compact - Google Patents
Method for controlling carbon content of metal powder compactInfo
- Publication number
- JPH07118705A JPH07118705A JP26060193A JP26060193A JPH07118705A JP H07118705 A JPH07118705 A JP H07118705A JP 26060193 A JP26060193 A JP 26060193A JP 26060193 A JP26060193 A JP 26060193A JP H07118705 A JPH07118705 A JP H07118705A
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- Prior art keywords
- hydrogen
- methane
- compact
- temperature
- gas
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は金属粉末成形体の炭素量
制御方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the carbon content of a metal powder compact.
【０００２】[0002]
【従来の技術】従来、金属焼結体（焼結合金ともいう）
は、原料の金属粉末と焼結助剤（有機結合剤）の計
量、混練、成形、脱脂、焼結の工程に従って作製
される。2. Description of the Related Art Conventionally, a metal sintered body (also called a sintered alloy)
Is produced according to the steps of measuring, kneading, molding, degreasing, and sintering a raw material metal powder and a sintering aid (organic binder).
【０００３】そして、金属粉末成形体の炭素量の制御方
法としては、特開平2-141503号公報で開示されているよ
うに、金属粉末と射出成形用有機バインダーとを混練す
る際、主バインダーの樹脂より残留炭素量が高い樹脂を
添加して混練し射出成形を行い、得られた成形体を大気
雰囲気下で脱脂する際に、残留炭素量の高い樹脂の酸化
・分解開始温度下で主バインダーを脱脂し、脱脂保持温
度、脱脂保持時間を変えることにより、金属粉末中に含
有される酸素の還元に必要な量より多くの炭素を均質に
残留させる方法が知られている。As a method of controlling the carbon content of the metal powder compact, as disclosed in Japanese Patent Application Laid-Open No. 2-141503, when the metal powder and the organic binder for injection molding are kneaded, the main binder When a resin with a higher residual carbon content than a resin is kneaded and injection molded, and the resulting molded product is degreased in the atmosphere, the main binder is at the oxidation / decomposition start temperature of the resin with a high residual carbon content. There is known a method in which a larger amount of carbon than the amount necessary for reducing oxygen contained in the metal powder remains homogeneously by degreasing and changing the degreasing holding temperature and the degreasing holding time.
【０００４】また、特開平3-64402 号公報で開示されて
いるように、焼結用金属粉末と有機物バインダーの射出
成形品を脱バインダー工程を経た後、焼結させる際、焼
結用金属粉末に必要以上に残留する炭素を所望の炭素量
に減少させる酸化鉄等の金属酸化物を添加すると共に、
還元性もしくは非酸化性雰囲気中で焼結する方法が知ら
れている。Further, as disclosed in Japanese Patent Laid-Open No. 3-64402, when an injection-molded product of a metal powder for sintering and an organic binder is subjected to a binder removal step and then sintered, the metal powder for sintering is used. In addition to adding a metal oxide such as iron oxide to reduce the residual carbon to a desired amount of carbon to a desired amount,
A method of sintering in a reducing or non-oxidizing atmosphere is known.
【０００５】また、特開平5-43906 号公報で開示されて
いるように、金属粉末あるいは合金粉末よりなる焼結用
粉末を成形して得られる成形体を露点が−20℃以下の水
素ガスを供給しながら、黒鉛粉末等の炭素質剤とともに
焼結する方法が知られている。Further, as disclosed in Japanese Patent Application Laid-Open No. 5-43906, a compact obtained by compacting a sintering powder made of a metal powder or an alloy powder is treated with hydrogen gas having a dew point of -20 ° C. or lower. A method is known in which sintering is performed together with a carbonaceous agent such as graphite powder while being supplied.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、前記従
来法の場合は、いずれも炭素量の調整操作が焼結工程以
前に行われることにある。従って、得られる焼結体中の
適正炭素量を見出だすための試行錯誤の過程で、グラフ
ァイトや金属酸化物の添加量を変えた何通りもの成形素
材を作製したり、時間のかかる脱脂や含炭処理を何度も
繰り返し行わなければならないため繁雑であり、非効率
さは避けられないという問題があった。また、得られる
焼結成形体の内部の炭素分布まで制御することは出来な
かった。However, in any of the above-mentioned conventional methods, the carbon content adjusting operation is performed before the sintering step. Therefore, in the process of trial and error to find the appropriate amount of carbon in the obtained sintered body, various molding materials with different amounts of graphite and metal oxide added were prepared, and time-consuming degreasing and There is a problem that inefficiency is unavoidable because it is complicated because the carbonization process must be repeated many times. Moreover, it was not possible to control even the carbon distribution inside the obtained sintered compact.
【０００７】本発明はかかる問題点を解消し、焼結過程
においてその雰囲気調整のみによって、金属焼結体全体
の炭素量、或いは金属焼結体内部の炭素量分布を制御す
ることが出来る金属粉末成形体の炭素量制御方法を提供
することを目的とする。The present invention solves the above problems and can control the amount of carbon in the entire metal sintered body or the distribution of carbon in the metal sintered body only by adjusting the atmosphere in the sintering process. An object of the present invention is to provide a method for controlling the carbon content of a compact.
【０００８】[0008]
【課題を解決するための手段】本発明者は前記目的を達
成すべく鋭意検討した結果、図１に示すＣＨ4 ⇔Ｃ＋２
Ｈ2 の平衡組成と温度との関係［金属熱処理技術便覧、
第285 頁、日刊工業新聞社、昭和49年10月15日 ９版発
行 より引用］中で水素とメタンの混合ガス中の水素量
によってある温度以上になるとメタンが炭素と水素に分
解移行する（ＣＨ4 ⇔Ｃ＋２Ｈ2 ）平衡曲線、特に気圧
1.0 における平衡曲線に着目した。尚、図中の曲線より
右側は炭素析出側を示す。Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that CH 4 ⇔ C + 2 shown in FIG.
Relationship between equilibrium composition of H 2 and temperature [Handbook of Metal Heat Treatment,
Quotation from page 285, published by Nikkan Kogyo Shimbun, October 15, 1974, 9th edition]] When the temperature exceeds a certain temperature due to the amount of hydrogen in the mixed gas of hydrogen and methane, methane is decomposed and transferred to carbon and hydrogen ( CH 4 ⇔ C + 2H 2 ) Equilibrium curve, especially atmospheric pressure
We focused on the equilibrium curve at 1.0. The right side of the curve in the figure shows the carbon deposition side.
【０００９】更に詳細に述べると、例えばSCM440水アト
マイズ粉末を板状に射出成形し、これを脱脂し、水素還
元した後、例えばメタン濃度40〜60％のメタン・水素混
合ガス中で温度600 ℃で１時間の含炭処理（メタン処
理）を行った。得られた処理体の炭素量のバラツキは
0.3〜0.4 ％であった。そして前記含炭処理に続けてメ
タン・水素混合ガス中で温度1150℃で１時間の焼結を行
ったところ、メタン・水素の混合比に応じてセメンタイ
ト量に多寡を生じた。このことから焼結過程におけるメ
タン・水素の混合比率の調整によって得られる焼結体中
の炭素量を制御出来ることを知見した。More specifically, for example, SCM440 water atomized powder is injection-molded into a plate shape, degreased and hydrogen-reduced, and then, for example, in a methane / hydrogen mixed gas having a methane concentration of 40 to 60% at a temperature of 600 ° C. At that time, a carbon-containing treatment (methane treatment) was performed for 1 hour. The variation in the carbon content of the obtained treated body is
It was 0.3 to 0.4%. Then, after the carbonization treatment, sintering was carried out in a methane / hydrogen mixed gas at a temperature of 1150 ° C. for 1 hour, and the cementite amount varied depending on the mixing ratio of methane / hydrogen. From this, it was found that the amount of carbon in the sintered body obtained by adjusting the mixing ratio of methane and hydrogen in the sintering process can be controlled.
【００１０】本発明はかかる知見に基づいてなされたも
のであり、金属粉末成形体を脱脂、水素還元した後、炭
化水素・水素混合ガス雰囲気中で炭化水素と水素の混合
比を調整しつつ焼結して金属焼結体中の炭素量を制御す
ることを特徴とする。The present invention has been made on the basis of such findings, and after degreasing and hydrogen reducing a metal powder compact, it is fired in a hydrocarbon / hydrogen mixed gas atmosphere while adjusting the mixing ratio of hydrocarbon and hydrogen. It is characterized in that the amount of carbon in the metal sintered body is controlled by binding.
【００１１】[0011]
【作用】金属粉末成形体を脱脂し、水素還元した後、炭
化水素と水素の混合ガス中で焼結すると炭素が含有され
た金属焼結体が得られる。還元された金属粉末成形体を
炭化水素と水素の混合雰囲気中で焼成処理すると、その
多孔質性から表面のみならず、内部までスーティングが
生じる。この焼結工程中に炭化水素と水素の混合比を調
整しながら焼結を行うと金属焼結体中の炭素量は制御さ
れる。The metal powder compact is degreased, reduced with hydrogen, and then sintered in a mixed gas of hydrocarbon and hydrogen to obtain a metal sintered compact containing carbon. When the reduced metal powder compact is calcined in a mixed atmosphere of hydrocarbon and hydrogen, sooting occurs not only on the surface but also inside because of its porosity. If sintering is performed while adjusting the mixing ratio of hydrocarbon and hydrogen during this sintering step, the amount of carbon in the metal sintered body is controlled.
【００１２】[0012]
【実施例】本発明は、還元された金属粉末成形体を炭化
水素と水素の混合ガス中で加熱処理、即ち焼結処理する
と、その多孔質性から表面のみならず、内部までスーテ
ィングが生じる。本発明はこの現象を利用して金属粉末
成形体の炭素量制御を行うものであり、金属粉末成形体
の脱脂工程の次工程に組み込まれる本発明方法（ここで
はメタン処理という）は、計量、混練に立ち戻らなけれ
ばならない例えばAmerican Society for Metals; Metal
s Hanbook Vol.7,203(1973) に開示されている従来のグ
ラファイト混合法に比べて効率的である。本発明方法
は、マスフローコントローラに連動するシリコニット炉
を用い、更に炭化水素と水素の混合比を調整しながらメ
タン処理、焼結処理を連続的に行って金属焼結体の組織
（密度、炭素量）の評価を行うものである。EXAMPLES In the present invention, when a reduced metal powder compact is heat-treated in a mixed gas of hydrocarbon and hydrogen, that is, sintered, soot is caused not only on the surface but also on the inside due to its porosity. . The present invention utilizes this phenomenon to control the carbon content of the metal powder compact, and the method of the present invention (herein referred to as methane treatment) incorporated in the next step of the degreasing step of the metal powder compact is Must return to kneading, for example American Society for Metals; Metal
It is more efficient than the conventional graphite mixing method disclosed in s Hanbook Vol.7, 203 (1973). The method of the present invention uses a silicon knit furnace linked to a mass flow controller, and further continuously performs methane treatment and sintering treatment while adjusting the mixing ratio of hydrocarbon and hydrogen, to obtain the structure (density, carbon amount) of the metal sintered body. ) Is evaluated.
【００１３】以下添付図面に従って本発明の実施例を説
明する。Embodiments of the present invention will be described below with reference to the accompanying drawings.
【００１４】図２は本発明方法を実施するための装置の
１例を示すもので、図中、１は金属粉末成形体を水素還
元し、例えばメタンガスと水素ガスの混合ガス雰囲気中
で焼結を施すためのシリコニット炉を示す。シリコニッ
ト炉１の一方にガス導入管２を接続すると共に、該数導
入管２に複数の分岐管３を配設し、各分岐管３の夫々に
シリコニット炉１内に導入するガス供給源４を接続し、
各分岐管３の夫々にマスフローコントローラ５を配置し
た。図示例ではガス供給源４をメタン（ＣＨ4 ）ガス、
水素（Ｈ2 ）ガス、窒素（Ｎ2 ）ガスとした。FIG. 2 shows an example of an apparatus for carrying out the method of the present invention. In the figure, 1 is a metal powder compact which is reduced with hydrogen and sintered, for example, in a mixed gas atmosphere of methane gas and hydrogen gas. 1 shows a silicon knit furnace for applying A gas introduction pipe 2 is connected to one of the silicon knit furnaces 1, a plurality of branch pipes 3 are arranged in the number introduction pipes 2, and a gas supply source 4 to be introduced into the silicon knit furnace 1 is provided in each of the branch pipes 3. connection,
A mass flow controller 5 is arranged in each of the branch pipes 3. In the illustrated example, the gas supply source 4 is methane (CH 4 ) gas,
Hydrogen (H 2 ) gas and nitrogen (N 2 ) gas were used.
【００１５】また、シリコニット炉１の他方にシリコニ
ットロ炉１内にガス導入管２を介して導入されたガス
（例えばメタンガスと水素ガスの混合ガス）を排出する
ための排出管６を接続した。A discharge pipe 6 for discharging a gas (for example, a mixed gas of methane gas and hydrogen gas) introduced into the silicon nitride furnace 1 through the gas introduction pipe 2 is connected to the other side of the silicon nitride furnace 1.
【００１６】また、各マスフローコントローラ５を電源
７（株式会社小島製作所製、商品名PSK-6FC ）を介して
マルチループコントローラ８（株式会社チノー製、商品
名マルチループコントローラSJ）に接続し、該マルチル
ープコントローラ８で並列的にプログラム制御させてシ
リコニット炉１内に導入する例えば水素ガスのような雰
囲気ガス流量を制御出来るようにした。Further, each mass flow controller 5 is connected to a multi-loop controller 8 (manufactured by Kojima Seisakusho Co., Ltd., trade name PSK-6FC) to a multi-loop controller 8 (Chino Co., trade name Multi-loop controller SJ), The multi-loop controller 8 is program-controlled in parallel so that the flow rate of an atmospheric gas such as hydrogen gas introduced into the silicon knit furnace 1 can be controlled.
【００１７】尚、図示例ではマスフローコントローラ５
として、Ｍ１には最大流量 100SCCM或いは 200SCCM、Ｍ
２には最大流量 500SCCM、Ｍ３には最大流量１SLM 、Ｍ
４には最大流量１SLM のマスフローコントローラ（いず
れも株式会社小島製作所製、商品名3610）を用いた。In the illustrated example, the mass flow controller 5
The maximum flow rate for M1 is 100SCCM or 200SCCM, M
Maximum flow rate of 500SCCM for 2 and maximum flow rate of 1SLM, M for M3
A mass flow controller with a maximum flow rate of 1 SLM (both manufactured by Kojima Seisakusho Co., Ltd., trade name 3610) was used for 4.
【００１８】次に、本発明方法を実施するための温度と
時間の関係の１例を図３により説明する。Next, an example of the relationship between temperature and time for carrying out the method of the present invention will be described with reference to FIG.
【００１９】前記装置のシリコニット炉１内に金属粉末
成形体を収容した後、炉１内に水素ガスを流量0.5 リッ
トル／分で導入しながら昇温速度800 ℃／時間で温度 4
00℃にし、更に昇温速度 133℃／時間で温度 600℃にし
て成形体に水素還元処理を施す。続いて炉１内にメタン
ガス濃度50％のメタンと水素の混合ガスを流量 0.7リッ
トル／分で導入しながら温度 600℃に１時間維持して成
形体にここではメタン処理を施す。次にメタン・水素混
合ガスの全流量を一定（ 0.5リットル／分）に保ちなが
ら、炉１内へ導入されるメタンガスの流量を減じると共
に、水素ガスの流量を増やし、昇温速度 300℃／時間で
温度1150℃に昇温した後、該温度1150℃に１時間維持し
て成形体に焼結処理を施す。続いて炉１内へのメタン・
水素混合ガスの導入を停止すると同時に、窒素ガスのよ
うな不活性ガスを流量0.3 〜0.05リットル／分で導入し
ながら降温速度120℃／時間で成形体を温度400 ℃まで
冷却し、以後炉冷とする。After accommodating the metal powder compact in the silicon knit furnace 1 of the above apparatus, while introducing hydrogen gas into the furnace 1 at a flow rate of 0.5 l / min, the temperature was raised at a rate of 800 ° C./hour.
The temperature is set to 00 ° C., and the temperature is increased to 133 ° C./hour to 600 ° C., and the compact is subjected to hydrogen reduction treatment. Subsequently, while introducing a mixed gas of methane and hydrogen having a methane gas concentration of 50% into the furnace 1 at a flow rate of 0.7 liter / min, the temperature is maintained at 600 ° C. for 1 hour, and the molded body is subjected to methane treatment here. Next, while keeping the total flow rate of the methane / hydrogen mixed gas constant (0.5 liters / minute), the flow rate of methane gas introduced into the furnace 1 is reduced, the flow rate of hydrogen gas is increased, and the heating rate is 300 ° C / hour. Then, the temperature is raised to 1150 ° C., and the temperature is maintained at 1150 ° C. for 1 hour to sinter the molded body. Then methane into the furnace 1
At the same time as stopping the introduction of the hydrogen-mixed gas, an inert gas such as nitrogen gas was introduced at a flow rate of 0.3 to 0.05 liters / minute, and the compact was cooled to a temperature of 400 ° C at a temperature-decreasing rate of 120 ° C / hour. And
【００２０】前記図２装置を用いて、本発明方法の具体
的実施例を比較例と共に説明する。A specific embodiment of the method of the present invention will be described together with a comparative example using the apparatus shown in FIG.
【００２１】実施例１ 原料の金属粉末として平均粒径6.77μm、タップ密度3.6
4ｇ／cm3 のSCM440水アトマイズ粉末（日本アトマイズ
加工株式会社製、商品名SF-SCM440 ）と、焼結助剤を重
量比 100：9.1 に計量し、 140〜160 ℃で90分間混練し
た。これを常法により射出成形して厚さ 3mm、幅12mm、
長さ70mmの板状の金属粉末成形体を作製した。Example 1 As a raw material metal powder, the average particle size was 6.77 μm and the tap density was 3.6.
4 g / cm 3 of SCM440 water atomized powder (manufactured by Nippon Atomize Co., Ltd., trade name SF-SCM440) and a sintering aid were weighed at a weight ratio of 100: 9.1 and kneaded at 140 to 160 ° C. for 90 minutes. This is injection molded by a conventional method to a thickness of 3 mm, a width of 12 mm,
A plate-shaped metal powder compact having a length of 70 mm was produced.
【００２２】作製された金属粉末成形体を脱脂炉内で大
気中で昇温速度12℃／時間で昇温し、 300℃に達した時
点で該温度を４時間維持して脱脂処理を行った後、炉内
で温度 100℃以下まで冷却した。The metal powder compact thus produced was heated in the degreasing furnace in the atmosphere at a temperature rising rate of 12 ° C./hour, and when it reached 300 ° C., the temperature was maintained for 4 hours for degreasing treatment. Then, it was cooled in the furnace to a temperature of 100 ° C or lower.
【００２３】脱脂処理された金属粉末成形体をシリコニ
ット炉１内のセラミック板上に載置し、室温から温度 6
00℃に達するまでの間、炉内にＭ３のマスフローコント
ローラ５の調整により水素ガスを流量 0.5リットル／分
で導入して水素還元処理を行った。The degreased metal powder compact was placed on the ceramic plate in the silicon knit furnace 1 and the temperature was changed from room temperature to 6 ° C.
Until the temperature reached 00 ° C., hydrogen gas was introduced into the furnace at a flow rate of 0.5 liter / min by adjusting the M3 mass flow controller 5 to carry out hydrogen reduction treatment.
【００２４】また、温度が 533℃に達した時点でＭ３の
マスフローコントローラ５およびＭ１，Ｍ２のマスフロ
ーコントローラ５の調整によりメタンガス濃度41.2％の
メタンと水素の混合ガスを流量0.85リットル／分で導入
し、該混合ガスの導入を温度600℃に達するまでの間（3
0分間）継続し、温度 600℃に達した後、該温度を１時
間維持せしめると共に、該温度に達した時点で炉１内へ
導入する混合ガスのメタンガス濃度をＭ３のマスフロー
コントローラ５およびＭ１，Ｍ２のマスフローコントロ
ーラ５の調整により50％とし、該ガスを流量 0.7リット
ル／分で導入しつつ、30分間維持した後、炉内へ導入さ
れるメタンガスの流量を逐次低下させた。一方、Ｍ３の
マスフローコントローラ５によって調整された水素ガス
流量は、600℃においては一定に保ち、 600℃を超えて
一時的に低下させた後、少しずつ増加させることによっ
てメタンガス濃度を徐々に減少させつつ、炉内温度を 6
00℃から1150℃まで昇温した。この時、メタン・水素混
合のガス流量は 0.7リットル／分から 0.5リットル／分
に減少させた。該焼結中の最終メタンガス濃度は 1.0％
となるようにした。When the temperature reaches 533 ° C., the mass flow controller 5 of M3 and the mass flow controllers 5 of M1 and M2 are adjusted to introduce a mixed gas of methane and hydrogen having a methane gas concentration of 41.2% at a flow rate of 0.85 liters / minute. , While introducing the mixed gas until the temperature reaches 600 ° C (3
(0 minutes), and after reaching a temperature of 600 ° C., the temperature is maintained for 1 hour, and when the temperature is reached, the methane gas concentration of the mixed gas to be introduced into the furnace 1 is set to M3 mass flow controllers 5 and M1, By adjusting the mass flow controller 5 of M2 to 50%, the gas was introduced at a flow rate of 0.7 liter / min and maintained for 30 minutes, and then the flow rate of methane gas introduced into the furnace was gradually decreased. On the other hand, the hydrogen gas flow rate adjusted by the mass flow controller 5 of M3 is kept constant at 600 ° C., temporarily decreases above 600 ° C., and then gradually increases to gradually decrease the methane gas concentration. While keeping the furnace temperature at 6
The temperature was raised from 00 ° C to 1150 ° C. At this time, the gas flow rate of the methane / hydrogen mixture was reduced from 0.7 l / min to 0.5 l / min. Final methane gas concentration during the sintering is 1.0%
So that
【００２５】そして、温度1150℃に達した時点で該温度
を１時間維持せしめて金属成形体に焼結処理を施した
後、炉内へのメタンと水素の混合ガスの導入を停止する
と同時に、Ｍ４のマスフローコントローラ５の調整によ
り、窒素ガスを流量0.3〜0.05リットル／分で導入し、
炉内温度を２００℃まで冷却して、金属焼結体を取り出
した。When the temperature reaches 1150 ° C., the temperature is maintained for 1 hour to sinter the metal compact, and then the introduction of the mixed gas of methane and hydrogen into the furnace is stopped and at the same time, By adjusting the mass flow controller 5 of M4, nitrogen gas is introduced at a flow rate of 0.3 to 0.05 liters / minute,
The temperature in the furnace was cooled to 200 ° C., and the metal sintered body was taken out.
【００２６】本実施例における炉内に導入するメタンガ
スと水素ガスの混合ガス中のメタンガス濃度と時間との
関係を図４にＡとして示すと共に、表１に記載した。
尚、混合ガス雰囲気中における金属成形体の温度と時間
との関係を図４にＴとして示した。The relationship between the concentration of methane gas in the mixed gas of methane gas and hydrogen gas to be introduced into the furnace in this example and time is shown as A in FIG. 4 and described in Table 1.
The relationship between the temperature of the metal compact and the time in the mixed gas atmosphere is shown as T in FIG.
【００２７】前記工程で作製された金属焼結体の内部炭
素量はEPMAの線分析により測定したＸ線強度を炭素量に
換算して求めた。試料（金属焼結体）の厚さ方向の炭素
量を図５にＦとして示した。尚、試料の炭素量はSCM440
の溶製材と水素焼結体（温度 600℃，１時間のみにメタ
ンガス濃度50％のメタン、水素の混合ガスを導入してメ
タン処理し、その後は水素ガス雰囲気中で1150℃で１時
間の焼成を施した焼結体）の夫々の炭素量を別個に測定
し、これを標準Ｘ線強度とし、他の炭素量測定用試料の
Ｘ線強度を標準Ｘ線強度の炭素量より換算して求めた。The internal carbon content of the metal sintered body produced in the above step was calculated by converting the X-ray intensity measured by EPMA line analysis into the carbon content. The carbon amount in the thickness direction of the sample (metal sintered body) is shown as F in FIG. The carbon content of the sample is SCM440.
Ingot and hydrogen sintered body (temperature 600 ℃, methane treatment by introducing a mixed gas of methane with a methane gas concentration of 50% only for 1 hour, methane treatment, and then calcination in hydrogen gas atmosphere at 1150 ℃ for 1 hour The carbon content of each of the sintered bodies is measured separately, and this is used as the standard X-ray intensity, and the X-ray intensity of the other carbon content measurement samples is calculated by converting it from the carbon content of the standard X-ray intensity. It was
【００２８】また、金属焼結体の試料の端を長手方向に
直角に切断し、金属成形体の組織を光学顕微鏡（顕微鏡
倍率×１９９）により調べたところ、試料のエジェクタ
面（炉内のセラミックス板面に接した試料の下側面）、
試料のスプルー面（炉内に導入せるガスの流れに接する
試料の上側面）共にその表面から深さ約0.05mmまではフ
ェライト層をなし、それから内部に向かってパーライト
結晶が徐々に増えて、中心部では最も多かった。Further, the end of the sample of the metal sintered body was cut at a right angle to the longitudinal direction, and the structure of the metal molded body was examined by an optical microscope (microscope magnification: 199). As a result, the ejector surface of the sample (ceramics in the furnace Lower surface of the sample in contact with the plate surface),
Both the sprue surface of the sample (upper side surface of the sample in contact with the gas flow introduced into the furnace) forms a ferrite layer up to a depth of about 0.05 mm from that surface, and then the pearlite crystal gradually increases toward the inside, It was the most in the department.
【００２９】また、焼結密度を測定したところ7.232g／
cm3 であり、その相対密度は92.4％であった。尚、相対
密度は溶製材（ＪＩＳ ＳＣＭ４４０）の密度7.828g／
cm3を真密度とし、焼結密度／真密度× 100（％）とし
て求めた。When the sintered density was measured, it was 7.232 g /
cm 3 and its relative density was 92.4%. The relative density is the density of ingot (JIS SCM440) 7.828 g /
cm 3 was taken as the true density, and the density was calculated as sintered density / true density × 100 (%).
【００３０】実施例２ 先ず、前記実施例１と同様の方法で脱脂処理された金属
粉末成形体を作製した。Example 2 First, a degreased metal powder compact was prepared in the same manner as in Example 1.
【００３１】脱脂処理された金属粉末成形体をシリコニ
ット炉１内のセラミック板上に載置し、室温から温度 6
00℃に達するまでの間、炉１内にＭ３のマスフローコン
トローラ５の調整により水素ガスを流量 0.5リットル／
分で導入して水素還元処理を行った。The degreased metal powder compact was placed on the ceramic plate in the silicon knit furnace 1 and the temperature was changed from room temperature to 6
Until the temperature reaches 00 ° C, the flow rate of hydrogen gas in the furnace 1 is adjusted to 0.5 L / liter by adjusting the M3 mass flow controller 5.
Introduced in minutes to perform hydrogen reduction treatment.
【００３２】そして、温度 600℃に達した時点でＭ３の
マスフローコントローラ５およびＭ１，Ｍ２のマスフロ
ーコントローラ５の調整によりメタンガス濃度50％のメ
タンと水素の混合ガスを流量 0.7リットル／分で導入し
つつ、該温度を１時間維持した後、炉内へ導入されるメ
タンガスの流量を逐次減少させると共に、Ｍ３のマスフ
ローコントローラ５の調整により水素ガスの流量を逐次
増加させた。メタン・水素混合ガスの流量は 0.5リット
ル／分である。このようにメタンガス濃度を徐々に減少
せしめながら、金属成形体の温度を1150℃まで昇温させ
た。該焼結中の最終メタンガス濃度は 1.0％となるよう
にした。When the temperature reaches 600 ° C., the mass flow controller 5 of M3 and the mass flow controllers 5 of M1 and M2 are adjusted to introduce a mixed gas of methane and hydrogen having a methane gas concentration of 50% at a flow rate of 0.7 liter / min. After the temperature was maintained for 1 hour, the flow rate of methane gas introduced into the furnace was successively decreased, and the flow rate of hydrogen gas was sequentially increased by adjusting the mass flow controller 5 of M3. The flow rate of methane / hydrogen mixed gas is 0.5 liter / min. Thus, the temperature of the metal compact was raised to 1150 ° C. while gradually reducing the methane gas concentration. The final methane gas concentration during the sintering was set to 1.0%.
【００３３】そして、金属成形体の温度が1150℃に達し
た時点で該温度を１時間維持せしめて金属成形体に焼結
処理を施した後、炉内へのメタンと水素の混合ガスの導
入を停止すると同時に、Ｍ４のマスフローコントローラ
５の調整により窒素ガスを流量 0.3〜0.05 リットル／
分で導入し、炉内の金属成形体を温度 200℃まで冷却し
て、金属焼結体を取り出した。When the temperature of the metal compact reaches 1150 ° C., the temperature is maintained for 1 hour to sinter the metal compact, and then a mixed gas of methane and hydrogen is introduced into the furnace. At the same time, the flow rate of nitrogen gas is adjusted to 0.3-0.05 liter / by adjusting the mass flow controller 5 of M4.
Introduced in minutes, the metal formed body in the furnace was cooled to a temperature of 200 ° C., and the metal sintered body was taken out.
【００３４】本実施例における炉内に導入するメタンガ
スと水素ガスの混合ガス中のメタンガス濃度と時間との
関係を図４にＢとして示すと共に、表１に記載した。
尚、混合ガス雰囲気中における金属成形体の温度と時間
との関係を図４にＴとして示した。The relationship between the concentration of methane gas in the mixed gas of methane gas and hydrogen gas introduced into the furnace in this example and time is shown as B in FIG. 4 and also shown in Table 1.
The relationship between the temperature of the metal compact and the time in the mixed gas atmosphere is shown as T in FIG.
【００３５】前記工程で作製された金属焼結体の内部炭
素量を前記実施例１と同様の方法で測定し、その結果を
図５にＧとして示す。The internal carbon content of the metal sintered body produced in the above step was measured by the same method as in Example 1, and the result is shown as G in FIG.
【００３６】また、金属焼結体の組織を前記実施例１と
同様の方法で調べたところ、表面のフェライト層の厚さ
はエジェクタ面側で約0.07mm、試料のスプルー面側で約
0.1mm であり、内部はほぼ均一なパーライト組織になっ
ていた。When the structure of the metal sintered body was examined by the same method as in Example 1, the thickness of the ferrite layer on the surface was about 0.07 mm on the ejector surface side, and on the sprue surface side of the sample.
It was 0.1 mm, and the inside had an almost uniform pearlite structure.
【００３７】また、焼結密度を測定したところ7.545g／
cm3 であり、その相対密度は96.4％であった。When the sintered density was measured, it was 7.545 g /
cm 3 and its relative density was 96.4%.
【００３８】実施例３ 先ず、前記実施例１と同様の方法で脱脂処理された金属
粉末成形体を作製した。Example 3 First, a degreased metal powder compact was prepared in the same manner as in Example 1.
【００３９】脱脂処理された金属粉末成形体をシリコニ
ット炉１内のセラミック板上に載置し、室温から温度 6
00℃に達するまでの間、炉１内にＭ３のマスフローコン
トローラ５の調整により水素ガスを流量 0.5リットル／
分で導入して水素還元処理を行った。The degreased metal powder compact was placed on the ceramic plate in the silicon knit furnace 1 and the temperature was changed from room temperature to 6
Until the temperature reaches 00 ° C, the flow rate of hydrogen gas in the furnace 1 is adjusted to 0.5 L / liter by adjusting the M3 mass flow controller 5.
Introduced in minutes to perform hydrogen reduction treatment.
【００４０】そして、温度 600℃に達した時点でＭ３の
マスフローコントローラ５およびＭ１，Ｍ２のマスフロ
ーコントローラ５の調整によりメタンガス濃度50％のメ
タンと水素の混合ガスを流量 0.7リットル／分で導入し
つつ、該温度を１時間維持した後、炉内へ導入されるメ
タンガスの流量を逐次減少させると共に、Ｍ３のマスフ
ローコントローラ５の調整により水素ガスの流量を逐次
増加させた。メタン・水素混合ガスの流量は 0.5リット
ル／分である。このようにメタンガス濃度を徐々に減少
せしめながら、金属成形体の温度を1150℃まで昇温させ
た。該焼結中の最終メタンガス濃度は 3.0％となるよう
にした。When the temperature reached 600 ° C., the mass flow controller 5 of M3 and the mass flow controllers 5 of M1 and M2 were adjusted to introduce a mixed gas of methane and hydrogen having a methane gas concentration of 50% at a flow rate of 0.7 liter / min. After the temperature was maintained for 1 hour, the flow rate of methane gas introduced into the furnace was successively decreased, and the flow rate of hydrogen gas was sequentially increased by adjusting the mass flow controller 5 of M3. The flow rate of methane / hydrogen mixed gas is 0.5 liter / min. Thus, the temperature of the metal compact was raised to 1150 ° C. while gradually reducing the methane gas concentration. The final methane gas concentration during the sintering was set to 3.0%.
【００４１】そして、金属成形体の温度が1150℃に達し
た時点で該温度を１時間維持せしめて金属成形体に焼結
処理を施した後、炉内へのメタンと水素の混合ガスの導
入を停止すると同時に、Ｍ４のマスフローコントローラ
５の調整により窒素ガスを流量 0.3〜0.05 リットル／
分で導入して、炉内の金属成形体を温度 200℃まで冷却
して、金属焼結体を取り出した。Then, when the temperature of the metal compact reaches 1150 ° C., the temperature is maintained for 1 hour to subject the metal compact to a sintering treatment, and then a mixed gas of methane and hydrogen is introduced into the furnace. At the same time, the flow rate of nitrogen gas is adjusted to 0.3-0.05 liter / by adjusting the mass flow controller 5 of M4.
Introduced in minutes, the metal compact in the furnace was cooled to a temperature of 200 ° C., and the metal sintered compact was taken out.
【００４２】本実施例における炉内に導入するメタンガ
スと水素ガスの混合ガス中のメタンガス濃度と時間との
関係を図４にＣとして示すと共に、表１に記載した。
尚、混合ガス雰囲気中における金属成形体の温度と時間
との関係を図４にＴとして示した。The relationship between the concentration of methane gas in the mixed gas of methane gas and hydrogen gas introduced into the furnace in this example and time is shown as C in FIG. 4 and also shown in Table 1.
The relationship between the temperature of the metal compact and the time in the mixed gas atmosphere is shown as T in FIG.
【００４３】前記工程で作製された金属焼結体の内部炭
素量を前記実施例１と同様の方法で測定し、その結果を
図５にＨとして示す。The internal carbon content of the metal sintered body produced in the above step was measured by the same method as in Example 1, and the result is shown as H in FIG.
【００４４】また、金属焼結体の組織を前記実施例１と
同様の方法で調べたところ、表面のフェライト層の厚さ
はエジェクタ面、スプルー面共に約0.02mmであり、内部
はパーライト組織とセメンタイト組織からなっていた。
また、エジェクタ面側のパーライト組織およびセメンタ
イト組織の結晶粒はスプルー面側よりも大きかった。The structure of the metal sintered body was examined by the same method as in Example 1, and the thickness of the ferrite layer on the surface was about 0.02 mm for both the ejector surface and the sprue surface, and the inside had a pearlite structure. It consisted of a cementite structure.
The crystal grains of the pearlite structure and the cementite structure on the ejector surface side were larger than those on the sprue surface side.
【００４５】また、焼結密度を測定したところ7.732g／
cm3 であり、その相対密度は98.8％であった。When the sintered density was measured, it was 7.732 g /
cm 3 and its relative density was 98.8%.
【００４６】比較例１ 先ず、前記実施例１と同様の方法で脱脂処理された金属
粉末成形体を作製した。Comparative Example 1 First, a degreased metal powder compact was prepared in the same manner as in Example 1.
【００４７】脱脂処理された金属粉末成形体をシリコニ
ット炉１内のセラミック板上に載置し、室温から温度 6
00℃に達するまでの間、炉１内にＭ３のマスフローコン
トローラ５の調整により水素ガスを流量 0.5リットル／
分で導入して水素還元処理を行った。The degreased metal powder compact was placed on the ceramic plate in the silicon knit furnace 1 and the temperature was changed from room temperature to 6 ° C.
Until the temperature reaches 00 ° C, the flow rate of hydrogen gas in the furnace 1 is adjusted to 0.5 L / liter by adjusting the M3 mass flow controller 5.
Introduced in minutes to perform hydrogen reduction treatment.
【００４８】そして、温度 600℃に達した時点でＭ３の
マスフローコントローラ５およびＭ２のマスフローコン
トローラ５の調整によりメタンガス濃度50％のメタンと
水素の混合ガスを流量 0.7リットル／分で導入しつつ、
該温度を１時間維持した後、炉内へのメタンガスの導入
を停止して、Ｍ３のマスフローコントローラ５の調整に
より水素ガスのみを流量 0.1リットル／分で導入しなが
ら、金属成形体の温度を1150℃までに昇温させた。When the temperature reaches 600 ° C., the mass flow controller 5 of M3 and the mass flow controller 5 of M2 are adjusted to introduce a mixed gas of methane and hydrogen having a methane gas concentration of 50% at a flow rate of 0.7 liter / min.
After maintaining the temperature for 1 hour, the introduction of methane gas into the furnace was stopped, and only the hydrogen gas was introduced at a flow rate of 0.1 liter / min by adjusting the mass flow controller 5 of M3, while the temperature of the metal compact was set to 1150. The temperature was raised to ° C.
【００４９】そして、金属成形体の温度が1150℃に達し
た時点で該温度を１時間維持せしめて金属成形体に焼結
処理を施した後、 120℃／時間の速度で降温し、 400℃
で水素ガスの導入を停止すると同時に、Ｍ４のマスフロ
ーコントローラ５の調整により窒素ガスを流量0.05リッ
トル／分で導入した。そして炉内の金属成形体を室温近
くまで冷却し、金属焼結体を取り出した。When the temperature of the metal compact reaches 1150 ° C., the temperature is maintained for 1 hour, the metal compact is sintered, and then the temperature is lowered at a rate of 120 ° C./hour to 400 ° C.
The introduction of hydrogen gas was stopped at the same time, and at the same time, nitrogen gas was introduced at a flow rate of 0.05 liter / min by adjusting the mass flow controller 5 of M4. Then, the metal formed body in the furnace was cooled to near room temperature, and the metal sintered body was taken out.
【００５０】本比較例における炉内に導入するメタンガ
スと水素ガスの混合ガス中のメタンガス濃度と時間との
関係を図４にＤとして示すと共に、表１に記載した。
尚、混合ガス雰囲気中における金属成形体の温度と時間
との関係を図４にＴとして示した。The relationship between the concentration of methane gas in the mixed gas of methane gas and hydrogen gas introduced into the furnace and time in this comparative example is shown as D in FIG. 4 and also shown in Table 1.
The relationship between the temperature of the metal compact and the time in the mixed gas atmosphere is shown as T in FIG.
【００５１】前記工程で作製された金属焼結体の内部炭
素量を前記実施例１と同様の方法で測定し、その結果を
図５にＩとして示す。The internal carbon content of the metal sintered body produced in the above step was measured by the same method as in Example 1, and the result is shown as I in FIG.
【００５２】また、金属焼結体の組織を前記実施例１と
同様の方法で調べたところ、試料全面に亘ってフェライ
ト組織であった。また、一部に輪状の介在物が散見され
た。これは焼結過程における水素流量が少なく、還元が
不十分なためと考察される。When the structure of the metal sintered body was examined by the same method as in Example 1, it was a ferrite structure over the entire surface of the sample. In addition, ring-shaped inclusions were found in some areas. It is considered that this is because the hydrogen flow rate in the sintering process is low and the reduction is insufficient.
【００５３】また、焼結密度を測定したところ6.401g／
cm3 であり、その相対密度は81.8％であった。When the sintered density was measured, it was 6.401 g /
cm 3 and its relative density was 81.8%.
【００５４】比較例２ 先ず、前記実施例１と同様の方法で脱脂処理された金属
粉末成形体を作製した。Comparative Example 2 First, a degreased metal powder compact was prepared in the same manner as in Example 1.
【００５５】脱脂処理された金属粉末成形体をシリコニ
ット炉１内のセラミック板上に載置し、室温から温度 6
00℃に達するまでの間、炉１内にＭ３のマスフローコン
トローラ５の調整により水素ガスを流量 0.5リットル／
分で導入して水素還元処理を行った。The degreased metal powder compact was placed on the ceramic plate in the silicon knit furnace 1 and the temperature was changed from room temperature to 6 ° C.
Until the temperature reaches 00 ° C, the flow rate of hydrogen gas in the furnace 1 is adjusted to 0.5 L / liter by adjusting the M3 mass flow controller 5.
Introduced in minutes to perform hydrogen reduction treatment.
【００５６】そして、温度 600℃に達した時点でＭ３の
マスフローコントローラ５およびＭ２のマスフローコン
トローラ５の調整によりメタンガス濃度50％のメタンと
水素の混合ガスを流量 0.7リットル／分で導入しつつ、
該温度を１時間維持した後、炉内への混合ガス（メタン
ガス濃度50％）の導入を継続しながら、温度を 600℃か
ら1150℃になるように昇温を行ったが、温度 900℃で異
常が見られたので、混合ガスの導入と、昇温を直ちに停
止すると共に、炉内に窒素ガスを導入して冷却を行っ
た。When the temperature reaches 600 ° C., the mass flow controller 5 of M3 and the mass flow controller 5 of M2 are adjusted to introduce a mixed gas of methane and hydrogen having a methane gas concentration of 50% at a flow rate of 0.7 liter / min.
After maintaining the temperature for 1 hour, the temperature was raised from 600 ° C to 1150 ° C while continuing to introduce the mixed gas (50% methane gas concentration) into the furnace. Since an abnormality was found, the introduction of the mixed gas and the temperature increase were immediately stopped, and nitrogen gas was introduced into the furnace for cooling.
【００５７】本比較例における炉内に導入するメタンガ
スと水素ガスの混合ガス中のメタンガス濃度と時間との
関係を図４にＥとして示すと共に、表１に記載した。
尚、混合ガス雰囲気中における金属成形体の温度と時間
との関係を図４にＴとして示した。The relationship between the methane gas concentration in the mixed gas of methane gas and hydrogen gas introduced into the furnace and the time in this comparative example is shown as E in FIG. 4 and also shown in Table 1.
The relationship between the temperature of the metal compact and the time in the mixed gas atmosphere is shown as T in FIG.
【００５８】炉内が室温になったので試料を取り出して
観察したところ、試料は金属粉末成形体の脱脂処理後の
大きさの１．１倍に肥大しており、金属粉間に過剰なス
スが見られ、全く焼結されておらず、簡単に手で折れて
しまった。Since the inside of the furnace reached room temperature, the sample was taken out and observed. As a result, the sample was enlarged to 1.1 times the size of the metal powder compact after degreasing treatment, and an excessive amount of soot was present between the metal powders. Was seen, it was not sintered at all, and it was easily broken by hand.
【００５９】[0059]
【表１】 [Table 1]
【００６０】前記実施例並びに比較例の結果（図５、表
１および組織調査結果）から明らかなように，本発明の
実施例は焼結処理された金属焼結体中の炭素量を制御出
来ることが確認された。As is clear from the results of the above-mentioned Examples and Comparative Examples (FIG. 5, Table 1 and the results of the structure investigation), the Examples of the present invention can control the carbon content in the sintered metal sintered body. It was confirmed.
【００６１】また、比較例２から明らかなようにメタン
ガス濃度50％のままでは温度1150℃に昇温させると炭素
量過剰のため溶融してしまうものと思われる。従って、
金属粉末成形体に焼結（例えば温度 600℃から1150℃に
昇温し、その間で焼結）を施す場合にはメタンガス濃度
を低減させながら焼結を行うことが必要であることが分
かる。Further, as is clear from Comparative Example 2, when the methane gas concentration remains at 50%, it is considered that when the temperature is raised to 1150 ° C., it will melt due to the excessive carbon content. Therefore,
It is understood that when the metal powder compact is subjected to sintering (for example, the temperature is raised from 600 ° C. to 1150 ° C. and during that period), it is necessary to perform the sintering while reducing the methane gas concentration.
【００６２】前記実施例では炭化水素としてメタンガス
を用いたが、本発明ではこれに限定されるものではな
く、前記メタンガスの他にエタンガス、プロパンガス、
ブタンガス等が挙げられる。Although methane gas was used as the hydrocarbon in the above-mentioned embodiment, the present invention is not limited to this, and in addition to the methane gas, ethane gas, propane gas,
Butane gas and the like can be mentioned.
【００６３】また、前記実施例では金属粉末としてＳＣ
Ｍ４４０水アトマイズを用いたが、本発明ではこれに限
定されるものではなく、鉄系粉末、超硬合金粉末、銅合
金粉末、アルミニウム合金粉末、ニッケル合金粉末、チ
タン合金粉末等が挙げられる。また、本発明法は従来金
属粉末射出成形法の対象材料として不向きであった炭素
鋼、構造用合金鋼、工具鋼等の製造にも利用することが
出来る。In the above embodiment, SC is used as the metal powder.
Although M440 water atomized was used, the present invention is not limited thereto, and examples thereof include iron-based powder, cemented carbide powder, copper alloy powder, aluminum alloy powder, nickel alloy powder, and titanium alloy powder. Further, the method of the present invention can also be used for producing carbon steel, structural alloy steel, tool steel and the like, which have been unsuitable as a target material for metal powder injection molding.
【００６４】前記実施例とは別に次のような実験を行っ
た。The following experiment was conducted separately from the above example.
【００６５】脱脂された金属成形体を室温から温度 600
℃までの過程で水素による還元処理を十分に行った金属
成形体に、メタンガス濃度を40％、50％、60％としたメ
タンと水素の混合ガス雰囲気中で、温度 600℃、１時間
の加熱処理を行って、得られた金属成形体の中の炭素量
とメタンガス濃度との関係を調べ、その結果を図６に示
す。The degreased metal molded body is heated from room temperature to a temperature of 600.
A metal compact that has been sufficiently reduced with hydrogen in the process up to ℃ is heated at a temperature of 600 ℃ for 1 hour in a mixed gas atmosphere of methane and hydrogen with methane gas concentrations of 40%, 50%, and 60%. After the treatment, the relationship between the carbon amount and the methane gas concentration in the obtained metal molded body was investigated, and the result is shown in FIG.
【００６６】図６から明らかなように、炭素量とメタン
ガス濃度は全く比例関係にあることが分かる。しかし、
各メタンガス濃度における炭素量はバラツキがあり、メ
タンガス濃度が高まるほど炭素量のバラツキが拡大す
る。これは多孔質体に対するスーティング現象の不安定
さのためと思われる。メタンガス濃度が40％では炭素量
のバラツキがほとんどないのはスーティングが起こらな
いためと見られる。As is clear from FIG. 6, the carbon amount and the methane gas concentration are in direct proportion. But,
The carbon amount in each methane gas concentration varies, and the higher the methane gas concentration, the greater the variation in carbon amount. This seems to be due to the instability of the sooting phenomenon for the porous body. When the methane gas concentration is 40%, there is almost no variation in the carbon content, which is considered to be because sooting does not occur.
【００６７】また、焼結された金属焼結体の組織を調べ
た結果、焼結工程における雰囲気中のメタンガス濃度が
が高いほどセメンタイト量が多いことが分かった。これ
はメタン処理工程以降の焼結工程で雰囲気中に残存せる
炭化水素により含炭（ここではメタン処理）が生じたこ
とを意味する。従って、焼結処理された金属焼結体中の
炭素量の増加を防止するには焼結工程において炭化水素
濃度の減少を速やかに行うことが必要となる。Further, as a result of examining the structure of the sintered metal sintered body, it was found that the higher the methane gas concentration in the atmosphere during the sintering step, the larger the amount of cementite. This means that carbonization (here, methane treatment) was caused by the hydrocarbons remaining in the atmosphere in the sintering process after the methane treatment process. Therefore, in order to prevent an increase in the amount of carbon in the sintered metal sintered body, it is necessary to promptly reduce the hydrocarbon concentration in the sintering process.
【００６８】[0068]
【発明の効果】本発明によるときは、金属粉末成形体を
脱脂し、水素還元した後、炭化水素と水素の混合ガス中
で焼結する際、炭化水素と水素の混合比を調整しながら
焼結するようにしたので、金属焼結全体の炭素量、或い
は金属焼結体内部の炭素量分布を制御した金属焼結体を
極めて簡単に製造することが出来る効果がある。According to the present invention, the metal powder compact is degreased and reduced with hydrogen, and then sintered in a mixed gas of hydrocarbon and hydrogen while adjusting the mixing ratio of hydrocarbon and hydrogen. Since they are bonded, there is an effect that a metal sintered body in which the carbon content of the entire metal sintered body or the carbon content distribution inside the metal sintered body is controlled can be extremely easily manufactured.
【図１】 ＣＨ4 ⇔Ｃ＋２Ｈ2 の平衡組成と温度との関
係を表す特性線図、FIG. 1 is a characteristic diagram showing the relationship between the equilibrium composition of CH 4 ⇔ C + 2H 2 and temperature,
【図２】 本発明方法を実施するための装置の１例の説
明図、FIG. 2 is an explanatory view of an example of an apparatus for carrying out the method of the present invention,
【図３】 本発明方法を実施するための温度と時間との
関係の１例を表す特性線図、FIG. 3 is a characteristic diagram showing an example of the relationship between temperature and time for carrying out the method of the present invention,
【図４】 本発明実施例の導入する混合ガス中のメタン
ガス濃度と時間との関係および温度と時間との関係を表
す特性線図、FIG. 4 is a characteristic diagram showing a relationship between methane gas concentration in a mixed gas to be introduced and time and a relationship between temperature and time according to the embodiment of the present invention;
【図５】 金属焼結体の厚み方向位置と炭素量との関係
を表す特性線図、FIG. 5 is a characteristic diagram showing the relationship between the position in the thickness direction of the metal sintered body and the amount of carbon,
【図６】 混合ガス中のメタンガス濃度と金属成形体の
炭素量との関係を表す特性線図。FIG. 6 is a characteristic diagram showing the relationship between the concentration of methane gas in a mixed gas and the carbon content of a metal compact.
Claims (1)
後、炭化水素・水素混合ガス雰囲気中で炭化水素と水素
の混合比を調整しつつ焼結して金属焼結体中の炭素量を
制御することを特徴とする金属粉末成形体の炭素量制御
方法。1. A metal powder compact is degreased and hydrogen-reduced, and then sintered in a hydrocarbon / hydrogen mixed gas atmosphere while adjusting the mixing ratio of hydrocarbon and hydrogen to reduce the amount of carbon in the metal sintered body. A method for controlling the amount of carbon in a metal powder compact, which is characterized by controlling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5260601A JP2797166B2 (en) | 1993-10-19 | 1993-10-19 | Method for controlling carbon content of metal powder compact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5260601A JP2797166B2 (en) | 1993-10-19 | 1993-10-19 | Method for controlling carbon content of metal powder compact |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07118705A true JPH07118705A (en) | 1995-05-09 |
| JP2797166B2 JP2797166B2 (en) | 1998-09-17 |
Family
ID=17350213
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5260601A Expired - Lifetime JP2797166B2 (en) | 1993-10-19 | 1993-10-19 | Method for controlling carbon content of metal powder compact |
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| Country | Link |
|---|---|
| JP (1) | JP2797166B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6533996B2 (en) | 2001-02-02 | 2003-03-18 | The Boc Group, Inc. | Method and apparatus for metal processing |
| JP2008544085A (en) * | 2005-06-22 | 2008-12-04 | ダンマークス テクニスケ ウニヴァシティット ディ・ティ・ウ | Carburizing method in hydrocarbon gas |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4939724A (en) * | 1972-08-28 | 1974-04-13 | ||
| JPS63183103A (en) * | 1987-01-26 | 1988-07-28 | Chugai Ro Kogyo Kaisha Ltd | Sintering method for injection molding |
| JPS63190103A (en) * | 1987-01-30 | 1988-08-05 | Mitsubishi Metal Corp | Method for controlling carbon potential in sintering furnace |
-
1993
- 1993-10-19 JP JP5260601A patent/JP2797166B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4939724A (en) * | 1972-08-28 | 1974-04-13 | ||
| JPS63183103A (en) * | 1987-01-26 | 1988-07-28 | Chugai Ro Kogyo Kaisha Ltd | Sintering method for injection molding |
| JPS63190103A (en) * | 1987-01-30 | 1988-08-05 | Mitsubishi Metal Corp | Method for controlling carbon potential in sintering furnace |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6533996B2 (en) | 2001-02-02 | 2003-03-18 | The Boc Group, Inc. | Method and apparatus for metal processing |
| US7018584B2 (en) | 2001-02-02 | 2006-03-28 | The Boc Group, Inc. | Method and apparatus for metal processing |
| JP2008544085A (en) * | 2005-06-22 | 2008-12-04 | ダンマークス テクニスケ ウニヴァシティット ディ・ティ・ウ | Carburizing method in hydrocarbon gas |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2797166B2 (en) | 1998-09-17 |
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