JP2000129310A - Degreasing method for stainless powder molded body - Google Patents
Degreasing method for stainless powder molded bodyInfo
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- JP2000129310A JP2000129310A JP10301335A JP30133598A JP2000129310A JP 2000129310 A JP2000129310 A JP 2000129310A JP 10301335 A JP10301335 A JP 10301335A JP 30133598 A JP30133598 A JP 30133598A JP 2000129310 A JP2000129310 A JP 2000129310A
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- Prior art keywords
- binder
- time
- temperature
- stainless steel
- molded body
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ステンレス粉末成
形体を焼結することによって、ステンレス粉末焼結体を
製造する際の脱脂方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degreasing method for manufacturing a stainless steel powder sintered body by sintering a stainless steel powder compact.
【０００２】[0002]
【従来の技術】粉末冶金を用いてステンレス粉末を所定
の形状に成形する方法としては、金型成形、静水圧成
形、ホットプレス成形、テープ成形、押出成形、鋳込成
形、金属粉末成形法等種々の方法がある。いずれの方法
も、ステンレス粉末を成形するために有機バインダーか
らなる結合材を添加、混合した後、それぞれの方法によ
り、金型内に投入し、押圧、打ち抜き、流し込み或いは
射出等を行って成形体を成形する。そして、得られた成
形体から結合材を除去し、焼結することによりステンレ
ス粉末焼結体としている。2. Description of the Related Art As a method of forming stainless steel powder into a predetermined shape using powder metallurgy, there are mold molding, hydrostatic molding, hot press molding, tape molding, extrusion molding, casting molding, metal powder molding method and the like. There are various methods. In any method, after adding and mixing a binder made of an organic binder to form a stainless steel powder, the mixture is put into a mold and pressed, punched, poured or injected by each method to form a molded body. Is molded. Then, the binder is removed from the obtained molded body and sintered to obtain a stainless steel powder sintered body.
【０００３】結合材の従来の除去方法としては、特開昭
５８−１２６９０１号公報に開示されているように、結
合材の流動点以上の温度まで加熱し、成形体表面の雰囲
気を流動させて不飽和状態とするのに充分な流量のバイ
ンダに関して非飽和である化学的に不活性な雰囲気を成
形体上に送風して除去する方法がある。As a conventional method for removing a binder, as disclosed in Japanese Patent Application Laid-Open No. 58-126901, the binder is heated to a temperature higher than the pour point of the binder and the atmosphere on the surface of the molded body is caused to flow. There is a method in which a chemically inert atmosphere, which is unsaturated with respect to a binder having a sufficient flow rate to be in an unsaturated state, is blown onto a molded body to remove the atmosphere.
【０００４】[0004]
【発明が解決しようとする課題】しかし、上述した従来
の方法では、以下の条件を満足する必要がある。第１
に、加熱によってステンレス粉末成形体から結合材を除
去する場合には、加熱の最高保持温度、最高保持温度の
保持時間を設定する必要がある。However, in the above-described conventional method, the following conditions must be satisfied. First
In addition, when the binder is removed from the stainless steel powder compact by heating, it is necessary to set the maximum holding temperature of heating and the holding time of the maximum holding temperature.
【０００５】第２に、結合材の除去の完了後のいわゆる
脱脂体は、全ての結合材をただ除去すべきでなく、ステ
ンレス粉末の鋼種によっては結合材を微量残存させる必
要がある。これは、ステンレス粉末は結合材との混合や
除去の各工程で酸化しており、焼結時に酸化物から酸素
を取り除く必要があり、この酸素の除去を行うための還
元反応を行うためである。かかる還元反応は、結合材内
の炭素によって、Ｃ＋Ｏ→ＣＯ、Ｃ＋２Ｏ→ＣＯ2 の反
応を行うことによってなされる。Second, the so-called degreased body after the completion of the removal of the binder must not only remove all the binder, but also needs to leave a trace amount of the binder depending on the type of stainless steel powder. This is because the stainless steel powder is oxidized in each step of mixing and removal with the binder, and it is necessary to remove oxygen from the oxide during sintering, and to perform a reduction reaction to remove this oxygen. . Such a reduction reaction is performed by performing a reaction of C + O → CO and C + 2O → CO 2 by carbon in the binder.
【０００６】この還元反応において、フェライト系もし
くはオーステナイト系ステンレスでは、焼結後の残留炭
素量を低く抑える必要があるため、脱脂体の残留炭素が
脱脂体中に残留している酸素との還元反応でほぼ消失す
る量としている。また、マルテンサイト系ステンレスで
は、さらに炭素を残留させて焼結後の焼結体中の含有炭
素量を上昇させている。従って、ステンレスの種別によ
って残留炭素に量を制御する必要がある。In this reduction reaction, in the case of ferritic or austenitic stainless steel, the residual carbon content after sintering needs to be kept low, so that the residual carbon in the degreased body reacts with the oxygen remaining in the degreased body. And almost disappear. Further, in the martensitic stainless steel, carbon is further left to increase the carbon content in the sintered body after sintering. Therefore, it is necessary to control the amount of residual carbon depending on the type of stainless steel.
【０００７】ところで、上述したように結合材の除去
は、その最高保持温度と最高保持温度の保持時間によっ
て決定される。また、結合材は、ある温度までは分解せ
ず、一定の温度を越えると分解速度が温度上昇と共に大
きくなる特性を有している。すなわち、低温で長時間加
熱しても結合材はあまり除去できず、高温で短時間加熱
した方が多くの結合材は除去される。[0007] As described above, the removal of the binder is determined by the maximum holding temperature and the holding time at the maximum holding temperature. Further, the binder has a characteristic that it does not decompose until a certain temperature, and when it exceeds a certain temperature, the decomposition rate increases as the temperature rises. That is, even if the material is heated at a low temperature for a long time, the binder cannot be removed much, and if the material is heated at a high temperature for a short time, more binder is removed.
【０００８】より具体的には、低温で長時間加熱した場
合の総熱量（Ｑ１）と、高温で短時間加熱した場合の総
熱量（Ｑ２）とは、Ｑ１＝Ｑ２とはならずに、Ｑ１＞Ｑ
２となる。このため、実際に最高保持温度と最高保持温
度の保持時間を設定するには、ステンレス粉末成形体が
脱脂体となったときの重量減量を測定し、このデータを
参考にして最高保持温度と最高保持温度の保持時間を設
定し直すトライアルを繰り返し、最終的な結合除去条件
を決定している。このため、これらの条件を設定するた
めに、多大な時間を要している。More specifically, the total amount of heat (Q1) when heated at a low temperature for a long time and the total amount of heat (Q2) when heated at a high temperature for a short time are not Q1 = Q2, but Q1 > Q
It becomes 2. Therefore, to actually set the maximum holding temperature and the holding time of the maximum holding temperature, measure the weight loss when the stainless steel powder compact becomes a degreased body, and refer to this data to determine the maximum holding temperature and the maximum holding temperature. The trial for resetting the holding time of the holding temperature is repeated to determine the final bond removal conditions. Therefore, it takes a lot of time to set these conditions.
【０００９】本発明は以上のような問題点を考慮してな
されたものであり、ステンレス粉末成形体から結合材を
除去する際の最高保持温度と最高保持温度の保持時間の
設定を速やかに行うことを可能としたステンレス粉末成
形体の脱脂方法を提供することを目的とする。The present invention has been made in consideration of the above problems, and promptly sets the maximum holding temperature and the maximum holding temperature when the binder is removed from the stainless steel powder compact. It is an object of the present invention to provide a method for degreasing a stainless steel powder compact that has made it possible.
【００１０】[0010]
【課題を解決するための手段】上記目的を達成するた
め、請求項１の発明は、フェライト系もしくはオーステ
ナイト系ステンレス粉末と結合材とを混合して成形体を
成形した後、前記成形体から結合材を除去し、その後焼
結を行ってステンレス粉末焼結体とする製造方法におい
て、前記結合材を除去するに際し、結合材の９５％以上
を分解除去できる温度をＴ0 ［℃］、その分解時間をｔ
0 ［Ｈ］としたとき、結合材の除去時の最高保持温度Ｔ
［℃］、最高保持温度の保持時間ｔ［Ｈ］を、 Ｔ×ｔ≦Ｔ0 ×ｔ0 で、且つＴ≧Ｔ0 とすることを特徴とする。In order to achieve the above object, the present invention is directed to a method of forming a molded body by mixing a ferrite or austenitic stainless steel powder and a binder, and then bonding the molded body. In a manufacturing method in which a material is removed and then sintering is performed to obtain a sintered stainless steel powder, the temperature at which 95% or more of the binder is decomposed and removed when removing the binder is T 0 [° C.] Time t
0 [H], the maximum holding temperature T when the binder is removed
[° C.] and the holding time t [H] at the maximum holding temperature are T × t ≦ T 0 × t 0 and T ≧ T 0 .
【００１１】上述したように、フェライト系もしくはオ
ーステナイト系ステンレス粉末焼結体では、残留炭素量
を低く押さえる必要がある。すなわち、結合除去後の脱
脂体の残留炭素量は、焼結時の還元反応、すなわちＣ＋
Ｏ→ＣＯ、Ｃ＋２Ｏ→ＣＯ2の反応に寄与する量のみ残
存させる必要がある。As described above, in a sintered ferrite or austenitic stainless steel powder, the amount of residual carbon must be kept low. That is, the residual carbon content of the degreased body after the removal of the bond is determined by the reduction reaction during sintering,
Only the amount that contributes to the reaction of O → CO, C + 2O → CO 2 needs to be left.
【００１２】そこで結合材の９５％以上が分解する温度
Ｔ0 ［℃］、その時の時間ｔ0 ［Ｈ］を示差熱重量測定
等により測定する。残留炭素量は極少量で良いため、よ
り高温Ｔ［℃］でかつ短時間ｔ［Ｈ］加熱することによ
り、結合材の分解を促進させ、所望の炭素量にすること
ができる。Therefore, the temperature T 0 [° C.] at which 95% or more of the binder is decomposed and the time t 0 [H] at that time are measured by differential thermogravimetry or the like. Since the amount of residual carbon may be very small, heating at a higher temperature T [° C.] and for a shorter time t [H] promotes the decomposition of the binder and can achieve a desired amount of carbon.
【００１３】請求項２の発明は、マルテンサイト系ステ
ンレス粉末と結合材とを混合して成形体を成形した後、
前記成形体から結合材を除去し、その後焼結を行ってス
テンレス粉末焼結体を得る製造方法において、前記結合
材を除去するに際し、結合材の９５％以上を分解除去で
きる温度をＴ0 ［℃］、その分解時間をｔ0 ［Ｈ］とし
たとき、結合材の除去時の最高保持温度Ｔ［℃］、最高
保持温度の保持時間ｔ［Ｈ］を、 Ｔ×ｔ≧Ｔ0 ×ｔ0 で、且つＴ≦Ｔ0 とすることを特徴とする。According to a second aspect of the present invention, after a martensitic stainless steel powder and a binder are mixed to form a molded body,
In the manufacturing method of removing the binder from the molded body and then performing sintering to obtain a stainless steel powder sintered body, when removing the binder, the temperature at which 95% or more of the binder is decomposed and removed is set to T 0 [ ° C.], when its degradation time t 0 [H], the maximum holding temperature T at the time of removal of the binder [° C.], the retention time of the maximum holding temperature t [H], T × t ≧ T 0 × t 0 and T ≦ T 0 .
【００１４】上述したように、マルテンサイト系ステン
レス粉末焼結体は残留炭素を多くする必要がある。すな
わち、結合材除去後の脱脂体の残留炭素量は焼結時の還
元反応、すなわちＣ＋Ｏ→ＣＯ、Ｃ＋２Ｏ→ＣＯ2 の反
応によって失われる炭素量よりも多く残存させる必要が
ある。As described above, it is necessary to increase the residual carbon in the martensitic stainless powder sintered body. That is, the residual carbon amount of the degreased body after the removal of the binder needs to remain more than the carbon amount lost by the reduction reaction at the time of sintering, that is, the reaction of C + O → CO and C + 2O → CO 2 .
【００１５】そこで結合材の９５％以上が分解する温度
Ｔ0 ［℃］、その時のｔ0 ［Ｈ］を示差熱重量測定等に
より測定する。残留炭素量は多量であるため、より低温
Ｔ［℃］でかつ長時間ｔ［Ｈ］加熱することで、結合材
の分解を抑制し、所望の炭素量にすることができる。Then, the temperature T 0 [° C.] at which 95% or more of the binder is decomposed and the temperature t 0 [H] at that time are measured by differential thermogravimetry or the like. Since the amount of residual carbon is large, by heating at a lower temperature T [° C.] and for a longer time t [H], the decomposition of the binder can be suppressed, and the desired amount of carbon can be obtained.
【００１６】[0016]
【発明の実施の形態】（実施の形態１）図１は、この実
施形態によって成形されるステンレス粉末成形体１を示
す。このステンレス粉末成形体１は、寸法Ａの高さ、寸
法Ｂ＋Ｃ＋Ｄの幅、寸法Ｅの奥行きを有したブロック状
となっており、Ａ＝６０ｍｍ、Ｂ＝Ｃ＝Ｄ＝２０ｍｍ、
Ｅ＝３５ｍｍである。また、Ｃ部分は切り欠きされてい
る。(Embodiment 1) FIG. 1 shows a stainless steel powder compact 1 formed according to this embodiment. The molded stainless steel powder 1 is in the form of a block having a height of dimension A, a width of dimension B + C + D, and a depth of dimension E, where A = 60 mm, B = C = D = 20 mm,
E = 35 mm. The portion C is cut out.
【００１７】この成形体の成形は、平均粒形１２μｍの
オーステナイト系ステンレス粉末（ＪＩＳ規格ＳＵＳ３
１６Ｌ）９１．２ｗｔ％と、ポリステチレン（ＰＳ）
２．８ｗｔ％、ポリメチルメタクリレート（ＰＭＭＡ）
２．６ｗｔ％、エチレン−ビニル酢酸共重合体（ＥＶ
Ａ）２．５ｗｔ％、パラフィンワックス０．９ｗｔ％か
らなる結合材とを混合混練し、この混合体を射出成形す
ることによって行う。The compact is formed by austenitic stainless steel powder (JIS standard SUS3) having an average grain size of 12 μm.
16L) 91.2 wt% and polystyrene (PS)
2.8 wt%, polymethyl methacrylate (PMMA)
2.6 wt% of an ethylene-vinyl acetic acid copolymer (EV
A) It is performed by mixing and kneading a binder composed of 2.5 wt% and 0.9 wt% of paraffin wax, and subjecting the mixture to injection molding.
【００１８】結合材であるポリスチレン（ＰＳ）、ポリ
メチルメタクリレート（ＰＭＭＡ）、エチレン−ビニル
酢酸共重合体（ＥＶＡ）、パラフィンワックスをステレ
ンス粉末と混合した際の混合比を、結合材のみの混合比
に換算する。その結果、重量比でポリスチレン（ＰＳ）
は３１．８ｗｔ％、ポリメチルメタクリレート（アクリ
ル、ＰＭＭＡ）は２９．５ｗｔ％、エチレン−ビニル酢
酸共重合体（ＥＶＡ）は２８．４ｗｔ％、パラフィンワ
ックスは１０．３ｗｔ％となる。この混合比の混合物を
示差熱重量測定器によって常圧大気下で測定することに
より、混合体が９６．２％分解する温度Ｔ0 ＝３５２．
３℃、分解に要する時間ｔ0 ＝８．４Ｈを得た。The mixing ratio when polystyrene (PS), polymethyl methacrylate (PMMA), ethylene-vinyl acetic acid copolymer (EVA), and paraffin wax as the binder are mixed with the stainless steel powder is determined by the mixing ratio of the binder alone. Convert to As a result, the weight ratio of polystyrene (PS)
Is 31.8 wt%, polymethyl methacrylate (acrylic, PMMA) is 29.5 wt%, ethylene-vinyl acetic acid copolymer (EVA) is 28.4 wt%, and paraffin wax is 10.3 wt%. The mixture having this mixing ratio is measured under a normal pressure atmosphere by a differential thermogravimeter, and the temperature T 0 at which the mixture is decomposed by 96.2% is T 0 = 352.
3 ° C. and time t 0 = 8.4H required for decomposition were obtained.
【００１９】その後、ステンレス粉末成形体１を脱脂炉
内に移送し、常圧大気下で昇温速度１４℃／Ｈ、最高保
持温度Ｔ＝３６５℃、最高保持温度の保持時間６Ｈで加
熱した。ここで、Ｔ×ｔ＝２１９０、Ｔ0 ×ｔ0 ＝２９
５９．３であり、Ｔ×ｔ≦Ｔ 0 ×ｔ0 且つＴ≦Ｔ0 とな
っている。Then, the stainless steel powder compact 1 is removed from the degreasing furnace.
Inside, and at normal temperature atmospheric pressure, the temperature rise rate is 14 ° C / H
Holding temperature T = 365 ° C, maximum holding temperature holding time 6H
Heated. Here, T × t = 2190, T0× t0= 29
59.3 and T × t ≦ T 0× t0And T ≦ T0Tona
ing.
【００２０】次に、結合材を除去した脱脂体を焼結炉に
移送し、昇温速度３００℃／Ｈ、最高保持温度１３５０
℃、最高保持温度の保持時間２Ｈで焼結を行い、最終的
なステンレス粉末焼結体とした。Next, the degreased body from which the binder has been removed is transferred to a sintering furnace, where the temperature is raised at a rate of 300 ° C./H and the maximum holding temperature is 1350.
Sintering was carried out at 2 ° C. and a holding time of 2H at the maximum holding temperature to obtain a final stainless powder sintered body.
【００２１】本実施例によれば、Ｔ0 より高温でかつｔ
0 より短時間の加熱のため、ステンレス粉末成形体中の
結合材は速やかに分解除去される。従って、脱脂後の脱
脂体の残留炭素量は焼結時の還元反応、すなわちＣ＋Ｏ
→ＣＯ、Ｃ＋２Ｏ→ＣＯ2 に必要な量しか残留せず、焼
結後の焼結体の残留炭素量は、０．０１２ｗｔ％と少な
く良好な焼結体を得ることができた。According to this embodiment, the temperature is higher than T 0 and t
Due to heating for a time shorter than 0 , the binder in the stainless steel powder compact is quickly decomposed and removed. Therefore, the residual carbon content of the degreased body after degreasing is reduced by sintering, that is, C + O
→ CO, C + 2O → Only a necessary amount of CO 2 remained, and the amount of residual carbon in the sintered body after sintering was as small as 0.012 wt%, and a good sintered body could be obtained.
【００２２】（実施の形態２）この実施の形態では、図
１に示す形状のステンレス粉末成形体１を成形する。す
なわち、平均粒形８μｍのフェライト系ステンレス粉末
（ＪＩＳ規格ＳＵＳ４３０粉末）９２．０ｗｔ％と、ポ
リプロピレン（ＰＰ）４．５ｗｔ％、ポリエチレン（Ｐ
Ｅ）３．２ｗｔ％、カルナウバワックス０．３ｗｔ％と
からなる結合材とを混合して混練した後、ステンレス粉
末成形体１を射出成形する。(Embodiment 2) In this embodiment, a stainless steel powder compact 1 having the shape shown in FIG. 1 is formed. That is, 92.0 wt% of ferrite stainless steel powder (JIS standard SUS430 powder) having an average grain size of 8 μm, 4.5 wt% of polypropylene (PP), and polyethylene (P
E) After mixing and kneading a binder composed of 3.2 wt% and 0.3 wt% of carnauba wax, the stainless steel powder compact 1 is injection-molded.
【００２３】フェライト系ステンレス粉末を除いた結合
材のみについての混合比は、ポリプロピレン５６．２ｗ
ｔ％、ポリエチレン３６．４ｗｔ％、カルナウバワック
ス７．４ｗｔ％であり、この結合材のみを示差熱重量測
定器によって常圧窒素下で測定し、９８．８％が分解す
る温度Ｔ0 ＝３４２．９℃、分解に要する時間ｔ0 ＝４
Ｈを得た。The mixing ratio of only the binder except for the ferrite stainless steel powder is 56.2 w / w polypropylene.
% of polyethylene, 36.4% by weight of polyethylene and 7.4% by weight of carnauba wax. This binder alone was measured by a differential thermogravimeter under normal pressure nitrogen, and the temperature T 0 = 342 at which 98.8% was decomposed 0.9 ° C., time required for decomposition t 0 = 4
H was obtained.
【００２４】その後、成形されたステンレス粉末成形体
１を脱脂炉内へ移送し、常圧窒素雰囲気下で、昇温速度
２０℃／Ｈ、最高保持温度Ｔ＝３７０℃、最高保持温度
の保持時間ｔ＝３．５Ｈで結合材を除去した。ここで、
Ｔ×ｔ＝１２９５、Ｔ0 ×ｔ 0 ＝１３７１．６であり、
従って、Ｔ×ｔ≦Ｔ0 ×ｔ0 且つＴ≦Ｔ0 である。Thereafter, the formed stainless steel powder compact
1 into a degreasing furnace and heated at a normal temperature in a nitrogen atmosphere.
20 ° C / H, maximum holding temperature T = 370 ° C, maximum holding temperature
The binder was removed at a retention time t of 3.5H. here,
T × t = 1295, T0× t 0= 1371.6,
Therefore, T × t ≦ T0× t0And T ≦ T0It is.
【００２５】結合材除去後の脱脂体を焼結炉に移送し、
昇温速度２５０℃／Ｈ、最高保持温度１３２０℃、最高
保持温度の保持時間１Ｈで焼結し、最終的なステンレス
粉末焼結体とした。The degreased body after removing the binder is transferred to a sintering furnace,
Sintering was performed at a heating rate of 250 ° C./H, a maximum holding temperature of 1320 ° C., and a holding time of the maximum holding temperature of 1 H to obtain a final stainless powder sintered body.
【００２６】本実施例によれば、Ｔ0 より高温でかつｔ
0 より短時間の加熱のため、ステンレス粉末成形体中の
結合材は速やかに分解除去される。従って、脱脂後の脱
脂体の残留炭素量は焼結時の還元反応、すなわちＣ＋Ｏ
→ＣＯ、Ｃ＋２Ｏ→ＣＯ2 に必要な量しか残留せず、焼
結後の焼結体の残留炭素量は０．０８ｗｔ％と少なく、
良好な焼結体を得ることができた。According to this embodiment, the temperature is higher than T 0 and t
Due to heating for a time shorter than 0 , the binder in the stainless steel powder compact is quickly decomposed and removed. Therefore, the residual carbon content of the degreased body after degreasing is reduced by sintering, that is, C + O
→ CO, C + 2O → Only the amount required for CO 2 remains, and the residual carbon content of the sintered body after sintering is as small as 0.08 wt%.
A good sintered body could be obtained.
【００２７】（実施の形態３）この実施の形態において
も、図１に示すステンレス粉末成形体１を成形する。す
なわち、平均粒形８．５μｍのマルテンサイト系ステン
レス（ＪＩＳ規格ＳＵＳ４４０Ｃ）９１．５ｗｔ％と、
結合材としてのポリアミド（ＰＡ）８．５ｗｔ％とを混
合して混練し、射出成形を行いステンレス粉末成形体１
を得る。(Embodiment 3) In this embodiment, too, a stainless steel powder compact 1 shown in FIG. 1 is formed. That is, 91.5 wt% of a martensitic stainless steel (JIS standard SUS440C) having an average particle size of 8.5 μm,
8.5 wt% of polyamide (PA) as a binder is mixed and kneaded, and injection molding is performed to form a stainless powder compact 1
Get.
【００２８】このとき、結合材であるポリアミドを真空
雰囲気１０-4ｔｏｒｒで示差熱重量測定器により９８．
６％分解する温度Ｔ0 ＝３５５．１℃、分解に要する時
間ｔ 0 ＝２．８Ｈを得た。At this time, the polyamide as the binding material is evacuated to a vacuum.
Atmosphere 10-Four98 torr by differential thermogravimetry.
6% decomposition temperature T0= 355.1 ° C, when required for decomposition
Interval t 0= 2.8H.
【００２９】次に、ステンレス粉末成形体１を脱脂炉内
に移送し、真空雰囲気１０-4ｔｏｒｒ、昇温速度２８０
℃／Ｈ、最高保持温度Ｔ＝３２０℃、最高保持温度の保
持時間ｔ＝３Ｈで結合材を除去した。ここで、Ｔ×ｔ＝
９６０, Ｔ0 ×ｔ0 ＝９９４．３であり、従って、Ｔ×
ｔ≧Ｔ0 ×ｔ0 且つＴ≦Ｔ0 である。Next, the stainless steel powder compact 1 is transferred into a degreasing furnace, and a vacuum atmosphere of 10 -4 torr and a heating rate of 280 are used.
The binder was removed at a temperature of ° C / H, a maximum holding temperature of T = 320 ° C, and a holding time of the maximum holding temperature of t = 3H. Here, T × t =
960, T 0 × t 0 = 994.3 and therefore T ×
t ≧ T 0 × t 0 and T ≦ T 0 .
【００３０】その後、結合材除去後の脱脂体を焼結炉へ
移送し、昇温速度３００℃、最高保持温度１２４０℃、
最高保持温度の保持時間２Ｈで焼結し、最終的なステン
レス粉末焼結体とした。Thereafter, the degreased body from which the binder was removed was transferred to a sintering furnace, where the temperature was raised at a rate of 300 ° C., the maximum holding temperature was 1240 ° C.,
Sintering was performed at a holding time of 2H at the maximum holding temperature to obtain a final stainless steel powder sintered body.
【００３１】本実施例によれば、Ｔ0 より低温でかつｔ
0 より長時間の加熱のためステンレス粉末成形体中の結
合材の分解除去は抑制される。従って、脱脂後の脱脂体
の残留炭素量は焼結時の還元反応、すなわちＣ＋Ｏ→Ｃ
Ｏ、Ｃ＋２Ｏ→ＣＯ2 に必要な量を上回る量が残留し
た。その結果、焼結後の焼結体の残留炭素量は、０．９
８ｗｔ％と多く良好な焼結体を得ることができた。According to this embodiment, the temperature is lower than T 0 and t
Due to heating for longer than 0, the decomposition and removal of the binder in the stainless steel powder compact are suppressed. Therefore, the residual carbon content of the degreased body after degreasing is reduced by sintering, that is, C + O → C
O, C + 2O → an amount exceeding the amount required for CO 2 remained. As a result, the residual carbon content of the sintered body after sintering was 0.9
As many as 8 wt%, a good sintered body could be obtained.
【００３２】なお、以上の実施の形態では、ステンレス
粉末成形体の成形方法として射出成形を用いたが、射出
成形以外の金型成形、静水圧成形、ホットプレス、テー
プ成形、押出成形、鋳込成形等を用いても同様な効果が
得られる。In the above embodiment, injection molding was used as a method for molding a stainless steel powder compact. However, other than injection molding, mold molding, hydrostatic molding, hot pressing, tape molding, extrusion molding, casting, and the like. Similar effects can be obtained by using molding or the like.
【００３３】[0033]
【発明の効果】以上説明したように、請求項１の発明に
よれば、フェライト系もしくはオーステナイト系ステン
レスからなる成形体に対し、焼結後の残留炭素を少なく
でき、速やかな結合材除去を行うことができる。As described above, according to the first aspect of the present invention, it is possible to reduce the residual carbon after sintering and quickly remove the binder from the molded body made of ferritic or austenitic stainless steel. be able to.
【００３４】請求項２の発明によれば、マルテンサイト
系ステンレスからなる成形体に対し、焼結後の炭素量を
上昇させることができる。According to the second aspect of the present invention, it is possible to increase the amount of carbon after sintering with respect to the formed body made of martensitic stainless steel.
【図１】本発明の各実施の形態で成形される成形体の斜
視図である。FIG. 1 is a perspective view of a molded body molded in each embodiment of the present invention.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 児玉 卓弥 東京都渋谷区幡ヶ谷２丁目43番２号 オリ ンパス光学工業株式会社内 (72)発明者 山口 博史 東京都渋谷区幡ヶ谷２丁目43番２号 オリ ンパス光学工業株式会社内 Ｆターム(参考） 4K018 AA33 BA17 BC12 CA23 CA27 CA29 CA32 DA03 EA02 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuya Kodama 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Inventor Hirofumi Yamaguchi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. F term (reference) 4K018 AA33 BA17 BC12 CA23 CA27 CA29 CA32 DA03 EA02
Claims (2)
ステンレス粉末と結合材とを混合して成形体を成形した
後、前記成形体から結合材を除去し、その後焼結を行っ
てステンレス粉末焼結体とする製造方法において、 前記結合材を除去するに際し、結合材の９５％以上を分
解除去できる温度をＴ 0 ［℃］、その分解時間をｔ
0 ［Ｈ］としたとき、結合材の除去時の最高保持温度Ｔ
［℃］、最高保持温度の保持時間ｔ［Ｈ］を、 Ｔ×ｔ≦Ｔ0 ×ｔ0 で、且つＴ≧Ｔ0 とすることを特徴とするステンレス粉末成形体の脱脂方
法。1. Ferrite or austenitic
Molded body was formed by mixing stainless steel powder and binder
Thereafter, the binder is removed from the molded body, and then sintering is performed.
In the method for producing a stainless powder sintered body, 95% or more of the binder is removed when the binder is removed.
The temperature at which the solution can be removed is T 0[° C] and the decomposition time is t
0[H], the maximum holding temperature T when the binder is removed
[° C.], the holding time t [H] at the maximum holding temperature is given by T × t ≦ T0× t0And T ≧ T0 Method for degreasing stainless powder compacts characterized by the following:
Law.
材とを混合して成形体を成形した後、前記成形体から結
合材を除去し、その後焼結を行ってステンレス粉末焼結
体を得る製造方法において、 前記結合材を除去するに際し、結合材の９５％以上を分
解除去できる温度をＴ 0 ［℃］、その分解時間をｔ
0 ［Ｈ］としたとき、結合材の除去時の最高保持温度Ｔ
［℃］、最高保持温度の保持時間ｔ［Ｈ］を、 Ｔ×ｔ≧Ｔ0 ×ｔ0 で、且つＴ≦Ｔ0 とすることを特徴とするステンレス粉末成形体の脱脂方
法。2. Bonding with martensitic stainless steel powder
After forming a molded body by mixing with a material,
Remove the mixture and then sinter to sinter stainless steel powder
In the manufacturing method for obtaining a body, at the time of removing the binder, 95% or more of the binder is separated.
The temperature at which the solution can be removed is T 0[° C] and the decomposition time is t
0[H], the maximum holding temperature T when the binder is removed
[° C.], the holding time t [H] at the maximum holding temperature is given by T × t ≧ T0× t0And T ≦ T0 Method for degreasing stainless powder compacts characterized by the following:
Law.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10301335A JP2000129310A (en) | 1998-10-22 | 1998-10-22 | Degreasing method for stainless powder molded body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10301335A JP2000129310A (en) | 1998-10-22 | 1998-10-22 | Degreasing method for stainless powder molded body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000129310A true JP2000129310A (en) | 2000-05-09 |
Family
ID=17895632
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10301335A Withdrawn JP2000129310A (en) | 1998-10-22 | 1998-10-22 | Degreasing method for stainless powder molded body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000129310A (en) |
-
1998
- 1998-10-22 JP JP10301335A patent/JP2000129310A/en not_active Withdrawn
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