JPH0518894B2 - - Google Patents
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- Publication number
- JPH0518894B2 JPH0518894B2 JP4562686A JP4562686A JPH0518894B2 JP H0518894 B2 JPH0518894 B2 JP H0518894B2 JP 4562686 A JP4562686 A JP 4562686A JP 4562686 A JP4562686 A JP 4562686A JP H0518894 B2 JPH0518894 B2 JP H0518894B2
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- JP
- Japan
- Prior art keywords
- powder
- reduced
- iron
- temperature
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 25
- 238000010438 heat treatment Methods 0.000 claims description 20
- 239000000843 powder Substances 0.000 claims description 19
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 18
- 238000005245 sintering Methods 0.000 claims description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 17
- 238000007906 compression Methods 0.000 claims description 15
- 230000006835 compression Effects 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 10
- 239000010949 copper Substances 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 239000010439 graphite Substances 0.000 claims description 8
- 229910002804 graphite Inorganic materials 0.000 claims description 8
- 229910052759 nickel Inorganic materials 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 229910052750 molybdenum Inorganic materials 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- 239000011651 chromium Substances 0.000 claims description 5
- 239000010941 cobalt Substances 0.000 claims description 5
- 229910017052 cobalt Inorganic materials 0.000 claims description 5
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 4
- 239000011572 manganese Substances 0.000 claims description 4
- 239000011812 mixed powder Substances 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 239000000314 lubricant Substances 0.000 claims description 3
- 239000011733 molybdenum Substances 0.000 claims description 3
- 238000011946 reduction process Methods 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 239000012535 impurity Substances 0.000 claims 1
- 238000000465 moulding Methods 0.000 description 10
- 238000009864 tensile test Methods 0.000 description 8
- 230000009467 reduction Effects 0.000 description 6
- 238000011282 treatment Methods 0.000 description 6
- 230000004913 activation Effects 0.000 description 4
- 238000003754 machining Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
〔産業上の利用分野〕
本発明は高強度焼結体の製造方法に関し、詳し
くは高強度の鉄系焼結体の製造方法に関するもの
である。
〔従来の技術〕
一般に、焼結体の高強度化は高密度化や熱処理
により行われている。高強度焼結体の製造は、通
常、原料紛の混合、成形、焼結、サイジング、熱
処理、機械加工の各工程により行われている（特
公昭58−50308号、特開昭59−38351号参照）。成
形は、成形体の密度が7.0ｇ／cm2程度になるよう
に行われ、焼結は1230ないし1300℃の高温で60な
いし120分加熱することにより行われている。熱
処理は高強度を得るために必要で焼き入れ、焼き
戻し処理が行われている。
〔発明が解決しようとする問題点〕
しかしながら、上記した製造方法では、成形体
密度は通常、高くても7.0ｇ／cm2であり、この程
度の密度では十分な強度が得られないため、熱処
理が必要であり、成形時の金型を高価な超硬金型
に変えて成形体の密度を更に高くするようにして
も密度は7.2ｇ／cm2止まりであつてなお熱処理が
必要であるので、工程数が増加し、生産性が低下
し、生産コストが上昇するという問題がある。ま
た、熱処理を施すと、大きな歪が焼結体に生じ
る。これに対処するため、一般に加工取り代を大
きくしているが、加工取り代を大きくすると原料
粉の使用量が増加し、コスト高になるとともに、
加工性（被削性）が悪化し、生産性が低下し、加
工費が大幅に上昇する。また、焼結体を熱処理を
施さずに、加工する場合でも加工性は良くなく、
加工費が上昇する。
更にまた、焼結を高温で比較的長時間行う必要
があるため、炉が傷みやすく、また、ランニング
コストが高くなるという問題もある。
本発明は上記問題点を解決するためのもので、
高温焼結及び熱処理せずに高強度焼結体を製造す
る方法を提供することを目的とするものである。
〔問題点を解決するための手段〕
本発明の高強度焼結体の製造方法は、
（） 重量比で、ニツケル（Ni）又はコバル
ト（Co）を１ないし６％、銅（Cu）、モリブデ
ン（Mo）、クロム（Cr）、マンガン（Mn）、ケ
イ素（Si）からなる群から選ばれる元素１種又
は２種以上を0.5ないし３％含み残部が２％以
下の不可避不純物と、鉄（Fe）とからなり、
ニツケル（Ni）又はコバルト（Co）が鉄
（Fe）と完全合金化していなく、かつその他の
元素が鉄（Fe）と混合又は部分合金化又は完
全合金化している鉄系合金粉末と黒鉛粉末と潤
滑剤とを混合する工程、
（） 混合した粉末から密度比80ないし90％の
圧粉体を成形する工程、
（） 圧粉体を還元雰囲気中で８℃／分ないし
30℃／分の昇温速度で加熱して800ないし950℃
に昇温させ、その温度に保持したのち、300℃
までを15℃／分以下の冷却速度で冷却して還元
処理し、還元後の圧粉体中の酸素を0.2重量％
以下、残留黒鉛を0.2重量％以上、化合炭素を
0.2重量％以下とする還元工程、
（） 還元処理した圧粉体を常温にて圧縮比
1.05以上で圧縮する工程、及び
（） 圧縮した圧粉体を1100ないし1150℃で10
ないし20分加熱したのち、400℃までを10℃／
分以上の冷却速度で冷却する焼結工程からなる
ことを特徴とするものである。
〔作用〕
本発明の高強度焼結体の製造方法は、圧粉体を
還元することにより圧粉体を構成する粉末の表面
を活性化し、その後の冷間圧縮により、該表面を
拡散点とさせるとともに、部分合金化したニツケ
ル（Ni）又はコバルト（Co）と鉄（Fe）により
形成されるオーステナイトが冷間圧縮により加工
誘起変態することによる歪活性の複合作用を利用
することにより、熱処理せず、かつ低温・短時間
の焼結でも高強度焼結体を得ることができるもの
である。
本発明の限定理由について詳細に説明する。な
お、特に記載しないかぎり、％は重量％を示す。
Ni又はCoは１％未満では形成されるオーステ
ナイトが不十分であり、６％を超えると、加工硬
化のため、圧縮比を1.05以上とすることが困難と
なるので、１ないし６％と限定した。
銅（Cu）、モリブデン（Mo）、クロム（Cr）、
マンガン（Mn）、ケイ素（Si）は高強度を得るた
めに効果があり、上記元素から選ばれる元素１種
又は２種以上は0.5％未満では焼結体の強度向上
が不十分であり、３％を超えると圧粉体の粉末が
硬くなるため、圧縮比を1.05以上とすることが困
難となり、拡散点形成及び歪活性が不十分とな
り、また、これらの元素は圧粉体の還元工程にお
いて十分に還元することが難しいので、十分に活
性化することが困難となるため、0.5％ないし３
％とした。
圧粉体の密度比は、密度比80％未満では冷間圧
縮にて歪活性が不十分で、十分な強度が得られ
ず、密度比90％を超えると、還元により活性化し
た気孔が冷間圧縮により接合する度合が減少する
ので、十分な歪活性が得られないため、80ないし
90％とした。
還元した圧粉体中の酸素は0.2％を超えると十
分に活性化することができないため、0.2％以下
とした。化合炭素が0.2％を超え、かつ残留黒鉛
が0.2％未満では、成形体が硬くかつ黒鉛の潤滑
効果が十分でないため、冷間圧縮で圧縮比を1.05
以上とすることが困難となるので、化合炭素は
0.2％以下、残留黒鉛は0.2％以上とした。
焼結は1100℃未満、10分未満では拡散が不十分
で高強度焼結体が得られず、1150℃超え、20分超
えても強度の向上が著しくないため、1100℃ない
し1150℃で10ないし20分とした。
上記した条件で製造することにより、引張り強
さ70Kgｆ／mm2以上の高強度焼結体を得ることがで
きる。
〔実施例〕
本発明を実施例により詳しく説明する。
実施例 １
Ni2％、Cu1.4％、Mo0.4％残部Feの組成の部
分合金粉と0.6％の黒鉛粉と成形用潤滑剤のステ
アリン酸亜鉛粉0.7％とをＶ形混合機で混合し、
混合粉を得た。
次いで、この混合粉を金型成形法により成形し
て引張り試験片（JSPM標準２−64）形状の圧粉
体を得た。この圧粉体の密度は、6.7ｇ／cm2（密
度比85％）とした。
次に、この圧粉体を還処理した。還元処理は連
続炉を用い、分解アンモニアガスを雰囲気とし、
12℃／mmの昇温速度で加熱して890℃に昇温し、
その温度で保持したのち、常温まで冷却した。冷
却速度は300℃までは10℃／mmとした。
次いで、還元した圧粉体の表面にステアリン酸
亜鉛粉末を塗布し、常温にて圧縮比1.075で圧縮
加工した。この加工によつて圧粉体の密度は7.2
ｇ／cm2となつた。
焼結は、圧縮加工した圧粉体を、連続炉を用い
て、ブタン変成ガス雰囲気（C.P＝0.6％）中で
1120℃の温度に15分間保持したのち、420℃まで
を13℃／mmの冷却速度で冷却することにより行つ
た。
得られた焼結体を引張り試験に供した。引張り
試験はクロスヘツドスピード３mm／mmで常温にて
行つた。結果を図に示す。
なお、還元した圧粉体を化学分析し、酸素、遊
離黒鉛、化合炭素を調べた。結果を処理条件とと
もに表に示した。
実施例 ２
Ni3.9％、Cu1.4％、Mo0.35％残部Feの組成の
部分合金粉と黒鉛とスリアリン酸亜鉛を実施例１
と同様の割合で実施例１と同様に混合したのち、
実施例１と同様にして成形、還元処理、圧縮加
工、焼結を行つた。
得られた焼結体を実施例１と同様に引張り試験
に供した。結果を図に示す。
なお、還元した圧粉体を化学分析し、酸素、遊
離炭素及び化合炭素を調べ、結果を表に示した。
実施例 ３
Co3.1％、Mo0.4％、Cr0.1％Si0.1％残部Feの
組成の部分合金粉と黒鉛とスリアリン酸亜鉛を実
施例１と同様の割合で実施例１と同様に混合した
のち、実施例１と同様にして成形、還元処理、圧
縮加工、焼結を行つた。
得られた焼結体を実施例１と同様に引張り試験
に供した。結果を図に示す。
なお、還元した圧粉体を化学分析し、酸素、遊
離炭素及び化合炭素を調べ、結果を表に示した。
比較例１〜６及び10
実施例１と同様の原料粉を用いて、表に示した
条件で実施例１と同様な方法で成形、還元処理、
圧縮加工及び焼結を行つた。
得られた焼結体を実施例１と同様にして引張り
試験した。結果を図に示す。なお、還元した圧粉
体中の酸素、遊離炭素、化合炭素を調べ、結果を
表に示した。
比較例７及び８
実施例１と同様の原料粉を用いて、表に示した
条件で実施例１と同様な方法で成形及び焼結体を
行つた。なお、還元及び圧縮は行わなかつた。
得られた焼結体を実施例１と同様にして引張り
試験した。結果を図に示す。
比較例 ９
Cu粉1.4％、Mo粉0.4％、黒鉛粉0.6％及び残部
純鉄粉（市販品）にステアリン酸亜鉛0.8％を配
合し、Ｖ型混合機で混合した。成形、還元処理、
圧縮加工、焼結は表に示す条件で実施例１と同様
な方法で行つた。
得られた焼結体を実施例１と同様にして引張り
試験した。結果を図に示す。なお、還元した圧粉
体中の酸素、遊離炭素、化合炭素を調べ、結果を
表に示した。
[Industrial Field of Application] The present invention relates to a method for manufacturing a high-strength sintered body, and more particularly to a method for manufacturing a high-strength iron-based sintered body. [Prior Art] Generally, the strength of a sintered body is increased by increasing its density or by heat treatment. The production of high-strength sintered bodies is usually carried out through the following steps: mixing raw material powder, molding, sintering, sizing, heat treatment, and machining (Japanese Patent Publication No. 58-50308, JP-A No. 59-38351) reference). Molding is performed so that the density of the molded body is approximately 7.0 g/cm 2 , and sintering is performed by heating at a high temperature of 1230 to 1300° C. for 60 to 120 minutes. Heat treatment is necessary to obtain high strength, and quenching and tempering treatments are performed. [Problems to be solved by the invention] However, in the above manufacturing method, the density of the molded product is usually 7.0 g/cm 2 at the highest, and sufficient strength cannot be obtained with this density, so heat treatment is not required. Even if we change the molding mold to an expensive carbide mold to further increase the density of the molded product, the density remains at 7.2 g/cm 2 and heat treatment is still required. , the number of steps increases, productivity decreases, and production costs increase. Further, when heat treatment is performed, large distortion occurs in the sintered body. To deal with this, the machining allowance is generally increased, but increasing the machining allowance increases the amount of raw material powder used, which increases costs.
Processability (machinability) deteriorates, productivity decreases, and machining costs increase significantly. In addition, even when processing a sintered body without heat treatment, the workability is not good,
Processing costs will rise. Furthermore, since it is necessary to perform sintering at a high temperature for a relatively long period of time, there are problems in that the furnace is easily damaged and running costs are high. The present invention is intended to solve the above problems,
The object of the present invention is to provide a method for producing a high-strength sintered body without high-temperature sintering or heat treatment. [Means for Solving the Problems] The method for producing a high-strength sintered body of the present invention includes () nickel (Ni) or cobalt (Co) in an amount of 1 to 6%, copper (Cu), and molybdenum in a weight ratio. Iron (Fe ) and consists of
Iron-based alloy powder and graphite powder in which nickel (Ni) or cobalt (Co) is not completely alloyed with iron (Fe), and other elements are mixed, partially alloyed, or completely alloyed with iron (Fe). () A process of forming a green compact with a density ratio of 80 to 90% from the mixed powder, () A process of mixing the green compact with a lubricant at 8°C/min or more in a reducing atmosphere.
Heating at a heating rate of 30℃/min to 800 to 950℃
After raising the temperature to 300℃ and keeping it at that temperature,
The powder is reduced by cooling at a cooling rate of 15℃/min or less, and the oxygen in the reduced compact is reduced to 0.2% by weight.
Below, residual graphite is 0.2% by weight or more, and compound carbon is
Reduction process to reduce the amount to 0.2% by weight or less, () Reduce the compression ratio of the reduced compact at room temperature.
The process of compressing at a temperature of 1.05 or higher, and () compressing the compressed powder body at 1100 to 1150℃
After heating for 20 minutes, heat up to 400℃ by 10℃/
This method is characterized by comprising a sintering process in which cooling is performed at a cooling rate of 1 minute or more. [Function] The method for producing a high-strength sintered body of the present invention activates the surface of the powder constituting the green compact by reducing the green compact, and then converts the surface into a diffusion point by cold compression. At the same time, by utilizing the combined effect of strain activation caused by deformation-induced transformation of austenite formed by partially alloyed nickel (Ni) or cobalt (Co) and iron (Fe), heat treatment is possible. Moreover, a high-strength sintered body can be obtained even by sintering at a low temperature and for a short time. The reasons for the limitations of the present invention will be explained in detail. In addition, unless otherwise specified, % indicates weight %. If Ni or Co is less than 1%, insufficient austenite will be formed, and if it exceeds 6%, it will be difficult to achieve a compression ratio of 1.05 or more due to work hardening, so it was limited to 1 to 6%. . Copper (Cu), molybdenum (Mo), chromium (Cr),
Manganese (Mn) and silicon (Si) are effective for obtaining high strength, and if one or more elements selected from the above elements are less than 0.5%, the strength of the sintered body is insufficiently improved; %, the powder of the green compact becomes hard, making it difficult to achieve a compression ratio of 1.05 or higher, resulting in insufficient diffusion point formation and strain activation. Since it is difficult to reduce the amount sufficiently, it is difficult to activate it sufficiently.
%. If the density ratio of the green compact is less than 80%, the strain activation during cold compression will be insufficient and sufficient strength will not be obtained, and if the density ratio exceeds 90%, the pores activated by reduction will become cold. Since the degree of bonding decreases due to inter-compression, sufficient strain activation cannot be obtained, so
It was set at 90%. Oxygen in the reduced green compact cannot be activated sufficiently if it exceeds 0.2%, so it was set to 0.2% or less. If the combined carbon content exceeds 0.2% and the residual graphite content is less than 0.2%, the compact will be hard and the lubricating effect of graphite will not be sufficient, so the compression ratio will be reduced to 1.05 in cold compression.
Since it is difficult to do more than that, compound carbon is
0.2% or less, and residual graphite was 0.2% or more. If sintering is carried out at temperatures below 1100℃ for less than 10 minutes, diffusion will be insufficient and a high-strength sintered body will not be obtained.If the sintering temperature exceeds 1150℃ for 20 minutes, the strength will not improve significantly. or 20 minutes. By manufacturing under the above conditions, a high-strength sintered body having a tensile strength of 70 Kgf/mm 2 or more can be obtained. [Example] The present invention will be explained in detail with reference to an example. Example 1 Partial alloy powder with a composition of 2% Ni, 1.4% Cu, 0.4% Mo, balance Fe, 0.6% graphite powder, and 0.7% zinc stearate powder as a molding lubricant were mixed in a V-shaped mixer. ,
A mixed powder was obtained. Next, this mixed powder was molded by a die molding method to obtain a green compact in the shape of a tensile test piece (JSPM standard 2-64). The density of this green compact was 6.7 g/cm 2 (density ratio 85%). Next, this green compact was subjected to reflux treatment. The reduction process uses a continuous furnace with decomposed ammonia gas as the atmosphere.
Heating at a heating rate of 12°C/mm to 890°C,
After being maintained at that temperature, it was cooled to room temperature. The cooling rate was 10°C/mm up to 300°C. Next, zinc stearate powder was applied to the surface of the reduced green compact and compressed at a compression ratio of 1.075 at room temperature. Through this processing, the density of the green compact is 7.2
g/ cm2 . For sintering, the compressed green compact is sintered in a butane converted gas atmosphere (CP = 0.6%) using a continuous furnace.
The temperature was maintained at 1120°C for 15 minutes, and then cooled to 420°C at a cooling rate of 13°C/mm. The obtained sintered body was subjected to a tensile test. The tensile test was conducted at room temperature at a crosshead speed of 3 mm/mm. The results are shown in the figure. The reduced compact was chemically analyzed to check for oxygen, free graphite, and compound carbon. The results are shown in the table along with the processing conditions. Example 2 Example 1 Partial alloy powder with a composition of 3.9% Ni, 1.4% Cu, 0.35% Mo, balance Fe, graphite, and zinc slyaphosphate
After mixing in the same proportion as in Example 1,
Molding, reduction treatment, compression processing, and sintering were performed in the same manner as in Example 1. The obtained sintered body was subjected to a tensile test in the same manner as in Example 1. The results are shown in the figure. The reduced compact was chemically analyzed to check for oxygen, free carbon, and combined carbon, and the results are shown in the table. Example 3 Partial alloy powder with a composition of 3.1% Co, 0.4% Mo, 0.1% Cr, 0.1% Si, balance Fe, graphite, and zinc slyaphosphate were mixed in the same proportions as in Example 1. After mixing, molding, reduction treatment, compression processing, and sintering were performed in the same manner as in Example 1. The obtained sintered body was subjected to a tensile test in the same manner as in Example 1. The results are shown in the figure. The reduced compact was chemically analyzed to check for oxygen, free carbon, and combined carbon, and the results are shown in the table. Comparative Examples 1 to 6 and 10 Using the same raw material powder as in Example 1, molding, reduction treatment, and
Compression processing and sintering were performed. The obtained sintered body was subjected to a tensile test in the same manner as in Example 1. The results are shown in the figure. In addition, oxygen, free carbon, and combined carbon in the reduced green compact were investigated, and the results are shown in the table. Comparative Examples 7 and 8 Using the same raw material powder as in Example 1, molding and sintering were carried out in the same manner as in Example 1 under the conditions shown in the table. Note that reduction and compression were not performed. The obtained sintered body was subjected to a tensile test in the same manner as in Example 1. The results are shown in the figure. Comparative Example 9 1.4% Cu powder, 0.4% Mo powder, 0.6% graphite powder, and the balance pure iron powder (commercially available) were blended with 0.8% zinc stearate and mixed in a V-type mixer. Molding, reduction treatment,
Compression processing and sintering were performed in the same manner as in Example 1 under the conditions shown in the table. The obtained sintered body was subjected to a tensile test in the same manner as in Example 1. The results are shown in the figure. In addition, oxygen, free carbon, and combined carbon in the reduced green compact were investigated, and the results are shown in the table.
本発明の製造方法は上記したような構成とした
ため、高温焼結及び熱処理を行わずに高強度の焼
結体を製造することができる。高温焼結を行わな
いため、焼結炉の傷みが低減されるとともに、熱
処理を行わないため、製造が簡略化され、生産性
が向上する。
また、本発明の製造方法によつて製造されて焼
結体は加工性（切削性）が良好で、生産性が向上
する。
Since the manufacturing method of the present invention has the above-described configuration, a high-strength sintered body can be manufactured without performing high-temperature sintering and heat treatment. Since high-temperature sintering is not performed, damage to the sintering furnace is reduced, and since no heat treatment is performed, manufacturing is simplified and productivity is improved. Further, the sintered body manufactured by the manufacturing method of the present invention has good workability (cutting property) and improves productivity.
図面は本発明の実施例により製造した焼結体の
引張り強さのグラフを表わす。
The drawing represents a graph of the tensile strength of a sintered body produced according to an embodiment of the present invention.
Claims (1)
ルト（Co）を１ないし６％、銅（Cu）、モリブ
デン（Mo）、クロム（Cr）、マンガン（Mn）、
ケイ素（Si）からなる群から選ばれる元素１種
又は２種以上を0.5ないし３％含み残部が２％
以下の不可避不純物と、鉄（Fe）とからなり、
ニツケル（Ni）又はコバルト（Co）が鉄
（Fe）と完全合金化していなく、かつその他の
元素が鉄（Fe）と混合又は部分合金化又は完
全合金化している鉄系合金粉末と黒鉛粉末と潤
滑剤とを混合する工程、 （） 混合した粉末から密度比80ないし90％の
圧粉体を成形する工程、 （） 圧粉体を還元雰囲気中で８℃／分ないし
30℃／分の昇温速度で加熱して800ないし950℃
に昇温させ、その温度に保持したのち、300℃
までを15℃／分以下の冷却速度で冷却して還元
処理し、還元後の圧粉体中の酸素を0.2重量％
以下、残留黒鉛を0.2重量％以上、化合炭素を
0.2重量％以下とする還元工程、 （） 還元処理した圧粉体を常温にて圧縮比
1.05以上で圧縮する工程、及び （） 圧縮した圧粉体を1100ないし1150℃で10
ないし20分加熱したのち、400℃までを10℃／
分以上の冷却速度で冷却する焼結工程からなる
ことを特徴とする高強度焼結体の製造方法。[Claims] 1 () 1 to 6% by weight of nickel (Ni) or cobalt (Co), copper (Cu), molybdenum (Mo), chromium (Cr), manganese (Mn),
Contains 0.5 to 3% of one or more elements selected from the group consisting of silicon (Si), with the remainder being 2%
Consists of the following inevitable impurities and iron (Fe),
Iron-based alloy powder and graphite powder in which nickel (Ni) or cobalt (Co) is not completely alloyed with iron (Fe), and other elements are mixed, partially alloyed, or completely alloyed with iron (Fe). () A process of forming a green compact with a density ratio of 80 to 90% from the mixed powder, () A process of mixing the green compact with a lubricant at 8°C/min or more in a reducing atmosphere.
Heating at a heating rate of 30℃/min to 800 to 950℃
After raising the temperature to 300℃ and keeping it at that temperature,
The powder is reduced by cooling at a cooling rate of 15℃/min or less, and the oxygen in the reduced compact is reduced to 0.2% by weight.
Below, residual graphite is 0.2% by weight or more, and compound carbon is
Reduction process to reduce the amount to 0.2% by weight or less, () Reduce the compression ratio of the reduced compact at room temperature.
The process of compressing at a temperature of 1.05 or higher, and () compressing the compressed powder body at 1100 to 1150℃
After heating for 20 minutes, heat up to 400℃ by 10℃/
A method for producing a high-strength sintered body, comprising a sintering step of cooling at a cooling rate of 1 minute or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4562686A JPS62202046A (en) | 1986-03-03 | 1986-03-03 | Manufacture of high strength sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4562686A JPS62202046A (en) | 1986-03-03 | 1986-03-03 | Manufacture of high strength sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62202046A JPS62202046A (en) | 1987-09-05 |
| JPH0518894B2 true JPH0518894B2 (en) | 1993-03-15 |
Family
ID=12724579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4562686A Granted JPS62202046A (en) | 1986-03-03 | 1986-03-03 | Manufacture of high strength sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62202046A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3871781B2 (en) * | 1997-10-14 | 2007-01-24 | 株式会社日立製作所 | Metallic powder molding material and manufacturing method thereof |
| JP3869620B2 (en) * | 1999-04-16 | 2007-01-17 | 株式会社日立製作所 | Alloy steel powder molding material, alloy steel powder processed body, and manufacturing method of alloy steel powder molding material |
| JP3871825B2 (en) * | 1999-04-16 | 2007-01-24 | 株式会社日立製作所 | Recompression molded body of metallic powder molding material, sintered body obtained from the recompression molded body, and production method thereof |
| KR100394694B1 (en) * | 2000-12-07 | 2003-08-19 | 정행웅 | Starting clutch outer sub assembly without non-working and method for manufacturing the same |
| JP5671761B2 (en) * | 2011-05-26 | 2015-02-18 | 住友電工焼結合金株式会社 | Sintered parts and manufacturing method thereof |
-
1986
- 1986-03-03 JP JP4562686A patent/JPS62202046A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62202046A (en) | 1987-09-05 |
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