JPH0578712A - Production of sintered part - Google Patents
Production of sintered partInfo
- Publication number
- JPH0578712A JPH0578712A JP27336891A JP27336891A JPH0578712A JP H0578712 A JPH0578712 A JP H0578712A JP 27336891 A JP27336891 A JP 27336891A JP 27336891 A JP27336891 A JP 27336891A JP H0578712 A JPH0578712 A JP H0578712A
- Authority
- JP
- Japan
- Prior art keywords
- weight
- sintered
- sintering
- hardness
- added
- 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.)
- Withdrawn
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は鉄粉に合金元素を添加し
た粉末材料を焼結し焼結部品を製造する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sintered part by sintering a powder material obtained by adding an alloying element to iron powder.
【０００２】[0002]
【従来の技術】ベーンポンプロータ、カムリング或いは
ギヤ等の高強度、高靭性、高耐摩耗性が要求され且つ複
雑な形状の部品を製造するのに従来から粉末冶金法が採
用されている。2. Description of the Related Art The powder metallurgy method has been conventionally used for manufacturing parts having complicated shapes which require high strength, high toughness, high wear resistance such as vane pump rotors, cam rings and gears.
【０００３】粉末冶金法は図１に示すように純鉄粉にＮ
i等の合金元素の微粉を熱処理により拡散・固着させた
複合合金鋼粉末材料にＣ（カーボン）等を添加して混合
し、この混合粉を型内に入れて加圧成形し、次いで１１
００〜１２５０℃の温度で２０〜６０分加熱して焼結さ
せ、必要に応じてサイジングを行なった後、機械的強度
を高めるべく熱処理を行ない、更に０℃以下まで冷却す
るサブゼロ処理を行なって結晶構造の変態に起因する経
年変化を防止するようにして焼結部品を製造している。
ここで、上記の混合粉の化学組成は以下の表１に示すも
のが一般的である。In the powder metallurgy method, as shown in FIG.
C (carbon) is added to and mixed with the composite alloy steel powder material in which fine powders of alloy elements such as i are diffused and fixed by heat treatment, and the mixed powder is put into a mold and pressure-molded, and then 11
After heating at a temperature of 00 to 1250 ° C. for 20 to 60 minutes to sinter, sizing if necessary, heat treatment is performed to increase mechanical strength, and further subzero treatment for cooling to 0 ° C. or less is performed. Sintered parts are manufactured so as to prevent aging due to crystal structure transformation.
Here, the chemical composition of the above mixed powder is generally shown in Table 1 below.
【０００４】[0004]
【表１】 [Table 1]
【０００５】[0005]
【発明が解決しようとする課題】従来法にあっては、機
械的強度を高めるために焼結後に熱処理を行なってい
る。この熱処理は焼結体を８５０〜９００℃で１〜３時
間加熱し、油冷焼入れした後に１５０〜１８０℃で１〜
２時間かけて焼戻しを行なうようにしている。In the conventional method, heat treatment is carried out after sintering in order to enhance mechanical strength. In this heat treatment, the sintered body is heated at 850 to 900 ° C. for 1 to 3 hours, oil-quenched, and then heated at 150 to 180 ° C. for 1 to 1.
I try to temper it over 2 hours.
【０００６】しかしながら上記の熱処理は処理時間が長
く熱エネルギーの損失が大きいだけでなく、焼結体は多
孔質であるので焼入れ性が悪く、製品の内部と外部との
硬度差及び強度差が大きい。また熱処理のための設備、
スペース及び要員が必要となり、更に熱処理によって生
じた歪を除くための研削工程が必要となる場合がある。
尚、焼入れ性が十分に現れる高Ｎi合金鋼も知られてい
るが、十分な機械的強度は得られずコストも高い。However, the heat treatment described above not only takes a long treatment time and causes a large loss of heat energy, but also because the sintered body is porous, the hardenability is poor, and the difference in hardness and strength between the inside and outside of the product is large. . Equipment for heat treatment,
Space and personnel may be required, and a grinding process may be required to remove strain caused by heat treatment.
Although a high Ni alloy steel showing sufficient hardenability is also known, sufficient mechanical strength cannot be obtained and the cost is high.
【０００７】[0007]
【課題を解決するための手段】本発明は上記課題を解決
して、従来工程における焼結後の熱処理を省略し、機械
的強度に優れ且つ焼結部品の内部硬度の均一な製品を得
るもので、化学組成がＮi；４．０〜６．０重量％、Ｃ
u；１．０〜２．０重量％、ＭO；０．４〜０．６重量
％、残部が実質的に鉄よりなる複合合金鋼粉にＣ ；
０．６〜０．９重量％及び成形潤滑材を添加した粉末材
料を密度７．０ｇ／ｃｍ3以上に成形し、次いでこの成
形体を１２５０〜１３００℃で焼結し、この焼結体を連
続冷却せしめ、マルテンサイトとベイナイトの混在組織
にしたことを特徴とする。SUMMARY OF THE INVENTION The present invention solves the above problems and eliminates the heat treatment after sintering in the conventional process, and obtains a product having excellent mechanical strength and uniform internal hardness of the sintered parts. And the chemical composition is Ni; 4.0 to 6.0% by weight, C
u: 1.0 to 2.0% by weight, MO: 0.4 to 0.6% by weight, the balance being C in a composite alloy steel powder consisting essentially of iron;
A powder material added with 0.6 to 0.9% by weight and a molding lubricant was molded to a density of 7.0 g / cm 3 or more, and then this molded body was sintered at 1250 to 1300 ° C. It is characterized by having a mixed structure of martensite and bainite by continuous cooling.
【０００８】上記の組成のうちＮi、Ｃu及びＭOについ
ては従来のものと変らず、例えばＮi；４．０〜４．８
重量％、Ｃu；１．３〜１．７重量％、ＭO；０．４５〜
０．５５重量％の市販のものを用いることができる。Of the above compositions, Ni, Cu and M0 are the same as the conventional ones, for example, Ni; 4.0 to 4.8.
% By weight, Cu; 1.3 to 1.7% by weight, MO; 0.45
A commercially available product having 0.55% by weight can be used.
【０００９】圧粉成形の密度については高いほど機械的
強度は高くなるが、金型強度及び摩耗等を考慮すると、
７．０ｇ／ｃｍ3以上で７．３ｇ／ｃｍ3以下が好まし
い。The higher the density of the green compact, the higher the mechanical strength. However, considering the die strength and wear,
It is preferably 7.0 g / cm 3 or more and 7.3 g / cm 3 or less.
【００１０】また焼結温度については、Ｎi、Ｃu、Ｍ
O、ＣはＦｅへの拡散温度が高く且つ拡散速度が遅いた
め、従来と同程度の温度では合金元素の固溶化が不十分
となるので、１２５０〜１３００℃で焼結する。またカ
ーボンの添加量については０．６〜０．９重量％とす
る。これはこの範囲外では引張り強度及び硬度が大きく
低下することによる。Regarding the sintering temperature, Ni, Cu, M
Since O and C have a high diffusion temperature to Fe and a low diffusion rate, the solid solution of alloying elements becomes insufficient at the same temperature as in the past, so sintering is performed at 1250 to 1300 ° C. The amount of carbon added is 0.6 to 0.9% by weight. This is because the tensile strength and hardness are significantly reduced outside this range.
【００１１】更に焼結後の冷却にあたってＣＣＴ線図
（連続冷却変態曲線）における冷却速度は５〜２０℃／
ｍｉｎとするのが好ましい。これは５℃／ｍｉｎ未満で
あると要求されるマルテンサイト組織が均一に現れなく
なるためであり、２０℃／ｍｉｎを超えると設備上新た
な冷却装置が必要になるからである。Further, upon cooling after sintering, the cooling rate in the CCT diagram (continuous cooling transformation curve) is 5 to 20 ° C. /
It is preferably set to min. This is because the required martensite structure does not appear uniformly when the temperature is less than 5 ° C / min, and a new cooling device is required for the equipment when the temperature exceeds 20 ° C / min.
【００１２】[0012]
【作用】一般に０．６重量％以上のカーボンを加えると
強度が低下するといわれているが、０．６重量％以上の
カーボンを添加しても焼結温度を高め、且つ連続冷却速
度を所定範囲とすることで、機械的強度及び硬度は向上
することが分った。It is generally said that the strength decreases when 0.6% by weight or more of carbon is added. However, even if 0.6% by weight or more of carbon is added, the sintering temperature is increased and the continuous cooling rate is within a predetermined range. It has been found that the mechanical strength and hardness are improved by the above.
【００１３】[0013]
【実施例】表２に示すように、Ｎiが４．３重量％、Ｃu
が１．６重量％、ＭOが０．５重量％、Ｓｉが０．０１
重量％、Ｍnが０．０５重量％、残部が実質的に鉄より
なる市販の複合合金鋼ベース粉を用意し、この複合合金
鋼ベース粉に実験例１にあっては０．３重量％のＣ（カ
ーボン）を、実験例２にあっては０．５重量％のＣを、
実験例３にあっては０．６重量％のＣを、実験例４にあ
っては０．８重量％のＣを、実験例５にあっては１．０
重量％のＣをそれぞれ添加し、さらに各実験例に成形潤
滑剤として０．８重量％のステアリン酸亜鉛を配合し、
次いで上記の材料粉を型内に入れて密度７．０５ｇ／ｃ
ｍ3の成形体とし、この成形体を１３００℃で６０分、
炉内雰囲気を９０％Ｎ2＋１０％Ｈ2で焼結し、更に焼結
後の連続冷却速度を７℃／ｍｉｎとして試験片を得た。
尚、焼結温度の比較のため、実験例６として実験例３と
同一成分の試験片を１１５０℃×４０ｍｉｎで焼結し
た。EXAMPLE As shown in Table 2, Ni was 4.3% by weight and Cu
1.6% by weight, MO 0.5% by weight, Si 0.01%
%, Mn is 0.05% by weight, and a commercially available composite alloy steel base powder having the balance substantially iron is prepared. C (carbon), in Experimental Example 2, 0.5% by weight of C,
In Experimental Example 3, 0.6% by weight of C was added, in Experimental Example 4, 0.8% by weight of C was added, and in Experimental Example 5, 1.0% by weight was added.
Wt% C was added, and 0.8 wt% zinc stearate as a molding lubricant was further added to each experimental example.
Then, the above material powder was put into a mold and the density was 7.05 g / c.
m 3 molded body, and this molded body at 1300 ° C. for 60 minutes,
The atmosphere in the furnace was sintered with 90% N 2 + 10% H 2 , and the continuous cooling rate after sintering was set to 7 ° C./min to obtain a test piece.
For comparison of the sintering temperatures, as Experimental Example 6, a test piece having the same components as in Experimental Example 3 was sintered at 1150 ° C. × 40 min.
【００１４】[0014]
【表２】 [Table 2]
【００１５】上記によって得られた各試験片の引張り強
さ、硬さ及び衝撃値とカーボン添加量との関係を表３及
び図２〜図４に示す。表３及び図２〜図４で明らかなよ
うに、Ｃ含有量が０．６重量％未満では引張強さ、硬さ
が目標値を達成することができず、またＣ含有量が１．
０重量％以上では硬さが若干増加する以外は硬化しすぎ
るため脆弱破壊が起り、引張強さ、衝撃値とも大幅に低
下している。本発明であるＣ；０．６〜０．９重量％の
ものはいずれも目標値を満足している。また比較のた
め、実験例３と同じ成分の試験片を用い、焼結温度１１
５０℃×４０ｍｉｎで焼結し熱処理（８５０℃×１Ｈ）
を施した従来法によって得られた試験片と本発明法実験
例４によって得られた試験片との表面からの硬さについ
ての比較を図５に示す。図５から明らかなように本発明
の方がバラツキが少ない。Table 3 and FIGS. 2 to 4 show the relationship between the tensile strength, hardness and impact value of each test piece obtained above and the amount of carbon added. As is clear from Table 3 and FIGS. 2 to 4, when the C content is less than 0.6% by weight, the tensile strength and hardness cannot reach the target values, and the C content is 1.
When the content is 0% by weight or more, except for a slight increase in hardness, the composition is excessively hardened, causing brittle fracture, and both tensile strength and impact value are significantly reduced. In the present invention, C: 0.6 to 0.9% by weight all satisfy the target value. For comparison, a test piece having the same composition as in Experimental Example 3 was used and the sintering temperature was 11
Sintering at 50 ℃ × 40min and heat treatment (850 ℃ × 1H)
FIG. 5 shows a comparison of the hardness from the surface of the test piece obtained by the conventional method and the test piece obtained by Experimental Example 4 of the present invention. As is clear from FIG. 5, the present invention has less variation.
【００１６】[0016]
【表３】 [Table 3]
【００１７】また、図６は本発明によって得られた試験
片の金属組織を示す顕微鏡写真（４００倍）、図７は従
来法によって得られた試験片の金属組織を示す顕微鏡写
真（４００倍）であり、これら写真から本発明方法によ
る場合は金属組織はほぼ均一なマルテンサイト，ベイナ
イト混在組織となり、従来法による場合と比べマルテン
サイト組織に点在する残留オーステナイト組織がないこ
とが分る。FIG. 6 is a photomicrograph (400 times) showing the metal structure of the test piece obtained by the present invention, and FIG. 7 is a photomicrograph (400 time) showing the metal structure of the test piece obtained by the conventional method. From these photographs, it can be seen that in the case of the method of the present invention, the metal structure is a substantially uniform mixed structure of martensite and bainite, and there is no retained austenite structure scattered in the martensite structure as compared with the case of the conventional method.
【００１８】[0018]
【発明の効果】以上の説明また実験結果を表わす表３〜
表４及び図２〜図５から明らかなように本発明の焼結法
によれば、焼結後の熱処理を不要とし、且つ従来法にお
いて焼結後に熱処理を行なった製品よりも引張り強度及
び衝撃値等の機械的強度に優れまた高硬度で内部硬さの
均一な信頼性の高い製品を得ることができる。[Effect of the invention]
As is clear from Table 4 and FIGS. 2 to 5, according to the sintering method of the present invention, the heat treatment after sintering is unnecessary, and the tensile strength and the impact are higher than those of the products subjected to the heat treatment after sintering in the conventional method. It is possible to obtain a highly reliable product having excellent mechanical strength such as value, high hardness, and uniform internal hardness.
【００１９】また熱処理及びこの後に行なうサブゼロ処
理も不要となるので、熱エネルギーの損失を少なくでき
るとともに設備を大巾に簡素化でき、コストダウンを図
ることができる。Further, since the heat treatment and the sub-zero treatment to be performed thereafter are unnecessary, it is possible to reduce the loss of thermal energy, greatly simplify the equipment, and reduce the cost.
【図１】従来の粉末冶金法の概略工程図FIG. 1 is a schematic process diagram of a conventional powder metallurgy method.
【図２】カーボン添加量と引張り強さとの関係を示すグ
ラフFIG. 2 is a graph showing the relationship between the amount of carbon added and the tensile strength.
【図３】カーボン添加量と硬度（ＨＲＡ）との関係を示
すグラフFIG. 3 is a graph showing the relationship between the amount of carbon added and the hardness (HRA).
【図４】カーボン添加量と衝撃値との関係を示すグラフFIG. 4 is a graph showing the relationship between the amount of carbon added and the impact value.
【図５】表面からの深さと硬度（ＨＲＡ）との関係を示
すグラフFIG. 5 is a graph showing the relationship between the depth from the surface and the hardness (HRA).
【図６】本発明によって得られた試験片の金属組織を示
す顕微鏡写真FIG. 6 is a micrograph showing the metal structure of a test piece obtained according to the present invention.
【図７】従来法によって得られた試験片の金属組織を示
す顕微鏡写真FIG. 7 is a micrograph showing the metal structure of a test piece obtained by a conventional method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 村上 修二 埼玉県行田市藤原町１丁目14番１号 株式 会社昭和製作所埼玉本社工場内 (72)発明者 峰岸 俊幸 千葉県千葉市川崎町１番地 川崎製鉄株式 会社千葉製鉄所内 (72)発明者 園部 秋夫 千葉県千葉市川崎町１番地 川崎製鉄株式 会社千葉製鉄所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Murakami 1-14-1 Fujiwara-cho, Gyoda-shi, Saitama Stock Company Showa Manufacturing Co., Ltd. Saitama Head Office Factory (72) Inventor Toshiyuki Minegishi Kawasaki-cho, Chiba-shi Chiba Prefecture Kawasaki Chiba Steel Works, Ltd. (72) Inventor Akio Sonobe 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Company, Chiba Works
Claims (1)
Ｃu；１．０〜２．０重量％、ＭO；０．４〜０．６重量
％、残部が実質的に鉄よりなる複合合金鋼粉にＣ ；
０．６〜０．９重量％及び成形潤滑材を添加した粉末材
料を密度７．０ｇ／ｃｍ3以上に成形し、次いでこの成
形体を１２５０〜１３００℃で焼結し、この焼結体を連
続冷却せしめ、マルテンサイトとベイナイトの混在組織
にしたことを特徴とする焼結部品の製造方法。1. A chemical composition of Ni; 4.0 to 6.0% by weight,
Cu: 1.0 to 2.0% by weight, MO: 0.4 to 0.6% by weight, and C in the composite alloy steel powder consisting essentially of iron as the balance.
A powder material added with 0.6 to 0.9% by weight and a molding lubricant is molded to have a density of 7.0 g / cm3 or more, and then this molded body is sintered at 1250 to 1300 ° C. A method for manufacturing a sintered part, characterized in that it is cooled to form a mixed structure of martensite and bainite.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27336891A JPH0578712A (en) | 1991-09-25 | 1991-09-25 | Production of sintered part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27336891A JPH0578712A (en) | 1991-09-25 | 1991-09-25 | Production of sintered part |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0578712A true JPH0578712A (en) | 1993-03-30 |
Family
ID=17526930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27336891A Withdrawn JPH0578712A (en) | 1991-09-25 | 1991-09-25 | Production of sintered part |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0578712A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007058370A1 (en) * | 2005-11-16 | 2007-05-24 | Jtekt Corporation | Iron-base sintered parts, process for production of iron-base sintered parts, and actuators |
| JP2008231538A (en) * | 2007-03-22 | 2008-10-02 | Toyota Motor Corp | Ferrous sintered compact and its manufacturing method |
-
1991
- 1991-09-25 JP JP27336891A patent/JPH0578712A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007058370A1 (en) * | 2005-11-16 | 2007-05-24 | Jtekt Corporation | Iron-base sintered parts, process for production of iron-base sintered parts, and actuators |
| US8491695B2 (en) | 2005-11-16 | 2013-07-23 | Jtekt Corporation | Iron-base sintered part, manufacturing method of iron-base sintered part and actuator |
| JP2008231538A (en) * | 2007-03-22 | 2008-10-02 | Toyota Motor Corp | Ferrous sintered compact and its manufacturing method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5671526B2 (en) | High strength low alloy sintered steel | |
| CN1116944C (en) | Steel powder for the prepn. of sintered products | |
| JP3504786B2 (en) | Method for producing iron-based sintered alloy exhibiting quenched structure | |
| JP6688287B2 (en) | Pre-alloyed iron-based powder, iron-based powder mixture containing pre-alloyed iron-based powder, and method of manufacturing press-formed and sintered parts from the iron-based powder mixture | |
| JP2010090470A (en) | Iron-based sintered alloy and method for producing the same | |
| US5552109A (en) | Hi-density sintered alloy and spheroidization method for pre-alloyed powders | |
| JP2015108195A (en) | Low alloy steel powder | |
| JP2004190141A (en) | Method for manufacturing powder metal component | |
| JP3258765B2 (en) | Manufacturing method of high-strength iron-based sintered body | |
| JP5114233B2 (en) | Iron-based sintered alloy and method for producing the same | |
| JP4060092B2 (en) | Alloy steel powder for powder metallurgy and sintered body thereof | |
| JP6738038B2 (en) | Iron-based sintered alloy and method for producing the same | |
| JPH0578712A (en) | Production of sintered part | |
| JP2674715B2 (en) | Method for manufacturing porous mold | |
| JP5929320B2 (en) | Alloy steel powder for powder metallurgy and method for producing alloy steel powder for powder metallurgy | |
| JPH09157805A (en) | High strength iron base sintered alloy | |
| JP4615191B2 (en) | Method for producing iron-based sintered body | |
| JP4301657B2 (en) | Manufacturing method of high strength sintered alloy steel | |
| JPH06212368A (en) | Low alloy sintered steel excellent in fatigue strength and its production | |
| KR102495092B1 (en) | Steel for mold, and mold | |
| JP3396285B2 (en) | Alloy steel powder for high-strength and high-toughness sintered materials and its sintered steel | |
| JP3303026B2 (en) | High strength iron-based sintered alloy and method for producing the same | |
| JPH07103442B2 (en) | Manufacturing method of high strength sintered alloy steel | |
| JP4054649B2 (en) | Method for producing ferrous sintered alloy exhibiting quenched structure | |
| JP3314596B2 (en) | Iron-based sintered alloy with excellent fatigue strength |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19981203 |