JP2000239710A - Sintered parts - Google Patents
Sintered partsInfo
- Publication number
- JP2000239710A JP2000239710A JP11041932A JP4193299A JP2000239710A JP 2000239710 A JP2000239710 A JP 2000239710A JP 11041932 A JP11041932 A JP 11041932A JP 4193299 A JP4193299 A JP 4193299A JP 2000239710 A JP2000239710 A JP 2000239710A
- Authority
- JP
- Japan
- Prior art keywords
- density
- carbon concentration
- initial
- surface layer
- decarburized
- 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.)
- Pending
Links
Landscapes
- Powder Metallurgy (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、粉末金属を焼結し
て製造される焼結部品に関する。より詳細には、本発明
は、粉末金属を焼結し、転造や再圧等の加圧処理を施
し、さらに、浸炭焼き入れ処理して製造されるスプロケ
ット等の焼結部品に関する。[0001] The present invention relates to a sintered part manufactured by sintering powdered metal. More specifically, the present invention relates to a sintered part such as a sprocket manufactured by sintering a powder metal, applying a pressure treatment such as rolling or re-pressing, and carburizing and quenching.
【０００２】[0002]
【従来の技術】焼結部品は、マンガン、ニッケル、モリ
ブデン等の合金材を鉄系材料に配合した粉末金属を所定
の形状に成形し、その後、焼き固めることにより製造さ
れる。近年の自動車産業のように、スプロケットのよう
な耐摩耗性及び曲げ強度が要求される部品においても、
生産性及び経済性が有利なことから焼結部品が採用され
るに至っている。しかし、焼結部品では、通常の成形及
び焼き固めでは、その密度を7.50g/cm3まで向上させる
ことが困難である。従来、スプロケットのような焼結部
品では、部品全体の強度、特に歯の曲げ強度を確保する
ために、種々の技術により焼結後の密度を高くすること
が提案されており、また、歯面の耐摩耗性を向上させる
ために、転造や再圧等の加圧処理を歯面に施すととも
に、浸炭等の熱処理を施すことが提案されている。例え
ば、米国特許第５，７２９，８２２号公報では、粉末金
属を複数回のプレス処理を施して所定密度に焼結し、表
層部を加圧処理して表面を硬化させ、浸炭等の熱処理を
施すことが提案されている。2. Description of the Related Art Sintered parts are manufactured by molding a powdered metal obtained by mixing an alloy material such as manganese, nickel, molybdenum or the like with an iron-based material into a predetermined shape and then sintering it. In parts where wear resistance and bending strength are required, such as sprockets, as in the recent automotive industry,
Due to the advantages of productivity and economy, sintered parts have been adopted. However, it is difficult to increase the density of sintered parts to 7.50 g / cm 3 by ordinary molding and baking. Conventionally, for sintered parts such as sprockets, it has been proposed to increase the density after sintering by various techniques in order to secure the strength of the entire part, particularly the bending strength of the teeth. In order to improve the abrasion resistance of the teeth, it has been proposed to apply pressure treatment such as rolling and re-pressing to the tooth surface and also to perform heat treatment such as carburization. For example, in U.S. Pat. No. 5,729,822, a powder metal is subjected to a plurality of press treatments to sinter it to a predetermined density, a surface layer is subjected to a pressure treatment to harden the surface, and a heat treatment such as carburizing is performed. It has been proposed to do so.
【０００３】[0003]
【発明が解決しようとする課題】ところが、粉末金属を
焼結しても、焼結後の部品の各部分は配合材料が均質と
なる。特に、炭素濃度が各部分において均一である場合
には、スプロケット等に要求される耐摩耗性と曲げ強度
の両方を同時に満足させることが困難である。例えば、
炭素濃度が高い粉末金属を利用して焼結部品を製造する
と、全体が硬く均質であるために、転造等の加圧処理を
施した場合に、部品全体の密度が向上する。加圧処理
は、表層部の密度だけを向上させて耐摩耗性を改善させ
たいが、従来の技術では、内部まで密度が向上して、表
層部の密度が所定値まで向上しにくくなる。そのため、
表層部における耐摩耗性が充分に改善されない。また、
焼結部品全体の炭素濃度が高いために脆性が低く、転造
等の加圧処理を施した場合、クラックや欠け等の問題を
生じる。一方、炭素濃度が低い粉末金属を利用して焼結
部品を転造等の加圧処理を施すると、部品全体の密度は
所定値まで向上するが、浸炭等の熱処理をしても表層部
の密度が邪魔をするため、表層部しか浸炭せず、内部の
炭素濃度が低くなって部品全体の強度不足を生じる問題
がある。本発明の目的は、表面における耐摩耗性と、内
部における強度とを合わせ持った焼結部品、すなわち、
表層部では初期密度及び初期炭素濃度より密度及び炭素
濃度を高くし、内部では初期密度及び初期炭素濃度を実
質的に維持した焼結部品を提供することにある。However, even when the powder metal is sintered, the respective parts of the sintered part have a uniform blending material. In particular, when the carbon concentration is uniform in each part, it is difficult to simultaneously satisfy both the wear resistance and bending strength required for a sprocket or the like. For example,
When a sintered part is manufactured using powdered metal having a high carbon concentration, the entire part is hard and homogeneous, and therefore, when subjected to a pressure treatment such as rolling, the density of the entire part is improved. In the pressure treatment, it is desired to improve the abrasion resistance by improving only the density of the surface layer portion. However, in the conventional technique, the density is improved to the inside and the density of the surface layer portion is hardly improved to a predetermined value. for that reason,
The wear resistance in the surface layer is not sufficiently improved. Also,
The brittleness is low due to the high carbon concentration of the entire sintered part, and when pressure treatment such as rolling is performed, problems such as cracks and chips occur. On the other hand, when a sintered part is subjected to a pressure treatment such as rolling using a powdered metal having a low carbon concentration, the density of the entire part is improved to a predetermined value, but even if a heat treatment such as carburizing is carried out, Since the density hinders, there is a problem that only the surface layer is carburized and the carbon concentration in the inside is reduced, resulting in insufficient strength of the whole part. An object of the present invention is a sintered part having both wear resistance on the surface and strength inside, that is,
It is an object of the present invention to provide a sintered part in which the density and the carbon concentration are higher than the initial density and the initial carbon concentration in the surface portion, and the initial density and the initial carbon concentration are substantially maintained in the inside.
【０００４】[0004]
【課題を解決するための手段】本発明は、炭素を配合し
た粉末金属を成形及び焼き固めた焼結部品において、該
焼結部品に初期炭素濃度より低い炭素濃度の脱炭表層部
と初期炭素濃度の内部とを形成し、前記焼結部品を加圧
処理して初期成形密度より高く真密度に近い密度で初期
炭素濃度より低い炭素濃度の脱炭表層部と実質的に初期
成形密度で初期炭素濃度の内部を形成し、前記焼結部品
を浸炭処理して初期成形密度より高く真密度に近い密度
で浸炭処理により炭素濃度を上げた表層部と実質的に初
期成形密度で実質的に初期炭素濃度の内部を一体に形成
した焼結部品により前記課題を解決した。SUMMARY OF THE INVENTION The present invention relates to a sintered part obtained by molding and sintering a powdered metal containing carbon, wherein the sintered part has a decarbonized surface layer having a carbon concentration lower than the initial carbon concentration and an initial carbon. The sintered part is subjected to a pressure treatment, and the sintered part is pressurized to a density close to the true density higher than the initial molding density and a decarburized surface layer having a carbon concentration lower than the initial carbon concentration, and substantially initialized at the initial molding density. The interior of the carbon concentration is formed, and the sintered part is carburized to increase the carbon concentration by the carburizing treatment at a density higher than the initial molding density and close to the true density. The above problem was solved by a sintered part in which the inside of the carbon concentration was integrally formed.
【０００５】[0005]
【発明の実施の形態】粉末金属を成形及び焼き固めた状
態において、その焼結部品は全体が均質な炭素濃度であ
り、このような状態で転造等の加圧処理を施すと、炭素
濃度の高低にかかわらず、全体が略々同じ密度に加圧さ
れる。最終製品に所望特性を与えるために、比較的高い
初期炭素濃度の粉末金属を利用することが好ましい。成
形及び焼き固めた状態において、初期炭素濃度は0.20〜
1.00％、好ましくは0.50〜0.80％、初期成形密度は7.20
g/cm3 〜7.50g/cm3 程度である。本発明では、加圧処理
に先立って脱炭処理を施すことにより、表層部のみ初期
炭素濃度より低い炭素濃度にし、内部と比較して低炭素
濃度の脱炭表層部が形成される。脱炭処理は焼結部品の
内部まで浸透しないので、内部の炭素濃度は初期の炭素
濃度のままである。この状態において、表層部の炭素濃
度は０．２０％未満である。初期成形密度に変化はな
い。次いで、焼結部品に転造等の加圧処理が施される。
このとき、脱炭表層部の脆性は内部と比較して高くなっ
ており、クラックや欠け等を生じることなく、加圧処理
が施される。また、脱炭表層部の炭素濃度が初期炭素濃
度より低くなっていることから、加圧処理において、密
度の向上は表層部で集中的に生じ、初期成形密度より高
く真密度に近い密度で初期炭素濃度より低い炭素濃度の
脱炭表層部と実質的に初期成形密度で初期炭素濃度の内
部が形成される。真密度に近い密度とは、具体的に、7.
60g/cm3 〜7.80g/cm3 程度である。なお、内部において
も密度が高くなるが、その密度は実質的に初期成形密度
を維持する。そして、この焼結部品に浸炭焼き入れを施
すことにより、表層部において高炭素濃度の表層部が形
成される。一方、内部では、初期炭素濃度の状態を維持
させておくことができるので、強度、特に、曲げ強度に
おいても充分な耐性を有する焼結部品を得ることができ
る。このように、本発明では、加圧処理及び浸炭焼き入
れを施す焼結部品において、表層部の耐摩耗性と内部の
強度という相反する性質及び表面の良好な緻密化加工性
を同時に合わせ持った焼結部品を得ることができる。BEST MODE FOR CARRYING OUT THE INVENTION In a state where a powder metal is formed and baked and hardened, the sintered part has a uniform carbon concentration as a whole. Irrespective of the height, the whole is pressed to substantially the same density. It is preferable to utilize a relatively high initial carbon concentration of the powdered metal to provide the desired properties to the final product. In the molded and baked state, the initial carbon concentration is 0.20-
1.00%, preferably 0.50 to 0.80%, the initial molding density is 7.20
a g / cm 3 ~7.50g / cm 3 about. In the present invention, by performing the decarburization treatment prior to the pressure treatment, only the surface layer has a lower carbon concentration than the initial carbon concentration, and a decarburized surface layer having a lower carbon concentration than the inside is formed. Since the decarburization treatment does not penetrate into the inside of the sintered part, the carbon concentration inside remains at the initial carbon concentration. In this state, the carbon concentration in the surface layer is less than 0.20%. There is no change in the initial molding density. Next, a pressure treatment such as rolling is performed on the sintered component.
At this time, the brittleness of the decarburized surface layer is higher than that of the inside, and the pressure treatment is performed without generating cracks, chips, or the like. In addition, since the carbon concentration of the decarburized surface layer is lower than the initial carbon concentration, the increase in density occurs intensively in the surface layer during the pressure treatment, and the initial density is higher than the initial molding density and close to the true density. A decarburized surface layer having a carbon concentration lower than the carbon concentration and the inside of the initial carbon concentration are formed substantially at the initial molding density. The density close to the true density specifically means 7.
Is 60g / cm 3 ~7.80g / cm 3 about. Although the density also increases inside, the density substantially maintains the initial molding density. By subjecting the sintered component to carburizing and quenching, a surface portion having a high carbon concentration is formed in the surface portion. On the other hand, since the state of the initial carbon concentration can be maintained inside, it is possible to obtain a sintered part having sufficient strength, particularly sufficient bending strength. As described above, in the present invention, in the sintered part subjected to the pressure treatment and the carburizing and quenching, the contradictory properties such as the wear resistance of the surface layer and the internal strength and the good densification workability of the surface are simultaneously obtained. A sintered part can be obtained.
【０００６】脱炭表層部は所定の厚みで形成することが
好ましい。平均直径１０乃至３００mm程度のスプロケッ
トにおいて、脱炭表層部は、0.05乃至0.50mmの厚みで形
成することが好ましい。脱炭表層部の厚みが0.05mmより
薄いと、表面近くまで初期炭素濃度の内部が近接するの
で、転造等の加圧処理のときに表層部の密度向上を期待
することができず、また、脆性の低い内部が表層部近く
まで存在するのでクラックや欠け等を発生する危険があ
る。一方、脱炭表層部の厚みが0.50mmより厚いと、浸炭
焼き入れのときに脱炭表層部の浸炭不足が生じて充分な
耐摩耗性を得ることができない。また、浸炭に長時間を
要するので、非経済的である。[0006] The decarburized surface layer is preferably formed with a predetermined thickness. In a sprocket having an average diameter of about 10 to 300 mm, the decarburized surface layer preferably has a thickness of 0.05 to 0.50 mm. If the thickness of the decarburized surface layer is less than 0.05 mm, since the inside of the initial carbon concentration is close to the surface, the density of the surface layer cannot be expected to be improved during pressure treatment such as rolling, and In addition, since the inside having low brittleness exists near the surface layer, there is a danger that cracks or chips may occur. On the other hand, if the thickness of the decarburized surface layer is greater than 0.50 mm, insufficient decarburization of the decarburized surface layer occurs during carburizing and quenching, and sufficient wear resistance cannot be obtained. Also, it takes a long time to carburize, which is uneconomical.
【０００７】[0007]
【実施例】以下、図面を参照して本発明による焼結部品
の実施例を説明する。図１は、焼結部品の例であるスプ
ロケットの正面図、図２は図１の部分拡大図である。ス
プロケット１０は、例えば、自動車エンジンのクランク
軸及びカム軸に固定され、それぞれのスプロケット１０
の間にはチェーンが捲回される。このような用途では、
スプロケット１０の歯１２にはチェーンから駆動力が伝
達され、歯面１４がチェーンと接触するとともに、歯面
１４にはチェーンから荷重が作用して、歯元１６にモー
メントが発生する。本発明の焼結部品は、摩耗の原因と
なる他部品との接触が生じる用途で、且つ、破損の原因
となる歯面１４への圧縮荷重または歯元１６へのモーメ
ントが作用する用途において有用である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sintered component according to the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a sprocket as an example of a sintered component, and FIG. 2 is a partially enlarged view of FIG. The sprocket 10 is fixed to, for example, a crankshaft and a camshaft of an automobile engine.
The chain is wound between. In such applications,
A driving force is transmitted from the chain to the teeth 12 of the sprocket 10, the tooth surface 14 contacts the chain, and a load acts on the tooth surface 14 from the chain to generate a moment at the root 16. INDUSTRIAL APPLICABILITY The sintered component of the present invention is useful in applications in which contact with other components that causes wear occurs, and in applications in which a compressive load on the tooth surface 14 or a moment on the tooth root 16 that causes breakage acts. It is.
【０００８】使用する粉末金属は、上記用途において
は、マンガン、ニッケル、銅、モリブデン等の合金材を
鉄系材料に配合した、鉄系マンガン、鉄系ニッケル、鉄
系銅または 鉄系モリブデンよりなる材料が好ましい。
これらの粉末金属に炭素が添加され、部品は、例えば、
スプロケットの形状に焼結される。焼結された状態にお
いて、部品全体の密度は略々均一である。このとき、初
期成形密度は7.20g/cm3〜7.50g/cm3 程度である。な
お、炭素濃度は、部品内部の強度を維持するために比較
的高い濃度、すなわち、初期炭素濃度は0.20〜1.00％、
好ましくは0.50〜0.80％の範囲であることが好ましい。In the above-mentioned application, the powder metal used is made of iron-based manganese, iron-based nickel, iron-based copper or iron-based molybdenum in which an alloy material such as manganese, nickel, copper, or molybdenum is mixed with an iron-based material. Materials are preferred.
Carbon is added to these powder metals, and the parts are, for example,
Sintered into the shape of a sprocket. In the sintered state, the density of the entire part is substantially uniform. At this time, the initial molding density is about 7.20 g / cm 3 to 7.50 g / cm 3 . The carbon concentration is relatively high in order to maintain the strength inside the part, that is, the initial carbon concentration is 0.20 to 1.00%,
Preferably, it is in the range of 0.50 to 0.80%.
【０００９】所定のスプロケットの形状に成形及び焼き
固められた後、脱炭雰囲気下における脱炭処理により、
部品には表層部においてのみ脱炭層１８が形成される。
なお、成形及び焼き固めと、脱炭処理を同時に行っても
よい。脱炭表層部１８の厚みは、直径１０〜３００mmの
スプロケットにおいて、0.05乃至0.50mmで形成すること
が好ましい。この脱炭処理により、表層部は初期炭素濃
度が低下して脆性を回復する。脱炭表層部１８の炭素濃
度は、脱炭雰囲気下で処理することで表面に近い程炭素
濃度が低くなる。脱炭表層部の炭素濃度は、初期炭素濃
度より低く、しかも、0.30％未満にすることが好まし
い。なお、部品内部は脱炭されずに初期炭素濃度を維持
した状態にあり、表層部と内部との間で炭素濃度に差異
ある部品が中間製品として製造される。表層部と内部と
で密度で実質的な変化は生じず、いずれも初期成形密度
のままである。After being formed into a predetermined sprocket shape and baked and hardened, a decarburization treatment is performed in a decarburized atmosphere,
A decarburized layer 18 is formed only on the surface of the component.
In addition, you may perform a shaping | molding and hardening, and a decarburization process simultaneously. Preferably, the thickness of the decarburized surface layer portion 18 is 0.05 to 0.50 mm for a sprocket having a diameter of 10 to 300 mm. By this decarburization treatment, the surface layer portion has a reduced initial carbon concentration and recovers brittleness. The carbon concentration of the decarburized surface layer portion 18 becomes lower as it is closer to the surface by performing the treatment in a decarburized atmosphere. The carbon concentration in the decarburized surface layer is preferably lower than the initial carbon concentration and less than 0.30%. In addition, the inside of the part is in a state in which the initial carbon concentration is maintained without being decarburized, and a part having a different carbon concentration between the surface portion and the inside is manufactured as an intermediate product. No substantial change occurs in the density between the surface layer portion and the inside, and both remain at the initial molding density.
【００１０】脱炭処理後、焼結部品は、転造や再圧等の
加圧処理が施される。前記中間製品は、全体が均一な密
度であり、表層部においてのみ炭素濃度が低くなってい
る。表層部は脱炭処理により比較的柔らかく脆性を回復
しており、加圧処理によって、炭素濃度の低い表層部に
おいて集中的に密度向上が生じ、脱炭表層部１８は真密
度（7.60〜7.80g/cm3 ）近くまでその密度を向上させ
る。しかも、脱炭雰囲気下で脱炭処理によって、上述に
したように、表面に近い程炭素濃度が低くなるので、加
圧処理による密度向上は、表面に近い程その効果が大き
くなる。一方、炭素濃度が初期濃度と変化しない部品内
部は、比較的硬度が高いので、加圧処理による密度変化
が抑えられた状態にある。図３は、本発明品と従来品を
対象として、転造による加圧処理後における密度の変化
を示す。本発明品は、炭素濃度0.40％、焼結密度7.50g/
cm3 の部品を脱炭処理した焼結部品であって、従来品は
脱炭処理を施さない焼結部品である。同じ加圧処理をそ
れぞれの焼結部品に施したところ、本発明品では、表面
に近い部位において集中的に真密度近くまで密度向上が
生じるという結果を得た。[0010] After the decarburization treatment, the sintered part is subjected to pressure treatment such as rolling and re-pressing. The intermediate product has a uniform density as a whole, and has a low carbon concentration only in the surface layer portion. The surface layer is relatively soft and has recovered its brittleness by the decarburization treatment, and the pressure treatment causes the concentration to be intensively increased in the surface layer having a low carbon concentration, and the decarburized surface layer 18 has a true density (7.60 to 7.80 g). / cm 3 ) to increase its density to near. In addition, as described above, the carbon concentration decreases as the surface is closer to the surface by the decarburizing treatment in a decarburizing atmosphere. Therefore, the effect of increasing the density by the pressure treatment is greater as the surface is closer to the surface. On the other hand, the inside of the part where the carbon concentration does not change from the initial concentration is relatively high in hardness, so that the change in density due to the pressure treatment is suppressed. FIG. 3 shows the change in density after the pressure treatment by rolling for the product of the present invention and the conventional product. The product of the present invention has a carbon concentration of 0.40% and a sintered density of 7.50 g /
A sintered part obtained by decarburizing a part of cm 3 , and a conventional part is a sintered part that is not subjected to decarburization. When the same pressure treatment was applied to each of the sintered parts, it was found that, in the product of the present invention, the density was improved near the true density intensively at a portion near the surface.
【００１１】加圧処理後、焼結部品は、浸炭焼き入れ処
理が施される。この処理によって、表層部の炭素濃度を
向上させる。表層部の炭素濃度は、浸炭焼き入れ処理に
よって異なるが、初期の炭素濃度以上までその濃度を向
上させることが好ましい。以上のように、焼結部品に脱
炭処理、加圧処理及び浸炭焼き入れ処理を施すことによ
り、高炭素濃度で真密度に近い密度の表層部と、初期炭
素濃度で初期成形密度の内部とが一体に形成された焼結
部品が得られる。After the pressure treatment, the sintered part is subjected to a carburizing and quenching treatment. This treatment improves the carbon concentration in the surface layer. The carbon concentration in the surface layer varies depending on the carburizing and quenching treatment, but it is preferable to increase the carbon concentration to an initial carbon concentration or more. As described above, by subjecting the sintered part to decarburization treatment, pressure treatment, and carburizing and quenching treatment, the surface layer portion with a high carbon concentration and a density close to the true density, and the inside of the initial molding density with an initial carbon concentration Are obtained integrally with each other.
【００１２】[0012]
【発明の効果】本発明は、脱炭処理後に加圧処理し、そ
の後に浸炭焼き入れを施すことで、高密度で高炭素濃度
の表層部と初期成形密度で初期炭素濃度の内部を一体に
形成させており、表層部の密度、特に、表層部の表面の
密度を真密度近くまで向上させることができる。その一
方で、部品内部は初期密度及び初期炭素濃度を維持した
状態にあるので、例えば、自動車エンジン用のスプロケ
ットのような表面の耐摩耗性と曲げ強度の両方の特性が
要求される用途において、本発明は特に有用である。し
かも、曲げ強度が発揮されるように、高炭素濃度の粉末
金属を利用して内部の炭素濃度を高く設定しても、脱炭
表層部を形成することで表層部の脆性を一時的に回復さ
せ、その後の加圧処理により真密度に近い密度の表層部
が形成されるので、転造等の加圧処理を施しても、表層
部にクラックを欠け等の損傷を発生させることなく、表
層部の耐摩耗性を向上させることができる。また、脱炭
表層部に転造等の加圧処理を施すので、従来より少ない
エネルギーで加圧処理を施すことができ、経済的に耐摩
耗性がある高強度の焼結部品を得ることができる。According to the present invention, the pressure treatment is performed after the decarburization treatment, followed by carburizing and quenching, whereby the surface layer having a high density and a high carbon concentration and the inside of the initial carbon concentration at an initial molding density are integrally formed. The density of the surface layer, in particular, the density of the surface of the surface layer can be improved to near the true density. On the other hand, since the inside of the part maintains the initial density and the initial carbon concentration, for example, in applications where both characteristics of surface wear resistance and bending strength are required, such as sprockets for automobile engines, The present invention is particularly useful. In addition, even if the internal carbon concentration is set high using powdered metal with a high carbon concentration so that the bending strength is exhibited, the brittleness of the surface layer is temporarily recovered by forming the decarburized surface layer. Then, the surface layer portion having a density close to the true density is formed by the subsequent pressurizing process, so that even if a pressurizing process such as rolling is performed, the surface layer portion does not suffer cracks or other damage, and the surface layer portion is not damaged. The wear resistance of the part can be improved. In addition, since the pressure treatment such as rolling is performed on the decarburized surface layer, the pressure treatment can be performed with less energy than before, and a high-strength sintered part having economical wear resistance can be obtained. it can.
【図１】 焼結部品の例であるスプロケットの正面図。FIG. 1 is a front view of a sprocket as an example of a sintered part.
【図２】 図１の部分拡大図で。FIG. 2 is a partially enlarged view of FIG.
【図３】 断面密度の変化を示すグラフ。FIG. 3 is a graph showing a change in cross-sectional density.
１０ 焼結部品のスプロケット １２ スプロケット歯 １４ 歯面 １６ 歯元 １８ 脱炭層 DESCRIPTION OF SYMBOLS 10 Sprocket of sintered part 12 Sprocket tooth 14 Tooth surface 16 Root 18 Decarburized layer
Claims (1)
固めた焼結部品において、該焼結部品に初期炭素濃度よ
り低い炭素濃度の脱炭表層部と初期炭素濃度の内部とを
形成し、前記焼結部品を加圧処理して初期成形密度より
高く真密度に近い密度で初期炭素濃度より低い炭素濃度
の脱炭表層部と実質的に初期成形密度で初期炭素濃度の
内部を形成し、前記焼結部品を浸炭処理して初期成形密
度より高く真密度に近い密度で浸炭処理により炭素濃度
を上げた表層部と実質的に初期成形密度で実質的に初期
炭素濃度の内部を一体に形成した、焼結部品。1. A sintered part formed by compacting and sintering a powdered metal containing carbon, wherein a decarburized surface layer having a carbon concentration lower than an initial carbon concentration and an interior having an initial carbon concentration are formed in the sintered part. Pressurizing the sintered part to form a decarburized surface layer portion having a carbon concentration lower than the initial carbon concentration at a density close to the true density higher than the initial forming density and an inner portion of the initial carbon concentration substantially at the initial forming density, The sintered part is carburized to form a surface layer portion having a carbon concentration increased by the carburizing treatment at a density higher than the initial molding density and closer to the true density and substantially the inside of the initial carbon density substantially at the initial molding density. Sintered parts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11041932A JP2000239710A (en) | 1999-02-19 | 1999-02-19 | Sintered parts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11041932A JP2000239710A (en) | 1999-02-19 | 1999-02-19 | Sintered parts |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000239710A true JP2000239710A (en) | 2000-09-05 |
Family
ID=12622015
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11041932A Pending JP2000239710A (en) | 1999-02-19 | 1999-02-19 | Sintered parts |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000239710A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2390372A (en) * | 2002-06-03 | 2004-01-07 | Tsubakimoto Chain Co | Sintered sprocket and manufacturing method |
| JP2004502028A (en) * | 2000-06-28 | 2004-01-22 | ホガナス アクチボラゲット | Method for manufacturing powder metal parts with densified surface |
| EP1552895A1 (en) * | 2002-10-04 | 2005-07-13 | Hitachi Powdered Metals Co., Ltd. | Sintered gear |
| JP2006161900A (en) * | 2004-12-03 | 2006-06-22 | Hitachi Powdered Metals Co Ltd | Silent chain transmission device |
-
1999
- 1999-02-19 JP JP11041932A patent/JP2000239710A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004502028A (en) * | 2000-06-28 | 2004-01-22 | ホガナス アクチボラゲット | Method for manufacturing powder metal parts with densified surface |
| GB2390372A (en) * | 2002-06-03 | 2004-01-07 | Tsubakimoto Chain Co | Sintered sprocket and manufacturing method |
| GB2390372B (en) * | 2002-06-03 | 2005-06-08 | Tsubakimoto Chain Co | Sintered sprocket |
| DE10319828B4 (en) * | 2002-06-03 | 2010-12-16 | Tsubakimoto Chain Co., Nakanoshima | Sintered sprocket and method of making the same |
| EP1552895A1 (en) * | 2002-10-04 | 2005-07-13 | Hitachi Powdered Metals Co., Ltd. | Sintered gear |
| EP1552895A4 (en) * | 2002-10-04 | 2007-04-04 | Hitachi Powdered Metals | Sintered gear |
| US7556864B2 (en) | 2002-10-04 | 2009-07-07 | Hitachi Powdered Metals Co., Ltd. | Sintered gear |
| JP2006161900A (en) * | 2004-12-03 | 2006-06-22 | Hitachi Powdered Metals Co Ltd | Silent chain transmission device |
| JP4518929B2 (en) * | 2004-12-03 | 2010-08-04 | 日立粉末冶金株式会社 | Silent chain transmission |
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