JP5100486B2 - Method for manufacturing turbocharger turbo parts - Google Patents
Method for manufacturing turbocharger turbo parts Download PDFInfo
- Publication number
- JP5100486B2 JP5100486B2 JP2008113455A JP2008113455A JP5100486B2 JP 5100486 B2 JP5100486 B2 JP 5100486B2 JP 2008113455 A JP2008113455 A JP 2008113455A JP 2008113455 A JP2008113455 A JP 2008113455A JP 5100486 B2 JP5100486 B2 JP 5100486B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- alloy powder
- amount
- content
- mass
- 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.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000000034 method Methods 0.000 title claims description 5
- 239000000843 powder Substances 0.000 claims description 66
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 48
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 23
- 239000011812 mixed powder Substances 0.000 claims description 18
- 238000005245 sintering Methods 0.000 claims description 14
- 229910052750 molybdenum Inorganic materials 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 12
- 229910052804 chromium Inorganic materials 0.000 claims description 9
- 150000001247 metal acetylides Chemical class 0.000 claims description 7
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 229910001566 austenite Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 230000007797 corrosion Effects 0.000 description 17
- 238000005260 corrosion Methods 0.000 description 17
- 230000000694 effects Effects 0.000 description 13
- 239000007791 liquid phase Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- 230000003647 oxidation Effects 0.000 description 9
- 238000007254 oxidation reaction Methods 0.000 description 9
- 230000001771 impaired effect Effects 0.000 description 7
- 238000002485 combustion reaction Methods 0.000 description 5
- 238000000280 densification Methods 0.000 description 5
- 229910001208 Crucible steel Inorganic materials 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 229910001096 P alloy Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000003779 heat-resistant material Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Landscapes
- Powder Metallurgy (AREA)
Description
本発明は、例えばターボチャージャー用ターボ部品、特に耐熱性とともに耐食性および耐摩耗性が要求されるノズルボディ等に好適な焼結機械部品の製造方法に関する。 The present invention relates to a method for manufacturing a sintered machine component suitable for a turbocharger turbocharger, for example, a nozzle body that is required to have corrosion resistance and wear resistance as well as heat resistance.
一般に、内燃機関に付設されるターボチャージャーでは、内燃機関のエキゾーストマニホールドに接続されたタービンハウジングに、タービンが回転自在に支持され、タービンの外周側を囲うように複数のノズルベーンが回動可能に支持されている。タービンハウジングに流入した排気ガスは、外周側からタービンに流れ込んで軸方向へ排出され、その際にタービンを回転させる。そして、タービンの反対側で同じ軸に設けられたコンプレッサが回転することにより、内燃機関へ供給する空気を圧縮する。 In general, in a turbocharger attached to an internal combustion engine, a turbine is rotatably supported by a turbine housing connected to an exhaust manifold of the internal combustion engine, and a plurality of nozzle vanes are rotatably supported so as to surround an outer peripheral side of the turbine. Has been. The exhaust gas flowing into the turbine housing flows into the turbine from the outer peripheral side and is discharged in the axial direction, and the turbine is rotated at that time. A compressor provided on the same shaft on the opposite side of the turbine rotates to compress the air supplied to the internal combustion engine.
ここで、ノズルベーンは、ノズルボディやマウントノズルといった名称で呼ばれるリング状の部品に回動可能に支持されている。ノズルベーンの軸はノズルボディを貫通し、そこでリンク機構に接続されている。そして、リンク機構が駆動されることによりノズルベーンが回動し、排気ガスがタービンに流れ込む流路の開度が調整される。本発明が問題とするのは、ノズルボディ（マウントノズル）あるいはこれに装着されるプレートノズルといった、タービンハウジング内に設けられるターボ部品である。 Here, the nozzle vane is rotatably supported by a ring-shaped component called by a name such as a nozzle body or a mount nozzle. The nozzle vane shaft passes through the nozzle body where it is connected to the linkage. Then, when the link mechanism is driven, the nozzle vane rotates, and the opening degree of the flow path through which the exhaust gas flows into the turbine is adjusted. The present invention has a problem with turbo parts provided in a turbine housing, such as a nozzle body (mount nozzle) or a plate nozzle attached thereto.
上記のようなターボチャージャー用ターボ部品は、高温の腐食性ガスである排気ガスと接触することから耐熱性と耐食性が要求されるとともに、ノズルベーンと摺接するために耐摩耗性も要求される。このため、従来より、例えば高Ｃｒ鋳鋼や、ＪＩＳ規格で規定されているＳＣＨ２２種に耐食性向上の目的でＣｒ表面処理を施した耐摩耗材料等が使用されている。また、耐熱性とともに耐食性および耐摩耗性に優れ、しかも価格が低廉な耐摩耗部品として、フェライト系ステンレス鋼の基地中に炭化物を分散させた耐摩耗部品が提案されている（例えば特許文献１）。 The turbocharger turbo parts as described above are required to have heat resistance and corrosion resistance because they are in contact with exhaust gas, which is a high-temperature corrosive gas, and are also required to have wear resistance because they are in sliding contact with the nozzle vanes. For this reason, conventionally, for example, high Cr cast steel or wear resistant material obtained by applying Cr surface treatment to SCH22 class defined by JIS standard for the purpose of improving corrosion resistance has been used. In addition, a wear-resistant component in which carbide is dispersed in a ferritic stainless steel base has been proposed as a wear-resistant component that is excellent in heat resistance, corrosion resistance and wear resistance, and is inexpensive (for example, Patent Document 1). .
しかしながら、ターボチャージャー用ターボ部品においては、近年の内燃機関の高速化、高出力化に伴い、より一層、耐熱性、耐食性および耐摩耗性とともに高温強度を向上させた耐摩耗部品が要望されている。また、ターボチャージャーの構成部品は、一般に、オーステナイト系耐熱材料で構成されるが、特許文献１に記載のターボチャージャー用ターボ部品はフェライト系の材料から構成されている。この場合、周囲の部材と熱膨張係数が異なるため、適用にあたっては部品設計が難しく、周囲のオーステナイト系耐熱材料と同等の熱膨張係数であることが望まれている。本発明は、それらの要望に充分に応えることができる耐摩耗部品の製造方法を提供することを目的としている。 However, in turbocharger turbo parts, with the recent increase in speed and output of internal combustion engines, wear-resistant parts that have improved high-temperature strength as well as heat resistance, corrosion resistance, and wear resistance have been demanded. . Moreover, the component parts of the turbocharger are generally made of an austenitic heat-resistant material, but the turbocharger turbo component described in Patent Document 1 is made of a ferrite-based material. In this case, since the thermal expansion coefficient is different from that of the surrounding members, it is difficult to design a part in application, and it is desired that the thermal expansion coefficient is the same as that of the surrounding austenitic heat-resistant material. An object of the present invention is to provide a method for manufacturing a wear-resistant component that can sufficiently meet these demands.
本発明のターボチャージャー用ターボ部品の製造方法は、質量比で、Ｃｒ：２５〜４５％、Ｎｉ：８〜１６．０％、Ｍｏ：０．８〜２．８％、Ｓｉ：０．８〜２．８％、Ｃ：０．５〜３．０％、残部Ｆｅおよび不可避不純物よりなる組成のＦｅ合金粉末に、Ｐ：１０〜３０質量％のＦｅ−Ｐ粉末を１．０〜５．０質量％、黒鉛粉末を１．０〜３．０質量％添加して混合した混合粉末を用い、この混合粉末を成形した後に１１００〜１３００℃で焼結することを特徴とする。また、黒鉛粉末の添加量は、１．５〜３．０質量％であることが好ましい。 The turbocharger turbo parts manufacturing method of the present invention is, in mass ratio, Cr: 25 to 45%, Ni: 8 to 16.0%, Mo: 0.8 to 2.8%, Si: 0.8 to 2.8%, C: 0.5 to 3.0%, Fe alloy powder having a composition composed of the balance Fe and inevitable impurities, P: 10 to 30% by mass of Fe-P powder is added to 1.0 to 5.0. A mixed powder obtained by adding 1.0 to 3.0% by mass of graphite powder and 1.0 to 3.0% by mass is mixed, and the mixed powder is molded and then sintered at 1100 to 1300 ° C. Moreover, it is preferable that the addition amount of graphite powder is 1.5-3.0 mass%.
本発明の製造方法では、液相化温度を下げて焼結時に液相を発生させ、これによって焼結体を緻密化させる。このため、ＰとＣについてはＦｅ−Ｐ粉末と黒鉛粉末の形態とし、他のＣｒ，Ｎｉ，Ｍｏ，ＳｉについてはＦｅ合金粉末の形態とし、これらを混合して混合粉末として用いる。以下、上記の数値限定の根拠を本発明の作用とともに説明する。なお、以下の説明において、「％」は「質量％」を意味する。 In the production method of the present invention, the liquidus temperature is lowered to generate a liquid phase during sintering, thereby densifying the sintered body. Therefore, P and C are in the form of Fe-P powder and graphite powder, and other Cr, Ni, Mo, and Si are in the form of Fe alloy powder, which are mixed and used as a mixed powder. Hereinafter, the grounds for the above numerical limitation will be described together with the operation of the present invention. In the following description, “%” means “mass%”.
Ｃｒ：
Ｃｒは、基地の耐熱性および耐食性の向上に寄与するとともに、Ｃと結合して炭化物を形成し耐摩耗性を向上させる。このようなＣｒの効果を基地中に均一に作用させるため、ＣｒはＦｅ合金粉末の形態で付与する。ここで、Ｆｅ合金粉末中のＣｒの含有量が２５％に満たないと、Ｃｒ炭化物の析出量が少なくなり、耐摩耗性が不充分になるとともに、基地の耐熱性および耐食性が低下する。一方、Ｃｒの含有量が４５％を超えると粉末の圧縮性が著しく損なわれる。よって、Ｆｅ合金粉末中のＣｒの含有量は２５〜４５％とした。例えば、本発明とＣｒ含有量が同程度の高Ｃｒ鋳鋼では、Ｃｒ炭化物は粒界に析出するので耐摩耗性の向上にあまり寄与しない。しかしながら、本発明では、ＣｒをＦｅ合金粉末の形態で添加しているので、微細な粒状のＣｒ炭化物が基地中に分散した金属組織が得られ、充分な耐摩耗性と耐酸化性を得ることができる。
Cr:
Cr contributes to the improvement of the heat resistance and corrosion resistance of the base, and combines with C to form a carbide to improve the wear resistance. In order to make the effect of Cr work uniformly throughout the base, Cr is applied in the form of Fe alloy powder. Here, if the content of Cr in the Fe alloy powder is less than 25%, the precipitation amount of Cr carbide is reduced, the wear resistance becomes insufficient, and the heat resistance and corrosion resistance of the base are lowered. On the other hand, if the Cr content exceeds 45%, the compressibility of the powder is significantly impaired. Therefore, the content of Cr in the Fe alloy powder is set to 25 to 45%. For example, in the high Cr cast steel having the same Cr content as that of the present invention, Cr carbide precipitates at the grain boundary, so it does not contribute much to the improvement of wear resistance. However, in the present invention, since Cr is added in the form of Fe alloy powder, a metal structure in which fine granular Cr carbide is dispersed in the matrix is obtained, and sufficient wear resistance and oxidation resistance are obtained. Can do.
Ｎｉ：
Ｎｉは基地に拡散して固溶強化するとともに、基地をオーステナイト化して耐磨耗部品の高温強度を向上させる。Ｎｉも、その効果を基地全体に均一に作用させるため、Ｆｅ合金粉末の形態で付与する。Ｆｅ合金粉末中のＮｉの含有量が８％未満では、高温強度が不十分となる。一方、Ｎｉの含有量が１６．０％を超えても、高温強度はそれ以上向上しない。よって、Ｆｅ合金粉末中のＮｉの含有量は８〜１６．０％とした。
Ni:
Ni diffuses into the base and strengthens the solid solution, and austenites the base to improve the high-temperature strength of the wear-resistant parts. Ni is also applied in the form of Fe alloy powder so that the effect acts uniformly on the entire base. If the Ni content in the Fe alloy powder is less than 8%, the high temperature strength is insufficient. On the other hand, even if the Ni content exceeds 16.0%, the high-temperature strength is not further improved. Therefore, the content of Ni in the Fe alloy powder is set to 8 to 16.0%.
Ｍｏ：
Ｍｏは基地の耐熱性および耐食性向上に寄与するとともに、Ｃと結合して炭化物を形成し耐摩耗性を向上させる。ＭｏもＣｒと同様、その効果を基地全体に均一に作用させるため、Ｆｅ合金粉末の形態で付与する。Ｆｅ合金粉末中のＭｏの含有量が０．８％に満たないと、基地の耐熱性および耐食性向上の効果が乏しく、一方、２．８％を超えてもその効果はさほど顕著には現れない。よって、Ｆｅ合金粉末中のＭｏの含有量は０．８〜２．８％とした。
Mo:
Mo contributes to improving the heat resistance and corrosion resistance of the base, and combines with C to form carbides and improve wear resistance. Similarly to Cr, Mo is applied in the form of Fe alloy powder so that the effect acts uniformly on the entire base. If the content of Mo in the Fe alloy powder is less than 0.8%, the effect of improving the heat resistance and corrosion resistance of the base is poor, while the effect is not so noticeable even if it exceeds 2.8%. . Therefore, the content of Mo in the Fe alloy powder is set to 0.8 to 2.8%.
Ｓｉ：
Ｆｅ合金粉末は、酸化しやすいＣｒを多量に含むため、Ｆｅ合金粉末を製造する際にＳｉを脱酸剤として添加することが有効である。また、Ｓｉは焼結性を向上させる。Ｆｅ合金粉末中のＳｉの含有量が０．８％未満ではその効果が乏しく、一方、２．８％を超えると、Ｆｅ合金粉末が硬くなり過ぎて圧縮性が著しく損なわれる。よって、Ｆｅ合金粉末中のＳｉの含有量は０．８〜２．８％とした。
Si:
Since the Fe alloy powder contains a large amount of easily oxidizable Cr, it is effective to add Si as a deoxidizer when producing the Fe alloy powder. Si also improves sinterability. If the content of Si in the Fe alloy powder is less than 0.8%, the effect is poor. On the other hand, if it exceeds 2.8%, the Fe alloy powder becomes too hard and the compressibility is significantly impaired. Therefore, the content of Si in the Fe alloy powder is set to 0.8 to 2.8%.
Ｐ：
Ｐは、Ｃとともに焼結時にＦｅ−Ｐ−Ｃ液相を発生させて、焼結体の緻密化を促進する。これにより、９５％以上の密度比が達成可能となる。また、焼結時の液相化を促進して緻密化を図るために、ＰはＦｅ−Ｐ粉末、つまりＦｅ−Ｐ合金粉末の形態で添加する。Ｆｅ−Ｐ粉末中のＰの含有量が１０％未満では、十分な液相が発生せず、焼結体の緻密化に寄与しない。一方、３０％を超えるとＦｅ−Ｐ粉末が硬くなり過ぎて、圧縮性が著しく損なわれる。
P:
P generates a Fe—PC liquid phase during sintering together with C, and promotes densification of the sintered body. Thereby, a density ratio of 95% or more can be achieved. Further, P is added in the form of Fe—P powder, that is, Fe—P alloy powder, in order to promote liquid phase formation during sintering and to achieve densification. When the content of P in the Fe—P powder is less than 10%, a sufficient liquid phase is not generated, and does not contribute to densification of the sintered body. On the other hand, if it exceeds 30%, the Fe—P powder becomes too hard and the compressibility is significantly impaired.
全体組成中のＰの含有量が０．１％未満では、液相発生量が乏しく十分な緻密化が達成できないため、密度比が９５％を下回るようになる。一方、全体組成中のＰの含有量が１．０％を超えると、発生する液相の量が過多となり、焼結時に型くずれが生じる虞がある。以上より、全体組成中のＰの含有量が０．１〜１．５％となるように、Ｐの含有量が１０〜３０％のＦｅ−Ｐ粉末を、混合粉末へ１．０〜５．０％添加する。 If the P content in the overall composition is less than 0.1%, the amount of liquid phase generated is so small that sufficient densification cannot be achieved, so the density ratio falls below 95%. On the other hand, when the content of P in the overall composition exceeds 1.0%, the amount of the generated liquid phase becomes excessive, and there is a possibility that the mold may be deformed during sintering. From the above, the Fe-P powder having a P content of 10 to 30% is added to the mixed powder so that the P content in the entire composition is 0.1 to 1.5%. Add 0%.
Ｃ：
Ｃは液相化温度を下げるので、焼結時にＦｅ−Ｐ−Ｃ液相を発生させ、焼結体の緻密化を促進する。また、ＣはＣｒ，Ｍｏと炭化物を形成して耐摩耗性に寄与する。Ｃの全量を黒鉛粉末の形態で付与すると、Ｆｅ合金粉末はＣｒ，ＭｏがＦｅ基地中に固溶された状態の粉末となり、Ｆｅ合金粉末が硬くなり過ぎて圧縮性が損なわれる。また、多量の黒鉛粉末の使用も、混合粉末の圧縮性を損なう原因となる。そのため、Ｃの一部をＦｅ合金粉末の形態で付与し、残りのＣを黒鉛粉末の形態で付与する。Ｃの一部をＦｅ合金粉末の形態で付与すると、Ｆｅ合金粉末中のＣｒ，Ｍｏが炭化物としてＦｅ合金粉末中に析出するため、Ｆｅ合金粉末の基地中に固溶されるＣｒ，Ｍｏの量が低減され、Ｆｅ合金粉末の圧縮性を改善できる。さらに、残りのＣを黒鉛粉末の形態で与えることにより、混合粉末の圧縮性も改善できる。このとき、Ｆｅ合金粉末中のＣの含有量が０．５％未満であると、Ｆｅ基地中に固溶するＣｒ，Ｍｏの量が多くなってＦｅ合金粉末が硬くなり、圧縮性が損なわれる。一方、３．０％を超えると、Ｆｅ合金粉末中に析出する炭化物の量が多くなり過ぎＦｅ合金粉末が硬くなるため、Ｆｅ合金粉末中のＣの含有量は０．５〜３．０％とした。
C:
Since C lowers the liquidus temperature, a Fe—P—C liquid phase is generated during sintering, and the densification of the sintered body is promoted. C forms carbides with Cr, Mo and contributes to wear resistance. When the total amount of C is applied in the form of graphite powder, the Fe alloy powder becomes a powder in a state where Cr and Mo are dissolved in the Fe base, and the Fe alloy powder becomes too hard and the compressibility is impaired. In addition, the use of a large amount of graphite powder also causes a deterioration in the compressibility of the mixed powder. Therefore, a part of C is applied in the form of Fe alloy powder, and the remaining C is applied in the form of graphite powder. When a part of C is applied in the form of Fe alloy powder, Cr and Mo in the Fe alloy powder are precipitated as carbides in the Fe alloy powder. Therefore, the amount of Cr and Mo dissolved in the base of the Fe alloy powder. And the compressibility of the Fe alloy powder can be improved. Furthermore, the compressibility of the mixed powder can be improved by providing the remaining C in the form of graphite powder. At this time, if the content of C in the Fe alloy powder is less than 0.5%, the amount of Cr and Mo dissolved in the Fe base increases, the Fe alloy powder becomes hard, and the compressibility is impaired. . On the other hand, if it exceeds 3.0%, the amount of carbides precipitated in the Fe alloy powder becomes too much, and the Fe alloy powder becomes hard, so the content of C in the Fe alloy powder is 0.5 to 3.0%. It was.
ＣｒやＭｏの炭化物の形成に必要な量のＣを、Ｆｅ合金粉末に固溶して与えるが、残りのＣについては、黒鉛粉末の形態で混合粉末に添加する。ところで、黒鉛粉末の一部は、焼結時にＦｅ合金粉末表面の酸化被膜の還元に費やされるため、その分を見込んで黒鉛粉末を添加する必要がある。焼結時に還元等で失われる黒鉛は約０．２％程度であるため、黒鉛粉末の添加量はその分を見込んで１．０％以上とするとよい。一方、黒鉛粉末を過度に添加すると、基地が脆化するとともに、炭化物の析出量が増大することによりベーン等の相手材を摩耗したり、基地中のＣｒ量を低減させて耐熱性および耐食性を低下させる。このため、黒鉛粉末の添加量の上限を３．０％とする。 An amount of C necessary for the formation of Cr or Mo carbides is given as a solid solution in the Fe alloy powder. The remaining C is added to the mixed powder in the form of graphite powder. By the way, a part of the graphite powder is consumed for the reduction of the oxide film on the surface of the Fe alloy powder at the time of sintering. Therefore, it is necessary to add the graphite powder in anticipation of the amount. Since graphite lost by reduction or the like during sintering is about 0.2%, the amount of graphite powder added is preferably 1.0 % or more in view of that amount. On the other hand, if graphite powder is added excessively, the matrix becomes brittle and the amount of carbide precipitates increases, so that the other material such as vane is worn away, or the Cr content in the matrix is reduced to reduce heat resistance and corrosion resistance. Reduce. For this reason, the upper limit of the addition amount of graphite powder shall be 3.0%.
以上より、Ｆｅ合金粉末の組成は、Ｃｒ：２５〜４５％、Ｎｉ：８〜１６．０％、Ｍｏ：０．８〜２．８％、Ｓｉ：０．８〜２．８％、Ｃ：０．５〜３．０％、残部：Ｆｅおよび不可避不純物とし、Ｆｅ−Ｐ合金粉末の組成は、Ｐ：１０〜３０％、残部：Ｆｅおよび不可避不純物とし、Ｆｅ合金粉末に、Ｆｅ−Ｐ粉末を１．０〜５．０％および黒鉛粉末を１．０〜３．０％添加して混合粉末を生成する。 From the above, the composition of the Fe alloy powder is Cr: 25 to 45%, Ni: 8 to 16.0%, Mo: 0.8 to 2.8%, Si: 0.8 to 2.8%, C: 0.5-3.0%, balance: Fe and inevitable impurities, Fe-P alloy powder composition: P: 10-30%, balance: Fe and inevitable impurities, Fe alloy powder, Fe-P powder the generating the mixed powder were added 1.0 to 5.0% and graphite powder from 1.0 to 3.0%.
上記構成の混合粉末を用い、通常の粉末冶金の手法で所望の形状に成形し、１１００〜１３００℃で焼結を行う。これにより、全体組成は、質量比で、Ｃｒ：２３〜４４．３％、Ｎｉ：７．４〜１５．８％、Ｍｏ：０．７〜２．８％、Ｓｉ：０．７〜２．８％、Ｐ：０．１〜１．５％、Ｃ：１．５〜５．７％、残部Ｆｅおよび不可避不純物となる。この結果、オーステナイト基地中に微細な粒状の炭化物が分散する金属組織を呈する焼結機械部品が得られる。本発明の製造方法により得られる焼結機械部品は、焼結時に液相収縮するため密度比が９５％以上となる。これにより、気孔内の酸化や孔食腐食が抑制されるため、耐食性が大幅に向上する。また、上記焼結機械部品は、基地組織がオーステナイト組織であるため高温強度および耐食性に優れており、オーステナイト系耐熱鋼と同等の熱膨張係数を示す。さらに、微細な粒状のＣｒ炭化物を基地中に分散させることにより、耐摩耗性と耐酸化性を向上させることができる。 Using the mixed powder having the above structure, the powder is formed into a desired shape by a general powder metallurgy technique, and sintered at 1100 to 1300 ° C. Thereby, the whole composition is Cr: 23 to 44.3%, Ni: 7.4 to 15.8%, Mo: 0.7 to 2.8%, Si: 0.7 to 2. 8%, P: 0.1 to 1.5%, C: 1.5 to 5.7%, remaining Fe and inevitable impurities. As a result, a sintered machine part having a metal structure in which fine granular carbides are dispersed in the austenite base is obtained. Since the sintered machine part obtained by the production method of the present invention undergoes liquid phase shrinkage during sintering, the density ratio is 95% or more. Thereby, since oxidation and pitting corrosion in the pores are suppressed, the corrosion resistance is greatly improved. Moreover, since the above-mentioned sintered machine part has an austenite structure as a base structure, it has excellent high-temperature strength and corrosion resistance, and exhibits a thermal expansion coefficient equivalent to that of an austenitic heat-resistant steel. Further, by dispersing fine granular Cr carbide in the matrix, the wear resistance and oxidation resistance can be improved.
本発明のターボチャージャー用ターボ部品の製造方法によれば、耐熱性、耐食性および耐摩耗性とともに高温強度を向上させる等の効果が得られ、オーステナイト系耐熱鋼と同等の熱膨張係数を示す焼結機械部品を得ることができる。
According to the method for producing a turbocharger turbocharger of the present invention, the effect of improving the high temperature strength as well as the heat resistance, corrosion resistance and wear resistance is obtained, and the sintering exhibits a thermal expansion coefficient equivalent to that of an austenitic heat resistant steel. Mechanical parts can be obtained.
図１および図２は本発明の実施形態を示す図である。図１は内燃機関用ターボチャージャーの一部を示す側断面図であり、図中の符号２はノズルボディである。ノズルボディ２の中央には、タービン３が軸受（図示略）によって回転自在に支持されている。タービン３の反対側の端部には、コンプレッサ（図示略）が接続されている。 1 and 2 are diagrams showing an embodiment of the present invention. FIG. 1 is a side sectional view showing a part of a turbocharger for an internal combustion engine. Reference numeral 2 in the drawing denotes a nozzle body. A turbine 3 is rotatably supported by a bearing (not shown) at the center of the nozzle body 2. A compressor (not shown) is connected to the opposite end of the turbine 3.
ここで、上記構成のうちノズルボディ２が本発明の耐摩耗部品の一例である。図２に示すように、ノズルボディ２はリング状をなし、その周縁には複数の軸受孔２ａが形成されている。この軸受孔２ａには、ノズルベーン４の軸５が回動可能に支持されている。軸５のノズルベーン４と反対側の端部には、リンク６が固定されている（図２では１個のみ示す）。そして、各リンク６を一様に駆動することによりノズルベーン４が回動し、外周側からタービン３に流れ込む排気ガスの流量を調整するようになっている。なお、本発明の耐摩耗部品には、上記のようなノズルボディ２の他に、これに適宜装着されるプレートノズル等の部品も含まれており、前述した焼結合金により構成される。
Here, the nozzle body 2 is an example of the wear-resistant component of the present invention. As shown in FIG. 2, the nozzle body 2 has a ring shape, and a plurality of bearing
以下に本発明の実施例を詳細に説明する。なお、以下の説明において「％」は全て「質量％」を意味する。表１および２に示す組成のＦｅ合金粉末、Ｆｅ−２０％Ｐ粉末および黒鉛粉末を用意し、表１、２に示す割合でそれら粉末を混合した。得られた混合粉末の全体組成を表１、２に併記する。これら混合粉末を用いて成形圧力６００ＭＰａで外径１０ｍｍ、高さ１０ｍｍの柱状に成形した後、アンモニア分解ガス中１２００℃で６０分焼結して、Ｎｏ．１〜３３の試料を作成した。従来材として、特許文献１のＮｏ．３の材料と表２に示す組成の高Ｃｒ鋳鋼の溶製材（Ｎｏ．３４、Ｎｏ．３５）を上記の柱形状に加工して用意した。各試料を大気中で１００時間、７００〜９００℃の温度範囲で加熱し、加熱後、各試料の重量増加量を測定した。その結果を表１および２に示す。また、各試料を８００℃に加熱して引張強さ（高温強度）および熱膨張係数を調べた。その結果も表１および２に示す。なお、表１のＮｏ．４の測定結果を表２にも併記した。 Examples of the present invention will be described in detail below. In the following description, “%” means “mass%”. Fe alloy powders, Fe-20% P powders and graphite powders having the compositions shown in Tables 1 and 2 were prepared, and these powders were mixed at the ratios shown in Tables 1 and 2. The overall composition of the obtained mixed powder is also shown in Tables 1 and 2. These mixed powders were molded into a columnar shape having an outer diameter of 10 mm and a height of 10 mm at a molding pressure of 600 MPa, and then sintered in an ammonia decomposition gas at 1200 ° C. for 60 minutes. Samples 1 to 33 were prepared. As a conventional material, No. No. 3 and a high Cr cast steel melted material (No. 34, No. 35) having the composition shown in Table 2 were prepared by processing them into the above-mentioned column shape. Each sample was heated in the air at a temperature range of 700 to 900 ° C. for 100 hours, and after heating, the weight increase of each sample was measured. The results are shown in Tables 1 and 2. Each sample was heated to 800 ° C., and the tensile strength (high temperature strength) and the thermal expansion coefficient were examined. The results are also shown in Tables 1 and 2. In Table 1, No. The measurement results of 4 are also shown in Table 2.
（１）Ｆｅ合金粉末中のＮｉの影響
表１のＮｏ．１〜７に示すように、Ｎｉの添加量が８．０％未満の場合には、高温強度が不充分となった。一方、Ｎｉの添加量が１６％までは高温強度が向上したが、１６％を超えると高温強度は低下した。
(1) Effect of Ni in Fe alloy powder As shown to 1-7, when the addition amount of Ni was less than 8.0%, the high-temperature strength was insufficient. On the other hand, the high temperature strength was improved up to 16% of Ni addition, but the high temperature strength was reduced when over 16%.
（２）Ｆｅ合金粉末中のＣｒの影響
表１のＮｏ．４およびＮｏ．８〜１１に示すように、Ｆｅ合金粉末中のＣｒの含有量が２５％以上では、重量増加量が大幅に低減された。これは、Ｃｒにより基地の耐熱性及び耐食性が向上されたためである。一方、Ｆｅ合金粉末中のＣｒの含有量が４５％を超えるＮｏ．２９では、Ｆｅ合金粉末の圧縮性が損なわれたため、試料を作製することができなかった。
(2) Effect of Cr in
（３）Ｆｅ合金粉末中のＣの影響
混合粉末中のＣ量を一定とし、Ｆｅ合金粉末中のＣ量と黒鉛粉末の添加量を変えてＦｅ合金粉末中のＣ量の影響を調べた。その結果を表１のＮｏ．１２〜２１に示す。Ｆｅ合金粉末中のＣが０．５％未満では、混合粉末の圧縮性が低下して成形密度が低くなる結果、耐食性および高温強度が低下する。一方、Ｆｅ合金粉末中のＣ量が０．５％以上では、Ｃ量の増加につれて黒鉛粉末の添加量が低減するため、原料粉末の圧縮性が向上して耐食性および高温強度が向上する。しかしながら、Ｆｅ合金粉末中のＣ量が３．０％を超えると、Ｆｅ合金粉末が硬くなるため、混合粉末の圧縮性が低下して耐摩耗性および高温強度が低下する。
(3) Effect of C in Fe alloy powder The effect of C in the Fe alloy powder was investigated by changing the amount of C in the Fe alloy powder and the amount of graphite powder added while keeping the amount of C in the mixed powder constant. The results are shown in Table 1. Shown in 12-21. When C in the Fe alloy powder is less than 0.5%, the compressibility of the mixed powder is lowered and the molding density is lowered. As a result, the corrosion resistance and the high temperature strength are lowered. On the other hand, when the amount of C in the Fe alloy powder is 0.5% or more, the amount of graphite powder added decreases as the amount of C increases, so that the compressibility of the raw material powder is improved and the corrosion resistance and high-temperature strength are improved. However, when the amount of C in the Fe alloy powder exceeds 3.0%, the Fe alloy powder becomes hard, so that the compressibility of the mixed powder is reduced, and the wear resistance and high-temperature strength are reduced.
（４）全体組成中のＰの影響
表１のＮｏ．４および表２のＮｏ．３０〜３３に示すように、Ｐの含有量が０．１％になると重量増加量が急減し、耐酸化性が著しく向上した。これは、Ｐの含有量が０．１％では、焼結時の液相化が促進され、気孔が減少して内部酸化が抑制されたためと考えられる。一方、Ｐの含有量が１．０％を超えると、発生する液相量が過多となって焼結時に型くずれが生じたため、試料を作製することができなかった。
(4) Effect of P in the
（５）混合粉末中の黒鉛粉末の影響
表１のＮｏ．４および表２のＮｏ．２２〜２９に示すように、黒鉛粉末の添加量が０．５〜３．０％では、重量増加量が小さく、耐酸化性は良好であり、熱膨張係数も向上した。黒鉛粉末により焼結時の液相化が促進され、気孔が減少して内部酸化が抑制されたことがわかる。一方、黒鉛粉末を３．５％添加したＮｏ．２９では、粉末の圧縮性が損なわれて試料を作製することができなかった。
(5) Effect of graphite powder in
（６）従来材との比較
本発明材と高Ｃｒ鋳鋼（従来材：Ｎｏ．３５）とを比較すると、表１および表２に示すように、密度比が１００％の従来材は高温強度が低く、酸化による重量増加が多い。また、本発明材とＮｏ．３４とを比較すると、耐酸化性に差は認められないものの、本発明材の方が高温強度が高いことが確認された。
(6) Comparison with conventional material When comparing the present invention material and high Cr cast steel (conventional material: No. 35), as shown in Table 1 and Table 2, the conventional material having a density ratio of 100% has high temperature strength. Low and there is much weight increase due to oxidation. In addition, the present invention material and No. When compared with No. 34, it was confirmed that although the oxidation resistance was not different, the material of the present invention had higher high-temperature strength.
２ ノズルボディ（耐摩耗部品）
２ａ 軸受孔
３ タービン
４ ノズルベーン
５ 軸
６ リンク
2 Nozzle body (wear-resistant parts)
2a Bearing hole 3
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008113455A JP5100486B2 (en) | 2008-04-24 | 2008-04-24 | Method for manufacturing turbocharger turbo parts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008113455A JP5100486B2 (en) | 2008-04-24 | 2008-04-24 | Method for manufacturing turbocharger turbo parts |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009263710A JP2009263710A (en) | 2009-11-12 |
| JP5100486B2 true JP5100486B2 (en) | 2012-12-19 |
Family
ID=41389931
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008113455A Active JP5100486B2 (en) | 2008-04-24 | 2008-04-24 | Method for manufacturing turbocharger turbo parts |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5100486B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5939384B2 (en) * | 2012-03-26 | 2016-06-22 | 日立化成株式会社 | Sintered alloy and method for producing the same |
| JP6229277B2 (en) * | 2013-03-01 | 2017-11-15 | 日立化成株式会社 | Sintered alloy and method for producing the same |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60255958A (en) * | 1984-05-30 | 1985-12-17 | Nissan Motor Co Ltd | Wear resistant sintered alloy |
| JP3784003B2 (en) * | 2001-01-31 | 2006-06-07 | 日立粉末冶金株式会社 | Turbo parts for turbochargers |
-
2008
- 2008-04-24 JP JP2008113455A patent/JP5100486B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009263710A (en) | 2009-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5100487B2 (en) | Manufacturing method of sintered machine parts | |
| US10006111B2 (en) | Sintered alloy and manufacturing method thereof | |
| JP5939384B2 (en) | Sintered alloy and method for producing the same | |
| JP3784003B2 (en) | Turbo parts for turbochargers | |
| JP2003268414A (en) | Sintered alloy for valve seat, valve seat and its manufacturing method | |
| JP6229277B2 (en) | Sintered alloy and method for producing the same | |
| JP2005325436A (en) | Hard-particle dispersion type iron-based sintered alloy | |
| JP4299042B2 (en) | Iron-based sintered alloy, valve seat ring, raw material powder for producing iron-based sintered alloy, and method for producing iron-based sintered alloy | |
| JP2018184656A (en) | Heat-resistant sintering material having excellent high-temperature wear resistance and salt damage resistance, and method for producing the same | |
| JP5100486B2 (en) | Method for manufacturing turbocharger turbo parts | |
| JP7150406B2 (en) | Heat-resistant sintered alloy material | |
| JP3763782B2 (en) | Method for producing wear-resistant iron-based sintered alloy material for valve seat | |
| JP7467904B2 (en) | Sintered alloy and method for producing the same | |
| JP6392530B2 (en) | Ferrous sintered alloy valve seat | |
| CN112368409B (en) | Sintered alloy and method for producing same | |
| JP4702803B2 (en) | Manufacturing method of sintered machine parts | |
| JP6508611B2 (en) | Sintered alloy and method of manufacturing the same | |
| JP3809944B2 (en) | Hard particle dispersed sintered alloy and method for producing the same | |
| JP5079417B2 (en) | Manufacturing method of high temperature corrosion resistant wear resistant sintered parts | |
| WO2016158738A1 (en) | Heat-resistant sintered material having excellent oxidation resistance, wear resistance at high temperatures and salt damage resistance, and method for producing same | |
| JP3749809B2 (en) | Piston ring composite wear-resistant ring with cooling cavity with excellent high-temperature wear resistance and thermal conductivity | |
| JP2009035786A (en) | Method for manufacturing sintered parts having corrosion resistance and abrasion resistance at high temperature | |
| JPS5974265A (en) | Heat and wear resistant sintered alloy | |
| JP2006193831A (en) | Abrasion resistance iron-based sintered alloy material for valve seat and valve seat made of iron-based sintered alloy | |
| JP2015036434A (en) | Sintered member |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20101227 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20120625 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120629 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120824 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120907 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120925 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20151005 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5100486 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |