• 제목/요약/키워드: Cast Stainless Exhaust Manifold

검색결과 6건 처리시간 0.021초

Exhaust Manifold 용 오스테나이트계 스테인리스 강의 고온 변형특성 (HIGH TEMPERATURE DEFORMATION BEHAVIOR OF AUSTENITIC STAINLESS STEELS FOR EXHAUST MANIFOLD)

  • 이규동;하태권;정효태
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 추계학술대회 논문집
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    • pp.314-317
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    • 2007
  • Domestic automobile industries have been focusing their effort on development of exhaust manifolds using high temperature stainless steel. Exhaust manifolds fabricated with stainless steels can be categorized into tubular and cast ones. The former is usually manufactured by forming and welding process and the latter by vacuum casting process. In the present study, high temperature mechanical properties of 5 austenitic stainless steels, one was sand cast and the others vacuum cast, were investigated by performing a series of high temperature tensile tests and high temperature low cycle fatigue tests.

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배기다기관용 주강소재의 고온특성 평가 (Characterization of High Temperature Mechanical Properties of Cast Stainless Steels for Exhaust Manifold)

  • 이규동;하태권;정재영
    • 소성∙가공
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    • 제18권3호
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    • pp.217-222
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    • 2009
  • Automobile industries have been focusing their efforts on the development of exhaust manifolds using high temperature stainless steels. Exhaust manifolds fabricated with stainless steels can be categorized into tubular and cast ones. The former is usually manufactured by forming and welding process and the latter by vacuum casting process. In the present study, high temperature mechanical properties of 5 austenitic and 4 ferritic stainless steels were investigated by performing a series of high temperature tensile and low cycle fatigue tests. One of the austenitic stainless steels was vacuum cast and the others sand cast. Fatigue life of ferritic stainless steels was higher than that of austenitic ones.

고내열 페라이트계 스테인레스 주강의 고온인장특성 평가 (High Temperature Tensile Properties of Heat-resistant Cast Ferritic Stainless Steels)

  • 정현경;이동근
    • 열처리공학회지
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    • 제34권1호
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    • pp.10-16
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    • 2021
  • Exhaust manifold is a very important component that is directly connected to air environment pollution and that requires strict mechanical properties such as high temperature fatigue and oxidation. Among stainless steels, the ferritic stainless steel with body-centered cubic structure shows excellent resistance of stress-corrosion cracking, ferromagnetic at room temperature, very excellent cold workability and may not be enhanced by heat treatment. The microstructural characteristics of four cast ferritic stainless steels which are high heat-resistant materials, were analyzed. By comparing and evaluating the mechanical properties at room temperature and high temperature in a range of 400℃~800℃, a database was established to control and predict the required properties and the mechanical properties of the final product. The precipitates of cast ferritic stainless steels were analyzed and the high-temperature deformation characteristics were evaluated by comparative analysis of hardness and tensile characteristics of four steels at room temperature and from 400℃ to 800℃.

박육 스테인리스 주강에 대한 유동 및 응고해석의 실험적 고찰 (Experimental Study of Flow and Solidification Simulation for Thin Wall Stainless Steel Castings)

  • 최학규;박홍일;정해용;배차헌;최병강
    • 한국주조공학회지
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    • 제20권5호
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    • pp.344-353
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    • 2000
  • In order to find out the casting conditions of the thin wall stainless steel exhaust manifold for automobile, the melt flow and solidification behavior simulated by the Z-CAST program were evaluated, and experimental casting result on the test casting and exhaust manifold of SSC13 alloy were investigated. From the results of this study, it was shown that the calculated results on fluid flow were in good agreement with practical thin wall test castings under the same casting conditions, as pouring metal is austenitic stainless steel(SSC13) and pouring temperature is 1575, 1630, and $1665^{\circ}C$ respectively. That calculated result with designed thin wall exhaust manifold was predicted filling up into the mold cavity, and practical casting was sound. The solidification simulation was predicted shrinkages at the bosses for original exhaust manifold, and designed it without bosses was predicted no defect. Therefore practical exhaust manifold casting was sound and in good agreement with calculated solidification results.

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EXPERIMENTAL APPROACH FOR EVALUATING EXHAUST FLOW DISTRIBUTION FOR PZEV EXHAUST MANIFOLDS USING A SIMULATED DYNAMIC FLOW BENCH

  • Hwang, I.G.;Myung, C.L.;Kim, H.S.;Park, S.
    • International Journal of Automotive Technology
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    • 제8권5호
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    • pp.575-581
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    • 2007
  • As current and future automobile emission regulations become more stringent, the research on flow distribution for an exhaust manifold and close-coupled catalyst(CCC) has become an interesting and remarkable subjects. The design of a CCC and exhaust manifold is a formidable task due to the complexity of the flow distribution caused by the pulsating flows from piston motion and engine combustion. Transient flow at the exhaust manifold can be analyzed with various computational fluid dynamics(CFD) tools. However, the results of such simulations must be verified with appropriate experimental data from real engine operating condition. In this study, an experimental approach was performed to investigate the flow distribution of exhaust gases for conventional cast types and stainless steel bending types of a four-cylinder engine. The pressure distribution of each exhaust sub-component was measured using a simulated dynamic flow bench and five-hole pitot probe. Moreover, using the results of the pitot tube measurement at the exit of the CCC, the flow distribution for two types of manifolds(cast type and bending type) was compared in terms of flow uniformity. Based on these experimental techniques, this study can be highly applicable to the design and optimization of exhaust for the better use of catalytic converters to meet the PZEV emission regulation.

25Cr-13Ni 스테인리스강의 고온 크리프-피로거동에 관한 연구 (High Temperature Creep-Fatigue Behavior of 25Cr-13Ni Stainless Steel)

  • 송전영;안용식
    • 열처리공학회지
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    • 제28권2호
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    • pp.68-74
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    • 2015
  • The low cycle fatigue (LCF) and creep-fatigue (hold time tension fatigue, HTTF) tests were performed on the modified 25Cr-13Ni cast stainless steel, which was selected as a candidate material for exhaust manifold in automotive engine. The exhaust manifold is subjected to an environment in which heating and cooling cycle occur due to the running pattern of automotive engine. Several types of fatigue behaviour such as thermal fatigue, thermal mechanical fatigue and creep-fatigue are belong to the main failure mechanisms. High temperature tensile test was firstly carried out to compare the sample with the traditional cast steel for the component. The low cycle fatigue and HTTF tests were carried out under the strain controlled condition with the total strain amplitude from ${\pm}0.6%$ to ${\pm}0.7%$ at $800^{\circ}C$. The hysteresis loops of HTTF tests showed significant stress relaxation during tension hold time. With the increase of tension hold time, the fatigue life was remarkably deceased which caused from the formation of intercrystalline crack by the creep failure mechanism.