• 제목/요약/키워드: 316L

검색결과 653건 처리시간 0.03초

오스테나이트 스테인레스강의 고온용융염 부식거동연구 (A Study on the Corrosion Behavior of Austenitic Stainless Steel in Hot Molten Salt)

  • 조수행;박상철;정명수;장준선;신영준
    • 한국재료학회지
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    • 제9권2호
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    • pp.211-216
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    • 1999
  • LiCl 및 $LiCl/Li_2O$ 용융염분위기에서 오스테나이트 스테인레스강, SUS 316L과 SUS 304L의 부식특성을 650­~$850^{\circ}C$ 온도범위에서 조사하였다. SUS 316L과 304L의 부식층은 외부 $Li(CrFe)O_2와 내부 Cr_2O_3$의 2층 구조를 형성하였다. LiCl 용융염중에서는 균일한 부식충이 형성되지만, $LiCl/Li_2O$ 혼합용융염중에서는 균일한 부식충 형성외에 업계부식이 발생되는 것을 알 수 있었다. $750^{\circ}C$까지 온도 증가에 따른 부식속도의 증가속도는 느리고, $750^{\circ}C$ 이상에서는 부식속도가 급격히 증가하였다. 용융염분위기에서 SUS 316L은 SUS 304L에 비하여 부식속도가 느려셔 보다 좋은 내식성을 나타내였다.

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Electrochemical Properties of NiO-YSZ Thin Films on 316 Stainless Steel Bipolar Plates Under a Simulated PEMFC Environment

  • Lee, W.G.;Jang, H.
    • Bulletin of the Korean Chemical Society
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    • 제33권4호
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    • pp.1177-1182
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    • 2012
  • The corrosion resistance of 316L stainless steel coated with NiO-YSZ (Ni added yttria stabilized zirconia) was examined in a proton exchange membrane fuel cell (PEMFC) environment. The NiO-YSZ coating was carried out using a sol-gel dip coating method, and the corrosion resistance and interfacial contact resistance (ICR) were determined by the composition and morphology of the NiO-YSZ film. The corrosion resistance increased with increasing Ni content in the NiO-YSZ film, but rapid corrosion was observed when the YSZ film contained more than 15 wt % Ni due to surface cracks. The polarization resistance was improved by several orders of magnitude when 316L stainless steel was coated with a 15 wt % NiO-YSZ film compared to bare 316L. The ICR of the NiO-YSZ film was decreased to that of bare 316L when the YSZ film contained 25 wt % NiO, suggesting the possible application of NiO-YSZ coated stainless steel for a bipolar plate.

Creq/Nieq비에 따른 AISI 304L 및 AISI 316L 스테인리스강 용접부의 미세조직 및 전기화학적 양극분극 평가 (Evaluations of Microstructure and Electrochemical Anodic Polarization of AISI 304L and AISI 316L Stainless Steel Weld Metals with Creq/Nieq Ratio)

  • 김연희;장아영;강동훈;고대은;신용택;이해우
    • 대한금속재료학회지
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    • 제48권12호
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    • pp.1090-1096
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    • 2010
  • This pitting corrosion study of welded joints of austenitic stainless steels (AISI 304L and 316L) has addressed the differentiating solidification mode using three newly introduced filler wires with a flux-cored arc welding process (FCAW). The delta ferrite (${\delta}$-ferrite) content in the welded metals increased with an increasing equivalent weight ratio of chromium/nickel ($Cr_{eq}/Ni_{eq}$). Ductility dip cracking (DDC) was observed in the welded metal containing ferrite with none of AISI 304L and 0.1% of AISI 316L. The potentiodynamic anodic polarization results revealed that the $Cr_{eq}/Ni_{eq}$ ratio in a 3.5% NaCl solution didn't much affect the pitting potential ($E_{pit}$). The AISI 316L welded metals with ${\ddot{a}}$-ferrite content of over 10% had a superior $E_{pit}$ value. Though the AISI 316L welded metal with 0.1% ferrite had larger molybdenum contents than AISI 304L specimens, it showed a similar $E_{pit}$ value because the concentration of chloride ions and the corrosion product induced severe damage near the DDC.

용융탄산염 연료전지의 Anode가스 분위기에서 AISI-type 316L stainless steel의 전기화학적 부식 특성 (Electrochemical Corrosion Characteristics of AISI-type 316 L Stainless Steel in Anode-Gas Environment of MCFC)

  • 이갑수;임태훈;홍성안;김화용
    • 전기화학회지
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    • 제5권2호
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    • pp.62-67
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    • 2002
  • 용융탄산염 연료전지의 성능 저하와 수명 감소의 원인이 되는 부식 현상을 규명하고자 분리판 재료로 가장 널리 사용되고 있는 AISI-type 316L stainless steel을 대상으로 62Li/38K계 용융탄산염 내에서의 부식 실험을 수행하였다. 부식의 형태 및 속도는 환경에 의하여 다양하게 변화하게 되며, 용융탄산염 내에서 AISI-type 316L stainless steel의 부식 속도는 부식 반응에 의하여 형성되는 부동태 산화막의 안정성에 의하여 크게 영향을 받는다. 전기화학적 분극 거동을 분석한 결과 용융탄산염 연료전지의 anode가슨 분위기에서는 안정한 부동태 산화막이 형성되지 않았다. 순환 전압전류법과 정전위법을 이용한 부식 생성물의 X-ray분석을 통하여 특정한 전기화학적 전위 영역에서 반응기구와의 인과관계를 규명하고 다양한 형태의 부식 반응들을 분리해 내었다.

금속사출성형을 이용한 STS 316L 밸브피팅 제작에 대한 연구 (A Study of STS 316L Threaded Elbow Fitting Fabrication by Metal Injection Molding)

  • 김재영;김성조;정성택;안석영
    • 소성∙가공
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    • 제24권2호
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    • pp.121-129
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    • 2015
  • A net-shape forming of small and complex-shaped metal parts by metal injection molding (MIM) has economic advantages in mass production, especially for STS 316L valve fitting. STS 316L offers excellent corrosion resistance, but it has poor machinability, which is a limitation in using it for a cost-effective production where both forging and machining are employed. Simulation and experimental analysis were performed to develop a MIM STS 316L 90° elbow fitting minimizing trial and error. A Taguchi method was used to determine which input parameter was the most sensitive to possible defects (e.g. sink mark depth) during the injection molding. The final prototype was successfully built. The results indicate that the simulation tool can be used during the design process to minimize trial and error, but the final adjustment of parameters based on field experience is essential.

고분자 전해질 연료전지 금속분리판 316L 스테인리스강의 부식거동 및 기체확산층(GDL)과의 계면접촉저항 측정 (Corrosion Behaviors of 316L Stainless Steel Bipolar Plate of PEMFC and Measurements of Interfacial Contact Resistance(ICR) between Gas Diffusion Layer(GDL) and Bipolar Plate)

  • 오인환;이재봉
    • Corrosion Science and Technology
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    • 제9권3호
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    • pp.129-136
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    • 2010
  • The corrosion behaviors of 316L stainless steel were investigated in simulated anodic and cathodic environments for proton exchange membrane fuel cell (PEMFC) by using electrochemical measurement techniques. Interfacial contact resistance(ICR) between the stainless steel and gas diffusion layer(GDL) was also measured. The possibility of 316L was evaluated as a substitute material for the graphite bipolar plate of PEMFC. The value of ICR decreased with an increase in compaction stress(20 N/$cm^2$~220 N/$cm^2$) showing the higher values than the required value in PEMFC condition. Although 316L was spontaneously passivated in simulated cathodic environment, its passive state was unstable in simulated anodic environment. Potentiostatic and electrochemical impedance spectroscopy (EIS) measurement results showed that the corrosion resistance in cathodic condition was higher and more stable than that in anodic condition. Field emission scanning electron microscopy (FE-SEM), and inductively coupled plasma(ICP) were used to analyze the surface morphology and the metal ion concentration in electrolytes.

Type 316L 스테인리스강의 고온 기계적 거동 (High-Temperature Mechanical Behaviors of Type 316L Stainless Steel)

  • 김우곤;이형연
    • 한국압력기기공학회 논문집
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    • 제16권1호
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    • pp.92-99
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    • 2020
  • High-temperature mechanical behaviors of Type 316L stainless steel (SS), which is considered as one of the major structural materials of Generation-IV nuclear reactors, were investigated through the tension and creep tests at elevated temperatures. The tension tests were performed under the strain rate of 6.67×10-4 (1/s) from room temperature to 650℃, and the creep tests were conducted under different applied stresses at 550℃, 600℃, 650℃, and 700℃. The tensile behavior was investigated, and the modeling equations for tensile strengths and elongation were proposed as a function of temperature. The creep behavior was analyzed in terms of various creep equations: Norton's power law, modified Monkman-Grant relation, damage tolerance factor(λ), and Z-parameter, and the creep constants were proposed. In addition, the tested tensile and creep strengths were compared with those of RCC-MRx. Results showed that creep exponent value decreased from n=13.55 to n=7.58 with increasing temperature, λ = 6.3, and Z-parameter obeyed well a power-law form of Z=5.79E52(σ/E)9.12. RCC-MRx showed lower creep strength and marginally different in creep strain rate, compared to the tested results. Same creep deformation was operative for dislocation movement regardless of the temperatures.