As wrought stainless steel, sintered stainless steel (STS) has excellent high-temperature anti-corrosion even at high temperature of 800ºC and exhibit corrosion resistance in air. The oxidation behavior and oxidation mechanism of the sintered 316L stainless was reported at the high temperature in our previous study. In this study, the effects of additives on high-temperature corrosion resistances were investigated above 800ºC at the various oxides (SiO2, Al2O3, MgO and Y2O3) added STS respectively as an oxidation inhibitor. The morphology of the oxide layers were observed by SEM and the oxides phase and composition were confirmed by XRD and EDX. As a result, the weight of STS 316L sintered body increased sharply at 1000oC and the relative density of specimen decreased as metallic oxide addition increased. Compared with STS 316L sintered parts, weight change ratio corresponding to different oxidation time at 900oC and 1000oC, decreased gradually with the addition of metallic oxide. The best corrosion resistance properties of STS could be improved in case of using Y2O3. The oxidation rate was diminished dramatically by suppression the peeling on oxide layers at Y2O3 added sintered stainless steel.

In this study, nitrogen ions were implanted into STS 316L austenitic stainless steel by plasma immersion ion implantation (PIII) to improve the corrosion resistance. The implantation of nitrogen ions was performed with bias voltages of −5, −10, −15, and −20 kV. The implantation time was 240 min and the implantation temperature was kept at room temperature. With nitrogen implantation, the corrosion resistance of 316 L improved in comparison with that of the bare steel. The effects of nitrogen ion implantation on the electrochemical corrosion behavior of the specimen were investigated by the potentiodynamic polarization test, which was conducted in a 0.5 M H2SO4 solution at 70 oC. The phase evolution and texture caused by the nitrogen ion implantation were analyzed by an X-ray diffractometer. It was demonstrated that the samples implanted at lower bias voltages, i.e., 5 kV and 10 kV, showed an expanded austenite phase, γN, and strong (111) texture morphology. Those samples exhibited a better corrosion resistance.

In this study, porous stainless steel (STS316L) sintered body was fabricated by powder metallurgy method and its properties such as porosity, compressive yield strength, hardness, and permeability were evaluated. 67.5Fe-17Cr-13Ni-2.5Mo (wt%) powder was produced by a water atomization. The atomized powder was classified into size with under 45 μm and over 180 μm, and then they were compacted with various pressures and sintered at 1210oC for 1 h in a vacuum atmosphere. The porosities of sintered bodies could be obtained in range of 20~53% by controlling the compaction pressure. Compressive yield strength and hardness were achieved up to 268 MPa and 94 Shore D, respectively. Air permeability was obtained up to 79 l/min·cm2. As a result, mechanical properties and air permeability of the optimized porous body having a porosity of 25~40% were very superior to that of Al alloy.

In this study, analysis on the oxidation behavior was conducted by a series of high-temperature oxidation tests at both 800oC, 900oC and 1000 in the air with sintered STS 316L. The weight gain of each oxidized specimen was measured, the oxidized surface morphologies and composition of oxidation layer were analyzed with Scanning Electron Microscope-Energy Dispersive x-ray Spectroscopy (SEM-EDS), finally, the phase change and composition of the oxidized specimen were shown by X-Ray Diffraction (XRD). As a result, the weight gain increased sharply at 1000oC when oxidation test was conducted for 210 hours. Also, a plentiful of pores were observed in the surface oxidation layers at 900oC for 210 hours. In addition, the following conclusions on oxidation behavior of sintered STS 316L can be obtained: Cr2O3 can be formed on pores by influxing oxygen through open-pores, (Fe0.6Cr0.4)2O3 can be generated on the inner oxidation layer, and Fe2O3 was on the outer oxidation layer. Also, NiFe2O4 could be precipitated if the oxidation time was kept longer.

In this study, STS 316L powders with 3 wt.% Cu and 1 wt.% Sn known as corrosion-resistance reinforce- ment elements, are prepared to make different kinds of specimens, in which, 3 wt.% Cu and 1 wt.% Sn are added in different forms by mixing, alloying and fully alloying. After sintering in the same condition, the corrosion resistance, wear resistance and their mechanical properties of specimens are tested respectively. According to the comparison, STS 316L specimen sintered at 1270o C showed the most excellent mechanical property: HRB 78 (hardness), 1130.7 MPa (RCS), 26.6% (Fraction Wear), It was similar with the specimen made of STS316L and fully alloyed Cu and Sn pow- ders, meanwhile, the latter one appears the best corrosion resistance, 75hrs-salt immersion test results. In addition, the specimens with Cu and Sn powders additive showed relatively worse wear resistance in compared with STS316L spec- imen.

A capsule is the device for irradiation test of nuclear materials and fuels in HANARO. The instrumentation cables are sealed tightly by brazing at the top of the capsule. In this study, the integrities at the brazing of both Inconel 600 and STS 310 materials were confirmed by tensile test, survey of damage on coating, and measurement of insulation resistance. At tensile test, brazing areas were not damaged but the thermocouples themselves were broken on both the materials. At flame heat test, the coating of STS 310 material was maintained without damage but the brittle fracture on Inconel 600 material was observed. Insulation resistances were confirmed to be satisfactory in case of both the materials. In this analysis, the thermocouple was expanded by 0.81mm on the direction of y-axis and the tube was contracted by 0.57mm on the direction of x-axis. As the result, cracks might be occurred with thermal stresses. EDX spectrum analysis showed that the BAg-1 filler metal formed a thin reaction layer on the surface of brazed metal.

Titanium carbonitride is more perspective materials compared to titanium carbide. It can be used in tool industry and special products because of its higher strength, abrasive wear-resistance and especially its strong chemical stability at high temperatures. We produced STS+TiCxNy composite by the spark plasma sintering for higher strength and studied the characteristics. The planar and cross-sectional microstructures of the specimens were observed by scanning electron microscopy. Characterizations of the carbon and nitride phases on the surface of composite were carried out using an X-ray diffractometer. During annealing TiCxNy particles diffusion into STS 430 was observed. After annealing, sintering isolations between particles were formed. It causes decreasing of mechanical strength. In addition when annealing temperature was increased hardness increased. Heterogeneous distribution of alloying elements particles was observed. After annealing composites, highest value of hardness was 738.1 MHV.

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke reduction of diesel engine is proposed. This new system is using vacuum equipment and STS filter for capture smoke. To confirm new system experiments were performed at engine dynamometer. As a result of this experiment, the smoke reduction ratio of this system was identified high reduction ratio than PDPF. But the power of this system application was measured 10% decrease than base engine performance. There were improvement effects of using STS filter than ceramic filter.

최근들어 수입량이 급증되고 있는 차가버섯의 분류체계를 확립하고, 이들 종 및 계통간의 유연관계 확립과 품종 구분을 위해 계통학적 정보를 지닌 ITS 영역의 염기서열, PCRRFLP 및 STS 프라이머를 사용하여 종 특이적인 마커를 개발하였다. 시베리아 캄차카 반도에서 수집된 74008 균주의 염기서열을 이용하여 Inonotus spp.의 유연관계를 분석한 결과 2개의 그룹으로 나뉘어 졌고, I. obliquus DSM 856P균주와 약 98%의 가장 높은 유사성을 나타내어 차가버섯임이 확인되었다. 또한 ITS 증폭산물을 제한효소로 처리하여 밴드패턴을 비교하였을 때 종 및 계통에 따라 밴드가 다르게 나타났으며, STS primer를 이용하여 증폭산물을 비교하였을 때 종간에는 밴드패턴이 다르나 계통내에서는 동일한 밴드패턴을 보였다. 따라서 차가버섯의 품종 구분을 위해서는 STS 마커와 PCR-RFLP를 동시에 사용함으로서 품종 구분이 좀 더 명확하리라 사료된다.

Fe-Cr steels are the most promising candidate for interconnect in solid oxide fuel cells. In this study, an effective, dense and well adherent (LaSr)(CrCo) [LSCC] coating layer was produced onto 430 stainless steel (STS-430) by atmospheric plasma spraying and the oxidation behavior as well as electrical properties of the LSCC coated STS-430 were investigated. A significant oxidation of pristine STS-430 occurred at in air environment, leading to the formation of and scale layer up to after 1200h, and consequently increased an area specific resistance of . Although the plasma sprayed LSCC coating contained the characteristic pore network, the coated samples presented apparent advantages in reducing oxidation growth of STS-430, resulting a decrease in oxide scale thickness of at after 1200h. The area specific resistance of the LSCC coated STS-430 was much reduced to after exposure at for 1200h, compared to that of the pristine STS-403.

이 연구의 목적은 ARCS(Attention, Relevance, Confidence, Satisfaction) 전략을 적용한 STS(Science, Technology and Society) 수업이 초등학교 5학년 학생들의 학습 동기와 과학적 태도에 미치는 영향을 알아보는 것이다. 이를 위해 53명의 초등학교 5학년 학생들을 표집하여 실험반과 통제반으로 구분하였다. 그리고 4주 동안 실험반에는 ARCS 전략을 적용한 STS 수업을 처치하였고, 통제반에는 전통적인 수업을 실시하였다. 연구 결과는 ARCS 전략을 적용한 STS수업이 전통적인 수업보다 초등학교 5학년 학생들의 학습 동기와 과학적 태도 향상에 효과적이었음을 보여주었다.