• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.741-746
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• 2022

In this paper, structural analysis was conducted on the base frame for materials of the conveyor system that automatically produces nurungji. The materials of the base frame were selected as SS400, STS304, Al6063-5. Structural analysis performed Von-Mises stress and maximum displacement for 38 hot plates in real situation, and performed weight of distribution force for yield strength, and calculated safety factor. SS400 and STS304 have little displacement, but Al6063-5 is deformed to 0.149mm, which is 2.6 times greater than other materials. However, since the safety factor was calculated as 8.5, it can be applied to the applicable food processing equipment. The weight of the distributed force for the yield strength of the materials was 17.7kN for SS400, 14.7kN for STS304, and 10.2kN for Al6063-T5. When manufacturing other processed foods with a base frame of the same size, a material suitable for the corresponding weight should be selected.

• Journal of the Korean institute of surface engineering
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• v.43 no.1
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• pp.12-16
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• 2010

The morphology of the passivated surface of stainless steel (SS) was quantitatively characterized based on fractal geometry. In particular, the surface irregularities of the passivated 304 and 439 SSs were comparatively analyzed in terms of their self-similar fractal dimensions. The passivated surface of 439 SS in an acid-based electrolyte proved to have a higher fractal dimension, as compared to that of 304 SS, esp. at a scale of several tens of nanometers, strongly indicating the higher irregularity of the passivated surface. It is anticipated that the fractal approach suggested herein might be effectively utilized to analyze the irregularity of the steel surface and/or the compactness of the oxide film.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.93-98
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• 2011

Saline corrosion is one of the major degradation mechanisms for stainless steel type 304 (SS304) dry storage cask during the spent fuel interim storage period. Slow strain rate test (SSRT) and neutral salt spray test (NSS) were performed at $85^{\circ}C$ and $200^{\circ}C$ with 0.5 wt% sodium chloride mist sprayed on the cold-rolled SS304 specimens of different degrees of reduction in this study. The weight changes of the NSS specimens tested at $85^{\circ}C$ for 2000 hours differed greatly from those at $200^{\circ}C$. The weight loss of NSS specimens was not significant at $85^{\circ}C$ but the weight gain decreased gradually with increasing the cold-rolled reduction. The yield strength (YS) and ultimate tensile stress (UTS) values obtained from the SSRT tests for lightly cold-rolled specimens in the salt spray environment at $85^{\circ}C$ and $200^{\circ}C$ are slightly lower than in air. But for those with 20% reductions, the specimen strengths were no longer changed by the saline corrosion. The preliminary results demonstrated that the quality and performance of cold-rolled SS304 is acceptable for fabrication of dry storage casks. However, more work on the corrosion behavior of cold-rolled stainless steel in the saline atmosphere is needed to better understand its long-term performance.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.465-474
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• 2001

Type 304SS coatings were performed at 200$\square$ onto AISI 1045 carbon steel substrate using unbalanced magnetron sputtering (UBMS) with an austenitic AISI 304 stainless steel (SS) target of 100mm diameter. The total deposition pressure in the active Ar gas was 2$\times$10$^{-3}$ Torr. Coatings were done at various target power densities and bias voltages. Chemical compositions of metallic elements of the coatings were measured by energy dispersive X-rays spectroscopy (EDS). The structure and the morphology of Type 304SS coatings were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Corrosion properties of the coated specimens were examined using electrochemical polarization measurements and electrochemical impedance spectroscopy in a deaerated 3.5% NaCl solution. The porosity rate was obtained from a comparison of the dc polarization resistance of the uncoated and coated substrates. Scratch adhesion testing was used to compare the critical loads for different coatings. XRD results showed that the sputtered films exhibit a ferritic b.c.c. $\alpha$-phase. Potentiodynamic polarization curves indicated that all samples had much higher corrosion potential and better corrosion resistance than the bare steel substrate. The corrosion performance increased with increasing power density and the adhesion was enhanced at the bias voltage of -50V. An improvement in the corrosion resistance can be obtained with a better coating adhesion. Finally, an optimized deposition condition for corrosion protection was found as $40W/cm^2$ and -50V.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.199-209
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• 2014

Crevice corrosion tests were conducted to examine the corrosion properties of HYBRID (HYdrazine Base Reductive metal Ion Decontamination) which was developed to decontaminate the PWR primary coolant system. To compare the corrosion properties of HYBRID with commonly existing decontamination agents, oxalic acid (OA) and citric oxalic acid (CITROX) were also examined. Type 304 Stainless Steel (304 SS) and Alloy 600 which are major components of the primary coolant system in Pressurized Water Reactor (PWR) were evaluated. Crevice corrosion tests were conducted under very aggressive conditions to confirm quickly the corrosion properties of primary coolant system structure components which have high corrosion resistance. Pitting and IGA were occurred in crevice surface under OA and CITROX conditions. But localized corrosion was not observed under HYBRID condition. Very low corrosion rate of less than $1.3{\times}10^{-3}{\mu}m/h$ was observed under HYBRID condition for both materials. On the other hand, under OA condition, Alloy 600 indicated comparatively uniform corrosion rate of $4.0{\times}10^{-2}{\mu}m/h$ but 304 SS indicated rapid accelerated corrosion in lower case than pH 2.0. In case of HYBRID condition, general corrosion and crevice corrosion were scarcely occurred. Therefore, material integrity of HYBRID in decontamination of primary coolant system in pressurized water reactor (PWR) reactor was conformed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.124-129
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• 1997

The experimental investigation is mainly focused to detect tool wear by cutting signal measurements in multi-insert face milling SS 41 and STS 304. This research have investigated the effects on the insert number, which has relationship with mean-cutting force. AE(acoustic emission) signal, tool life and surface roughness in machining SS41 and STS 304. The cutting force and AE signal are monitored to analyse the cutting process, The surface roughness of the specimens machined by TiN coated tool with the various insert numbers measured at various cutting speeds, feed rates and depths of cut, The width of flank wear is also observed.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.235-240
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• 1996

본 연구에서는 고온의 천이 열하중을 받는 304 SS 재질의 액체금속로 원통용기에 대하여 진행성 변형기구인 열적 라체팅(thermal ratcheting) 변형거동을 해석하였다. 재료의 반복 소성을 나타내는 구성식으로서 Chaboche모델을 이용하였으며 이 모델의 적용을 위하여 ABAQUS의 사용자 프로그램을 개발하였다. 열천이 과정이 반복되는 동안에 축방향의 온도분포 이동에 따른 탄소성 해석을 수행한 결과 소성변형이 각 싸이클마다 누적되어 점진적 변형이 일어났으며 이 해석결과를 시험치와 비교함으로써 해석의 타당성을 검토하였다. 반복 소성거동에 대한 Chaboche 모델을 이용하면 천이 열하중을 받는 304 SS. 재질의 고온구조물에 대하여 라체팅 거동을 정량적으로 평가 할 수 있는 것으로 나타났다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.1
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• pp.100-106
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• 2014

It is well known that fatigue failures occur on welded structures in industrial application due to repetitive load force. In order to decrease the incidence of fatigue failure, we analyzed the mechanical properties based on structural aspects in rolled steel(SS 400) welded onto stainless steel (STS 304) by the MIG welding method as well as the structure of rolled steel welded onto itself. We compared the hardness, tensile and fatigue properties with two types of samples which had no defects on the welding parts as observed by X-ray topographic analysis. It was found that the tensile and fatigue strength levels of SS 400 welded onto STS 304 by the MIG welding method were higher than those of STS 304 welded onto itself.

• Proceedings of the KWS Conference
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• 1994.10a
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• pp.77-81
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• 1994

• Journal of Acupuncture Research
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• v.24 no.6
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• pp.195-206
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• 2007

Objectives : The aim of this study is to investigate the safety of Acupuncture needles made from duplex stainless steel. Methods : In order to check the safety concern of the DSS Acupuncture needle, we employed biochemical measures, DSS and SS304 Acupuncture needles were tested for pH level, heavy metals and UV absorbance spectrum along with cytotoxicity and hemolysis. As a guideline, we have referred to the 'standards for acupuncture needles', 'standards for disposable needles' and 'standards and experimental procedures for stents' for the Korean Food & Drug Administration(KFDA). Results & Conclusions : The DSS Acupuncture needle extract satisfied these requirements. There was no significant difference between the DSS and SS304 Acupuncture needle extract. In conclusion, the DSS Acupuncture needle displayed biochemical safety.