• 대한기계학회논문집
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• 제13권6호
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• pp.1193-1202
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• 1989

본 논문에서는 발전소의 소재로 많이 쓰이고 있는 304 스테인리스강(앞으로는 304SS로 표기함)과 316스테인리스강(앞으로는 316SS로 표기함)의 크립 균열 발생 거동 을 각각 600.deg. C와 625.deg. C에서 조사한다. 이 온도는 발전소의 반응기(reactor)에 사용 되는 304SS와 316SS이 받는 온도이다. 즉 304SS와 316SS의 크립 균열 발생을 지배 하는 파괴 매개변수가 무엇인지가 크립 파괴 실험을 통하여 조사된다. 실험 결과는 이미 제안되어 있는 크립 균열 발생 모델에서 예측된 결과와 비교된다. 특히 304SS 와 316SS은 고온에서의 연성도가 변형률 속도에 따라 변하는 것으로 알려져 있다. 본 연구에서는 '변형률 속도에 따른 재료의 연성도의 변화에 근거한 균열 발생 모델' 을 제안하고, 그 모델에서 예측된 크립 발생 거동을 실험 결과와 비교한다.

• 대한조선학회논문집
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• 제34권3호
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• pp.61-69
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• 1997

CT 시험편을 사용하여 평면응력 파괴인성치를 산정하는 간단하고 새로운 방법론을 제안하였다. 평면응력 조건하의 균열선단에서 발생하는 좌굴을 방지하는 판을 부착하여 SS304와 SS316의 평면응력 파괴인성치를 정확하게 결정하였다. SS304와 SS316의 피로균열 전파거동이 피로하중 주파수에 미치는 영향을 영상해석법(LAT)을 사용하여 규명하였다.

• 한국안전학회지
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• 제7권1호
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• pp.65-72
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• 1992

Objective of this research is to evaluate fracture behaviors of fresh-butt welded metal by the acoustic emission technique. The specimens used are medium carbon steel(SM45C), mild steel (SS41) and stainless steel(SUS304), which have different weldability. The similar welding and dissimilar welding processes are considered, in the former SM45C, SS41 and SUS304 are used, in the later the following metals are used SM45C and SS41, SM45C and SUS304 and SS41 and SUS304. The characteristics of fracture in weld metal are eshmated by the tension test with nominal speciemns, the fracture toughness test with compact tension specimens and fractography analysis. The results of tension test show for base metals and similar welding materials that the yield strength and ultimate strength of similar welding materials are increased, the elongation of those are decreased. The weldability of SUS304 is better than that of SM45C and SS41 In similar welding materials. Mechanical properties of dissimilar welding mateiiths we lower than those of similar welding materials. In dissimilar welding materials, the weldability of SM45C and SUS304 is better than that of SM45C and SS41, and also weidability of SS41 and SUS304 is better than SS41 and SM45C. Comparing mechanical properties with AE counts, it is found that AE conuts appeared on a small before the limit load of elasticity(P$_{e}$), and apper greatly near yield strength region in tension test. These results could contribute to the safety analyses and the evaluation of strength for welding structure.e.

• 대한화학회지
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• 제58권1호
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• pp.25-32
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• 2014

Corrosion inhibition of 304 stainless steel (SS) in 1 M HCl by aqueous extract of coriander seeds was studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Values of inhibition efficiency obtained are dependent upon the concentration of extract and temperature. Generally, inhibition was found to increase with inhibitor concentration, but decrease with temperature. Physical adsorption mechanism has been proposed for the inhibition with Langmuir adsorption isotherm obeyed. Values of activation energy of the inhibited corrosion reaction of 304 SS are greater than the value obtained for the blank. Thermodynamic consideration reveals that adsorption of aqueous extract of coriander seeds 304 SS surface is spontaneous.

• 한국결정성장학회지
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• 제23권4호
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• pp.207-212
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• 2013

산업시설에는 용접된 구조물에 반복 하중이 발생하여 피로파괴가 발생하고 있는데 이 피로파괴를 줄이기 위해 일반구조용압연강재(SS400)와 스테인리스강(STS304)을 $CO_2$ 용접하여 기계적 특성 분석을 하였다. X-ray 촬영을 하여 결함검사를 하고 용접부에 결함이 없는 시험편으로 경도, 인장, 피로 시험을 하였다. 경도는 SS400과 STS304가 용접된 시험편이 SS304만 용접된 시험편보다 높게 나타났다. 그리고 인장강도와 항복강도는 반대로 SS304만 용접된 시험편이 높았으며 피로한도 또한 마찬가지였다. 따라서 $CO_2$ 용접을 할 경우 융점이 낮고 용접성이 좋은 SS400만으로 용접할 때 더 좋은 성능을 보여준다.

• Journal of Welding and Joining
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• 제27권5호
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• pp.34-41
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• 2009

Thermal and mechanical characteristics in dissimilar SS400-STS304 steel weldment have been investigated by 3D thermal elastic-plastic analysis. Moreover, the influence of welding residual stresses on the mechanical behaviour of this welded joint, by applying superimposed external load (tension load) was determined. The residual stresses obtained by numerical simulation were compared with the experimentally measured results. The FE results were in good agreement with the measured values. The mechanical test (hardness, tensile test) and metallurgical analysis was carried out to ensure the weld integrity. Hence, possibility of applying SS400-STS304 dissimilar steels in industries has been established.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.219-220
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• 2017

• 한국안전학회지
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• 제9권1호
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• pp.9-18
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• 1994

In this study, we conducted experimental tests to evaluate fracture behaviors of fresh-butt welded metal by Acoustic Emission technique. We selected similar welding and dissimilar welding process, the one welded for SM45C, SS41 and SUS304 of each material, the other for SM45C and SS41, SM45C and SUS304 and SS41 and SUS304. The fracturing processes of weld metal were estimatied through the fracture toughness test with compact tension specimens and fractography analysis. In ASTM test method E-399, type I curves for materials of this study were obtained by load-cod diagram of fracture toughness test. and 5% offset load( $P_{5}$) was estimated as the estimated crack initial load( $P_{Q}$), The estimated crack initial load( $P_{Q}$) of similar welding materials generally lower than base matal, and then SM45C appeared greatly in decreasing rate of PB, SS41 and SUS304 appeared in order. $P_{Q}$ of dissimilar welding materials were lower than the similar welding materials. $P_{Q}$ of welding of SM45C and SS41 appeared in small, SUS304 and SS41 appeared greatly in dissimilar welding materials. In fracture toughness test, AE counts increased before the inflection point of the slope, decreased after that. It was found that increasing of AE counts were due to the microcrack formation at the crack tip near the $P_{5}$ point through AE data. For welding materials in this study, both low and high AE amplitude appeared simulataneously. It was confirmed that the low AE amplotude was due to formation of micro void, micro crack or micro dimple, the high AE amplitude was caused by microvoid coalescence and quasi-cleavage fracture through analyses of fractograpy.apy.apy.apy.

• 한국안전학회지
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• 제8권1호
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• pp.59-63
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• 1993

It is very difficult to find not only optimized welding condition but also fatigue characteristics of the dissimilar weld. In this study. Low carbon steel (SS41) and austenitic stainless steel (STS304) were welded by GTAW welding with STS309 stainless wire rod and Single Edge Notch specimens were used for the examination of fatigue behavior on welding heat cycle. The fatigue crack growth rate in HAZ of SS41 was the highest. The second was in STS304 bond line and the lowest was in HAS of STS304.

• 전기화학회지
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• 제17권1호
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• pp.26-29
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• 2014

The corrosion behavior of stainless steel 304 (SS 304), titanium, nickel and aluminium is studied by immersion and anodic polarization tests in non-aqueous electrolytes. Tetraethyl ammonium tetrafluoroborate is used as a supporting electrolyte in the three kinds of solvents. The immersion test shows that chemical corrosion rate in propylene carbonate-based electrolyte is lower than those in acetonitrile- or ${\gamma}$-butyrolactone-based electrolytes. Surface analyses do not reveal any corrosion product formed after the immersion test. In the anodic polarization tests, a higher concentration of supporting electrolyte gives a higher current density. In addition, a higher temperature increases the current density in the active region and reduces the potential range in the passive region. SS 304 shows the highest corrosion potential while Al shows the lowest corrosion potential and the highest current density in all studied conditions. Based on the conducted corrosion tests, the corrosion resistance of metal substrates in the organic solvents can be sorted in descending order as follows: SS 304 - Ti - Ni - Al.