• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1990년도 특별강연 및 춘계학술발표 개요집
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• pp.131-134
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• 1990

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1998년도 특별강연 및 춘계학술발표 개요집
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• pp.126-130
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• 1998

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1999년도 춘계학술발표회 초록집
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• pp.101-101
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• 1999

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.321.1-321
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• 2002

• 한국분말재료학회지
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• 제9권4호
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• pp.203-210
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• 2002

A new PIM in-process joining technique has been developed for more complicated and functional PIM components by application of the exuded wax from the green compacts during solvent debinding step. At first, various stainless steels and iron compacts with rectangular shape were combined, and the joining behaviors and properties were investigated by shear and tensile test, and microscopic observation. Subsequently, perfect joined three pieces of thin and hollow compacts were obtained for the combination of same and different stainless steels, and it was difficult to join the iron and stainless steel compacts in hydrogen atmosphere because of the different starting temperature of shrinkage. However, pretty good joined iron and stainless steel compacts were obtained by consideration of particle size and vacuum atmosphere. Finally, for the combination of ferro-silicon and austenitic stainless steel compacts, high functionality (magnetic (1.60Tes1a) & non-magnetic) and perfect joint were obtained.

• 국제강구조저널
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• 제18권4호
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• pp.1139-1152
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• 2018

Many studies on the application of stainless steels as structural materials in buildings and infra-structures have been performed thanks to superior characteristics of corrosion resistance, fire resistance and aesthetic appeal. Experimental investigation to estimate the ultimate strength and fracture mode of the fillet-welded connections of cold-formed austenitic stainless steel (STS304L) with better intergranular corrosion resistance than that of austenitic stainless steel, STS304 commonly used has carried out by authors. Specimens were fabricated to fail by base metal fracture not weld metal fracture with main variables of weld lengths according to loading direction. All specimens showed a block shear fracture mode. In this paper, finite element analysis model was developed to predict the ultimate behaviors of welded connection and its validity was verified through the comparison with test results. Since the block shear behavior of welded connection due to stress triaxiality and shear-lag effects is different from that of bolted connection, stress and strain distributions in the critical path of tensile and shear fracture section were investigated. Test and analysis strengths were compared with those by current design specifications such as AISC, EC3 and existing researcher's proposed equations. In addition, through parametric analysis with extended variables, the conditions of end distance and longitudinal weld length for block shear fracture and tensile fracture were suggested.

• Corrosion Science and Technology
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• 제22권5호
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• pp.330-340
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• 2023

The objective of this study was to analyze effects of aging time on property degradation of super austenitic stainless steel of PRE 52.8 and super duplex stainless steel of PRE 48.7. To analyze corrosion properties based on aging time, a critical pitting temperature test was performed in a solution of 6% FeCl₃ + 1% HCl and an anodic polarization test was performed in deaerated 0.5N HCl + 1N NaCl solution at a temperature of 50 ℃. Surface hardness was measured to analyze mechanical properties. It was found that corrosion properties and mechanical properties deteriorated rapidly as aging time increased. Critical pitting temperature had the most effect on critical aging time at which property changes occurred rapidly, followed by pitting potential and hardness. This trend was found to be closely related to the fraction of sigma phase. Rate of sigma phase formation was found to be significantly faster in duplex stainless steel than in austenitic stainless steel.

• 동력기계공학회지
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• 제10권3호
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• pp.51-57
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• 2006

The effect of grain size on corrosion resistance and high temperature oxidation behavior was studied in 22Cr-15Ni-5W super austenitic stainless steels for desulfurization equipment as a heat power station. In the high temperature oxidation test, oxidation rate was increased as the temperature increased from $600^{\circ}C\;to\;800^{\circ}C$. In vapor, oxidation rate was faster than that in air. Because the vapor was inhibited nucleation of $Cr_2O_3$ film. And the high temperature oxidation resistance at $600^{\circ}C{\sim}800^{\circ}C$ was excellent from all specimens and specimen of the smallest grain size was the most excellent. Because increasing of diffusion course through the grain-boundary was promoted nucleation and growth of $Cr_2O_3$ film. In the test temperature at $600^{\circ}C{\sim}800^{\circ}C$, Cr rich round particle oxide was formed in air, whereas Fe rich needle type oxide was developed in vapor.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.583-584
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• 2006

This work presents mechanical properties and corrosion resistance of duplex stainless steels obtained through powder metallurgy starting from austenitic, martensitic powders by controlled addition of alloying elements in the right quantity to obtain the chemical composition of the structure similar to biphasic one. In the mixes preparations the Schaffler's diagram was taken into consideration. Prepared mixes of powders have been sintered in a vacuum furnace with argon backfilling. After sintering rapid cooling was applied using nitrogen. Corrosion properties have been studied through electrochemical methods in 1M NaCl.

• 열처리공학회지
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• 제11권4호
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• pp.258-267
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• 1998

For the purpose of investigating the growth characteristics and composition of nitrides, gas nitridings of the austenitic stainless steel, STR 36 heat resisting steel and martensitic stainless steel are investigated at the temperature ranges between $500^{\circ}C$ and $675^{\circ}C$ for 5hours under the $75%NH_3+5%CO_2+20%$Air gas atmosphere. When gas nitriding the austentic stainless steel and STR 36 heat resisting alloy, the abnormal growth behavior of compound layer deviating from the conventional diffusion law with increasing temperature appears, while the compound layer of martensitic stainless steel shows the normal diffusional growth behavior. From the examination of microstructure, X-ray diffraction and hardness test, it is concluded that the abnormal growth behavior of compound layer with increasing temperature induces from the formation and dissolution of CrN and ${\gamma}^{\prime}-Fe_4N$ at the nitriding temperature ranges of $600{\sim}650^{\circ}C$.