• 대한기계학회논문집A
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• 제30권4호
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• pp.428-434
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• 2006

Pulse laser welding of AISI 304 stainless steel plate was simulated to find optimal welding conditions by using commercial finite element code MARC. Due to geometric symmetry, a half model of AISI 304 stainless steel plate was considered and user subroutines were applied to boundary condition for the heat transfer. Material properties such as conductivity, specific heat, mass density and latent heat were given as a function of temperature. A moving heat source was designed on the basis of experimental data. As a result, Nd:YAG laser welding for AISI 304 stainless steel was successfully simulated and it should be useful to determine optimal welding condition.

• Journal of Welding and Joining
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• 제32권3호
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• pp.89-94
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• 2014

AISI 304 austenitic stainless steel is widely used for LNG pipes for LNG transmission thanks to its good metallurgical and mechanical properties. In the present research, impact toughness of a gas tungsten arc welded AISI 304 stainless steel pipe was evaluated between room and liquid nitrogen ($-196^{\circ}C$) test temperatures. In addition, a comparative study was made of the fracture behavior of FCC crystal structured stainless steel weldments and BCC crystal structured mild steels(A-grade and SS400). The results showed a slight decrease in the impact energy of the AISI 304 base metal, heat affected zone(HAZ), and welded zone with decreasing test temperature. In addition, the welded metal has the highest absorbed impact energy, followed by HAZ and the base metal.

• 소성∙가공
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• 제3권1호
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• pp.38-50
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• 1994

Fundamental deformation mechanism and plastic behavior of AISI304 austenitic stainless steel were investigated to evaluate press formability. Local and uniform deformation capacity of AISI304 steel were compared to those of ferritic AISI430 steel and Al killed low carbon steel. Nine kinds of austenitic stainless steels having different austenite stabilities were made in laboratory scale to examine the transformation behavior in various deformation mode and variation of mechanical properties. Deformation path and strain distributions along edge corner of commercial sink die were illustrated and effect of austenite stability on press forming of sink die was clarified with experiments using square cup drawing tools.

• 한국레이저가공학회지
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• 제8권1호
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• pp.19-25
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• 2005

Pulse laser welding of AISI 304 stainless steel plate was simulated to optimize welding conditions by using commercial finite element code MARC. Due to geometric symmetry, a half model of AISI 304 stainless steel plate was considered. for the heat transfer analysis, user subroutines were applied to boundary condition. The material properties such as conductivity, specific heat, and mass density were given as a function of temperature and the latent heat associated with a given temperature range was considered. A moving heat source was designed on the basis of experimental data. As a result, Nd:YAG laser welding for AISI 304 stainless steel was successfully simulated and it should be useful to determine optimal welding condition.

• Journal of Advanced Marine Engineering and Technology
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• 제14권1호
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• pp.83-89
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• 1990

Electrochemical methods have been proposed as non-destructive, rapid and quantitative means for determining the degree of sensitization associated with Chromium depleted zones surrounding precipitates of Cr carbide and formation of secondary phase in stainless steel. In this study, the specimen of AISI 304 stainless steel and its welded sections, which welded by TIG, MIG, $CO_2$ and ARC, were tested corrosion resistance by electrochemical methods in 0.5N HCl and 1N $H_2SO_4$ with or without 0.01N KSCN. The results were confirmed that electrochemical methods could be used as a test method of corrosion resistance evaluation for the welded AISI 304 stainless steel.

• 연구논문집
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• 통권23호
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• pp.29-43
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• 1993

Photoetching of AISI 304 stainless steel in ferric chloride solution has been studied. This paper investigated on the single side etching characteristics of 304 stainless steel, especially influence of etching temperature, spray pressure of ferric chloride etchant, and etching time with $50\mum$ and $75\mum$ line width photomask.

• 한국표면공학회지
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• 제30권3호
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• pp.159-166
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• 1997

The metalliding technique was adopted to obtain the diffusion coating of zirconium on AISI 304 Stainless Steel in molten mixed chlorides (32.9wt.%LICl-34.8wt.%NaCl-32.3wt.%). Experiments were carried out in argon gas atmosphere. The electrolytic cell was consisted of a AISI 304 Stainless steel cathode and a consumable zirconium anode. The quality of deposit was analysed by SEM, Optical Microscope, EDS, and also examined by the Micro-Vickers hardness and corrosion tests. Interface of deposit layer was identified as zirconium-iron alloy layer caused by diffusion process at elevated temperatures. The optimum condition for the metalliding was found to be the bath temperature of $550^{\circ}C$, the concentration of $K_2ZrF_6$ ,5wt.%, cathodic current derrent density of 7.0 to 10.0mA/$\textrm{cm}^2$ , and anodic current density of 2.0mA/$\textrm{cm}^2$.

• Journal of Advanced Marine Engineering and Technology
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• 제15권4호
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• pp.22-28
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• 1991

The crevice corrosion behavior on austenitic AISI 304 and 316L stainless steel welded by TIG, MIG, $CO_2$ and SMA was studied. The results are as follows : In 10% $FeCl_3$ solution and natural sea water sampled near Mokpo port, the base metal of 304 stainless steel showed small amount corrosion, whereas 316L stainless steel did not showed any corrosion in the test periods. The weight loss caused by crevice corrosion increased with increasing weld heat input and residual .delta. ferrite formed in welded part. The corrosion resistance of the welded part was in the order of TIG, MIG, $CO_2$ and SMA. From this tendency, it is proved that the smaller heat input gives the better corrosion resistance.

• 한국표면공학회지
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• 제28권1호
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• pp.23-33
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• 1995

AISI 304 stainless steel has high resistance to corrosion due to the presence of a self-healing chromium oxide film on the surface, which also accounts for the difficulty in plating. Surface cleaning of this alloy is of fundamental importance in gold plating since its effectiveness puts an upper limit on the quality of the final coating. The cleaning of AISI 304 stainless steel was investigated with elimination of artificial passive oxide film and degreasing of remaining buffing wax as stearic acid. The familiar cleaning methods i.e. ultrasonic cleaning, electro-cleaning and activation treatment were fabricated in this study. Activation treatment showed best cleaning efficiency for elimination of passive oxide film among these methods, which was also confirmed by AES (Auger electron spectrometer) analysis. However, the best condition of cleaning was obtained by combining these methods. Electrocleaning time, for degreasing the stearic acid layer, was decreased with increasing amount of added KCN.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.137-146
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• 2008

Nd:YAG pulse laser welding of stainless steel plate was simulated to find welding condition by using commercial finite element code MARC. Due to geometric symmetry, a half model of AISI 304 stainless steel plate was considered and user subroutines were applied to boundary condition for the heat transfer. Material properties such as conductivity, specific heat, mass density and latent heat were given as a function of temperature. As results, Three dimensional heat source model for pulse laser beam conditions of butt welding has been designed by the comparison between the finite element analysis results and experimental data on AISI 304 stainless steel plate. Nd:YAG laser welding for AISI 304 stainless steel was successfully simulated and it should be useful to determine optimal welding condition.