• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1120-1125
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• 2004

Welding characteristics of STS304 stainless steel and Inconel 600 using a continuous wave Nd:YAG laser are experimentally investigated. Alloy 600 being used in steam generator tubing of pressurized water reactor(PWR) exposed to some corrosion environment, stress corrosion cracking can occur on this material. Presented here are the results from a series of experiments in which dissimilar metal welds were made using the gas tungsten arc welding process with pure argon shielding gas. But It is well known that solidification cracking susceptibility of austenitic alloys depends on the solidification temperature range and amount/distribution of solute rich liquid that exists at the terminal stages of solidification. An experimental study was conducted to determine effects of welding parameters and to optimize those parameters that have the most influence on eliminating or reducing the extent welding zone formation at dissimilar metal welds.

• Journal of Welding and Joining
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• v.24 no.3
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• pp.49-54
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• 2006

The Plasma Transferred Arc (PTA) overlaying method is lately introduced as one of the most useful surface modification method of the engine component. In this paper, the characteristics of the Co-base and Ni-base super alloy overlay layers by PTA method were investigated through the metallurgical, abrasive and cavitation erosion test. Experimental results showed that the abrasive wear resistance of the Co-base Stellite 6 overlayer was the most superior and followed in order of Nimonic 80A, Inconel 625 and Inconel 718. However, the cavitation erosion characteristic of the Stellite 6 overlayer was the most inferior and it was better in order of Inconel 625, Inconel 718 and Nimonic 80A.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.359-367
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• 2023

The localized corrosion resistance of the Ni-based Inconel 718 alloy after solution heat treatment was evaluated using electrochemical techniques in a solution of 25 wt% NaCl and 0.5 wt% acetic acid. Solution heat treatment at 1050 ℃ for 2.5 hours resulted in an increased average grain diameter. Both Ti carbides (10 ㎛ diameter) and Nb-Mo carbides (1 - 9 ㎛ diameter) were distributed throughout the material. Despite heat treatment, the shape and composition of these carbides remained consistent. An increase in solution temperature led to a decrease in pitting potential value. However, the pitting potential value of solution heat-treated Inconel 718 was consistently higher than that of as-received Inconel 718 at all tested temperatures. Localized corrosion initiation occurred at 0.4 V_SSE in a temperature environment of 80 ℃ for both as-received and solution heat-treated Inconel 718 alloys. X-ray photoelectron spectroscopic analysis indicated that the composition of the passive film formed on specimen surfaces remained largely unchanged after solution heat treatment, with O1s, Cr2p_3/2, Fe2p_3/2, and Ni2p_3/2 present. The difference in localized corrosion resistance between as-received and solution heat-treated Inconel 718 alloys was attributable to microstructural changes induced by the heat treatment process.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.352-355
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• 2004

Inconel 625 is useful in variety of industrial applications because of the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to over $1090^{\circ}C$, in combination with good law- and high temperature mechanical strength. Rencently, this material is also used widely in offshore processing piping in order to extend the maintenance tenn and improve the quality of anti-corrosion. In general, high quality weldments for this material are readily produced by commonly used processes. Not all processes are applicable to this material group, Ni-alloys. Metallurgiad characterictics or the unavailability of matching, position or suitable welding processes. Nowadays, the flux cored wire is developed and applied for the better productivity in several welding position including the vertical position. in this study, the weldability and weldment characteristics of inconel 625 are considered in FCAW weld associated with the several shielding gases($80\%Ar\;+\;20\%\;CO_2,\;50\%Ar\;+\;50\%\;CO_2,\;100\%\;CO_2$) in viewpoint of welding productivity.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.234-238
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• 2004

Inconel 625 is useful in variety of industrial applications because of the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to aver $1090^{\circ}C$, in combination with good law- and high temperature mechanical strength. Rencently, this material is also used widely in offshore processing piping in order to extend the maintenance term and improve the quality of anti-corrosion. In general, high quality weldments for this material are readily produced by commonly used processes. Not all processes are applicable to this material group, Ni-alloys. Metallurgical characterictics or the unavailability of matching, position or suitable welding processes. Nowadays, the flux cored wire is developed and applied for the better productivity in several welding position including the vertical position. in this study, the weldability and weldment characteristics (mechanical properties) of inconel 625 are considered in FCAW(Flux Core Arc Welding) associated with the several shielding gases($80\%Ar\;+\;20\%CO_2,\;50\%Ar+50CO_2,\;100CO_2$) in viewpoint of welding productivity.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.96-100
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• 2004

Inconel 625 is useful in a variety of industrial applications because of the resistance to attack in various corrosive media at temperatures from $200^{\circ}C$ to over $1090^{\circ}C$, in combination with good low and high temperature mechanical strength. Rencently this material has also been widely used in offshore processing piping in order to extend the maintenance term and improve the quality of anti-corrosion. In general, high quality weldings for this material are readily produced by commonly used processes. How, not all processes are applicable to this material group of Ni-alloys. Metallurgical or the unavailability of matching, position or suitable welding processes produce a lower quality. Nowadays, the flux cored wire is developed and applied for increased productivity in several welding positions, including the vertical position. In this study, the weldability and weldment characteristics(mechanical properties) of inconel 625 are considered in FCAW(Flux Core Arc Welding) associated with the several shielding gases$(80\%Ar+20\%CO2,\;50\%Ar+50CO2,\;100CO2)$ in view of welding productivity.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.9-13
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• 2005

Inconel 625 is useful in variety of industrial applications because of the resistance to attack on various corrosive media at temperature from $200^{\circ}C$ to over $1090^{\circ}C$, in combination with good low and high temperature mechanical strength. Recently, this material is also used widely in offshore processing piping in order to extend the maintenance term and improvement the quality of anti-corrosion. In general, high quality weldments for this material are readily produced by commonly used processes. Not all processes are applicable to this material group, Ni-alloys. Metallurgical characteristics or the unavailability of matching, position or suitable welding process. Nowadays, the flux cored wire is developed and applied for the better productivity in several welding position including the vertical position. In this study, the weldability and weldment characteristics(mechanical properties) of inconel 625 are considered in FCAW(Flux Cored Arc Welding) associated with the severial shielding gases($80%Ar+20%CO_2,\;50%Ar+50%CO_2,\;100%CO_2$) in viewpoint of welding productivity.

• Korean Journal of Materials Research
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• v.17 no.5
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• pp.268-272
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• 2007

Inconel 617 is a candidate tube material for high temperature gas-cooled reactors(HTGR). The microstructure and mechanical properties of Inconel 617 were studied after exposure at high temperature($1050^{\circ}C$). The dominant oxide layer was Cr-oxide. The internal oxide and Cr-depleted region were observed below the Cr-oxide layer. The depth of Cr-depleted zone and internal oxide increased with exposure time. The major phases of carbides are $M_{23}C_6\;and\;M_6C$. The composition of $M_{23}C_6\;and\;M_6C$ were determined to be Cr-rich and Mo-rich, respectively. $M_6C$ carbide is more stable than $M_{23}C_6$ at high temperature. From the results of high temperature compression test, there were no significant changes in hardness and yield strength upon increasing exposure time.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.8
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• pp.1-8
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• 2022

Inconel 718 is nickel-based and is increasingly being used as a key component in the nuclear, aerospace, and chemical industries which require high fatigue strength and oxidation, because of its excellent corrosion resistance, heat resistance, and wear resistance. It is a heat-resistant alloy which has excellent mechanical properties; however, material deformation, cracking, and shaking occur because of the high cutting temperature accumulated on the cutting surface during cutting processing, and heat accumulated at the insert boundary. Owing to these characteristics, various studies have been conducted, such as developing a tool exclusively for non-deletion, analyzing tool wear, and developing a tool cooling system. However, the optimization of the cutting process is still insufficient. In this study, the optimal process conditions were derived experimentally by cutting conditions according to the insert type during the cutting of Inconel 718.

• Journal of Ocean Engineering and Technology
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• v.28 no.4
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• pp.356-362
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• 2014

Wear and corrosion of the engine parts surrounded with combustion chamber is more serious compared to the other parts of the engine because temperature of the exhaust gas in a combustion chamber is getting higher and higher with increasing of using the heavy oil of low quality. Therefore, an optimum repair weldment as well as an available choice of the base metal for these parts are very important to prolong their lifetime in a economical point of view. It reported that there was an experimental result for repair weldment on the forged steel which would be generally used with piston crown material, however, it is considered that there is no study for the repair weldment on the cast steel of piston crown material. In this study, four types of electrodes such as 1.25Cr-0.5Mo, 0.5Mo Inconel 625 and 718 were welded with SMAW and GTAW methods on the cast steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected zone and base metal were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. In the cases of Inconel 625, 718, the weld metals and base metals exhibited the best and worst corrosion resistance respectively, however, 1.25Cr-0.5Mo and 0.5Mo indicated that corrosion resistance of the base metal was better than the weld metal. And the weld metal welded with electrodes of Inconel 625 revealed the best corrosion resistance among the electrodes, and Inconel 718 followed the Inconel 625. Hardness relatively also indicated higher value in the weld metal compared to heat affected zone and base metal. In particular, Inconel 718 indicated the highest value of hardness compared to other electrodes in the heat affected zone.