• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.121-126
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• 2009

Stainless steel 316L (STS 316L) is widely used as a material of biopsy needle. However it has a side effect that tissue can be damaged by electrochemical operation between tissue and STS 316L. Many studies have been made on the ceramic coating of biopsy needle to reduce the side effect. In this study, STS 316L was coated with three bioceramics, $Al_2O_3$, $SiO_2$ and $ZrO_2$ using a RF magnetron sputtering method. The effects of ceramic coating on the electrical conductivity and coating strength of ceramic-coated STS 316L were investigated. The results showed that the electrical conductivity of ceramic-coated STS 316L was much lower than that of uncoated STS 316L. The coating strength of $ZrO_2$-coated STS 316L was 30% and 70% higher, respectively than those of $Al_2O_3$-coated STS 316L and $SiO_2_3$-coated STS 316L.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.68-74
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• 2011

This papers investigated the mechanical characteristics and the weldability of identical as well as dissimilar welding by GTAW for STS 304 and STS 316L. It is applied to double wall gas pipe of duel fuel engine for LNG carrier. Consequently, the weldability of dissimilar and identical welded zone of STS 304 decreased compared to base metal significantly. The result of microstructure observation for welded zone, a degree of acicular ferrite in welding zone for STS 304 presented more than STS 316L. The hardness of welding zone for STS 304 presented higher value than that for STS 316L by this effect.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.4
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• pp.171-178
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• 2021

In the present study, we comparatively investigated the microstructures of two hot-rolled stainless steel clad plates; STS 304L - low carbon steel A516-70N and STS 316L - A516-70N. The STS 304L/A516-70N clad plate (Clad_304L_Ni) had a Ni-interlayer between stainless steel and carbon steel and a 90 ㎛ thick deformation band of unrecrystallized austenite grains on the stainless steel. The STS 316L/A516-70N clad plate (Clad_316L) had no interlayer and almost fully recrystallized austenite grains. Clad_304L_Ni exhibited the thinner a decarburized layer in carbon steel and a total carburized layer in stainless steel than Clad_316L. However, a severely carburized layer in stainless steel was thicker for Clad_304L_Ni than Clad_316L. Hardness profiles near the interface of clad plates matched well with microstructures at locations where the hardness values were measured.

• Corrosion Science and Technology
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• v.20 no.5
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• pp.281-288
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• 2021

Due to advancement of the industry, operation of a device in a harsh environment is increasing. Especially, the marine environment contains Cl^- ions which causes localized corrosion such as pitting and crevice corrosion of stainless steel and various metals. In this study, electrochemical corrosion behaviors of austenitic stainless steel (STS 316L) and nickel alloy (Inconel 600) with different seawater concentrations (fresh water, seawater, mixed water) were investigated. The STS 316L and Inconel 600 were etched in 10% oxalic acid and composed of an austenitic phase. Results of Tafel analysis in seawater showed that STS 316L and Inconel 600 presented the highest corrosion current densities of 7.75 × 10^-4 mA/cm² and 1.11 × 10^-4 mA/cm² and the most negative pitting potentials of 0.94 V and 1.06 V, respectively. The maximum damage depths and surface damage ratio by pitting corrosion increased with chloride concentration. The STS 316L had higher PREN than Inconel 600. However, the surface damage and weight loss of Inconel 600 were superior to STS 316L. It was difficult to compare the pitting resistance of STS 316L based on Fe and Inconel 600 based on Ni with PREN simply.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.156-164
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• 2003

STS316L had been used as the structural material for energy environmental facilities, because austenite stainless steels like 316L have superior mechanical properties of which toughness, ductility, corrosion resistant and etc. However, those welded structures are receiving severe damage due to increasing of the aged degradation. Most studies until now have been carried out against fatigue behaviors of weldments, and were not well studied on nondestructive evaluation methods. In this study, the fatigue crack propagation behavior of STS316L weldment usually used for vessels of the nuclear power plant was investigated. Also, the degradation characteristics of 316L stainless steel weldments were evaluated by the ultrasonic parameter such as ultrasonic velocity, attenuation factor and time-frequency analysis. The results of this study can be used as a basic data for the prediction of the fatigue crack life of weldments structures without disjointing or stopping service of structures in service.

• Korean Journal of Materials Research
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• v.20 no.4
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• pp.194-198
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• 2010

Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a $B_4C$ layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a $B_4C$ target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and $B_4C$ were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of $sp^3$ BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.

• Journal of Ocean Engineering and Technology
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• v.17 no.2
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• pp.40-46
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• 2003

The corrosion resistance of super duplex stainless steel on both its fibrous and dispersed phase was investigated. These structures consist of various volume fraction and distribution of austenite structure, which were obtained by changing the heat treatment temperature and cycle. The fibrous phase had higher austenite volume fraction than that of the dispersed phase at the same temperature. Corrosion resistance of super duplex stainless steel was evaluated through an immersion test and an impingement test, using 35% HCI and sea water, respectively. Super duplex stainless steel was compared with STS316L and STS304. The corrosion resistance of super duplex stainless steel was superior to ST316L and STS304. The dispersed phase of super duplex stainless steel was more stabilized than the fibrous phase in corrosion. The magnitude of corrosion rate was in order STS304, STS316L, fibrous phase of super duplex stainless steel and dispersed phase of super duplex stainless steel.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.136-140
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• 2002

High temperature fatigue crack growth behavior of P92 and STS 316L steel were investigated under four load conditions using CT type specimens. Loading and unloading times for the low wave forms were combinations of 1 sec. and 50 sec., which were two symmetric wave forms and two unsymmetric wave forms. Their behaviors are characterized using ΔK parameter. In STS 316L, Crack growth rate generally increases as frequency decreases. However, sensitivity of the loading rate to crack growth rate was fecund to be far greater than that of the unloading time. It is because as loading time increases, creep occurs at crack tip causing the crack growth rate to increase. However creep does not occur at the crack tip even if the unloading time is increased. In P92 steel, crack growth rate showed same behavior as in STS 316L. But the increase in loading or unloading time made almost no difference in crack growth rate, suggesting that no significant creep occurs in P92 steel even though loading time increases. After conducting high temperature tensile tests and comparing high temperature fatigue crack growth rates under various wave forms, it was proved that P92 steel has not only good high temperature properties but also improved, better high temperature fatigue properties than STS 316L.

• Journal of Powder Materials
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• v.20 no.3
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• pp.203-209
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• 2013

In this study, STS 316L powders with 3 wt.% Cu and 1 wt.% Sn known as corrosion-resistance reinforcement elements, are prepared to make different kinds of specimens, in which, 3 wt.% Cu and 1 wt.% Sn are added in different forms by mixing, alloying and fully alloying. After sintering in the same condition, the corrosion resistance, wear resistance and their mechanical properties of specimens are tested respectively. According to the comparison, STS 316L specimen sintered at $1270^{\circ}C$ showed the most excellent mechanical property: HRB 78 (hardness), 1130.7 MPa (RCS), 26.6% (Fraction Wear), It was similar with the specimen made of STS316L and fully alloyed Cu and Sn powders, meanwhile, the latter one appears the best corrosion resistance, 75hrs-salt immersion test results. In addition, the specimens with Cu and Sn powders additive showed relatively worse wear resistance in compared with STS316L specimen.

• Journal of Power System Engineering
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• v.20 no.3
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• pp.43-50
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• 2016

The current study was carried to understand the immersion characteristics and mechanical properties of heat treated stainless steels. Stainless steels (STS310S, STS316L and STS347H) were thermally treated at temperature ranges from 480 to $720^{\circ}C$. Nominal stress was determined to be slightly different depending on the heat treatment temperature. The Cr concentration in STS310S was increased at the temperatures of 600 and $660^{\circ}C$, whereas the Cr concentration in STS316L and STS347H were almost constant regardless of heat treatment temperatures. Vickers hardness was found larger as a thermal treatment temperature was increased. Immersion tests of the stainless steels were also carried out in acidic solution and alkaline solution for 240 hours. Among three different stainless steels, the pitting was detected in the acidic solution, not in the alkaline solution. The pitting of STS347H was occurred more than STS310S and STS316L.