• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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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.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1058-1062
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• 2004

High-temperature cylindrical stainless steel/sodium heat pipe was manufactured and tested under long-term operation. The container material was stainless steel 316L and the working fluid was sodium. The heat pipe was 25.4 mm in diameter and 1000 mm in length with a two-layer screen mesh wick. The evaporator part was 600 mm and the condenser part was 300 mm in length. Total measurement points on heat pipe were 15 points and 12 points were located in condenser part. The heat pipe was heated for 142 days(3400 hours) at $800^{\circ}C$. In the test period, the maximum temperature difference was increased from $18^{\circ}C$ o $28^{\circ}C$ and the maximum thermal resistance was as low as $0.015^{\circ}CW$.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.353-358
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• 2014

This paper reports a simple, yet effective 1-step surface modification method for stainless steel. Electrochemical etching in dilute Aqua Regia forms hierarchical micro and nanoscale structure on the surface. The surface becomes highly hydrophobic (${\sim}150^{\circ}$) as a result of the etching in terms of static contact angle (CA). However the liquid drops easily pinned on the surface because of high contact angle hysteresis (CAH), which is called a "petal effect": The petal effect occur because of gap between surface microstructures, despite of intrinsic hydrophobicity of the base material. The pore size and period of surface structure can be controlled by applied voltage during the etching. This method can be applied to wide variety of industrial demand for surface modification, while maintaining the advantageous anti-corrosion property of stainless steel.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.82-86
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• 1999

An experimental study has been carried out to reduce bending load, surface roughness and springback in bending process of stainless steel sheets. A U-bending test has been performed to investigate appropriate process parameters for getting better surfaces and accurate dimensions of stainless steel products. In the test, selected process parameters are die material, lubricant, and die clearance. Die materials used in the test are STD11(HRC60), STD11(TiCN), and AMPCO. From the test results, we can suggest that AMPCO dies are most suitable for reducing bending load and surface roughness of stainless steel sheets. And STD11 dies are favorable for avoiding spring-back in the stainless steel sheet-bending.

• Journal of Power System Engineering
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• v.14 no.4
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• pp.56-62
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• 2010

This paper is concerned with the stochastic nature of elevated temperature tensile strength and creep rupture time in 18Cr-8Ni stainless steels. The Weibull statistical analysis using the NRIM data sheet has been performed to investigate the effects of variability of the elevated temperature tensile strength and creep rupture time on the testing temperature. From those investigations, the distributions of temperature tensile strength and creep rupture time were well followed in 2-parameter Weibull. The shape parameter and scale parameter for the Weibull distribution of tensile strength were decreased with increasing the testing temperature. For the creep rupture time, generally, the shape parameter were decreased with increasing the testing temperature.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.848-851
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• 2008

유리섬유 및 폴리에스테르와 같은 섬유질 흡음재의 단점을 보완하기 위하여 다공성 알루미늄과 같은 강체 흡음재가 개발되고 있다. 본 연구에서는 스테인리스 스틸을 이용한 다공성 강체에 대하여 수직입사 흡음성능을 조사하였다. 밀도, 두께, 세부 프로파일 등에 따른 성능비교를 위하여 서로 다른 9개의 시험편의 성능을 측정하였다. 측정결과 밀도가 낮고 두께가 두꺼운 다공성 강체의 흡음성능이 다소 높은 것으로 나타났으며, 두께의 증가에 따라 중저주파수 대역의 흡음특성이 증가되었다. 배후 공기층이 형성되는 경우 중 저주파수 대역의 흡음성능이 매우 향상되는 것으로 나타났다. 또한 접착제가 사용된 실험편에 배후공기층이 형성되는 경우 전주파수 대역에서 매우 평탄한 수직입사 흡음특성을 갖는 것으로 나타났다. 향후 스테인리스 스틸 다공성 강체가 방음시설물, 흡음.확산용 내장재 등으로 사용될 수 있을 것으로 판단된다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.226-227
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• 2015

인쇄회로기판에 솔더 페이스트를 인쇄하기 위하여 스테인리스 스틸 (Stainless steel, (i.e., SUS)) 재질의 솔더 페이스트 인쇄용 스텐실 마스크가 사용되고 있다. 하지만, 솔더 페이스트가 스텐실 마스크에 쉽게 달라붙기 때문에 솔더 페이스트에 의한 오염으로 인하여 생산성이 떨어지며, 스텐실 마스크 수명이 짧아지는 문제점이 발생되고 있다. 이를 해결하기 위하여 본 연구에서는 스텐실 마스크 표면에 소수성을 가진 고분자 코팅을 함으로써 솔더 페이스트가 쉽게 붙는 것을 억제하고자 하였다. 더욱 중요하게 스텐실 마스크에 전해연마 및 플라즈마 처리를 통한 표면 개질을 부여함으로써 고분자 코팅의 내구성을 향상시키고자 하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2008.11a
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• pp.39.2-39.2
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• 2008

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.349-349
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.584-585
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• 2010