• Title/Summary/Keyword: 연속파형 Nd:YAG 레이저

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Study of Welding Characteristics of Inconel 600 Alloy using a Continuous Wave Nd:YAG Laser Beam (연속파형 Nd:YAG 레이저를 이용한 인코넬 600 합금의 맞대기 용접 특성 연구)

  • Song, Seong-Wook;Yoo, Young-Tae;Shin, Ho-Jun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1154-1159
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    • 2004
  • Laser beam welding is increasingly being used in welding of structural steels. The laser welding process is one of the most advanced manufacturing technologies owing to its high speed and deep penetration. The thermal cycles associated with laser welding are generally much faster than those involved in conventional arc welding processes, leading to a rather small weld zone. Experiments are performed for Inconel 600 plates changing several process parameter such as laser power, welding speed, shielding gas flow rate, presence of surface pollution, with fixed or variable gap and misalignment between plate and plate, etc. The follow conclusions can be drawn that laser power and welding speed have a pronounced effect on size and shape of the fusion zone. Increase in welding speed resulted in an increase in weld depth/ aspect ratio and hence a decrease in the fusion zone size. The penetration depth increased with the increase in laser power . Welding characteristics of austienite Inconel 600 using a continuous wave Nd:YAG laser are experimentally investigated. This paper describes the weld ability of inconel 600 for machine structural use by Nd:YAG laser.

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Dissimilar Metal Welding of Inconel 600 and STS304 by a continuous wave Nd:YAG Laser (연속파형 Nd:YAG레이저를 이용한 Inconel 600와 STS 304의 이종금속용접)

  • Shin, Ho-Jun;Yoo, Young-Tae;Song, Seong-Wook
    • 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.

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Comparison of Welding Characteristics of Austenitic 304 Stainless Steel and SM45C Using a Continuous Wave Nd:YAG Laser (오스테나이트계 스테인리스강과 SM45C의 연속파형 Nd:YAG 레이저 용접특성비교)

  • 유영태;오용석;노경보;임기건
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.3
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    • pp.58-67
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    • 2003
  • Welding characteristics of austienite 304 stainless and SM45C using a continuous wave Nd:YAG laser n experimentally investigated Laser beam welding is increasingly being used in welding of structural steels. The laser welding process is one of the most advanced manufacturing technologies owing to its high speed and deep penetration. The thermal cycles associated with laser welding are generally much Inter than those involved in conventional welding processes, leading to a rather small weld zone. Experiments are performed for 304 stainless steel plates changing several process parameter such as laser power, welding speed, shielding gas flow rate, presence of surface pollution, with fixed or variable gap and misalignment between the similar and dissimilar and plates, etc. The Nd:YAG laser welding process is one of the most advanced manufacturing technologies owing to its high speed and penetration. This paper describes the weld ability of SM45C carbon steel for machine structural use by Nd:YAG laser. The follow conclusions can be drawn that laser power and welding speed have a pronounced effect on size and shape of the fusion zone. Increase in welding speed resulted in an increase in weld depth/aspect ratio and hence a decrease in the fusion zone size. The penetration depth increased with the increase in laser power.

Influence of Process Parameters on Characteristics of the Cut Surface for the Case of Cutting of CSP IN Sheet Using High Power CW Nd:YAG Laser (고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 박판재 절단시 공정변수의 절단표면특성에 미치는 영향)

  • 안동규;김민수;이상훈;유영태;박형준
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.286-291
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    • 2004
  • The objective of this research work is to investigate the influence of process parameters, such as power of laser, travel speed of laser and material thickness, on roughness and striation of the cut surface for the case of cutting of CSP 1N sheet using high power Nd:YAG laser with continuous wave(CW). In order to find the practical cutting region and the relationship between process parameters on the roughness and the striation, several laser cutting experiments are carried out. From the results of experiments, the allowable cutting region and an optimal cutting speed for each cutting condition have been obtained to improve the quality of the cut surface. In addition, it has been shown that the surface roughness is related to the number of striation and depth of valley of the cut surface.

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Multi-thin plate welding characteristics of Low Carbon Steel for Ni-MH battery of using Continuous Wave Nd:YAG laser (연속파 Nd:YAG 레이저를 이용한 Ni-MH전지용 저탄소강의 다층 박판 용접 특성)

  • Yang, Yun-Seok;Hwang, Chan-youn;Yoo, Young-Tae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.6
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    • pp.720-728
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    • 2011
  • Lap joint welding conducts low carbon steel plates using a 2.0kW continuous wave Nd:YAG laser beam. The specimen is composed of thin plate of 20 sheets. Process Variables contain two controlled parameters of the laser power and the welding speed. In order to quantitatively examine the characteristics of the lap welding, the welding quality of the cut section, stain-stress behavior, and the hardness of the welded part are investigated. The weld width difference between the top and the bottom because the welding speed is increased. The reason, cooling rate is decreased because of fast welding speed. When the heat input is higher, larger volume of the base metal will melt and the welding heat has longer time to conduct into the bottom from the top. The microstructure and tensile properties of the joints are investigated in order to analyze the effects of heat input on the quality of laser welded specimen. From the results of the investigation, We observe that welding quality is good for the laser power of 1800W, and laser welding speed from 1.8m/min to 2.2m/min.

Three-dimensional heat transfer analysis of laser cutting process for CSP 1N sheet using high power CW Nd:YAG laser (고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 냉연강판 절단 공정의 3 차원 열전달 해석)

  • Kim M.S.;Ahn D.G.;Lee S.H.;Yoo Y.T.;Park H.J.;Shin H.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.162-165
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    • 2005
  • The objective of this research work is to investigate into the three-dimensional temperature distribution using quasi steady-state heat transfer analysis fur the case of the laser cutting of CSP 1N sheet using high power CW Nd:YAG laser. The laser heat source is assumed as a volumetric heat source with a gaussian heat distribution in a plane. Through the comparison of the results of analyses with those of the experiments, the optimal finite element model is obtained. Finally, characteristics of the three-dimensional heat transfer and temperature distribution have been estimated by the optimal finite element model.

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A Study on the Characteristics of Repair Welding for Mold Steel using Continuous Wave Nd:YAG Laser (연속파형 Nd:YAG 레이저를 이용한 금형강의 보수용접 특성에 관한 연구)

  • Yoo, Young-Tae;Shin, Ho-Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.11
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    • pp.7-16
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    • 2010
  • In this study, wire was used as the filler material for the laser repair welding, and the phenomenon in which the supplied filler material was melted and beaded down into the specimen was examined with varying laser powers and welding speeds. The optimal processing condition was found to be the laser power of 1,300 W, the welding speed and feed wire supply speed of 0.5 ml/in and the defocused distances of +2mm. At this time, the heat input(E) was $65{\sim}75\;J/mm^2$, and no internal defect occurred. When repair welding was carried out as the optimal processing for the part that had an external defect with the radius of 2mm, the filler metal was melted, resulting in the volume smaller than the defect part and thus causing the part unfilled. Therefore, it was found to be necessary to carry out repair welding two to three times by multiple passes rather than does it only once by single pass.

Decrease of Porosity and Cracking in the cw Nd:YAG Laser Welding of SM45C (SM45C의 연속파형 Nd:YAG 레이저 용접시 발생하는 기공과 결함의 감소)

  • 유영태;오용석;노경보;신호준;임기건
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.65-73
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    • 2003
  • The effect of pre-heating on the mechanical properties of laser welding joints has been investigated for the case of SM45C carbon steel welded by a cw Nd:Y AG laser. The occurrence of porosity and cracking was inspected in various welding conditions to find the optimal welding parameters. The results of laser welding experiment with pre-heating technique showed that porosity and cracking can be reduced significantly in most of welding conditions and the welded joints have improved mechanical properties, such as higher tensile strength and better durability.

Characteristics of Laser Surface Hardening for SM45C Medium Carbon Steel using Continuous Wave Nd:YAG Laser (연속파형 Nd:YAG 레이저를 이용한 SM45C 중탄소강의 레이저표면경화 특성)

  • Yoo, Young-Tae;Shin, Ho-Jun;Ahn, Dong-Gu
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.11 s.176
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    • pp.51-58
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    • 2005
  • Laser surface hardening technologies have been used to improve characteristics of wear and to enhance the fatigue resistance for automotive parts. The objective of this research work is to investigate the influence of the process parameters, such as power of laser and defocused spot position, on the characteristics of laser heat treatment for the case of SM45C medium carbon steel. CW Nd:YAG laser is selected as the heat source. The optical lens with the elliptical profile is designed to obtain a wide heat treatment area with a uniform hardness. From the results of the experiments, it has been shown that the maximum hardness is approximatly 780 Hv when the power and the travel speed of laser are 1,095 W and 0.6 m/min, respectively. In addition, the hardening width using the elliptical lens was three time larger than that using the defocusing of laser beam.

Characteristics of Surface Hardening for Hot Work Tool Steel using Continuous Wave Nd:YAG Laser (연속파형 Nd:YAG 레이저를 이용한 열간금형 공구강의 표면경화 특성)

  • Shin, Ho-Jun;Shin, Byung-Heon;Yoo, Young-Tae
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.4 s.193
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    • pp.57-67
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    • 2007
  • Laser surface hardening technologies have been used to improve characteristics of wear and to enhance the fatigue resistance fur mold parts. The objective of this research work is to investigate the influence of the process parameters, such as power of laser and defocused spot position, on the characteristics of laser surface hardening for the case of SKD61 steel. CW Nd:YAG laser is selected as the heat source. The optical lens with the elliptical profile is designed to obtain a wide surface hardening area with a uniform hardness. From the results of the experiments, it has been shown that the maximum average hardness is approximatly 780 Hv when the power, focal position and the travel of laser are 1,095 W, 0mm and 0.3 m/min, respectively. In samples treated with lower scanning speeds, some small carbide particles appear in the interdendritic regions. This region contains fine martensite and carbide in proportions which depend on the local thermal cycle.