• Title/Summary/Keyword: Welding Speed

Search Result 282, Processing Time 0.104 seconds

Effect of welding condition on microstructures of weld metal and mechanical properties in Plasma-MIG hybrid welding for Al 5083 alloy (알루미늄 5083 합금의 플라즈마 미그 하이브리드 용접시 용접부 미세조직과 기계적 성질 변화에 미치는 용접조건의 영향)

  • Park, Sang-Hyeon;Lee, Hee-Keun;Kim, Jin-Young;Chung, Ha-Taek;Park, Young-Whan;Kang, Chung-Yun
    • Journal of Welding and Joining
    • /
    • v.33 no.1
    • /
    • pp.61-71
    • /
    • 2015
  • The effect of welding condition on microstructure and mechanical property of Plasma-MIG Hybrid Weld between Al 5083 plates(thickness : 10mm) was investigated. 1 pass weld without any defects such as puckering, undercut, and lack of fusion was obtained by 150~200A of plasma current and 5~7mm of welding speed. Gas porosities and shrinkage porosities were existed in the weld near fusion line. As welding speed and plasma current were decreasing, the area fraction of porosity was increasing. The hardness of the weld is increasing as welding speed. On the basis of microstructural analysis, Mg segregated region near dendrite boundaries tends to increase with the welding speed. In the result of hardness test, Distribution of hardness in fusion zone showed little change with the plasma current. However, when the welding speed increased, hardness in weld metal markdly increased. It could be considered that effect of heat input to growth of the dendritic solidification structures. Based on tensile test, tensile properties of weld metal was predominated by area fraction of porosities. Consequently, tensile properties can be controlled by formation site and area fraction of porosity.

Analysis of friction stir welding characteristics of aluminum alloy using machining center (머시닝센터를 활용한 알루미늄합금의 마찰교반용접 특성 분석)

  • Seung, Young-Chun;Park, Kyoung-Do;Lee, Chun-Kyu
    • Journal of the Korea Society of Die & Mold Engineering
    • /
    • v.14 no.4
    • /
    • pp.46-51
    • /
    • 2020
  • The purpose of this study was to analyze the change in tensile strength characteristics of the weld when the welding speed and rotational speed of the tool, which are representative variables of the friction stir welding process. The equipment used in the experiment was Machining Center No. 5. The material used in the experiment is an AA6061-T6 alloy, and a rolled plate with a thickness of 2mm was used. Two experimental variables were selected, the welding speed of the tool and the rotational speed of the tool. The experimental conditions were selected in the range in which a healthy weld could be obtained through a preliminary experiment. The welding speed of the tool was increased to 100mm/min, 200mm/min, and 300mm/min, and the rotational speed of the tool was increased to 1000rpm, 2000rpm, and 3000rpm. As a result of the experiment, the tensile strength increased as the rotational speed of the tool changed at each tool welding speed. In addition, as the welding speed of the tool increased, the tensile strength of the weld was increased. The condition with the highest tensile strength of the weld was found to be a tool feed speed of 300 mm/min and a tool rotation speed of 3000rpm.

  • PDF

Weldability with Process Parameters During Fiber Laser Welding of a Titanium Plate (II) - The Effect of Control of Heat Input on Weldability - (티타늄 판재의 파이버 레이저 용접시 공정변수에 따른 용접특성 (II) - 입열량 제어에 따른 영향 -)

  • Kim, Jong Do;Kim, Ji Sung
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.12
    • /
    • pp.1055-1060
    • /
    • 2016
  • Laser welding is a high-density energy welding method. Hence, deep penetration and high welding speed can be realized with lower heat input as compared with conventional welding. The heat input of a CW laser welding is determined by laser power and welding speed. In this study, bead and lap welding of $0.5mm^t$ pure titanium was performed using a fiber laser. Its weldability with laser power and welding speed was evaluated. Penetration, bead width, joining length, and bead shape were investigated, and the mechanical properties were examined through tensile-shear strength tests. Welds with sound joining length were obtained when the laser power and welding speed were respectively 0.5 kW and 2.5 m/min, and 1.5 kW and 6 m/min, and the weld obtained at low output presented better ductility than that obtained at high output.

Effect of Welding Condition on Microstructure of Transient Zone in Overlay Weld of 3Cr-1Mo Steel/STS-309L (3Cr-1Mo강/STS-309L 오버레이 용접부의 천이영역 조직에 미치는 용접조건의 영향)

  • 김동진;김병훈;지병하;김정태;김성곤;강정윤;박화순
    • Journal of Welding and Joining
    • /
    • v.18 no.2
    • /
    • pp.176-176
    • /
    • 2000
  • Recently developed Austenite stainless steel,309L was to overlay on 3Cr-1Mo-V-Ti-B steels, using Electroslag welding process, which wide electrodes were adopted. Transition region in welding interlayer relating to disbonding crack was investigated. Also. the effect of welding condition on the width of transition region and coarsening grains of the austenite were studied.1) With increasing welding speed the width of martensite at transient region was increased, but the amount of delta ferrite in weld metal was reduced, being fine grained.2) The form of martensite at the transition region was occured by reversible transition region, leading to increasing Ms point.3) With increasing welding speed, the grain of austenite formed at the welding interface was finer. With increasing welding current under the same welding speed, the grain size of the austenite was finer. At high current, original grain size of the austenite is coarse, but the austenite has fine grains because the austenite was transformed to martensite during cooling.4) In the case of high welding speed, the width of martensite at the welding interface was increased, but the grain size of austenite at the welding interface was finer. This indicates that the inhibition of disbonding crack may be achieved through dispersening fine carbides in the grain boudary.(Received August 3, 1999)

Effect of Welding Condition on Microstructure of Transient Zone in Overlay Weld of 3Cr-1Mo Steel/STS-309L (3Cr-1Mo강/STS-309L 오버레이 용접부의 천이영역 조직에 미치는 용접조건의 영향)

  • 김동진;김병훈;지병하;김정태;김성곤;강정윤;박화순
    • Journal of Welding and Joining
    • /
    • v.18 no.2
    • /
    • pp.49-56
    • /
    • 2000
  • Recently developed Austenite stainless steel, 309L was used to overlay on 3Cr-1Mo-V-Ti-B steels, using Electroslag welding process, which wide electrodes were adopted. Transition region in welding interlayer relating to disbonding crack was investigated. Also, the effect of welding condition on the width of transition region and coarsening grains of the austenite were studied. 1) With increasing welding speed the width of martensite at transient region was increased, but the amount of delta ferrite in weld metal was reduced, being fine grained. 2) The form of martensite at the transition region was occurred by reversible transformation during cooling since the interdiffusion of Cr and Ni from weld metal and Fe and C from base metals at the transition region, causes to lowering the concentration of Cr and Ni at the transition region, leading to increasing Ms point. 3) With increasing welding speed, the grain of austenite formed at the welding interface was finer. With increasing welding current under the same welding speed, the grain size of the austenite was finer. At high current, original grain size of the austenite is coarse, but the austenite has fine grains because the austenite was transformed to martensite during cooling. 4) In the case of high welding speed, the width of martensite at the welding interface was increased, but the grain size of austenite at the welding interface was finer. This indicates that the inhibition of disbonding crack may be achieved through dispersening fine carbides in the gain boundary.

  • PDF

Effect of Welding Speed on Mechanical Properties and Formability in Nd:YAG Laser Welds of 1000MPa Grade DP Steel (1000MPa급 DP강의 Nd:YAG 레이저 용접부의 기계적 성질과 성형성에 미치는 용접 속도의 영향)

  • Jang, Jin-Young;Choi, Woo-Nam;Jung, Byung-Hun;Kang, Chung-Yun
    • Journal of Welding and Joining
    • /
    • v.27 no.2
    • /
    • pp.69-75
    • /
    • 2009
  • The effects of welding speed were investigated on penetration characteristics, defects and mechanical properties including formability test in Nd:YAG laser welded 1000MPa grade DP steels. A shielding gas was not used and bead-on-plate welding was performed with various welding speeds at 3.5kW laser power. Defects of surface and inner beads were not observed in all welding speeds. As the welding speed increased, the weld cross-section varied from the trapezoid having wider bottom bead, through X type, finally to V type in partial penetration range of welding speeds. The characteristic of hardness distribution was also investigated. The center of HAZ had maximum hardness, followed by a slight decrease of hardness as approaching to FZ. Significant softening occurred at the HAZ near BM. Regardless of the welding speed, the weld showed approximately the same hardness distribution. In the perpendicular tensile test with respect to the weld direction, all specimens were fractured at the softening zone. In the parallel tensile test to the weld direction, the first crack occurred at weld center and then propagated into the weld. Good formability over 80% was taken for all welding conditions.

Optimization of Process Parameters Using a Genetic Algorithm for Process Automation in Aluminum Laser Welding with Filler Wire (용가 와이어를 적용한 알루미늄 레이저 용접에서 공정 자동화를 위한 유전 알고리즘을 이용한 공정변수 최적화)

  • Park, Young-Whan
    • Journal of Welding and Joining
    • /
    • v.24 no.5
    • /
    • pp.67-73
    • /
    • 2006
  • Laser welding is suitable for welding to the aluminum alloy sheet. In order to apply the aluminum laser welding to production line, parameters should be optimized. In this study, the optimal welding condition was searched through the genetic algorithm in laser welding of AA5182 sheet with AA5356 filler wire. Second-order polynomial regression model to estimate the tensile strength model was developed using the laser power, welding speed and wire feed rate. Fitness function for showing the performance index was defined using the tensile strength, wire feed rate and welding speed which represent the weldability, product cost and productivity, respectively. The genetic algorithm searched the optimal welding condition that the wire feed rate was 2.7 m/min, the laser power was 4 kW and the welding speed was 7.95 m/min. At this welding condition, fitness function value was 137.1 and the estimated tensile strength was 282.2 $N/mm^2$.

Improvement of Penetration Characteristics by Plasma Augmented Laser Welding of Small Diameter Stainless Steel Tubes (PALW을 이용한 소경 스테인리스강 튜브의 용입특성 개선)

  • Hwang Jae-Ryeon;Yoon Suk-Hwan;Na Suck-Joo
    • Journal of Welding and Joining
    • /
    • v.22 no.6
    • /
    • pp.30-35
    • /
    • 2004
  • Laser welding is obviously an attractive method to join small, thin parts such as small stainless steel tubes, but it is very sensitive to the joint clearance and tolerance, and this makes laser welding difficult to obtain consistent welding qualities over time. Recently, Plasma Augmented Laser Welding(PALW) is being developed to solve these problems. In this study, plasma arc welding(PAW) was introduced to join conventional V-grooved butt joint of thin stainless steel strips using single laser heat source in manufacturing small stainless steel tubes. The effect of the welding speed enhancement is investigated by the experiments. Effects of welding directions, distance between the heat sources and intensity of arc heat source on the optimal welding speed was investigated. Through this research, it was confirmed that PALW process has higher welding speed and robustness than laser welding process.

A Study on the Bead Stability in High Speed TIG Welding (고속 TIG 용접의 비드 안정성에 관한 연구)

  • 조상명
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.18 no.3
    • /
    • pp.68-77
    • /
    • 1994
  • TIG welding process is applied for the active metal such as aluminum and titanium, also sometimes for overlay welding of superalloy. However the welding speed to be applied is very low because of the unstable bead formed in the region of high current and high welding speed. The present study was carried out to examine the basic phenomena of high speed TIG melt run welding by the 2% Th - W electrode(dia.3.2mm) of various tip shapes.

  • PDF

The Joints Characteristics of Al 5052 Aluminium Alloy in Friction Stir Welds (마찰교반 용접조건에 따른 Al 5052 알루미늄 합금의 접합특성)

  • Kang, Dae-Min;Jang, Jin-Suk;Park, Kyong-Do;Lee, Dai-Yeal
    • Journal of Power System Engineering
    • /
    • v.20 no.3
    • /
    • pp.51-56
    • /
    • 2016
  • In this study, the tensile tests and hardness tests were carried out for the joints characteristics in friction stir welds of Al 5052 alloy. Three way factorial design was applied to optimal welding conditions, whose control factors were shoulder diameter, rotation speed and welding speed of tool. From the results of this study, the optimum condition for maximum yield strength was predicted as the shoulder diameter of 15 mm, welding speed of 500mm/min and rotating speed of 1000 rpm. And the presumed optimal yield strength was estimated to be $167.36{\pm}7.82MPa$ with 99% reliability. In addition the increaser rotation speed of tool and the decreaser welding speed, the decreaser the hardness at welding part.