• Title/Summary/Keyword: welding speed

Search Result 815, Processing Time 0.028 seconds

Effect of the welding speed on the characteristics of Nd:YAG laser welds for automotive application : 600MPa PH high strength steel (600MPa급 자동차용 석출경화형 고장력강판 Nd:YAG 레이저 용접부의 특성에 미치는 용접속도의 영향)

  • Han, Tae-Kyo;Jung, Byung-Hun;Kang, Chung-Yun
    • Laser Solutions
    • /
    • v.10 no.3
    • /
    • pp.25-32
    • /
    • 2007
  • The effect of welding speed on the weldability, microstructures, hardness, tensile property of Nd:YAG laser welding joint in 600MPa grade precipitation hardening high strength steel was investigated. A shielding gas was not used, and bead-on-plate welding was performed using various welding speeds at a power of 3.5kW. Porosity in the joints occurred at 1.8m/min, but were not observed over the welding speed of 2.1m/min. However, spatter occurred over the welding speed of 6.6m/min. The hardness was the highest at heat affected zone(HAZ) near fusion zone(FZ), and was decreased on approaching to the base metal. The maximum hardness increased with increasing welding speed. The microstructure of FZ was composed of coarse grain boundary ferrite and bainite(upper) but the HAZ near the FZ contained bainite(Lower) and fine ferrite at a low welding speed. With increasing welding speed, ferrite at the FZ and the HAZ became finely and upper binite changed to lower bainite. In a perpendicular tensile test to the weld line, all specimens were fractured at the base metal, and the tensile strength and the yield strength of joints was equal to those of raw material. Elongation was found to be lower than that of the raw material.

  • PDF

Effect of Tin Coating on the High Speed Seam Weldability of Thn Gage Sheet Steels (박판 강재의 고속 심 용접성에 미치는 Sn 도금의 영향)

  • 김기철;이목영
    • Journal of Welding and Joining
    • /
    • v.16 no.5
    • /
    • pp.86-92
    • /
    • 1998
  • High speed wire seam weldability of tin coated thin gage sheet steels was investigated. Thickness and coating weight ranges of the test materials were 0.21~0.35mm and 1.1/1.1~2.8/11.2g/$m^2$, respectively. Test results indicated that the surface roughness value, Rz decreased as increasing the coating weight. The Rz was thought to be one of the important factors to influence the optimum welding condition range, $\triangle$Q. The $\triangle$Q showed close relationship with welding conditions such as welding pressure and travel speed. Higher welding pressure widened the $\triangle$Q while higher travel speed reduced the $\triangle$Q value. Results also demonstrated that tin coating weight should be optimized based on the weldability or the serviceability after welding. At th HAZ of sheet materials with thinner coating layer, tin depleted zone was produced since molten film of the coating material on the base metal agglomerated by the surface tension, which could result in reducing the corrosion resistance of the HAZ in the service environment.

  • PDF

Effect of Process Parameters on the High Speed Seam Weldability of Tin Coated Steels for the Small Containers

  • Kim, K.C.;Lee, M.Y.
    • International Journal of Korean Welding Society
    • /
    • v.1 no.1
    • /
    • pp.13-16
    • /
    • 2001
  • High speed seam weldability of tin coated steels was investigated. Welding was performed by the laboratory wire seam welder that was equipped with process monitoring system Test results showed that increase in applied current and pressure reduced the total resistance across the welding electrodes. Lower and upper limits of welding current increased as the sheet thickness increased, while the acceptable welding condition range decreased. However, extremely low electrode pressure produced unstable welding condition range. The results also demonstrated that slower welding speeds widened the optimum welding heat input range.

  • PDF

A Study on Welding Performance Improvement in $CO_2$ Inverter Arc Welding Machine by Constant Wire Feeding Rate Control ($CO_2$ 인버터 아크용접기의 송급속도 제어에 의한 용접성능향상에 관한 연구)

  • 김길남;고재석;채영민;원충연;김규식;목형수;최규하
    • Proceedings of the KIPE Conference
    • /
    • 1999.07a
    • /
    • pp.563-568
    • /
    • 1999
  • Generally the control method of wire feeding motor in welding machine has been used full-wave phase control method. The fire-angle control generates low frequency speed ripple, and it causes the output current ripple. So it results in the variation of welding condition and low welding performances such as spatter generation and bead state. For the purpose of welding performances improvement by speed controller in wire feeding motor, in this paper the constant speed control method for welding machine is proposed. The proposed system is composed of speed control loop and current control loop. As a result of experiment by using proposed constant wire feed experiment by using proposed constant wire feed speed controller, the output voltage and current waveform and metal transfer are maintained stably. And moreover the number of instantaneous short circuit occurrence is reduced remarkably.

  • PDF

Effect of Welding Condition on Tensile Properties of Friction Stir Welded Joints of Al-7075-T651 Plate (용접 조건이 Al-7075-T651의 마찰교반용접부의 인장 특성에 미치는 영향)

  • Kim, C.O.;Kim, S.J.
    • Journal of Power System Engineering
    • /
    • v.15 no.2
    • /
    • pp.61-68
    • /
    • 2011
  • This paper investigates the tensile properties of the friction stir welded joints of Al 7075-T651 aluminum plate according to the welding conditions. A 7075-T651 aluminum alloy plate with a thickness of 6.0 mm was used in this investigation. For the friction stir welding (FSW) process, a tool with shoulder diameter of 20 mm and probe diameter of 9 mm was used. The rotation speed and traverse speed conditions were changed in this study, the other welding conditions are constant. The welding direction was aligned with the material rolling direction, and dimension of the FSW plate were $250{\times}100{\times}6\;mm$. As far as this work is concerned, the optimal FSW conditions are determined as the rotation speed, 600 rpm and traverse speed 0.8 mm/sec or the rotation speed, 800 rpm and traverse speed 0.5 mm/sec.

A study on the influence of the traverse speed on the mechanical strength of friction stir welding A5083 (A5083 마찰교반접합(F.S.W)시 이송속도가 기계적 강도에 미치는 영향에 관한 연구)

  • 성기완;이준형;오세헌;박근형;윤병수;민택기
    • Proceedings of the KWS Conference
    • /
    • 2001.05a
    • /
    • pp.114-116
    • /
    • 2001
  • This study deals with friction stir welding of aluminum alloy(A5083). Welding conditions were applied that revolution 2000rpm, friction pressure 25MPa, angle between stir rod section and plate 4$^{\circ}$, projection pin diameter 4mm, traverse speed 0.5mm/sec, 1.0mm/sec, 1.5mm/sec. The experimental results as follows; 1. Welding beads were superior in traverse speed 1.0mm/sec and it were formed plenty of flash in traverse speed 0.5 mm/sec. Welding beads were rough in traverse speed 1.5mm/sec. 2. The maximum tensile strength was 211MPa in traverse speed 1.0mm/sec, in this case the strength was 85% of A5083 base metal tensile strength.

  • PDF

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 Parameters on the Friction Stir Weldability of 5052 Al alloy (5052 알루미늄 합금 마찰교반접합부 특성에 미치는 접합인자의 영향)

  • 이원배;김상원;이창용;연윤모;장웅성;서창제;정승부
    • Journal of Welding and Joining
    • /
    • v.22 no.3
    • /
    • pp.69-76
    • /
    • 2004
  • Effects of friction stir welding parameters such as tool rotation speed and welding speed on the joints properties of 5052 Al alloys were studied in this study. A wide range of friction stir welding conditions could be applied to join 5052 AA alloy without defects in the weld zone except for certain welding conditions with a lower heat input. Microstructures near the weld zone showed general weld structures such as stir zone (SZ), thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ). Each zone showed the dynamically recrystallized grain, transient grain and structure similar to base metal's, respectively. Hardness distribution near the weld zone represented a similar value of the base metal under wide welding conditions. However, in case of 800 rpm of tool rotation speed, hardness of the stir zone had a higher value due to the fine grain with lots of dislocation tangle, a higher angle grain boundary and some of Al3Fe particles. Except joints with weld defects, tensile strength and elongation of the joints had values similar to the base metal values and fracture always occurred in the regions approximately 5mm away from the weld center.

Dissimilar Friction Stir Welding Characteristics of Mg Alloys(AZ31 and AZ61) (AZ31와 AZ61 마그네슘 합금의 이종 마찰교반용접 특성)

  • Park, Kyoung Do;Lee, Hae Jin;Lee, Dai Yeol;Kang, Dae Min
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.16 no.5
    • /
    • pp.99-104
    • /
    • 2017
  • Friction stir welding is a solid-state joining process and is useful for joining dissimilar metal sheets. In this study, the experimental conditions of the friction stir welding were determined by the two-way factorial design to evaluate the characteristics of the dissimilar friction stir welding of AZ31 and AZ61 magnesium alloys. The levels of rotation speed and welding speed, which are welding variables, were 1000, 2000, 3000 rpm and 100, 200, 300 mm/min, respectively. From the results, the greater the rotation speed and the lower the welding speed of the tool were, the greater the tensile strength of the welded part was. The contribution of the welding speed of the tool is larger than that of the rotation speed of the tool. In addition, the optimal conditions for tensile strength in the dissimilar friction stir joint were predicted to be the rotation speed of 3000 rpm and welding speed of 100 mm/min, and the tensile strength under the optimal conditions was estimated to be $214{\pm}6.57Mpa$ with 99% reliability.