Journal articles: 'Autogenous welding'

1

Ahn, Young Nam, and Cheol Hee Kim. "Evaluation of Crack Sensitivity and Gap Bridging Ability during Laser Butt Welding of Aluminum 5J32 and 6K21 Alloys." Materials Science Forum 695 (July 2011): 247–50. http://dx.doi.org/10.4028/www.scientific.net/msf.695.247.

Full text

Abstract:

Growing demand to reduce fuel consumption has accelerated the application of Al sheets to the body structure of automobiles. While recent studies on laser welding of Al 5xxx series and Al 6xxx series alloys have examined weldability, the laser autogenous welding usually results in low gap bridging capability and weld defects such as porosity, underfill, cracking, and so on. In this study, we evaluated the gap bridging capability and the crack sensitivity during laser autogenous welding, laser welding with filler wire, and laser-arc hybrid welding, respectively. Al 5J32 and 6K21 sheets were used as the base metal and Al 4xxx series and Al 5xxx series wires were used as the filler metal. Employing adequate welding conditions, the gap bridging capability during butt welding was investigated for each welding process. To clarify the solidification crack sensitivity, bead-on-plate welding was implemented for a tapered specimen as a self-restraint crack test. Compared with the laser autogenous welding, laser welding with filler wire and the laser-arc hybrid welding showed improved gap bridging capability and reduced crack sensitivity.

APA, Harvard, Vancouver, ISO, and other styles

2

Zhang, Shiwei, Junhao Sun, Minhao Zhu, Lin Zhang, Pulin Nie, and Zhuguo Li. "Fiber laser welding of HSLA steel by autogenous laser welding and autogenous laser welding with cold wire methods." Journal of Materials Processing Technology 275 (January 2020): 116353. http://dx.doi.org/10.1016/j.jmatprotec.2019.116353.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Lisiecki, A. "Welding of Thermomechanically Rolled Steel by Yb:YAG Disk Laser / Spawanie Stali Walcowanej Termomechanicznie Laserem Dyskowym Yb:YAG." Archives of Metallurgy and Materials 60, no. 4 (December 1, 2015): 2851–60. http://dx.doi.org/10.1515/amm-2015-0456.

Full text

Abstract:

Autogenous laser welding of 5.0 mm thick butt joints of thermomechanically rolled steel S700MC was investigated. The Yb:YAG disk laser TruDisk 3302 emitted at 1.03 μm was used for the trials of autogenous welding. The effect of laser welding parameters and thus thermal conditions of welding on weld shape, microstructure of weld metal and heat affected zone (HAZ), tensile strength, bending angle, impact toughness and microhardness profile was determined. Studies have shown that it is advantageous to provide a high welding speed and low heat input. High cooling rate of weld metal and HAZ leads to the formation of a favorable structure characterized by a large proportion of fine-grained acicular ferrite and provides high mechanical properties of butt joints.

APA, Harvard, Vancouver, ISO, and other styles

4

Allen, C. M., G. Verhaeghe, P. A. Hilton, Chris P. Heason, and Philip B. Prangnell. "Laser and Hybrid Laser-MIG Welding of 6.35 and 12.7mm Thick Aluminium Aerospace Alloy." Materials Science Forum 519-521 (July 2006): 1139–44. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.1139.

Full text

Abstract:

Fusion welding of 7xxx aluminium alloy plates has been investigated for aerospace applications using autogenous laser welding and hybrid laser-MIG welding. Nd:YAG and Yb-fibre lasers have been used, with two different focussed spot sizes in each case. Autogenous and hybrid welding of 12.7mm thick plate using the Yb-fibre laser with a 0.6mm diameter spot was selected for further development, on the basis of penetration and weld quality achieved. These welds were acceptable to the highest quality class B (stringent) of BS EN ISO 13919-2:2001, with a porosity of only 0.3% of the cross-sectional area of the weld, and close to class A of AWS D17.1. Transverse proof strengths of ~60% of parent material were achieved. Development of hybrid welding is ongoing with novel fillers to refine weld metal grain structure and improve weld properties.

APA, Harvard, Vancouver, ISO, and other styles

5

Adamiec, Janusz, and Robert Kocurek. "Effect of Autogenous Laser Weld on Microstructure and Mechanical Properties of Inconel 617 Nickel Alloy." Solid State Phenomena 226 (January 2015): 43–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.226.43.

Full text

Abstract:

One of the most advanced manufacturing technologies is laser welding. Due to the limited power of the beam, the difficulty of precise preparation of the joint and the possibility of hardening in a narrow heat affected zone laser welding is used only for basic low carbon and low alloy steels. In this work the effects of autogenous weld parameters on microstructure and properties of the Inconel 617 alloy were studied. For this purpose the technological test of laser autogenous weld was performed.

APA, Harvard, Vancouver, ISO, and other styles

6

D'amato, Clayton, Maurizio Fenech, Stephen Abela, John C. Betts, and Joseph Buhagiar. "Autogenous Laser Keyhole Welding of AISI 316LTi." Materials and Manufacturing Processes 25, no. 11 (December 3, 2010): 1269–77. http://dx.doi.org/10.1080/10426914.2010.490862.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Caiazzo, Fabrizia, Vittorio Alfieri, and Vincenzo Sergi. "Investigation on Mechanical Properties of Disk Laser Welded Aerospace Alloys." Advanced Materials Research 702 (May 2013): 128–34. http://dx.doi.org/10.4028/www.scientific.net/amr.702.128.

Full text

Abstract:

The original micro structure of the base metal is significantly affected by a welding thermal cycle, irrespective of the type of the heat source. Hence, new phases and different grain size result in the welding bead. The tensile strength of the overall structure is affected in turn. Tensile tests are normally conducted to eventually test a square butt joint configuration. In conjunction, micro hardness is thought to be a good indicator to predict where the fracture would occur in the welded structure. Referring to common metal alloys for aerospace and considering a diode-pumped disk-laser source, the response of the base metal to the laser beam is investigated in this paper. Autogenous welding of aluminum alloy 2024, autogenous welding of titanium alloy Ti-6Al-4V and dissimilar welding of Haynes 188 with Inconel 718 are discussed, with respect to micro structure changes in the fused zone and in the heat affected zone. The failure mode is examined.

APA, Harvard, Vancouver, ISO, and other styles

8

Abdolvand, Hamidreza, Mike Keavey, H. Dai, Alison Mark, N. O’Meara, Joanna Walsh, S. Bate, B. Pellereau, John A. Francis, and Philip J. Withers. "On the Stress Development in SA508 Autogenous Weld." Materials Science Forum 783-786 (May 2014): 2123–28. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.2123.

Full text

Abstract:

Considering the significant role that residual stresses play in determining the lifetime-service of materials, it is mandatory to have a good understanding of and a means of predicting those that develop during welding processes. For this purpose, a User MATerial subroutine (UMAT) is developed to study the effects of various parameters that influence solid state phase transformations and residual stress evolution during welding of SA508 ferritic steel. The temperature dependent elastic and kinematic hardening parameters for each of the individual phases that can potentially develop during cooling from elevated temperatures are measured and are used for calculating stress development during low (75 mm/min) and high (300 mm/min) speed gas-tungsten arc welding (GTAW) on SA508 grade 3. These two speeds are selected to cover a wide range of cooling rates in the heat affected zone so that different phase proportions would be present. The results of the numerical simulations for residual stresses are compared against those measured by neutron diffraction. It is shown here that a low speed weld results in bainite formation whereas a high speed weld results in bainitic as well as subsequent martensitic phase transformations where each welding rate results in different residual stress development.

APA, Harvard, Vancouver, ISO, and other styles

9

Betini, Evandro Giuseppe, Maurilio Pereira Gomes, Cristiano Stefano Mucsi, Temístocles de Souza Luz, Marcos Tadeu D'azeredo Orlando, and Jesualdo Luiz Rossi. "Study of the Thermal Diffusivity Variation in Thin Duplex Steel Plates Welded by GTAW Process." Materials Science Forum 930 (September 2018): 460–65. http://dx.doi.org/10.4028/www.scientific.net/msf.930.460.

Full text

Abstract:

This study describes the thermal diffusivity of thin duplex steel plates in the thickness direction measured using the laser-flash method after welding. The work reports the experimental efforts in recording temperature profiles of the grade UNS S32304 duplex steel during autogenous welding. The butt weld autogenous joints were carried out by the GTAW (gas tungsten arc welding) process with either argon or argon - 2% nitrogen atmospheres. The amount of nitrogen in the heat affected regions, after welding, was measured and correlated with the variation of the thermal diffusivity of the studied material. The temperature profiles were obtained using k-type thermocouples connected to a digital data acquisition system. Different thermal cycles and thermal diffusivity values were observed in the heat-affected zone (HAZ) for both samples. In the solidified zone (SZ) was observed similar increase of the thermal diffusivity values for the plates welded with pure argon and argon plus nitrogen atmosphere.

APA, Harvard, Vancouver, ISO, and other styles

10

Hu, B., and I. M. Richardson. "Autogenous laser keyhole welding of aluminum alloy 2024." Journal of Laser Applications 17, no. 2 (May 2005): 70–80. http://dx.doi.org/10.2351/1.1896964.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Zhang, Mingjun, Shun Chen, Yingzhe Zhang, Genyu Chen, and Zhuming Bi. "Mechanisms for Improvement of Weld Appearance in Autogenous Fiber Laser Welding of Thick Stainless Steels." Metals 8, no. 8 (August 9, 2018): 625. http://dx.doi.org/10.3390/met8080625.

Full text

Abstract:

High-power fiber laser welding is an efficient and effective way to produce heavy section structures. However, there is a significant challenge in producing the welds with free of imperfections such as nail-head-shaped welds, spatters, and root sagging. This is partially due to a lack of understanding of the welding mechanism of high-power fiber laser. In this paper, we were especially interested in the mechanism to improve the appearance of welds, and we focused on the autogenous laser welding on thick stainless steel plates by a 10 kW fiber laser. To look into the relations of process parameters and the quality of welds, a high-speed imaging system was applied to observe the molten pool flow and vapor plume during the welding process. The appearances of welds subjected to different welding conditions were analyzed. The results showed that (1) nail-head-shaped welds were suppressed by using a gas jet during laser welding process. (2) In the forward welding, a gentle upwelling molten metal flow on the rear keyhole wall, a deeper weld pool and a weaker vapor plume resulted in no spatter. (3) The gravity affected the formation of underfills and root sagging significantly during autogenous laser welding of thick plates. (4) When the workpiece was placed vertically in the transverse position, the welding process was stable without an aggregation of molten melt at the back surface. Moreover, the mechanisms of forming root sagging and humps were different at the top surface.

APA, Harvard, Vancouver, ISO, and other styles

12

Alkhaldi, Mohammed S., Ali A. Majeed Ali, and Sobhi Khirallah. "Impact of the Welding Parameters on the Width of the Welding beat in TIG Carbon Steel Welding." International Journal of Engineering and Advanced Technology 10, no. 3 (February 28, 2021): 24–29. http://dx.doi.org/10.35940/ijeat.a1816.0210321.

Full text

Abstract:

Tungsten Inert Gas (TIG) welding is otherwise known as the Gas Tungsten Arc soldering (GTAW) process which when significant levels of weld quality or high precision welding are required, is known to represent an advanced arc welding process. However the impact of the welding factors on this form of welding is important for its welding produced in single-pass welding. In this investigation, the autogenous Tungsten Inert Gas (TIG) welding was performed on a carbon mild steel plate with four parametric welding variables. High and low values of material thickness, welding current, welding speed and filler rod diameter have been measured in order to have an impact on an observable parametric response i.e. welding distance. Geometry of the weld bead has been investigated. An expert statistical software design expert has created a mathematical model, The experimental design is central composite design (CCD) and the sold width is the response measured by the Surface Response Methodology (RSM). It has been shown that the maintenance of a suitable parametric welding factor for a carbon steel plate gives substantial values of welding width.

APA, Harvard, Vancouver, ISO, and other styles

13

Banerjee, Amit Jyoti, Manoja Kumar Biswal, A. K. Lohar, H. Chattopadhyay, and Naga Hanumaiah. "Review on experimental study of Nd:YAG laser beam welding, with a focus on aluminium metal matrix composites." International Journal of Engineering & Technology 5, no. 3 (August 26, 2016): 92. http://dx.doi.org/10.14419/ijet.v5i3.5984.

Full text

Abstract:

The demand for high performance materials particularly in aviation and automobile industries gradually increases, CO2 and Nd: YAG lasers are becoming most popular in processing these advanced materials. In this context, one of the most important process is joining by welding. It has been a constant endeavour by researchers to explore various methods and techniques to enhance the process efficiency of autogenous Nd: YAG laser welding of various materials i.e. without any filler materials. In this work, we present a comprehensive review of major research findings for the last decades or so, obtained by researchers about the effect of process parameters on autogenous laser beam welding (LBW) process performance. Main objective of such experimental research was to improve laser weld quality such as tensile strength, weld micro structure, heat affected zone (HAZ), weld penetration etc. In this paper, discussions are also made about different parameter optimisation techniques, design of experiments (DOE), modelling and simulation techniques, adopted by different researchers to achieve optimum weld quality. This review tries to bring out a foresight for direction of further research needed in this field.

APA, Harvard, Vancouver, ISO, and other styles

14

Tseng, Kuang Hung, and Hsiang Lin Sung. "Evaluation Study on Angular Distortion and Residual Stress of Stainless Steel Pulsed TIG Weldment." Advanced Materials Research 291-294 (July 2011): 905–9. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.905.

Full text

Abstract:

The aim of this study was to investigate the effect of pulsed current welding parameters on angular distortion and residual stress of TIG weldment. Autogenous TIG welding was applied on type 316L stainless steel sheet to produce bead-on-plate welds. Angular distortion was determined using the mean vertical displacement method. Residual stress was determined using the hole-drilling strain- gage method. The results showed that the pulsed current TIG welding has a number of advantages, including lower heat input and consequently a reduction in distortion and residual stress of weldment.

APA, Harvard, Vancouver, ISO, and other styles

15

Sunar Baskoro, Ario, Indra Milyardi, and Mohammad Azwar Amat. "The Effect of Welding Parameter on Mechanical Properties and Macrostructure of AA1100 Using Autogenous Tig Welding." International Journal of Automotive and Mechanical Engineering 17, no. 1 (March 30, 2020): 7562–69. http://dx.doi.org/10.15282/ijame.17.1.2020.05.0560.

Full text

Abstract:

In this paper, an autogenous tungsten inert gas (TIG) welding was performed to understand the characteristic effect of butt joint weld on AA1100 under various parameters. The effect of TIG current and welding speed was selected to study the mechanical properties, porosity, and macrostructure of the weld metal (WM). Based on experimental results, the top bead width (TBW) will increase directly proportional to the increased of welding current. Furthermore, welding current and welding speed affected the strength drop in the heat-affected zone (HAZ). More heat added will result in a deeper drop in strength. Mechanical properties result showed that the tensile strength reduced by 40 – 45% and the hardness reduction in the WM and HAZ area from the base metal (BM) was 17.3% and 27.7%, respectively. Subsequently, X-Ray radiography images showed that there was no large porosity occur in all welding current. The macrostructure showed that the weld bead typically has the concavity shape or U-shaped geometry from a cross-sectional view.

APA, Harvard, Vancouver, ISO, and other styles

16

Haikal, Haikal, Moch Chamim, Deni Andriyansyah, Emanuel Budi Raharjo, Ario Sunar Baskoro, and Isnarno Isnarno. "Effect of Magnetic Field Induce Arc in Autogenous TIG Welding of 304 Stainless Steel Butt Joint." Automotive Experiences 4, no. 1 (February 5, 2021): 27–35. http://dx.doi.org/10.31603/ae.4199.

Full text

Abstract:

This paper reports the use of External Magnetic Field-Tungsten Inert Gas (EMF-TIG) method in butt joint applications to determine the effect of welding arc compression on the quality of butt joint of SS 304 thin plate was reported. The welding process was performed without using filler or autogenous welds. The external magnetic field was generated by placing a magnetic solenoid around the TIG welding torch. The results of this study showed that EMF-TIG welding can produce a more uniform bead width along the weld line compare with conventional TIG. Moreover, the D/W ratio obtained under external magnetic field was higher than without magnetic. However, the tensile strength of butt joint decreased with EMF-TIG because there is constriction in arc welding which produces shrinkage weld pool volume. In addition, high welding speeds result in a decrease in the tensile strength of both conventional TIG and EMF-TIG welds.

APA, Harvard, Vancouver, ISO, and other styles

17

Caiazzo, Fabrizia, Vittorio Alfieri, Antonello Astarita, Antonino Squillace, and Giuseppe Barbieri. "Investigation on laser welding of Ti-6Al-4V plates in corner joint." Advances in Mechanical Engineering 9, no. 1 (January 2017): 168781401668554. http://dx.doi.org/10.1177/1687814016685546.

Full text

Abstract:

The article deals with laser beam welding of Ti-6Al-4V plates for aerospace applications. A number of trials are conducted to weld 3-mm-thick plates in corner joint configuration; a specific device for clamping and shielding to prevent oxidation is used. Autogenous welding is investigated, the joint being accessed from the outside, as a butt-welded corner joint. Referring to international standards, the results are first discussed in terms of geometry of the welding bead in the cross-section since titanium alloys are reported to be notch sensitive. Moreover, microstructure and microhardness are investigated. An optimum processing condition is suggested in order to perform laser beam welding with minimal undercut and porosity.

APA, Harvard, Vancouver, ISO, and other styles

18

García-García, V., H. Hernández-Belmontes, I. Mejía, F. Reyes-Calderón, and C. Maldonado. "Effect of the Heat Input on the Heat Affected Zone in the Austenitic Stainless Steel Welding by the GTAW Process-An Experimental and Computational Analysis." MRS Advances 2, no. 61 (2017): 3781–86. http://dx.doi.org/10.1557/adv.2017.594.

Full text

Abstract:

ABSTRACTArc welding processes such Gas Tungsten (GTAW), Gas Metal (GMAW) and Submerged Arc (SAW) are typically used in order to produce a weld joint in stainless steels (SS). However, welding thermal cycle generates a sensitization by formation of chromium carbides. In addition, the heat affected zone (HAZ) is also susceptible to sensitization and fracture of the weldment. Weld bead geometric parameters such depth penetration, fusion zone (FZ) width and size of HAZ are mainly determined by welding operation parameters. This research work studies the influence of welding current, welding speed and arc gap on the width and grain size in the HAZ produced by a single pass of autogenous GTAW process applied to a plate butt-welded joint of AISI 304 SS. The welded specimens were prepared for analysis by light optical (LOM) and scanning electron (SEM) microscopies to identify the interfaces between FZ-HAZ and base material as well as the grain growth in the HAZ. Adams equation for 2-D heat distribution was used to estimate theoretically the width of the HAZ. Furthermore, computational simulation which solved a convective-diffusion problem of the volumetric heat applied during the weld pool formation allowed to correlate the thermal gradient and the molten material flow of the FZ with the welding depth penetration, and width and grain size in the HAZ. The results demonstrated that the high heat input generates an important grain growth in the HAZ caused by low heat diffusion in the adjacent material to the fusion line. Welding speed was the main factor in the thermal gradient changes. Simulation results indicate that outward recirculating flow in the molten metal produced by surface tension forces is responsible for the shallow penetration of the autogenous GTAW process. Theoretical and computational estimations of the HAZ are in good agreement with the experimental results.

APA, Harvard, Vancouver, ISO, and other styles

19

Shanmugarajan, B., G. Padmanabham, H. Kumar, S. K. Albert, and A. K. Bhaduri. "Autogenous laser welding investigations on modified 9Cr–1Mo (P91) steel." Science and Technology of Welding and Joining 16, no. 6 (August 2011): 528–34. http://dx.doi.org/10.1179/1362171811y.0000000035.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Li, Zhang, G. Fontana, and M. Penasa. "Autogenous laser welding of austenitic stainless steel to copper alloy." Science and Technology of Welding and Joining 3, no. 2 (April 1998): 81–87. http://dx.doi.org/10.1179/stw.1998.3.2.81.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Du Toit, M., and P. C. Pistorius. "Nitrogen Control During the Autogenous ARC Welding of Stainless Steel." Welding in the World 47, no. 9-10 (September 2003): 30–43. http://dx.doi.org/10.1007/bf03266398.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Sojiphan, Kittichai. "Microstructure Characterization of Pure Tungsten Electrodes Used in Gas Tungsten Arc Welding of Aluminum Alloy." Key Engineering Materials 728 (January 2017): 91–95. http://dx.doi.org/10.4028/www.scientific.net/kem.728.91.

Full text

Abstract:

Autogenous gas tungsten arc welding (GTAW) using different non-consumable pure tungsten electrodes (EWP) from eight different manufacturers was performed on aluminum alloy 5083 samples. Due to the limited literatures of how tungsten microstructure may affect the weld quality, this paper attempts to investigate the change in microstructure of tungsten electrode after welding compared to the original microstructure in as-received condition. The scanning electron micrograph results reveal different grain shapes and sizes and also different grain growth rate during welding. It was found that the ability to control the grain growth or limit grain size within the balled end of pure tungsten electrode during aluminum welding plays a very important role in determining the quality of the electrode and how long the electrode would last.

APA, Harvard, Vancouver, ISO, and other styles

23

Venkatesan, G., Veerappan Muthupandi, and N. Ashok. "On the Bead Geometry of Dissimilar Joints between SA516Gr65 and 304L Produced by TIG and A-TIG Welding." Materials Science Forum 863 (August 2016): 19–22. http://dx.doi.org/10.4028/www.scientific.net/msf.863.19.

Full text

Abstract:

Dissimilar autogenous square butt joints between SA516Gr65 and 304L steels were produced by TIG welding and A-TIG welding with SiO2 and TiO2single component fluxes used in the as-received condition and dried at 150°C for one hour. Results showed that with A-TIG welding considerable improvement in depth of penetration could be achieved. Reversal of Marangoni convection could be the operative mechanism with the use of flux in the as-received condition while arc constriction could also contribute with the use of dried fluxes. Between the two single component fluxes viz., SiO2 and TiO2 studied SiO2 was found to be more effective in improving the depth of penetration.

APA, Harvard, Vancouver, ISO, and other styles

24

Haikal, Haikal, Moch Chamim, Deni Andriyansyah, Apri Wiyono, Ario Sunar Baskoro, and Isnarno Isnarno. "Peningkatan Kedalaman Penetrasi Las Stainless Steel 304 dengan Medan Magnet Eksternal pada Pengelasan Autogenous Tungsten Inert Gas Welding." Jurnal Rekayasa Mesin 12, no. 1 (May 31, 2021): 87. http://dx.doi.org/10.21776/ub.jrm.2021.012.01.10.

Full text

Abstract:

In this study, research on the use of the External Magnetic Field method – Tungsten Inert Gas was done to determine the effect of welding arc compression on the quality of AISI 304 thin plate weld. The welding process was performed using autogenous welds. In this study, an external magnetic field was generated by placing a magnetic solenoid around the TIG welding torch. Enabling this electromagnetic field is done dynamically using a microcontroller. Welding parameters used are welding current 100; 105; 110 A and welding speed 1.6; 1.8; 2.05 mm/s. The results of this study showed that EMF-TIG welding can produce a more uniform bead width along the weld line with a standard deviation of 0.08 compared with conventional TIG welding of 0.12. Increased welding speed of 2.05 mm/s causes no effect on the addition of an external magnetic field to the width of the weld bead. The current parameters are 105 A with a speed of 1.6; 1.8; 2.05 mm/s resulted in compression of the top bead width by 0.87; 0.61; 0.1 mm. The welding parameters with a current of 105 A and welding speed of 1.6 mm/s have a larger upper bead compression effect of 0.84 mm compared to 110 A currents of 0.38 mm. Moreover, the D/W ratio obtained under an external magnetic field was higher than without magnetic.

APA, Harvard, Vancouver, ISO, and other styles

25

Brytan, Z., and J. Niagaj. "Corrosion Resistance and Mechanical Properties of TIG and A-TIG Welded Joints of Lean Duplex Stainless Steel S82441 / 1.4662." Archives of Metallurgy and Materials 61, no. 2 (June 1, 2016): 771–84. http://dx.doi.org/10.1515/amm-2016-0131.

Full text

Abstract:

Abstract This paper presents results of pitting corrosion resistance of TIG (autogenous and with filler metal) and A-TIG welded lean duplex stainless steel S82441/1.4662 evaluated according to ASTM G48 method, where autogenous TIG welding process was applied using different amounts of heat input and shielding gases like pure Ar and Ar+N2 and Ar+He mixtures. The results of pitting corrosion resistance of the welded joints of lean duplex stainless steel S82441 were studied in as weld conditions and after different mechanical surface finish treatments. The results of the critical pitting temperature (CPT) determined according to ASTM G48 at temperatures of 15, 25 and 35°C were presented. Three different surface treatment after welding were applied: etching, milling, brushing + etching. The influence of post weld surface treatment was studied in respect to the pitting corrosion resistance, basing on CPT temperature. Research on TIG welding of lean duplex stainless steel S82441/1.4662 showed a clear influence of the applied shielding gas mixtures, where the addition of 5 to 15% N2 to Ar virtually no effect on the level of resistance to pitting corrosion, only 5% N2 addition has a positive effect, while use of a mixture of 50% Ar + 50% He compared with welding at 100% Ar atmosphere, can significantly reduce the resistance to pitting corrosion. Definite good results were obtained during TIG welding with the participation of activation flux (A-TIG). The weld surface of lean duplex stainless S82441/1.4662 obtained in A-TIG welding without the addition of filler metal has a much lower tendency to pitting corrosion than traditional welds made by TIG method. Pitting corrosion resistance of welds made by A-TIG improved with the increase of the heat input in the tested range of welding current 100-200 A. It was also found that the intensity of the occurrence of pitting does not affect the method of cleaning welds after welding, but the mechanical removal of a thin surface layer of metal significantly reduces their intensity.

APA, Harvard, Vancouver, ISO, and other styles

26

Dhinakaran, V., N. Siva Shanmugam, and K. Sankaranarayanasamy. "Experimental investigation and numerical simulation of weld bead geometry and temperature distribution during plasma arc welding of thin Ti-6Al-4V sheets." Journal of Strain Analysis for Engineering Design 52, no. 1 (September 30, 2016): 30–44. http://dx.doi.org/10.1177/0309324716669612.

Full text

Abstract:

Numerical and experimental investigations of autogenous plasma arc welding of thin titanium alloy of 2 mm thick and modelling the temperature distribution for predicting the weld bead geometry are presented. The finite element code COMSOL Multiphysics is employed to perform non-linear unsteady heat transfer analysis using parabolic Gaussian heat source. Temperature-dependent material properties such as thermal conductivity, density and specific heat are used to enhance the efficiency of simulation process. A forced convective heat transfer coefficient was used to account for the effect of convection. The experimental trials were conducted by varying the welding speed and current using Fronius plasma arc welding equipment. The simulation results are in good agreement with the experimental results.

APA, Harvard, Vancouver, ISO, and other styles

27

Landowski, M. "Influence of Parameters of Laser Beam Welding on Structure of 2205 Duplex Stainless Steel." Advances in Materials Science 19, no. 1 (March 1, 2019): 21–31. http://dx.doi.org/10.2478/adms-2019-0002.

Full text

Abstract:

AbstractLaser welding is used in modern industry, having many advantages comparing to traditional welding technologies. Nowadays, industry sectors such as shipbuilding, automotive and aviation can’t be imagined without laser processing technologies. Possibility of increase of welded joint properties, autogenous welding and high level of process automation makes the technology of laser welding perspective part of the industry. Physical multidimensional processes complexity requires a deeper understanding of the impact of laser welding parameters on the quality of welded joints for industrial implementation. The paper presents results of microstructure investigations of laser beam welded stainless steel under various welding parameters. Welded joints was achieved by Ytterbium fiber laser type without the use of the filler material. Material for test was 2205 ferritic-austenitic duplex stainless steel (DSS) plates with thickness of 8 mm in delivery condition. The objectives of this research was to investigate influence of laser welding parameters on weld geometry of butt-welded joints. Investigations of bead shape revealed correlation between laser beam focus position and weld penetration depth.

APA, Harvard, Vancouver, ISO, and other styles

28

Widyianto, Agus, Ario Sunar Baskoro, and Gandjar Kiswanto. "Mechanical Properties and Microstructure of Pulsatile Current Gas Tungsten Arc Welding (PC-GTAW) of AISI 304L Butt Joint Weld." Materials Science Forum 1000 (July 2020): 339–47. http://dx.doi.org/10.4028/www.scientific.net/msf.1000.339.

Full text

Abstract:

In this research, investigation of mechanical properties and microstructure on Pulsatile Current Gas Tungsten Arc Welding (PC-GTAW) was carried out. AISI 304L was chosen as a base material with autogenous welding and butt joint configuration. The dimension of the base material was 120 x 50 mm and the thickness of 3 mm. The welding with pulsatile current and constant current were used in the welding process in this study. In the pulsatile current, the mean current was made all the same with a constant current of 100 amperes. The peak current, base current and time of peak and base current were varied to make it the same. The welding speed used is constant at 2.0 mm/s. The result shows that the HAZ area will get shrinkage if welded using pulsatile current welding. The welding with a pulsatile current can produce more fine cellular dendritic structure than the welding with a constant current. The UTS in the welding with a pulsatile current was lower than the welding with constant current, while the impact toughness in the welding with a pulsatile current was higher than the welding with a constant current. The highest of the UTS and the impact toughness of 577.62 MPa on parameter 65-A and 27 J on parameter 65-C, respectively.

APA, Harvard, Vancouver, ISO, and other styles

29

Lisiecki, A. "Welding of Thermomechanically Rolled Fine-Grain Steel by Different Types of Lasers/ Spawanie Stali Drobnoziarnistej Walcowanej Termomechanicznie Laserami Różnego Typu." Archives of Metallurgy and Materials 59, no. 4 (December 1, 2014): 1625–31. http://dx.doi.org/10.2478/amm-2014-0276.

Full text

Abstract:

Abstract The autogenous laser welding of 2.5 mm thick butt joints of thermomechanically rolled fine-grain steel grade S420MC was investigated. Butt joints were laser welded by the Yb:YAG Disk laser, emitted a circular laser beam with spot diameter of 200 μm at 1.03 μm wavelength, and also by the high power direct diode laser, emitted a rectangular beam with dimension of 1.8x6.8 mm at 808 nm wavelength. Different welding modes were identified for the lasers applied. The conduction welding mode was observed in whole of the diode laser welding parameters. While high quality joints, without any internal defects and characterized with satisfactory mechanical performance were produced in a wide range of parameters. The butt joints produced by Disk laser were welded at keyhole mode. In this case a slight tendency to weld porosity was found.

APA, Harvard, Vancouver, ISO, and other styles

30

Chae, H.-B., C.-H. Kim, J.-H. Kim, and S. Rhee. "The effect of shielding gas composition in CO2 laser—gas metal arc hybrid welding." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 222, no. 11 (November 1, 2008): 1315–24. http://dx.doi.org/10.1243/09544054jem944.

Full text

Abstract:

In carbon dioxide (CO2) laser—gas metal arc hybrid welding, a shielding gas is supplied to isolate the molten metal from the ambient air, suppress the laser-induced plasma, remove the plume out of the keyhole, and stabilize the metal transfer. In this study, a shielding gas consisting of helium, argon, and CO2 was used, and its effects on the composition of the welding phenomena, such as behaviours of laser-induced plasma generation, molten pool flow, and droplet transfer in gas metal arc welding, were investigated. High-speed video observation was used to investigate the welding phenomena inside the arc regime. Consequently, helium was found to have a dominant role in suppressing laser-induced plasma; minimum helium content at a laser power of 8 kW was suggested for laser autogenous and hybrid welding. Argon and CO2 govern the droplet transfer and arc stability. A 12 per cent addition of CO2 stabilizes the metal transfer and eliminates undercut caused by insufficient wetting of molten metal.

APA, Harvard, Vancouver, ISO, and other styles

31

Lisiecki, A., R. Burdzik, G. Siwiec, Ł. Konieczny, J. Warczek, P. Folęga, and B. Oleksiak. "Disk Laser Welding of Car Body Zinc Coated Steel Sheets / Spawanie Laserem Dyskowym Blach Ze Stali Karoseryjnej Ocynkowanej." Archives of Metallurgy and Materials 60, no. 4 (December 1, 2015): 2913–22. http://dx.doi.org/10.1515/amm-2015-0465.

Full text

Abstract:

Autogenous laser welding of 0.8 mm thick butt joints of car body electro-galvanized steel sheet DC04 was investigated. The Yb:YAG disk laser TruDisk 3302 with the beam spot diameter of 200 μm was used. The effect of laser welding parameters and technological conditions on weld shape, penetration depth, process stability, microstructure and mechanical performance was determined. It was found that the laser beam spot focused on the top surface of a butt joint tends to pass through the gap, especially in the low range of heat input and high welding speed. All test welds were welded at a keyhole mode, and the weld metal was free of porosity. Thus, the keyhole laser welding of zinc coated steel sheets in butt configuration provides excellent conditions to escape for zinc vapours, with no risk of porosity. Microstructure, microhardness and mechanical performance of the butt joints depend on laser welding conditions thus cooling rate and cooling times. The shortest cooling time t8/5 was calculated for 0.29 s.

APA, Harvard, Vancouver, ISO, and other styles

32

Tseng, Kuang Hung, and Hsiang Lin Sung. "Advances in Fusion Welding Technique of Austenitic Stainless Steels." Key Engineering Materials 480-481 (June 2011): 527–32. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.527.

Full text

Abstract:

Activated flux assisted tungsten inert gas (TIG) welding of austenitic 316L stainless steel was investigated. Autogenous TIG welding was used to produce a bead-on-plate weld. The FeO, FeS, and FeF2 were selected as the flux powders. The results showed that the FeS and FeO fluxes produced high aspect ratio welds, while the FeF2 flux produced a relatively low aspect ratio weld. The undercut defect was produced with use of the FeS flux. An experimental result suggested the constriction of arc column as a mechanism in improving activated TIG penetration. In addition, activated TIG process can increase the delta-ferrite content in austenitic stainless steel weld metal.

APA, Harvard, Vancouver, ISO, and other styles

33

Cao, X., and A. Nolting. "Autogenous fiber laser welding of 70/30 Cu-Ni alloy plates." Materials & Design 181 (November 2019): 108075. http://dx.doi.org/10.1016/j.matdes.2019.108075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Li, Zhang, S. L. Gobbi, and K. H. Richter. "Autogenous welding of Hastelloy X to Mar-M 247 by laser." Journal of Materials Processing Technology 70, no. 1-3 (October 1997): 285–92. http://dx.doi.org/10.1016/s0924-0136(97)02939-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

B., Shanmugarajan, Chary J.N., Padmanabham G., Arivazhagan B., Shaju K. Albert, and Bhaduri A.K. "Studies on autogenous laser welding of type 304B4 borated stainless steel." Optics and Lasers in Engineering 51, no. 11 (November 2013): 1272–77. http://dx.doi.org/10.1016/j.optlaseng.2013.05.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Shanmugarajan, B., P. Sathiya, and G. Buvanashekaran. "Effect of Shielding Gases in Autogenous Laser Welding of P92 Material." Transactions of the Indian Institute of Metals 72, no. 7 (March 7, 2019): 1707–20. http://dx.doi.org/10.1007/s12666-019-01638-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Bahrami, Alireza, Daniel T. Valentine, Brian T. Helenbrook, and Daryush K. Aidun. "Study of mass transport in autogenous GTA welding of dissimilar metals." International Journal of Heat and Mass Transfer 85 (June 2015): 41–53. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2015.01.074.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Paula, Thalita Cristina de, Cintia Cristiane Petry Mazzaferro, Daniela Fátima Giarollo, Gelsa Edith Navarro Hidalgo, and Breno Basso. "Effect of autogenous GTAW on the reciprocating sliding wear behavior of a carbon martensitic steel." Acta Scientiarum. Technology 43 (February 26, 2021): e50488. http://dx.doi.org/10.4025/actascitechnol.v43i1.50488.

Full text

Abstract:

Martensitic steels have been successfully employed in resource-based industries where components must endure aggressive conditions. In industrial practice, many parts of these components are joined by welding techniques. The aim of this work was to understand the influence of welding on the wear resistance of quenched and tempered carbon martensitic steel subjected to dry linear reciprocating sliding micro-wear tests. Weld-joints were produced using autogenous Gas Tungsten Arc Welding process (GTAW). Micro-wear tests were performed at base metal (BM), weld metal (WM), coarse grained heat affected zone (CG-HAZ) and lowest hardness region of heat affected zone (LHR-HAZ). LHR-HAZ was softened during welding process so plastic deformation was facilitated, and consequently adhesion, material displacement and micro-ploughing. WM and CG-HAZ presented a similar martensitic structure, which explain the similarities found on wear behavior. These regions presented the lowest worn volume average values (w). It was interesting to note that despite its highest microhardness value, the highest w was observed for BM. For some BM samples, debris had a key role promoting material loss by micro-cutting which causes great extent of material removal compared to other micro-wear mechanisms as micro-ploughing and adhesion. Due to debris action BM also presented a great dispersion in w results. The results suggest that material loss of welded joint and BM was strongly controlled by micro-wear mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

39

Kurc-Lisiecka, A., J. Piwnik, and A. Lisiecki. "Laser Welding of New Grade of Advanced High Strength Steel STRENX 1100 MC." Archives of Metallurgy and Materials 62, no. 3 (September 26, 2017): 1651–57. http://dx.doi.org/10.1515/amm-2017-0253.

Full text

Abstract:

AbstractThe article presents results of investigations on autogenous laser welding of new grade STRENX 1100 MC steel. The modern Disk laser was applied for of 5.0 mm thick butt joints welding. The influence of laser welding parameters, mainly the energy input of laser welding on the penetration shape, weld quality, structure and mechanical performance was investigated. It was found that the investigated steel has surprisingly low carbon equivalent CET just 0.328, and also relatively high temperature of martensitic transformation Msat 430.6°C. Despite very rapid cooling times t8/5in a range from 0.6 to 1.3 s, thus rapid solidification there was no tendency to cracking of weld metal or HAZ. Significant drop of microhardness in the HAZ resulted in a decrease of tensile strength of joints, compared to the base metal. Impact toughness of test joints was at only 50÷60% of the base metal.

APA, Harvard, Vancouver, ISO, and other styles

40

Garavaglia, Matteo, Ali Gökhan Demir, Stefano Zarini, Brian M. Victor, and Barbara Previtali. "Fiber laser welding of AA 5754 in the double lap-joint configuration: process development, mechanical characterization, and monitoring." International Journal of Advanced Manufacturing Technology 111, no. 5-6 (October 15, 2020): 1643–57. http://dx.doi.org/10.1007/s00170-020-06128-6.

Full text

Abstract:

Abstract Aluminum alloys are widely spread in many industrial sectors due to their desirable characteristics as low density, good formability, high specific strength, and good resistance to corrosion. Autogenous laser welding is a technology that enables the use of these materials in the industrial process due to its high repeatability, reliability, and ease of automatization. In particular, in automotive applications, Al-alloys are welded in lap-joint configurations with more than 2 layers of material. The welding condition should be monitored in order to detect the complete penetration, hence guaranteeing the appropriate weld resistance. The use of non-invasive and coaxial monitoring solutions is highly desirable for the identification of weld defects during the process. This study investigates an autogenous laser welding process and monitoring in the double lap-joint configuration of sheets of AA 5754. First, the process parameters are investigated to identify the geometrical and mechanical characteristics of the resultant welding seams at different process conditions. The employed high-brilliance 3 kW fiber laser provided the possibility of reading the back-reflected light signal from an internal photodiode. The capability of this signal to be used as a non-invasive, coaxial, and remote monitoring system in order to predict the process outcome was tested. In the experiments the back-reflected light intensity could be correlated to the weld seam width at the second interface, as well as the strength of the joint to shear. Finally, the monitoring signal behavior was demonstrated under simulated weld defect conditions. The results show that weld anomalies such as lack of penetration, misalignment, and gap formation can be sensed through the monitoring approach.

APA, Harvard, Vancouver, ISO, and other styles

41

Kandavel, T. K., and D. Vijay. "Experimental Investigations on Welding and Mechanical Characteristics of Sintered-Forged Plain Carbon Steel under Autogenous TIG Welding." Materials Performance and Characterization 7, no. 1 (January 1, 2018): 20170022. http://dx.doi.org/10.1520/mpc20170022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Kumar, Kamlesh, Pankaj Ahirwar, and Manoj Masanta. "Effect of Varying Root Gap on Butt Welding of 6 mm Thick AISI 1020 Plate by Autogenous TIG Welding Process." Materials Science Forum 880 (November 2016): 21–24. http://dx.doi.org/10.4028/www.scientific.net/msf.880.21.

Full text

Abstract:

In this study, AISI 1020 plate of 6 mm thickness has been welded by autogenous TIG welding process maintaining different root gap (0, 0.5, 0.75 and 1 mm). The weld bead profile and the tensile strength of the welded joint has been analysed. From the experimental results it is revealed that, for increasing the root gap, weld depth penetration increases; whereas weld bead width and heat affected zone (HAZ) is almost uniform. However, at the similar condition, under-filling of the weld joint increases with the increase in root gap. For using 1 mm root gap, weld joint exhibit full depth of penetration and maximum tensile strength, along with higher under-filling.

APA, Harvard, Vancouver, ISO, and other styles

43

Yurtisik, Koray, Suha Tirkes, Igor Dykhno, C. Hakan Gur, and Riza Gurbuz. "Characterization of duplex stainless steel weld metals obtained by hybrid plasma-gas metal arc welding." Soldagem & Inspeção 18, no. 3 (September 2013): 207–16. http://dx.doi.org/10.1590/s0104-92242013000300003.

Full text

Abstract:

Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex microstructure without compromising the welding efficiency. 11.1 mm-thick standard duplex stainless steel plates were joined in a single-pass using this novel technique. Same plates were also subjected to conventional gas metal arc and plasma arc welding processes, providing benchmarks for the investigation of the weldability of the material. In the first place, the hybrid welding process enabled us to achieve less heat input compared to gas metal arc welding. Consequently, the precipitation of secondary phases, which are known to be detrimental to the toughness and corrosion resistance of duplex stainless steels, was significantly suppressed in both fusion and heat affected zones. Secondly, contrary to other keyhole techniques, proper cooling time and weld metal chemistry were achieved during the process, facilitating sufficient reconstructive transformation of austenite in the ferrite phase.

APA, Harvard, Vancouver, ISO, and other styles

44

Chukkan, Jazeel Rahman, M. Vasudevan, S. Muthukumaran, K. C. Ganesh, Ravi Kumar, S. Murugan, and V. Maduraimuth. "Numerical Simulation of Pulsed Nd-YAG Laser Butt Welding of AISI 304L Stainless Steel Sheet and Experimental Validation." Applied Mechanics and Materials 592-594 (July 2014): 565–70. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.565.

Full text

Abstract:

The objective of this work is to carry out thermo-elasto-plastic analysis of pulsed Nd-YAG laser-beam butt welding of 304L Stainless Steel sheets using Finite Element Modelling. Thermo-mechanical analysis was done by using commercial Finite Element software SYSWELD. Thermal analysis provided thermal cycles and weld bead geometry. Then using thermo-mechanical analysis, residual stresses and distortion values were estimated. In order to validate the model predictions, a single pass autogenous welding with pulsed laser beam was performed on 304L stainless steel sheets. Thermocouples were used to record temperatures at different places close to the fusion line. Vertical displacements after welding were measured using Vertical height gauge equipment. The longitudinal residual stress after welding was measured using an ultrasonic technique. Metallography was employed to view the cross sections of the weld bead. The Finite Element Analysis results were then compared with experimental results. Thermal cycles, distortion and residual stresses obtained in FEA and experiments were found to be in good agreement.

APA, Harvard, Vancouver, ISO, and other styles

45

Hamelin, Cory J., Ondrej Muránsky, and Lyndon Edwards. "The Influence of Austenite Grain Size during Welding Simulations of Ferritic Steels." Advanced Materials Research 996 (August 2014): 512–17. http://dx.doi.org/10.4028/www.scientific.net/amr.996.512.

Full text

Abstract:

In recent years, considerable progress has been made in the simulation of ferritic steel welding processes. The successful validation of a single-pass autogenous TIG beam weld in SA508 Gr.3 Cl.1 steel has identified key simulation variables required for the accurate prediction of post-weld residual stress in ferritic weldments. The present work outlines a sensitivity study performed to examine the influence of austenite grain growth on predicted solid-state phase transformation kinetics and consequently, residual stress predictions.

APA, Harvard, Vancouver, ISO, and other styles

46

Dong, Wenchao, Shanping Lu, Dianzhong Li, and Yiyi Li. "Modeling of the Weld Shape Development During the Autogenous Welding Process by Coupling Welding Arc with Weld Pool." Journal of Materials Engineering and Performance 19, no. 7 (November 5, 2009): 942–50. http://dx.doi.org/10.1007/s11665-009-9570-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Ning, Jie, Lin-jie Zhang, Qing-lin Bai, Xian-qing Yin, Jing Niu, and Jian-xun Zhang. "Comparison of the microstructure and mechanical performance of 2A97 Al-Li alloy joints between autogenous and non-autogenous laser welding." Materials & Design 120 (April 2017): 144–56. http://dx.doi.org/10.1016/j.matdes.2017.02.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Demirorer, Mete, Wojciech Suder, Supriyo Ganguly, Simon Hogg, and Hassam Naeem. "Development of laser welding of high strength aluminium alloy 2024-T4 with controlled thermal cycle." MATEC Web of Conferences 326 (2020): 08005. http://dx.doi.org/10.1051/matecconf/202032608005.

Full text

Abstract:

An innovative process design, to avoid thermal degradation during autogenous fusion welding of high strength AA 2024-T4 alloy, based on laser beam welding, is being developed. A series of instrumented laser welds in 2 mm thick AA 2024-T4 alloys were made with different processing conditions resulting in different thermal profiles and cooling rates. The welds were examined under SEM, TEM and LOM, and subjected to micro-hardness examination. This allowed us to understand the influence of cooling rate, peak temperature, and thermal cycle on the growth of precipitates, and related degradation in the weld and heat affected area, evident as softening. Although laser beam welding allows significant reduction of heat input, and higher cooling rates, as compared to other high heat input welding processes, this was found insufficient to completely supress coarsening of precipitate in HAZ. To understand the required range of thermal cycles, additional dilatometry tests were carried out using the same base material to understand the time-temperature relationship of precipitate formation. The results were used to design a novel laser welding process with enhanced cooling, such as with copper backing bar and cryogenic cooling.

APA, Harvard, Vancouver, ISO, and other styles

49

Theron, Maritha, Herman Burger, Lilian Ivanchev, and Corney van Rooyen. "Property and Quality Optimization of Laser Welded Rheo-Cast F357 Aluminum Alloy." Solid State Phenomena 192-193 (October 2012): 167–72. http://dx.doi.org/10.4028/www.scientific.net/ssp.192-193.167.

Full text

Abstract:

F357, a hypo-eutectic Al-7%Si-0.6%Mg alloy without beryllium, was processed with CSIR-Rheo technology to the Semi-Solid Metal (SSM) state and cast in plates by means of High Pressure Die Casting. The castings were either left in the as-cast (F) condition or subjected to T4 or T6 heat treatments prior to autogenous Nd:YAG laser welding. A welding operating window was established and within this window, the weld porosity and undercut were minimised. Butt welds complying with ISO 13919-2: 2001 could be produced by means of the optimum parameters of 3.8 kW laser power and a welding speed of 4 m/min with a twin spot laser beam configuration. The mechanical properties of age-hardenable Al-Si-Mg alloys are dependent on the rate at which the alloy is cooled after the solution heat treatment. The low heat input provided by the laser welding process resulted in high enough cooling rates to ensure that both the fusion zone and HAZ were in the T4 condition after welding. Tensile properties equivalent to the parent metal in T6 condition were obtained after subjecting welded T4 plates to conventional artificial ageing treatment.

APA, Harvard, Vancouver, ISO, and other styles

50

Charunetratsamee, Sittisak, Bovornchok Poopat, and Chalermkiat Jirarungsatean. "Feasibility Study of Acoustic Emission Monitoring of Hot Cracking in GTAW Weld." Key Engineering Materials 545 (March 2013): 236–40. http://dx.doi.org/10.4028/www.scientific.net/kem.545.236.

Full text

Abstract:

Acoustic emission testing can be used to detect the energy emitted from material fracture and the advantage of this method is the real time monitoring, however the weld metal discontinuities are normally inspected by using conventional NDT methods such as Penetrant Testing (PT), Magnetic particle Testing (MT), Ultrasonic Testing (UT) and Radiographic Testing (RT) after the completion of welding. The weld defect must be repaired, which involves the cost and consumes a lot of time as well as reduce the reliability of manufactures. This paper presents the application of acoustic emission (AE) technique for monitoring and detecting the discontinuities during welding. In this study, gas tungsten arc welding (GTAW) was selected as test process. Carbon steel plate and autogenous welding technique were used to simulate the hot crack. The data acquisition (DAQ) and AE sensor were used to capture the acoustic signal generated during welding. The AE signals were amplified and filtered by using preamplifier. Then, signals were modified by wavelet transforms (WT) technique and classified by Fast Fourier Transform (FFT) technique. The results showed the possibility to use AE technique for monitoring and detecting the low signal amplitude generated from crack by using frequency domain. The advantage of this research is to propose the technique for monitoring the weld metal discontinuities during welding.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Autogenous welding'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles