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Hybrid Joining Processes
Published in R. Ganesh Narayanan, Jay S. Gunasekera, Sustainable Material Forming and Joining, 2019
V. Satheeshkumar, R. Ganesh Narayanan
The laser–MIG hybrid welding technique has been developed to combine the advantages of both the processes in order to meet the welding industry needs. Arc welding is beneficial as it is inexpensive and uses available energy source. It has a considerable effect in changing microstructure by acceptable melting of the groove. On the other hand, laser welding has high welding rate and produces deeper welds. As a result, in the hybrid variety, arc stability and thermal efficiency improve because of the presence of plasma. Figure 13.1 shows the schematic of laser–MIG hybrid welding. The two sources involved in hybrid laser–MIG process act complementarily, and hence, faster welding, deep bead penetration associated with the formation of keyhole, and high energy concentration achieved by the laser beam are observed. Gap bridging and cost-effectiveness are the other advantages of the process. The type of laser source (Nd:YAG, CO2, fiber laser), arc welding/laser-welding parameters, shielding gas composition, filler wire composition, number of laser welding/arc welding sources, and location of energy sources are some of the variables identified during the welding process, which can be optimized for sustainable welding.
Engineering Control Measures of ANSI Z136.1
Published in D. C. Winburn, Practical Laser Safety, 2017
Eye protection shall be provided for the ultraviolet and blue-green spectral region (0.2 to 0.55 μm) for laser welding processes. On the basis of currently available data, a minimum optical density, Dλ, of 2.0(neutral density) or welding shade 7 (see American National Standard Practice for Occupational and Educational Eye and Face Protection, ANSI Z87.1·1979 or the latest revision thereof) is recommended for emission in the ultraviolet and blue-green spectral regions. The optical density values given above would apply for the laser induced plasma, such as that associated with typical laser welding systems. Greater optical densities are required for higher power laser welding systems.
Manufacturing Processes
Published in Quamrul H. Mazumder, Introduction to Engineering, 2018
Laser welding is recognized as an advanced process to join materials with laser beams of high-power, high-energy density in every industrial field. The power density of a laser beam, which is equivalent to that of an electron beam, is much higher than that of an arc or plasma. Consequently, a deep, narrow keyhole is formed during welding with a high-power laser or electron beam and a deep, narrow penetration weld can be effectively produced. In electron beam welding, the chamber for a vacuum environment and X-ray protection should be used. Arc and plasma welding cannot be employed in a vacuum; however, laser welding can be performed and a sound, deep weld bead can be produced in a similar way to electron beam welding.
Laser and hybrid laser welding of type 316L(N) austenitic stainless steel plates
Published in Materials and Manufacturing Processes, 2020
The laser beam possesses a higher power density than arc which helps in achieving maximum depth of penetration autogenously in a single pass. Laser welding process has more benefits namely low heat input, narrow HAZ, no filler wire usage, no groove preparation, low residual stress, low distortion and faster welding speed which altogether result in higher quality and productivity. However, laser beam welding has some limitations such as porosity formation, requirement for stringent clamping, higher power capacity for welding high thickness components and cracking due to faster cooling rates. The shortcomings of the laser welding can be surmounted by coupling another heat source to the laser and this resulted in the development of a new advanced welding process called hybrid laser welding process.
The microstructure and mechanical properties features of laser welded joints of low-carbon tubular steel
Published in Welding International, 2020
L. S. Derevyagina, A. I. Gordienko, A. G. Malikov, A. M. Orishich, P. O. Kashiro
The growing level of requirements for the quality of pipeline construction, associated with the intensive development of the Arctic regions of the country, dictates the need for a deep study of the issues of ensuring the strength and reliability of the operation of welded structures. Among the numerous ways to implement the welding process, the use of highly concentrated fluxes of laser radiation energy is currently one of the promising directions in the development of technologies for obtaining permanent joints [1–7]. Due to the high concentration of the laser beam energy on a small heating area, it is possible to obtain narrow seams and join workpieces of large thicknesses [6,7]. The high speeds of laser welding significantly increase its productivity compared to traditional welding methods. It was shown [4,7] that for corrosion-resistant and low-carbon pipe steels, laser welding allows ensuring the properties of welded joints at the level of the base metal and, at the same time, increasing the welding productivity by three times. At the same time, the impact toughness of laser welded joints is an order of magnitude higher than in arc welding under flux [7].
Experimental investigation and optimization of co-axial ring + core dual beam laser welding parameters for SUS301 stainless steel sheet
Published in Materials and Manufacturing Processes, 2023
Zuguo Liu, Huiyang Chen, Xiangzhong Jin
In this paper, the hump heights of the weld are considered as two response variables. Normally, laser welding is a process in which materials are neither added nor removed, but the similar or dissimilar materials are fused together to achieve connection. Therefore, if there are large humps in the weld, a part of the material will inevitably be removed, resulting in some defects, such as undercut, collapse, and pores. These defects will directly seriously affect the tensile properties of the welded parts. As what mentioned in the above analysis, the weld fracture easily appears at the position of the undercut.