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Shielding gas

About: Shielding gas is a research topic. Over the lifetime, 6697 publications have been published within this topic receiving 58668 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, conditions for consistent coupling of a CO2 laser beam to weld 5182 aluminum alloy sheet were determined for consistent welds on 0.8 and 1.8 mm sheets.
Abstract: Conditions were determined for consistent coupling of a CO2 laser beam to weld 5182 aluminum alloy sheet. Full penetration butt and bead-on-plate welds on 0.8 and 1.8 mm sheets were performed. Process conditions examined included beam mode, spot size and irradiance, shielding gas flow, and edge quality and fitup. The observed weld quality variations with the different process parameters were consistent with physical phenomena and a threshold irradiance model. Optimal conditions were determined for obtaining consistent welds on 5182 alloy sheets. Formability and tensile tests were performed on the welded samples. All test failures occurred in the fusion zone. Reduction in formability and tensile strength of the welded samples are discussed with respect to weld profiles and process parameters.

24 citations

Journal ArticleDOI
TL;DR: In this article, a TIG melted surface of a microalloy steel substrate, with or without incorporating pre-placed SiC particles, in either argon or argon-helium environments, was shown to reach a maximum temperature of 375°C in the second third of the track.
Abstract: The use of a tungsten inert gas (TIG) welding torch has resulted in the development of an economical route for surface engineering of alloys, giving similar results to the more expensive high power laser. Owing to the preheating generated by both techniques, the extent of the temperature rise is sufficient to produce significant changes to the melt dimensions, microstructure and properties between the first and last tracks melted during the coating of a complete surface. The present study examines if similar changes can occur between the start and finish locations of a single track of 50 mm length. The results show that for a TIG melted surface of a microalloy steel substrate, with or without incorporating preplaced SiC particles, in either argon or argon–helium environments, a maximum temperature of 375°C developed in the second third of the track. Even over this short distance, a hardness decrease of >300 HV was recorded in the resolidified SiC coated substrate melt zone, microstructure of a cas...

24 citations

Journal ArticleDOI
B.H. Choi1, B.K. Choi1
TL;DR: In this article, the effect of welding condition according to mechanical properties of pure titanium and presents the optimum welding condition through the evaluation about the weldability of pure Titanium by the welding conditions such as the welding pass, the amount of shielded gas and the welding time interval.

24 citations

Journal ArticleDOI
TL;DR: In this paper, a new vacuum chamber was designed to put on the welding zone of a workpiece, which has no size limit with this chamber, so that a large and thick plate could be welded with laser under low pressure.
Abstract: Unlike the normal vacuum chamber that a workpiece is put inside, a new vacuum chamber was designed to put on the welding zone of a workpiece, which has no size limit with this chamber, so that a large and thick plate could be welded with laser under low pressure. In this new vacuum chamber, a local subatmospheric pressure on the welding zone was achieved with side draught by a vacuum pump. A series of spot welding experiments were performed with fiber laser under subatmospheric pressure, normal atmospheric pressure with and without shielding gas side-blowing, respectively. The feature of weld surfaces and cross-section profiles for above different conditions were compared. A high-speed camera was applied to observe the behavior of plasma plume. The results indicated that the deeper welding penetration and narrower weld bead width could be obtained under subatmospheric pressure. The characteristics of spot weld bead under local subatmospheric pressure were quite different from the one under normal atmospheric pressure with shielding gas side-blowing method. The plasma plume was suppressed more effectively by local subatmospheric pressure than that by shielding gas side-blowing. Additional experiments of continuous laser welding under local subatmospheric pressure were tried and sound welds could be obtained.

24 citations

Patent
27 Jan 1977
TL;DR: In this article, a method for butt welding a pair of vertically disposed tubular members having a wall thickness of more than 12 mm in end-to-end relationship by multi-pass shielded arc welding with a consumable electrode, comprising the steps of preparing the opposed edges of the tubular member by forming a root face the width of which being in the range of 0.5 mm to 3.0 mm, performing a root pass by continuously feeding an electrode having a diameter not larger than about 1.
Abstract: A method for butt welding a pair of vertically disposed tubular members having a wall thickness of more than 12 mm in end-to-end relationship by multi-pass shielded arc welding with a consumable electrode, comprising the steps of preparing the opposed edges of the tubular members by forming a root face the width of which being in the range of 0.5 mm to 3.0 mm and beveling the edges adjacent to the root face to a bevel angle in the range of 40° to 50°, coaxially aligning said tubular members so that the gap between the root faces is not larger than 1.5 mm, performing a root pass by continuously feeding an electrode having a diameter not larger than about 1.0 mm into the groove between the prepared edges supplying a shielding gas consisting of 0-40% carbon dioxide and the balance argon, energizing an arc between the electrode and the root face alternately changing the voltage supplied to the arc between a low value and a high value, adjusting the low voltage to produce a droplet metal transfer during short circuit periods, adjusting the high voltage to produce a spray metal transfer, adjusting the welding speed and the electrode feeding speed to deposit metal in the groove in the range of 0.15 to 0.35 grams per mm length of the pass, and successively depositing overlapping passes for filling the groove.

24 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202357
2022103
2021107
2020168
2019206
2018206