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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.


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Journal ArticleDOI
TL;DR: In this paper, a laser welded-brazed Al/steel lapped joint was successfully obtained under various shielding gas contents (pure Ar, CO2+Ar and pure CO2) with laser power of 2000W.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the suitability of keyhole gas tungsten arc welding (GTAW) for welding of duplex stainless steels has been investigated, and the preferred shielding gas for welding duplex and superduplex with the keyhole GTAW process was found.
Abstract: Keyhole gas tungsten arc welding (GTAW) is a relatively new variant used for fabrication of pressure equipment where up to 10-mm-thick material can be autogenously welded in one pass. As the shielding gas used for keyhole mode is typically Ar + 5% H2, the suitability of this method for welding of duplex stainless steels has been investigated. Duplex UNS S31803 and superduplex UNS S32750 schedule 40 seamless pipe was welded using a closed square butt joint configuration. Shielding gas compositions were applied with increasing nitrogen content in argon or argon-hydrogen mixtures. An investigation of the completed welds included examinations of the microstructure, corrosion and mechanical properties of the weld metal. All shielding gases resulted in high-quality welds free from defects, showed high strength and excellent corrosion resistance. Hydrogen additions increased the weld metal nitrogen loss and resulted in lower austenite formation. Ar + 5% H2 showed up to 20 vol.% less austenite than the gas types containing nitrogen and also showed the lowest impact toughness. At least 2% nitrogen would be recommended for optimizing the phase balance and impact toughness. Taking all aspects into account, Ar + 2% N2 is the preferred shielding gas for welding duplex and superduplex with the keyhole GTAW process.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of the dynamic characteristics of power sources on the stability of melting and electrode metal transfer to the weld pool in consumable consumable materials was investigated. And the results of investigations carried out by the authors showed that power sources can significantly affect the transfer stability of metal.
Abstract: The results of investigations carried out to study the effect of the dynamic characteristics of power sources on the stability of melting and electrode metal transfer to the weld pool in consumable...

19 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the influence of reduced heat input on microstructural and mechanical properties of modified dip arc processes for butt welding of alloy 617 (2.4663).
Abstract: The widespread application of nickel-based alloys as structural materials in chemical, nuclear and power generation industries is often limited due to weldability issues. Technological and metallurgical problems such as lack of fusion or hot cracking require specific welding guidelines as well as knowledge of the welding metallurgy to produce welds that fulfill high quality requirements. Due to the lower heat input modified dip arc welding is a potential alternative joining technique for hot crack sensitive nickel-based alloys. This paper contributes to the application of modified dip arc processes for butt welding of alloy 617 (2.4663). The influence of reduced heat input on microstructural and mechanical properties were investigated. Particular attention was given to the occurrence of hot cracking in the weld metal and base metal HAZ (heat-affected zone) using light optical microscopy, EDS analysis and electron probe microanalysis. The results indicate that the modified dip arc processes provide excellent weld quality and economic efficiency. However, microstructural observations showed that hot cracking in the form of microcracks could not be completely avoided. The modified dip arc welded joints exhibited good tensile strength and impact toughness. The mechanical properties are comparable to commonly GMA (gas metal arc) pulsed arc welding and are not influenced by the microcracks.

19 citations


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