Effect of shielding gas on fusion characteristics and weld metal properties in flux cored arc welding
- Indian Inst. of Science, Bangalore (India)
- Welding Research Inst. BHEL, Trichy (India)
The study relates to the effect of shielding gas mixture (CO{sub 2}/Ar) on some of the fusion characteristics and weld metal properties in Flux Cored Arc Welding of ASTM SA515Gr70 steel plates using basic (E 70T-5) flux cored wire. The investigation has shown that as the CO{sub 2} content is increased in CO{sub 2}/Ar mixture, penetration, dilution and plate melting efficiency are appreciably improved, while in the case of bead width and bead wetting angle no clear trend is observed. Further, at higher CO{sub 2} contents, the weld metal oxygen and elemental loss (Mn and Si) are both higher. The microstructural studies have revealed significant influence of CO{sub 2} content on inclusions, acicular ferrite and proeutectoid ferrite. Besides CO{sub 2} content, heat input also appears to affect the microstructure appreciably. With regard to weld metal properties, COD and NDTT are both significantly affected by the CO{sub 2} content as well as heat input. As CO{sub 2} content is increased, CTOD (COD value determined relates to CTOD at crack initiation) decreases exponentially and NDTT increases. Maximum toughness has been obtained for a shielding gas mixture of 40%CO{sub 2} + 60%Ar and at lower heat input. The results obtained in the study suggest that the optimum CO{sub 2} content in CO{sub 2}/Ar shielding gas mixture for basic type (E70T-5) flux cored wire is 40%, beyond which excessive arc spattering and irregular metal transfer are observed.
- OSTI ID:
- 442970
- Report Number(s):
- CONF-950682-; ISBN 0-87170-567-2; TRN: IM9712%%395
- Resource Relation:
- Conference: 4. international conference on trends in welding research, Gatlinburg, TN (United States), 5-9 Jun 1995; Other Information: PBD: 1996; Related Information: Is Part Of Trends in welding research: Proceedings of the 4. international conference; Smartt, H.B.; Johnson, J.A. [eds.] [Idaho National Engineering Lab., Idaho Falls, ID (United States)]; David, S.A. [ed.] [Oak Ridge National Lab., TN (United States)]; PB: 836 p.
- Country of Publication:
- United States
- Language:
- English
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