Experimental study on effect of flux composition on element transfer during submerged arc welding

Abstract

The effects of flux composition on transfer of the elements have been studied through developed agglomerated fluxes on mild steel plates. The elements transferred to the welds have been shown in terms of a delta (D) quantity, which may be positive, negative or zero depending upon the composition of flux, wire and base plate. Carbon and manganese contents both show negative D quantity for most of the welds, indicating that both have been transferred from the weld metal to the slag. The results of this study show that for most of the welds, desulphurization and removal of phosphorus have been reported. The amount of element transferred is different for different welds depending upon the flux composition, dilution and slag metal reactions. Response surface methodology has been used for developing models for element transfer. The suggested model has been given for sulphur transfer to the weld. In this study the transfers of carbon, manganese, sulphur, phosphorus, silicon and nickel have been studied.Keywords. Submerged arc welding; basicity index; element transfer; slag metal reactions; oxidizing power of the flux. Sådhanå (2018) 43:26 Ó Indian Academy of Sciences https://doi.org/10.1007/s12046-018-0782-5S adhana(0123456789().,-volV)FT3 ](0123456789().,-volV)

Aluminium-Assisted Alloying of Carbon Steel in Submerged Arc Welding with Al-Cr-Ni Unconstrained Metal Powders: Thermodynamic Interpretation of Gas Reactions

“…Similar to reaction G for the reduction in the MnO content from the molten flux, FeO may also be reduced by aluminium; see reaction (7) in the text. These aluminium based reduction reactions, the reactions as displayed in Equations ( 5)- (8) in the text, are exothermic and therefore release chemical energy in the form of heat into the weld pool. This extra added heat can be used to melt and dissolve metal powder into the weld pool.…”

“…Although these welding parameters are highly important parameters in the SAW process, the weld metal chemistry is mostly set by the flux composition, which in turn sets the oxygen potential in the arc cavity [4,7]. Flux compositions are designed to achieve specific weld metal chemistries through element transfer between the slag and the weld pool [3,[8][9][10][11]. Slags must also exhibit specific physico-chemical properties to facilitate the SAW process.…”

“…For example, the flux composition is formulated to ensure optimum levels of slag surface tension and slag viscosity to sufficiently shield the weld pool from atmospheric gasses by covering the weld bead completely. The flux is also formulated to ensure that the slag liquidus temperature is 50 • C lower than the weld metal solidification temperature to ensure sufficient reaction time between the weld pool and slag for chemical reactions and inclusion removal [4][5][6]8].…”

Effect of substituting fine rutile of the flux with nano TiO2 on the improvement of mass transfer efficiency and the reduction of welding fumes in the stainless steel SMAW electrode

“…The properties of the weldment like mechanical strength, deep penetration, smooth finish etc are depended on the efficacy of metal transfer from electrode to weld pool during the welding process with minimum loss [11][12][13][14][15]. Nevertheless, welding fumes are formed during such processes by (i) evaporation, followed by the nucleation and rapid condensation of metal vapors and (ii) spatters, which are particles expelled from the agitated molten weld pool during welding [16][17][18][19][20][21].…”

“…The exposures of various welding fumes particulates (Fe, Mn, Ni, Cr etc) cause harmful diseases to the welders and other occupants [22][23][24][25][26][27]. Though, few investigations reported on the improvement of mass transfer efficiency by varying the flux compositions, its information on reduction of emissions were scarce [11][12][13][14][15]. Therefore, a systematic study on the effect of mass transfer efficiency of elements in the flux coated electrodes on fume emission reduction is required.…”