Design and development of submerged arc welding fluxes using TiO₂-SiO₂-CaO and SiO₂-CaO-Al₂O₃flux system

Abstract

Submerged arc welding is widely used in pipeline manufacturing due to higher efficiency as compared to the other welding processes. In present study, TiO2-SiO2-CaO and SiO2-CaO-Al2O3–based submerged arc welding fluxes were developed for joining of linepipe steel. Twenty-one fluxes were formulated based on mixture design methodology. Fluxes were analysed using X-ray florescence (XRF), thermogravimetric, differential-scanning calorimetry, Hot-disc and X-ray diffraction (XRD) techniques. The structural behaviour of rutile basic fluxes were analysed using Fourier transformed infrared spectroscopy (FTIR). Thermo-gravimetric analysis and differential scanning calorimetry were performed from 25 ℃ to 900 ℃ in order to determine the thermal stability and change in enthalpy of fluxes. Thermal conductivity, thermal diffusivity and specific heat of each flux were evaluated by hot disc technique. The density and grain fineness number for flux particles was evaluated at room temperature. Multi objective optimisation was performed to derive the optimised flux formulations. Individual effect of all the mixture constituents is rarely observed on the physicochemical properties of fluxes as compared to the binary and ternary mixture effects. The binary compositions significantly affect the density. TiO2-CaO is the most effective binary mixture which has increasing effect on density while all remaining binary mixture constituents have decreasing effect. The weight loss of fluxes observed during thermogravimetric analysis is affected by binary and ternary mixture constituents. Both binary and ternary flux mixtures affect change in enthalpy observed during differential scanning calorimetry. SiO2.Al2O3 is the only most effective binary mixture constituent of flux having increasing effect on thermal conductivity. Binary mixture constituents TiO2.CaF2, SiO2.Al2O3 and CaO.Al2O3 are the most effective and having synergistic effect on thermal diffusivity.

Investigations on microstructural and mechanical properties of BSK 46 steel weldments

“…Conventional welding techniques such as shielded metal arc welding, gas tungsten arc welding, gas metal arc welding (GMAW) and submerged arc welding are widely used for joining the BSK 46 steels. [9][10][11][12][13][14][15][16][17][18] GMAW is preferred over the other arc welding processes because of its cost-effectiveness, higher filling rate, relatively easy to operate and higher productivity. [19][20][21][22][23][24] In GMAW, the arc generated between the workpiece and wire electrode melts the workpiece and produces a permanent joint.…”

Wettability study of Developed Silicon based SMAW Electrode Coating Fluxes using SiO 2 -CaO-TiO 2 and SiO 2 -CaO-MgO Ternary System

“…There hasn't been any in-depth study of the interactions between the constituent minerals on a binary and tertiary level and how they affect the wettability characteristics of the electrode coating. Previous research efforts have predominantly focused on exploring the influence of these interactions on the mechanical properties and chemistry of the weld metal and the physicochemical properties of fluxes [44][45][46][47][48][49][50][51][52]. It is still uncertain how the wettability behaviour of a flux is related to its structural aspect.…”

High-temperature wettability study of mineral waste added CaO–CaF2–SiO2 and CaO–TiO2–SiO2-based electrode coating for offshore welds

“…Significant work is reported on studying the effect of binary and tertiary interactions on the physicochemical properties of fluxes, weld metal chemistry, and mechanical properties of the weld. [18][19][20][21][22][23][24][25] Correlation between the structural aspect of flux and its wettability behavior is still unexplored.…”