Fluxes in submerged arc welding of high-strength low-alloy steels are not readily available, flux compositions are not clear and compositions are patented. This study aims at the design, development and optimization of flux for submerged arc welding of high-strength low-alloy steel. Extreme vertices design suggested by McLean and Anderson is used to formulate twenty-one fluxes to study the effect of flux constituents on tensile strength, percentage elongation, impact strength, diffusible hydrogen content and microstructure of the weld metal. Mathematical models for ultimate tensile strength, percentage elongation, impact strength and diffusible hydrogen content for welded specimens versus flux constituents have been developed. From the experiments, it is found that tensile strength and elongation are affected the most with Al2O3 content, whereas CaO and CaF2 contents have significant effect on impact strength. Synergic binary effect of CaO·CaF2, CaO·MgO and Al2O3·CaF2 mixtures is more than other binary mi...

Investigation on flux design for submerged arc welding of high-strength low-alloy steel:

Temperature distribution patterns in any welding process control the microstructure, residual stress, and distortion. Welding process parameters can be optimized to obtain the desired micro...

Three-Dimensional Finite Element Analysis to Predict the Effects of Shielded Metal Arc Welding Process Parameters on Temperature Distributions and Weldment Zones in Butt and One-Sided Fillet Welds

In oil and gas industries, submerged arc welding is the only primarily used process to weld high thickness, large distance structural oil pipes. Welding process parameters play a significant role in determining the quality of a weld joint in submerged arc welding. In the present work, an attempt has been made to optimize the weld bead parameters: weld bead form factor, dilution, microhardness and diffusible hydrogen content for welding of structural pipe steel (API 5L X65 grade) by desirability function approach used by Derringer and Harrington. For design of experiments, response surface methodology had been used. Mathematical models for output responses had been developed in terms of welding parameters and checked for adequacy using t-test and analysis of variance (F-test). It was found that welding current was the most significant parameter controlling all the responses, and arc voltage had increasing effect on all the responses except microhardness.

Effect of welding parameters on bead profile, microhardness and H2 content in submerged arc welding of high-strength low-alloy steel

Chemical and mechanical properties of the welded joint are greatly affected by flux composition. The resulting chemical compositions of C, Si, Mn, P and S in the weld metal have been studied using ...

Modeling flux chemistry for submerged arc weldments of high-strength low-alloy steel

To automate a welding process, which is the present trend in fabrication industry, it is essential that mathematical models have to be developed to relate the process variables to the weld bead parameters. Submerged arc welding (SAW) is characterized by its high reliability, deep penetration, smooth finish and high productivity especially for welding of pipes and boiler joints. In the present work mathematical models have been developed for SAW using developed fluxes. Response surface methodology has been used to predict critical dimensions of the weld bead geometry and shape relationships. The models developed have been checked for their adequacy and significance by using the F-test and the t-test, respectively. Main and interaction effects of the process variables on bead geometry and shape factors are presented in graphical form and using which not only the prediction of important weld bead dimensions and shape relationships but also controlling the weld bead quality by selecting appropriate process parameter values are possible.

Arun Kumar Bhaduri

Papers

Welding Processes and Technology for Stainless Steels