Fuzzy Logic Optimization for Low Sulphur and Phosphorus in Submerged Arc Weldments

This aim of this study was to design the flux for low sulphur and low sulphur content in the weldments using SAW fluxes for low carbon steels. RSM technique has been used to design the number of experiments. CCD has been used as it suggests minimum number of experiments between the input and output variables. The base fluxes were selected using binary and ternary phase diagrams according to the melting point of the steel. The sulphur and phosphorus contents both enhance embrittlement and are not supposed to be good for impact strength and UTS so, these should be kept at minimum level in the welds. This study may help in selection of flux for low sulphur and low phosphorous welds. It is found that the weld sulphur and phosphorus are found minimum when CaF2, FeMn and NiO are 5%, 8% and 5% respectively. Key words: SAW, RSM, Optimization, Element transfer