Investigating the Influence of ASAW Process Parameters on Chemical Composition, Mechanical Properties and Corrosion Rate of HSLA Steel Weldments

Multipass and multilayer advanced submerged arc welding (ASAW) was performed on the ASTM A709 Grade 36 to develop an acceptable welding system to enhance the structural integrity in the real field situation. In the present work, the effect of ASAW parameters like open-circuit voltage, wire feed rate, welding speed, nozzle-to-plate distance and preheat current on chemical composition, mechanical properties and corrosion rate of weld metal has been investigated as per the Taguchi design (L-8). Subsequently, the mathematical relationships amid the ASAW parameters and responses have been established in context with the least linear regression model. The effect of variable process parameters on selected responses was analysed with ANOVA. Further, the Fractography analysis with electron-dispersive spectroscopy of tensile and CVN toughness fractured surfaces was carried out to investigate the failure mechanism of all weld metals. Finally, the microstructure of all weld metals was analysed to study the corresponding phases and grain size. Overall, the results disclose that open-circuit voltage, welding speed and preheat current significantly affect the chemical composition, mechanical properties and corrosion rate of all weld metals.