Effect of heat input on weld bead geometry of submerged arc welded ASTM A709 Grade 50 steel joints

► Increasing heat input increases reinforcement, bead width, penetration, penetration and deposition areas, and HAZ size, but decreases contact angle. ► A linear correlation is found between cooling time and total nugget area, cooling interface length, as well as nugget parameter. ► The bead width-to-depth ratio and percent dilution do not vary appreciably with heat input. ► Electrode melting efficiency increases with increasing heat input for single wire welding, but plate melting efficiency does not change.