A welder is tasked with joining two sections of Schedule 40 carbon steel pipe in the 5G position for a process piping application. The specifications call for a root pass with deep penetration and good fusion, followed by fill and cap passes that provide high impact toughness and crack resistance. Given these requirements, which electrode combination is most appropriate?

Question: A welder is tasked with joining two sections of Schedule 40 carbon steel pipe in the 5G position for a process piping application. The specifications call for a root pass with deep penetration and good fusion, followed by fill and cap passes that provide high impact toughness and crack resistance. Given these requirements, which electrode combination is most appropriate?

Answer options: ✅ E6010 for the root pass, followed by E7018 for fill and cap passes.

• E7018 for the root pass, followed by E6010 for fill and cap passes.
• E6013 for all passes due to its versatility.
• E6011 for the root pass, followed by E7024 for fill and cap passes.

Correct answer: E6010 for the root pass, followed by E7018 for fill and cap passes.

Explanation: E6010 is ideal for root passes, especially in pipes, due to its deep penetration and excellent fusion characteristics, capable of burning through contaminants. E7018 electrodes are then used for subsequent passes because they offer high deposition rates in all positions, produce welds with good mechanical properties, including high impact toughness, and are resistant to cracking, making them suitable for critical applications.