Which type of welding has a maximum arc efficiency of approximately 90%?

The correct answer is based on the characteristics of Submerged Arc Welding (SAW), which is known for having a high arc efficiency, typically around 90%. Arc efficiency refers to the percentage of electrical energy that is converted into useful heat by the welding arc in the welding process.

In the case of SAW, the arc is submerged beneath a layer of granular flux, which not only protects the weld from contamination but also helps in maximizing heat utilization during the welding process. This results in a minimal loss of heat to the surrounding environment, thereby allowing for a higher input to the weld compared to other welding processes.

The high efficiency also contributes to the production of high-quality welds at faster deposition rates, making SAW particularly beneficial for thick materials and larger fabrication tasks.

In comparison, other welding processes like GTAW (Gas Tungsten Arc Welding), SMAW (Shielded Metal Arc Welding), and FCAW (Flux-Cored Arc Welding) generally exhibit lower arc efficiencies due to factors like increased heat loss and lower heat utilization during the welding process. This distinction emphasizes why SAW is uniquely identified for its high performance in terms of arc efficiency.