Question

Identify the type of arc welding processes:

• A. Electron beam welding
• B. Laser beam welding
• C. Thermit welding
• D. Electro slag welding

Hint:

To classify welding processes, focus on the energy source:

• Arc Welding: Electric arc (plasma).

• Resistance Welding: Electrical resistance (\(I^2R\)).

• Beam Welding: Focused beam (electrons, photons).

• Chemical Welding: Exothermic reaction (Thermit).

• Solid-State Welding: Friction, pressure.
ESW is a hybrid that starts with an arc and continues with resistance heating.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The question asks to identify a process from the list that is classified as a type of arc welding process. This requires knowing the energy source and mechanism for each welding process.

Step 2: Detailed Explanation:
Let's analyze the classification of each process:

• (A) Electron beam welding (EBW): This is a

high-energy beam welding process. It uses a focused beam of high-velocity electrons to generate heat. It is not an arc welding process.

• (B) Laser beam welding (LBW): This is also a

high-energy beam welding process. It uses heat from a concentrated, coherent light beam (a laser). It is not an arc welding process.

• (C) Thermit welding (TW): This is a

chemical welding process. The heat for welding is produced by an exothermic chemical reaction between aluminum powder and a metal oxide. It does not use an electric arc.

• (D) Electro slag welding (ESW): This is a progressive welding process used for very thick sections in the vertical position. Although the main source of heat during the run is the electrical resistance of a molten slag bath (\(I^2R\) heating), the process is

initiated by an electric arc. The arc is struck at the bottom of the joint to melt the initial flux and form the molten slag pool. Once the pool is established, the arc is extinguished, and the process continues as a resistance heating process. Due to its initiation method and use of electrical energy, it is often grouped with or considered a derivative of arc welding processes. Among the given choices, it is the only one that involves an electric arc in any capacity.

Step 3: Final Answer:
Among the options provided, Electroslag welding is considered a type of arc welding process because it is initiated by an electric arc, even though the primary heat source during operation is resistance heating of the molten slag.