Question

Consider the following:
Assertion (A): In SAW, the welding arc is not visible during welding.
Reason (R): The arc is completely submerged under a layer of granular flux.

• A. Both A and R are true, and R is the correct explanation of A
• B. Both A and R are true, but R is not the correct explanation of A
• C. A is true, but R is false
• D. A is false, but R is true

Hint:

SAW provides deep penetration, high deposition rate, and completely shielded arc due to flux cover, making it ideal for heavy fabrication.

Answer 1

The Correct Option is A

Concept: Submerged Arc Welding (SAW) is an automatic or semi-automatic arc welding process in which the arc zone is completely covered by a thick layer of granular flux. This flux plays multiple roles such as shielding the arc from atmospheric contamination, stabilizing the arc, and improving weld quality. A key characteristic feature of SAW is that the arc is not visible during operation, which distinguishes it from processes like SMAW and GMAW where the arc is exposed.

Step 1: Understand the assertion (A). The assertion states that the welding arc is not visible during SAW. In SAW:
• The arc is formed between the continuously fed electrode and workpiece.
• A thick blanket of granular flux covers the arc region.
• The operator cannot visually observe the arc during welding. Hence, the assertion is TRUE.

Step 2: Understand the reason (R). The reason states that the arc is completely submerged under granular flux. In SAW:
• Flux is poured over the joint before welding.
• The arc burns beneath this flux layer.
• This flux layer acts as a protective shield against oxygen and nitrogen. Thus, the reason is also TRUE.

Step 3: Establish the relationship between A and R. The invisibility of the arc is a direct consequence of the flux covering the arc zone. Therefore:
• Flux covering $\Rightarrow$ arc becomes hidden
• Arc submerged under flux $\Rightarrow$ not visible to observer Hence, Reason (R) correctly explains Assertion (A). Final Answer: \[ \boxed{\text{Both A and R are true, and R is the correct explanation of A}} \]