Preheating is essential in welding

A. Cast iron

B. High speed steel

C. All nonferrous materials

D. All of the above

Answer: Option A

Solution(By Examveda Team)

Preheating minimizes the temperature difference between the welding arc and the base material. .
Slowing the cooling rate also allows hydrogen to escape the weld puddle as it hardens to help minimize cracking.
preheating introduces the necessary heat into the weld area to ensure proper penetration.