Q205
Preheating is essential in welding
A.
Cast iron
AnswerB.
High speed steel
C.
All nonferrous materials
D.
All of the above
Answer: Option A
Solution
Answer: Option A
Solution:
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.