Multiple Choice
Why must metal that is below 70°F (20°C) be preheated before welding?
A) If the metal is too cold, you cannot get a weld pool established.
B) Because the cold metal quenches the weld.
C) The arc on cold metal is not stable, and it will wander around the surface making it hard to keep the weld going along the joint.
D) The hot metal on the cold plate will not stick, it just bounces off.
Correct Answer:

Verified
Correct Answer:
Verified
Q30: _ steels contain specified larger proportions of
Q31: High-carbon steels usually have a carbon content
Q32: Medium-carbon steel has _ % carbon content.<br>A)
Q33: What is the most common preheating temperature
Q34: Why must all surface contamination be removed
Q35: Explain the meaning of the numbers in
Q36: For steels containing more than _ %
Q37: Most welding processes produce a(n) _ in
Q38: In both steel classification systems, the first
Q40: _ stainless steels contain almost no nickel