Question

Which of the following is not true regarding pre-heating of heat affected zone ?

(a) Pre-heating does not help to reduce heat affected zone cracks

(b) Pre-heating increases the cost of welding

(c) It is done to remove surface moisture in highly humid conditions

(d) It is done to disperse hydrogen away from weld pool and heat affected zone

The question was posed to me in an internship interview.

I'd like to ask this question from Types and Properties of Welding topic in portion Welded Connections of Design of Steel Structures

Answer 1

Correct option is (a) Pre-heating does not help to reduce heat affected zone cracks

The explanation: Pre-heating of joints help to reduce heat affected zone cracks but increases the cost of welding. It is done to remove surface moisture in highly humid conditions, to disperse hydrogen away from weld pool and heat affected zone, to bring steel to ambient temperature in cold climates.