Welding

Question 1

What is welding?

Answer 1

A manufacturing process where 2 or more metal parts are joined together

Question 2

What does the carbon equivalent measure?

Answer 2

The ability to form martensite

Question 3

What to the 3 types of CE represent

Answer 3

CE < 0.35 - no preheat of post-weld heat treatment

0. 35 < CE < 0.55 - preheat
1. 55 > CE - preheat and post-weld heat treatment

Question 4

What are 4 reasons to preheat?

Answer 4

1. Reduced the cooling rate, which reduces the chance of forming martensite in steels
2. Reduces distortion and shrinkage stress
3. Reduces the danger of weld cracking
4. Allows hydrogen to escape

Question 5

What are the 3 reasons to do post-weld heat treatment?

Answer 5

1. The fast cooling rates associated with welding often produce martensite
2. During post-weld heat treatment martensite is tempered
3. Residual stress is also reduced by the post-weld heat treatment