test3v weld faults

Question 1

Dimensional defects?

Answer 1

Prior to and after welding

Question 2

Structural discontinuities?

Answer 2

in the weld or on the weld surface

Question 3

Defective properties ?

Answer 3

mechanical or chemical

Question 4

Arc blow is what,

Answer 4

not a weld fault

Question 5

Mechanical properties that may be defective are,

Answer 5

tensile strength yield strength, ductility, hardness and fracture toughness

Question 6

Ductility means

Answer 6

the ability of a material to bend or permanently deform without breaking

Question 7

Yield strength,

Answer 7

the amount of force required for material to take a permanent deform or upset

Question 8

Tensile strength,

Answer 8

amount of weight you can throw on it or pull on it if exceed material tears apart

Question 9

Notch effect occurs,

Answer 9

whenever a notch is placed or formed within the cross section of a material, creating point of weakness

Question 10

Notch affect can be cause of,

Answer 10

poor joint design, poor weld profile, structural discontinuities in the weld

Question 11

Tapered transition ratio is

Answer 11

3;1

Question 12

distortion caused by,

Answer 12

lack of control over heat input, inadequate control of weld pass sequence, inadequate control of fit up, incorrect joint design

Question 13

Structural discontinuities are also,

Answer 13

surface defects or internal defects

Question 14

Stray arc arc strike also known as

Answer 14

(metallurgical notch)

Question 15

Internal defects fall into two categories,

Answer 15

spherical, laminar

Question 16

Spherical faults

Answer 16

porosity, slag or other inclusions are not as serious unless found in large amounts

Question 17

Laminar faults are

Answer 17

not acceptable almost ever they come in the form of lack of fusion.incomplete penetration or cracking

Question 18

Lack of fusion found,

Answer 18

especially in GMAW short circuit metal transfer ,cause riding puddle

Question 19

Cold cracks in the weld metal may occur

Answer 19

in any orientation with respect to the weld axis

Question 20

Haz cracks are usually

Answer 20

longitudinal and often most occur at the root or toes of the weld

Question 21

Transverse cracks,

Answer 21

across the weld may start in weld metal and may extend through the HAZ and beyond

Question 22

Notch effect in a weld has stress flow lines where,

Answer 22

concentrated at one point

Question 23

A high concentration of stress in a weld causes,

Answer 23

a notch affect

Question 24

Effective way to control excessive pen on a grove weld,

Answer 24

decrease root gap

Question 25

Undercut most commonly caused by,

Answer 25

incorrect electrode angle

Question 26

Brittle condition left in weld,

Answer 26

stray arc

Question 27

Longitudinal cracks in a weld can be caused by,

Answer 27

excessive joint restraint

Question 28

Incomplete pen usually caused by,

Answer 28

to narrow of root gap