Chapter 12 SMAW

Question 1

What is arc blow?

Answer 1

When the arc is deflected from its normal path by magnetic forces. It can present a challenge during arc welding.

Question 2

Why is arc blow not a problem when AC is used?

Answer 2

Because the magnetic field is continually cancelled as the current changes direction therefore arc blow is not a problem when AC is used.

Question 3

What is worn under the welding helmet to protect from reflected arc rays?

Answer 3

Eye protection

Question 4

An electrode is generally held with one hand. It can be gripped like a ___________ or _____________

Answer 4

hammer or screwdriver

Question 5

How do you strike an arc?

Answer 5

There are two methods:
1. welder scratches the electrode on the metal then withdraws it
2. use a straight up and down or pecking motion

Question 6

Which of the following results in the least arc blow?
a. DCEN
b. DCEP
c. AC
d. DC

Answer 6

b. AC

Question 7

The magnetic field around the electrode is deflected at ___________________ of a weld joint.

Answer 7

ends of the weld joint

Question 8

If arc blow occurs, what step should you take?

Answer 8

Use the shortest arc possible to produce a good weld. A short arc permits the filler metal to enter the weld pool before being affected. A good short arc also permits the arc force to overcome the arc blow force.

Question 9

A ______________ permits the arc force to overcome the arc blow force.

Answer 9

good short arc

Question 10

The width of a stringer bead should be _______________ times the electrode diameter

Answer 10

two to three times

Question 11

What is the travel angle?

Answer 11

It describes the position of the electrode as it is tilted along the weld axis

Question 12

What is work angle?

Answer 12

It describes the position of the electrode as it tilts side to side about the weld axis.

Question 13

What is backhand method

Answer 13

The welding end of the electrode points backward toward the weld bead that has been completed

Question 14

What is forehand method?

Answer 14

The welding end the electrode points forward in the direction of travel

Question 15

When restarting an arc, how far in front of the existing crater is the arc struck?

Answer 15

3/8” (10 mm)

Question 16

Excessive current produces a weld that is wide, low, and has a great deal of ___________

Answer 16

spatter

Question 17

Metal less than 1/4” thick is welded using a ______________________

Answer 17

square-groove butt joint

Question 18

True or False: No edge preparation is required for metal 1/4” thick.

Answer 18

True

Question 19

True or False: A bevel-, V-, J-, or U-groove joint is used on thicker metal.

Answer 19

True

Question 20

What is a root pass?

Answer 20

The first and most important weld pass

Question 21

What is the keyhole?

Answer 21

An enlarged root opening. Must be seen throughout the root pass to ensure penetration.

Question 22

What is the whip and pause technique used on?

Answer 22

The whip and pause technique is used on a root pass of a butt weld. It involves moving the electrode towards a distance equal to about one electrode diameter and pausing very briefly.

Question 23

_______________ occurs when the base metal at the weld toe area is melted but is not filled with filler metal.

Answer 23

Undercut

Question 24

What is the work angle for a fillet weld on a T-joint?

Answer 24

45 degrees