SMAW and Oxyfuel Cutting on Mild Steel 120301c

Comprehensive practice flashcards covering Shielded Metal Arc Welding (SMAW) and Oxyfuel Cutting techniques, joint preparation, position rules, and coupon standards on mild steel.

What must all surfaces in and around the joint be free of?

Oil, grease, paint, rust, and scale

What angle should both edges be beveled to?

30°

What root face (land) should be prepared?

2.5 mm - 3.2 mm (3/32" - 1/8")

When fitted together, what included angle should the two pieces form?

60°

What root gap should be used?

2.5 mm - 3.2 mm (3/32" - 1/8")

What is the rule of thumb for preparation of open groove welds?

The land equals the gap

Why must the joint be prepared accurately?

If the bevel angle, land, or gap is inaccurate, the joint is much more difficult to weld successfully

During fit-up, what should the root gap be approximately equal to?

The root face (land)

Where should tack welds be placed?

On the back side at the plate ends

How long should tack welds be?

6.4 mm - 9.6 mm (1/4" - 3/8") maximum

Why must tack welds be good quality?

Because they become part of the finished weld

What should tack welds be free of?

Blisters (shrinkage cavities) and visible defects

In the 3G position, what is the electrode angle and inclination?

1/2 the included joint angle, 0 - 10 backhand to forehand for all passes

What electrode is required for the root pass?

E4310 (E6010)

Why is E4310 (E6010) used for the root pass?

Because it has deep penetration and a fast-freeze puddle

What technique is used for the root pass?

Stringer bead with a manipulative (stepping) technique

During the root pass, what should you do as you move the electrode forward?

Shorten the arc into the keyhole

As the puddle starts to cool during the root pass, what should you do?

Bring the electrode back while slightly lengthening the arc

What is the approximate travel movement during the root pass?

One electrode diameter forward and ½ diameter backward

What electrode is used for the fill passes?

E4918 (E7018)

What weave technique is used for the fill pass?

Herringbone weave

What should you do when crossing the centre on the fill pass?

Shorten the arc to increase metal deposit and penetration into the root bead

What should you do on the sides during the fill pass?

Lengthen the arc slightly to increase fluidity and blend with the bevelled surface

Where should you pause during the fill pass?

On the edges to allow the puddle to blend in

What weave is recommended for the cap pass with E4918 (E7018)?

Herringbone weave

What arc length should be used for the cap pass?

Short to normal arc length

What is the rule of thumb for pausing on the cap pass?

Pause with one half of the electrode diameter on the top edge of the bevel

How do you prevent the weld centerline from becoming too convex?

Increase travel speed across the centre and pause longer on the edges

Why is slag removal necessary between passes?

To prevent slag entrapment

In how many passes is a 3G weld commonly completed?

3 or 4 passes

What is a common problem with inclination in 4G?

As the electrode melts off, the inclination changes to forehand

What can excessive forehand inclination on the root pass cause?

The root pass is generally fused but appears concave

What can improper inclination on the fill pass result in?

Undercutting of the bevel, leaving a high crown bead with trapped slag

What can happen to the cap pass with improper inclination?

It may become undercut on the edges with an increased weld crown

What is a good rule of thumb for electrode inclination in 4G?

Maintain an inclination perpendicular to the plate surface

What does the GF designation stand for?

Groove/Fillet combination weld

In 4GF groove welds with backing, how much of a gap is there between the plates?

13 mm (1/2")

In 4G groove welds with backing, what should the electrode angle be in relation to the previous pass?

½ the angle formed by the previous pass to the base plate

What standard must the root pass meet in 4G groove welds with backing?

CSA Standard W47.1

Where are stop/starts placed on root passes in 4G groove welds with backing?

Approximately 38 mm (1½") from each end of the coupon

Where is the first stop/start placed in 4G groove welds with backing?

On the fillet side of the joint

Does the test specify a set number of fill passes for 4G groove welds with backing?

No, but stringer beads are specified

What is the acceptable fillet weld size range for 4G groove welds with backing?

5 mm - 8 mm (3/16" - 5/16")

How much can weld size vary along the weld in 4G groove welds with backing?

No more than 1.6 mm (1/16")

How many root bend coupons are required for 4G groove welds with backing?

2

How many face bend coupons are required for 4G groove welds with backing?

1

How wide must each bend coupon be for 4G groove welds with backing?

38 mm (1½")

What direction should grinding marks run?

Transverse to the weld

Why should grinding marks NOT run parallel to the weld?

They create a notching effect that can lead to weld failure during bending

What angle should the torch be set at for bevel cutting in flat position?

30° from vertical

What torch inclination should be used for bevel cutting in flat position?

0°-10° forehand

What methods can be used for piercing holes?

Still or travelling torch method