Smaw Fillet Welds On Mild Steel Flashcards
Cover pass / cap / wash coat
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AIT
Hot pass = first fill
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Electrode angle
Fillet welds
Butt joints
One half the included joint angle
45 degrees material surface
Perpendicular to surface
If undercut becomes a problem
Point heat source towards undercut, this forces area to become hotter, molten metal flows to the hottest point
Welding parameters should not exceed heat sink capabilities of base metal
Hotter is not always better
Electrode inclination
Backhand - forehand
Backhand has the electrode pointed back of puddle
Forehand electrode pointed in direction of travel
Smaw electrode inclination
5-30 degrees
Forehand or backhand
Forehand
Flatter, wider, smooth metal flow, less penetration
Backhand
Arc force holds the molten metal back from crater, deeper pen, narrow bead with more build up
Root and hot pass
Exaggerate backhand to get deeper penetration to dig out impurities
Inclination : flat
5 forehand 15 backhand
Inclination : vertical
0 - 10 forehand
Inclination : overhand
5 forehand - 15 backhand
Inclination : uphill pipe
5 backhand in over head
5 forehand inclination other positions
Rule of thumb: always point to centre of pipe
AIT
Manipulative welding technique
Whipping action (6010)
Root face is
The land
Stringer padding
Stringer beads to uniformly build up a surface, over lap previous bead by 1/3
Stringer fill
Planned to blend into a finished contour and made with a series of overlapping stringer beads
Short arc - choked arc
Excessive penetration, poor metal flow, narrow high crowned beads
Too fast cooling rate =
Hardness
Weave bead should not exceed …
2/3 times electrode diameter
Too wide can make slag entrapment at the toes (edges) of the bead
AIT
Herringbone weave variation eliminates …
Undercut
Crescent weave can lead too…
Undercut
Lazy L weave
Cover pass
Horizontal position
Sawtooth weave
Acts as a gravitational correction particularly along the top edge of the weld
E4310 (E6010)
1/8 - DC-EP - 80-140 amps
E4918(E7018)
3/32 - AC - DC - EP - 70-100
1/8 - AC - DC - EP - 80 - 175
E7014
AC - DC - EN / EP
Polarity check rod
6010
Puddle is smooth, crisp sounds of bacon with 6010
Electrode positive
Puddle is violent with appearance of longer arc, higher fume emissions, hissing sound with 6010
Machine is electrode negative
AIT
Starting arc two methods
Tapping method
Scratch method
(Never start arc outside weld zone)
Arc length
Normal arc length is …
Considered to be same as the diameter of the core wire of the electrode
Short arc (choked arc)
Deeper penetration, higher rate of weld metal deposition, narrow, less fluid puddle that tends to build up
Long arc
Shallow penetration, lower deposition rate, wider more fluid puddle that blends well at the edge of bead
Crucible cup (inverted cup)
Helps stabilize electrode maintains consistent arc length
Electrodes with high iron powder = contact electrodes
7024, 7014
1F
Flat fillet
Joint surface approximately 45 degrees to horizontal plane
2F
5 - 30 backhand root
0 - 30 backhand for all other passes
More backhand = more penetration
More straight on = better blending
3F
Position lap joint
Vertical
Angle to the sides to reduce undercut
3 passes, 1/2 included angle
0-10 backhand or forehand for each pass
4F
Over head fillet
1-7 passes
Stringer padding means that the base metal surfaces are to be
Built up uniformly using stringer beads
A root pass is produced when the
First penetrating bead is at the root of the joint
Weave beads are deposited when the electrode is
Moved forward and side to side while welding
A cover pass is a
Thin weave or a series of passes used as the final layer of weld metal
What is the main purpose of pausing on the edges of a weave bead
To obtain a blend to eliminate undercut at the toes of the weld bead
Electrode angle is …
Normally one half of the angle of the joint
When the arc length is increased during welding, what happens to these characteristics
- penetration
- puddle fluidity
Penetration decreases
Puddle is more fluid
What are two commonly used methods for striking the arc with Smaw
Tapping method and scratch start
Where would you strike the arc on a stop:restart
Start the arc within the weld zone where the arc marks are to be remelted with the weld progression
Excessive current settings for Smaw are indicated by
Excessive spatter
A normal arc length is considered equivalent to the
Diameter of the core wire of the electrode
What arc length gives the following characteristics
A) best blend into the edges of a weld bead
B) deepest penetration
C) highest rate of metal deposit
D) widest bead
A) long arc
B) short arc
C) short arc
D) long arc
What is the best method for determining the current setting for an electrode
Set current according to the manufacturer recommendations and then test on a piece of scrap approximately the same thickness as the metal needed for the weld project
What should you do to maintain a normal arc length with electrodes that have a high iron powder coating
Keep the flux coating in contact with the metal surface
When you deliberately shorten the arc length what are you expecting to achieve
Deeper penetration with decreased puddle fluidity
What electrode inclination is recommended for the first pass of a 2F weld on 10 mm material using 3.2 mm E4310(6010) electrode
5-30 backhand
What type of bead is usually used for the cover pass on a 2F weld on 10 mm material
Stringer bead
What procedure is recommended to complete a 3F weld using E4310 ( 6010) electrodes on a 10 mm material
Use one root bead followed by a weave full and weave cover pass
What action would you take to avoid excessive build up at the center of the cover pass of a 3F weld
Travel faster across the center with a slight increase in arc length
What polarity is recommended for these electrodes
A) E4310 (6010)
B) E4914 (7014)
C) E4918 (7018)
A) DCEP only
B) AC or DCEN
C) AC or DCEP
A quick test for polarity can be done using which electrode
E4310 (6010)
Changing the inclination of the electrode in relation to the direction of travel
Affect the depth of penetration
The number and letter combinations 3F and 2G for example represent
The required position and type of weld
Why is it important to remove the slag between passes on a multi pass weld
To help prevent slag inclusions between passed
How should you position yourself relative to the weld
So that your body is supported and you are able to see the weld zone clearly
Which electrode normally requires a manipulative welding technique when doing stringer beads in the flat position
E4310 (6010)
Which electrode normally uses a drag technique when doing stringer beads
E4914 (7014)
A filler weld placed on the underside of the joint with one vertical leg and one horizontal leg is ..
A horizontal overhead fillet weld
Inclination
Moving up or down
Forehand backhand
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Angle
Moving the electrode side to side
To change the degree of where the electrode is on the metal
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