Ch. 4 Shielded Metal Arc Welding Of Plate

Front 1

SMAW or Stick Welding

Back 1

- is a common method used to join plate. This method provides a high temp. and concentration of heat, which allows a small molten weld pool to be built up quickly.

- The addition of filler metal from the electrode adds reinforcement and increases the strength of the weld

- It can be performed on almost any type of metal 1/8 inch thick or thicker

Front 2

Striking an arc

Back 2

- Arc strikes on the metals surface that are not covered up by the weld are considered to be weld defects by most codes

- Striking an arc in the incorrect spot may cause damage to the base metal.

Front 3

Welding with too low of a current (amperage)

Back 3

- results in poor fusion and poor arc stability

- the weld may have slag or gas inclusions, because the molten weld pool was not fluid long enough for the flux to react.

- the arc length has too very short; a very short arc length results in frequent shorting and sticking of the electrode

Front 4

Welding with too high of a current ( amperage)

Back 4

- weld bead is wide and flat with deep penetration

- the spatter is excessive and is mostly hard.

- the electrode covering is discolored more than 1/8 in. to 1/4 in from the end of the electrode.

- it can cause the electrode to discolor, crack, glow red, or burn.

Front 5

Hard spatter

Back 5

- it is called _____ because it fuses to the base plate and is difficult to remove

Front 6

1/8 in. E6010 welding range

Back 6

- 70-130 amps

Front 7

1/8in. E6011 welding range

Back 7

- 85-125 amps

Front 8

1/8in. E6013 welding range

Back 8

- 70-120 amps

Front 9

1/8in. E7018 welding range

Back 9

- 90-165 amps

Front 10

3/32in. E6010 welding range

Back 10

- 40-80 amps

Front 11

3/32in. E6011 welding range

Back 11

- 50-70 amps

Front 12

3/32in. E6013 welding range

Back 12

- 40-85 amps

Front 13

3/32in. E7018 welding range

Back 13

- 70-110 amps

Front 14

Do not change the current settings during welding

Back 14

- a change in the setting may cause arcing inside the machine, resulting in damage to the machine.

Front 15

Small diameter electrodes

Back 15

- requires less skill

- the deposition rate is slower

- more time is required when welding on thicker plate.

Front 16

Large diameter electrodes

Back 16

- may overheat the metal if the metal is too thin or too small.

Front 17

To correct an overheating problem

Back 17

- a welder can turn down the amperage

- use a shorter arc length

- travel at a faster rate

- use a chill plate

- use a smaller electrode at a lower current setting.

Front 18

The term " heat and amperage"

Back 18

- welders use these terms interchangeabley when they are speaking about making welding current changes.

- EX: turn up the heat is the same as turn up the amperage.

Front 19

Arc length

Back 19

- is the distance the arc must jump from the end of the electrode to the plate or weld pool surface.

Front 20

Chill Plate

Back 20

- a large piece of metal used to absorb excessive heat.

Front 21

Arc jumping and how to prevent it

Back 21

- an arc will jump to the nearest metal conductor.

- joints that are too deep or narrow may pull the arc to one side and not to the root causing poor fusion.

- If a very short arc is used, the arc is forced into the root for better fusion.

Front 22

Shorter arcs

Back 22

- produce less heat and penetration.

-using this technique, metal as thin as 16 gauge can be arc welded easily.

- higher arc settings are required to maintain a short arc.

Front 23

Amperage range

Back 23

- the lower and upper limits of welding power, in amperage, that can be produced by a welding machine or used with an electrode or by a process.

Front 24

Electrode angle

Back 24

- is measured from the electrode to the surface of the metal.

- the term used to identify the electrode angle is affected by the direction of travel, generally leading or trailing.

Front 25

Leading angle

Back 25

- this angle pushes molten metal and slag ahead of the weld.

- when welding in the flat position, caution must be taken to prevent cold lap and slag inclusions.

- a leading angle can be used to minimize penetration or to help hold molten metal in place for vertical welds.

Front 26

Suggestions for preventing cold lap and slag inclusions:

Back 26

- use as little leading angle as possible

- ensure that the arc melts the base metal completely

- use a penetrating type electrode that causes little buildup

- move the arc back and forth across the molten weld pool to fuse both edges.

Front 27

Trailing angle

Back 27

- this angle pushes the molten metal away from the leading edge of the molten weld pool toward the back where it solidifies.

- as the molten metal is forced away from the bottom of the weld, the arc melts more of the base metal, which results in deeper penetration.

Front 28

What does electrode manipulation help control when welding?

Back 28

- penetration

- buildup

- width

- porosity

- undercut

- overlap

- and slag inclusions

Front 29

Weave pattern

Back 29

- the movement of the welding electrode as it progresses.

Front 30

The circular pattern

Back 30

- is often used for flat position welds

Front 31

The C and square patterns

Back 31

- are both good for most 1G (flat) welds but can also be used for vertical (3G) positions.

Front 32

The J pattern

Back 32

- works well on flat ( 1F) lap joints, all vertical (3G) joints, and horizontal (2G) butt and lap (2F) welds.

- this pattern allows the heat to be concentrated on the thicker plate.

Front 33

The T pattern

Back 33

- works well with fillet welds in the vertical (3F) and overhead (4F) positions.

Front 34

The straight step pattern

Back 34

- can be used for stringer beads, root pass welds, and multiple pass welds in all positions.

- For this pattern, the smallest quantity of metal is molten at one time as compared to other patterns. Therefore the weld is more easily controlled.

Front 35

The figure 8 and the zigzag pattern

Back 35

- are used as cover passes in the flat and vertical positions.

- Do not weave more than 2 1/2 times the width of the electrode.

- a shelf can be used to support the molten weld pool with these patterns.

Front 36

Arc welding electrodes

Back 36

- are grouped into three filler metal (F number) classes according to their major welding characteristics.

Front 37

E6010 and E6011 Electrodes

Back 37

- group F3

- have cellulose-based fluxes.

- these electrodes have a forceful arc with little slag left on the weld bead.

Front 38

E6012 and E6013 Electrodes

Back 38

- group F2

- have rutile- based fluxes, giving a smooth, easy arc with a thick slag left on the weld bead.

Front 39

E7016 and E7018 Electrodes

Back 39

- group F4

- have a mineral-based flux. The resulting arc is smooth and easy, with a very heavy slag left on the weld bead.

Front 40

Electrodes with rutile based fluxes

Back 40

- give an easy arc with low spatter

- are easier to control and are used for flat stringer beads and butt joints.

Front 41

Electrodes with mineral based fluxes

Back 41

- should be the last choice

- make welds with good appearance, but strong welds are hard to obtain.

Front 42

Stringer bead

Back 42

- is a straight weld bead on the surface of a plate, with little or no side to side electrode movement.

- they are the most commonly used type of bead for vertical, horizontal, and overhead welds.